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Derailment

In rail transport, a derailment is defined as the event where on-track equipment leaves the rails for reasons other than collisions, explosions, highway-rail grade crossing impacts, or other specified causes.^[1] These incidents can involve passenger, freight, or other rail vehicles and may range from minor events affecting a single wheelset to catastrophic failures derailing entire trains.^[2] Derailments have historically accounted for about 71% of all train accidents in the United States (1975–2023).^[3] Common causes include track and roadbed defects (such as broken rails or improper alignment), mechanical and electrical failures (like overheated bearings or brake issues), human factors in train operations (including signal violations or excessive speed), and signal or communication malfunctions.^[4] In the U.S., an average of three trains derail daily, equating to over 1,000 incidents annually, though the vast majority are minor and occur on non-mainline tracks with limited consequences.^[5] From 2018 to 2024, nationwide derailments have resulted in few fatalities (under 10) and several hundred injuries, underscoring their generally low severity compared to other accident types.^[6]^[7] Despite their frequency, derailments can lead to substantial economic, environmental, and public health impacts, particularly when hazardous materials are involved.^[8] About 23% of derailments in recent years have included cars carrying hazardous substances, raising risks of spills, fires, or toxic releases.^[6] Notable examples include the February 2023 Norfolk Southern derailment in East Palestine, Ohio, which involved a defective wheel bearing and led to a chemical spill, evacuation, and ongoing remediation efforts.^[9]^[10] Prevention measures have evolved through regulatory oversight by the Federal Railroad Administration (FRA), including mandatory track inspections, implementation of Positive Train Control (PTC) systems to prevent overspeed and misaligned switch incidents, and enhanced hazardous materials routing protocols.^[11] These efforts have contributed to a decline in accident rates, with the train accident rate dropping 33% since 2005 and derailment rates improving 40% over the same period as of 2024.^[7]

Fundamentals

Definition and Overview

A derailment in rail transport is defined as an event in which on-track equipment, such as a train or locomotive, leaves the rails for reasons other than a collision, explosion, highway-rail grade crossing impact, or similar external forces.^[1] This can involve one or more wheels departing the rail, leading to potential loss of control, structural damage to the vehicle or infrastructure, and in severe cases, accidents resulting in injuries or fatalities.^[12] Rail vehicles remain on tracks primarily through the design of their wheels and the rail profile, which ensure stable contact and guidance. The wheels feature a conical tread—a slightly tapered running surface that is thicker near the inside flange and narrower toward the outside—allowing the wheelset to self-center on straight track by naturally adjusting to equalize diameters on both rails.^[13] The flange, a raised rim on the inner edge of each wheel, acts as a secondary safeguard, contacting the rail's inner side to prevent lateral displacement during deviations such as curves or minor perturbations, though excessive flange contact indicates instability.^[14] Initial signs of an impending derailment may include wheel lift, where vertical forces exceed the wheel's weight, or lateral displacement, where the wheel climbs the rail due to unbalanced forces.^[15] Derailments represent a critical aspect of rail safety, as they constitute the most common type of train accident and can disrupt operations, damage equipment, and pose risks to personnel and the public.^[16] They occur thousands of times annually in the United States, underscoring the ongoing need for robust safety measures in rail systems.^[17] Reportable derailments under Federal Railroad Administration (FRA) rules include those causing damage exceeding $12,400 (as of 2025).^[18]

Types of Derailments

Derailments are classified by speed to distinguish between those occurring at low velocities, typically under 10 mph in switching yards or sidings, where the reduced kinetic energy often limits damage to minor disruptions and easy recovery, accounting for approximately 74% of all incidents on Class I railroads (as of 2024).^[8] In contrast, high-speed derailments, generally exceeding 50 mph on mainline tracks, involve greater dynamic forces that amplify severity, leading to potential overturning, cargo spillage, or chain reactions along the train consist.^[19] Classification by extent differentiates partial derailments, where one or more wheels or axles leave the rails but the vehicle may remain controllable or stop without full separation from the track, from complete derailments, in which an entire railcar or locomotive departs the rails entirely.^[15] Complete events frequently result in secondary effects like jackknifing, where cars angle sharply against each other, or telescoping, where one car partially overrides another, exacerbating structural damage and complicating rescue efforts.) By context, derailments vary between freight and passenger operations, with freight incidents predominantly occurring in low-speed classification yards during coupling or sorting maneuvers, while passenger derailments more commonly arise on dedicated high-speed corridors emphasizing rapid transit.^[8] Urban environments feature higher densities of switches and grade crossings that contribute to localized risks, whereas rural settings involve extended straight tracks or gentle curves susceptible to isolation-related maintenance challenges. Derailments on curved sections or at switches outnumber those on straight track due to elevated lateral forces, though this typology intersects with operational contexts like mainline versus branch line service.^[16] Emerging classifications include intentional derailments from sabotage, such as deliberate track removal or switch misalignment, which pose targeted security threats beyond accidental failures and require vigilant infrastructure monitoring.^[20] Extreme weather-induced derailments, driven by events like flooding that undermines track foundations or thermal expansion from heat waves that warps rails, represent a growing category amid climate variability, often amplifying risks in vulnerable geographic contexts.^[21]

Historical Context

Early Incidents and Developments

The origins of rail transport and associated derailments trace back to the 18th century, when horse-drawn wagonways were employed in European mining districts, particularly in Britain and Germany, to convey coal and ore along rudimentary wooden tracks laid on stone or wooden supports. These primitive systems, often spanning uneven terrain with minimal grading, were highly susceptible to derailments caused by rail warping, wheel flange failures, or track subsidence under load. Such incidents, though commonplace in mining operations, were infrequently recorded due to their routine nature and the era's limited documentation practices. In the UK, early steam-era derailments, such as those on the Liverpool and Manchester Railway in the 1830s, similarly highlighted infrastructure challenges. The advent of steam-powered railways in the 1820s introduced greater speeds and loads, exacerbating derailment risks on early infrastructure. In the United States, wooden rails predominated during this decade, as seen on lines like the 1826 Granite Railway in Massachusetts, where the combination of wooden stringers topped with thin strap iron frequently led to structural failures and derailments; the strap iron would loosen from pounding traffic, curling upward into a "snakehead" that snagged wheels or punctured cars. One early steam example occurred in 1829 on the Delaware and Hudson Railway, where the British-built Stourbridge Lion locomotive derailed shortly after its trial run due to the tracks' inadequacy for its weight, underscoring the mismatch between imported technology and nascent American infrastructure.^[22]^[23] By the 1830s, as U.S. railroads expanded to link canals and inland routes—facilitating the shift from water-based to rail transport—derailments persisted amid construction haste and material limitations. The first recorded fatal passenger train derailment in the United States took place on November 8, 1833, on the Camden and Amboy Railroad near Hightstown, New Jersey, when a fractured axle caused the cars to overturn, killing two passengers (one immediately and one later) and injuring most of the 24 passengers aboard, including former President John Quincy Adams who escaped unharmed. In response to these recurring issues with wooden and strap rail designs, engineers transitioned to wrought iron rails by the mid-1830s, which offered superior strength and reduced breakage rates on lines like the Baltimore and Ohio Railroad.^[24]^[25]^[22] Significant mid-19th-century events further illuminated derailment vulnerabilities, particularly involving bridges integrated into expanding networks. On May 6, 1853, the Norwalk rail accident on the New York and New Haven Railroad in Connecticut became the first major U.S. railroad bridge disaster when a passenger train, misjudging an open swing bridge over the Norwalk River, plunged 15 feet into the water below, killing 46 people and injuring dozens more. Such collapses, often tied to wooden bridge designs under increasing train weights, contributed to growing awareness of structural risks in early rail systems.^[26]

Evolution of Safety Standards

The evolution of railway safety standards in the late 19th century marked a pivotal shift toward formalized regulations in response to growing accident rates from rapid network expansion. In the United Kingdom, the Regulation of Railways Act 1889 required the installation of continuous automatic brakes on all passenger trains, enabling quicker stops and mitigating derailment risks from inadequate braking during emergencies.^[27] This legislation built on earlier efforts, such as the formation of inspection protocols under the 1842 Railway Regulation Act, which empowered authorities to assess track and operational safety before line openings.^[28] In the United States, the widespread standardization of track gauge to 4 feet 8.5 inches in the 1880s, driven by cooperative agreements among railroads like the Southern Railway Association and culminating in the 1886 Great Gauge Change, eliminated incompatibilities that had caused frequent derailments at gauge transitions.^[29] Early 20th-century innovations further advanced derailment prevention through material and technological improvements. The transition to steel rails, which began in the 1870s and was nearly complete by 1900, replaced brittle iron ones and substantially reduced rail fractures—a leading cause of track failures—due to steel's superior tensile strength and resistance to fatigue.^[30] By the 1920s, experiments with Automatic Train Control (ATC) systems emerged in both the UK and US to enforce signal adherence and speed restrictions. In the UK, a 1920 government committee recommended ATC adoption following successful trials on the Great Western Railway, while US railroads tested intermittent inductive devices to automatically apply brakes on signal violations. These efforts targeted dynamic derailment mechanisms like overspeeding. Mid-20th-century developments emphasized international coordination and regulatory enforcement. The Union Internationale des Chemins de fer (UIC), established in 1922, developed unified standards for track design, loading gauges, and interoperability, fostering safer cross-border operations and reducing incompatibility-related incidents.^[31] In the US, the Interstate Commerce Commission (ICC) intensified oversight with rules mandating periodic inspections of locomotives, cars, and tracks under the Boiler Inspection Act amendments (last updated in 1940) and safety appliance standards, aiming to preempt equipment failures.^[32] This era saw a key transition from reactive post-incident remedies to proactive strategies, with ultrasonic rail testing developed in the 1950s by companies like Sperry and formal Federal Railroad Administration (FRA) track safety standards established in 1971, requiring visual inspections at least weekly or twice weekly depending on track class and ultrasonic testing for certain high-speed or heavy-traffic sections.^[33]^[34] These foundational measures influenced later technologies like Positive Train Control.

Causes

Track-related causes of derailment primarily stem from infrastructure failures that compromise the integrity and stability of the railway path, leading to wheel-rail separation under load. These issues often arise from material degradation, design flaws, or environmental stresses on the track components, independent of vehicle or operational factors. According to analyses of U.S. freight train accidents, track defects account for a significant portion of mainline derailments, with infrastructure failures contributing to over 70% when combined with rolling stock issues.^[35]^[36] Broken rails represent one of the most prevalent track-related derailment triggers, often resulting from fatigue cracks that propagate due to repeated cyclic loading from train wheels. These fractures can also originate from thermal expansion during temperature fluctuations, which induces tensile stresses, or manufacturing defects such as inclusions in the steel that weaken the rail over time. Rails exceeding 30 years in service or subjected to high annual gross tonnage—typically over 100 million tons—are particularly susceptible, as cumulative wear accelerates crack initiation and growth. In U.S. mainline operations, broken rails or welds were responsible for approximately 15-20% of derailments between 2001 and 2010, underscoring their role as the leading track cause. Recent FRA data indicates that track defects remain a primary cause, though overall derailment rates have declined by about 40% since 2005 due to enhanced inspection protocols.^[37]^[38]^[19]^[39] Track geometry defects, including misalignment of rails, uneven settlement of the substructure, and errors in superelevation on curved sections, can induce lateral instability and excessive lateral forces on wheels. Misalignment occurs when rails deviate from their designed horizontal or vertical alignment, often due to subsidence or insufficient tamping, while superelevation errors—where the outer rail on a curve is not raised adequately—fail to counterbalance centrifugal forces, promoting wheel climb. These defects were implicated in about 7.3% of U.S. train derailments from 2001 to 2010, with higher risks on curves where geometry tolerances are tighter.^[19]^[40]^[41] Failures in switches and crossings, such as malfunctioning points or inadequate guard rail gaps, allow wheels to diverge from the intended path, particularly at junctions where track geometry changes abruptly. Point malfunctions may stem from wear on switch rails or improper lubrication, causing the switch to not fully align, while gaps in guard rails at crossings can permit wheel flanges to drop through, leading to sudden lateral shifts. Such issues contribute notably to yard and siding derailments, though they also affect mainlines, with switch-related problems highlighted in investigations of dynamic derailment behaviors at turnouts. The implementation of Positive Train Control (PTC) since 2015 has significantly reduced misaligned switch incidents.^[19]^[42] Degradation of ballast and ties undermines track support, resulting in shifts or settlements that alter geometry and reduce lateral resistance. Ballast erosion from fouling—accumulation of fines and moisture—diminishes drainage and load distribution, potentially halving track stability under lateral forces, while tie rot or deterioration, especially in wooden ties exposed to moisture, leads to rail seat abrasion and uneven support. In degraded conditions, these factors can cause rapid track component failure and increase derailment risk by concentrating wheel loads.^[43]^[44]^[45] Vehicle-related causes of train derailments often stem from defects in the rolling stock components, which can compromise stability and lead to loss of contact between wheels and rails. Defective wheels, such as those with cracks, flat spots, or out-of-roundness due to wear, generate excessive vibrations and uneven forces that increase the risk of flange climbing or wheel lift-off.^[46] Wheel flats, in particular, are a prevalent surface defect caused by wheel-slide during braking, and they are identified as a significant contributor to derailments by inducing dynamic instabilities.^[47] Additionally, axle bearing failures can cause wheelsets to seize, resulting in sudden locking and lateral displacement that precipitates derailment.^[48] Such failures often manifest as overheated bearings, leading to catastrophic wheelset malfunctions during operation.^[49] Suspension and bogie issues further exacerbate derailment risks by disrupting the even distribution of weight across the rail vehicle. Faulty springs or degraded suspension components can cause uneven load transfer, tilting the vehicle and reducing wheel-rail contact on one side.^[50] Bogie frame failures, such as cracks or collapses in side frames, lead to structural instability, allowing wheels to shift off the rails under load. In one analysis, multiple derailments were attributed to similar side frame failures initiating at stress concentration points, propagating to full collapse and derailing subsequent cars. Brake system malfunctions represent another critical vehicle-related factor, often producing asymmetric forces that destabilize the train. Locked wheels from brake binding create high frictional drag on one side, generating lateral forces that can force flanges over rail heads. Uneven braking, due to partial application or air pressure inconsistencies, causes buff forces between cars, amplifying shear and leading to mid-train derailments.^[51] These issues are particularly hazardous on curves, where combined lateral and longitudinal forces exceed safe thresholds. In freight operations, overloaded or shifting cargo introduces unique vehicle-related hazards by altering the center of gravity and load dynamics. Overloading individual cars increases axle loads beyond design limits, promoting wheel unloading and instability during negotiation of track irregularities. Shifting cargo, such as unsecured lading in containers, can cause sudden weight redistribution, raising the risk of rollover or derailment through dynamic imbalances.^[53] Such shifts have been documented in accident databases as contributing to a small but notable percentage of derailment incidents involving hazardous materials releases.^[54]

Operational and Human Factors

Operational and human factors contribute significantly to train derailments, often stemming from errors in train handling, signaling interpretation, procedural adherence, and crew condition. According to data from the U.S. Federal Railroad Administration (FRA), human factors account for more than one-third of all train accidents in the U.S. railroad industry, with improper operations frequently leading to derailments through loss of control or misalignment of equipment.^[55] These errors are distinct from mechanical or environmental issues, as they arise from decision-making and execution by crew members or dispatchers, amplifying risks during routine maneuvers.^[56] Signal and communication malfunctions, such as faulty signals or dispatch errors independent of human misinterpretation, also contribute, accounting for approximately 10-15% of train accidents in recent FRA data (2015-2024).^[57] Harsh train handling, such as excessive acceleration, abrupt deceleration, or overspeeding on curves, generates unbalanced centrifugal forces that can cause wheels to climb flanges or lose contact with the rail, resulting in derailment. In 2005, improper train handling or misuse of the automatic braking system was responsible for 14% of human-factor accidents occurring on main tracks, often exacerbating lateral forces on curved sections where speed limits are critical.^[56] Analysis of major derailment incidents indicates that such handling errors are particularly prevalent at speeds exceeding 25 mph, where rapid changes in velocity overwhelm the train's stability.^[19] Improper use of control systems, including misreading signals or overriding safety interlocks, can position trains on fouled tracks or conflicting routes, leading to low-speed or high-impact derailments. Signal passed at danger (SPAD) events, where crews fail to correctly interpret stop signals, have been identified as a recurring human error contributing to derailments, with regulatory bodies noting that misperception or misinterpretation increases the probability of such incidents despite low overall frequency.^[58] FRA accident cause codes classify these under train operation human factors, encompassing failures to adhere to interlocking protocols that prevent equipment from entering hazardous alignments.^[4] Switching errors in yards or sidings, such as incorrect coupling during shunting or misalignment during maneuvers, frequently result in low-speed derailments due to wheels derailing at points of switch. Human factors like improper switch operation were a leading cause of derailments on yard tracks in a study of major incidents, where procedural lapses during coupling or routing decisions allowed cars to deviate from intended paths.^[19] Investigations, including those by the National Transportation Safety Board (NTSB), have attributed specific derailments to switch positioning errors by crew, highlighting how brief oversights in verification can cascade into equipment instability.^[59] Fatigue and training deficiencies among crew members further elevate the risk of operational errors, with exhaustion impairing judgment and reaction times during critical tasks. A review of 98 rail incident reports found fatigue as a contributory factor in 23 cases, including derailments, underscoring its role in degraded performance.^[60] FRA research shows that highly fatigued crews experience more than triple the average accident cost, with fatigue elevating the probability of human-factor incidents from 11% to 65% in affected operations.^[55]^[61] Inadequate training on handling protocols compounds these issues, as gaps in procedural knowledge lead to repeated error patterns across incidents.^[62]

External and Environmental Causes

Derailments can result from collisions with external obstacles, such as debris on the tracks, impacts with other trains during switching operations, or strikes with vehicles at highway-rail grade crossings, where the sudden force disrupts wheel-rail contact and initiates secondary derailment of one or more cars. Highway-rail grade crossing collisions are a separate category of FRA-reported incidents from train accidents and can lead to derailments; between 2008 and 2017, over 19,000 such crossing incidents were recorded, resulting in thousands of injuries and some derailments when trains could not maintain stability post-collision.^[19]^[63] Extreme weather conditions pose significant risks by altering track infrastructure or train dynamics outside normal operational parameters. Flooding from heavy precipitation or river overflow erodes ballast and subgrade, leading to track washouts and sudden loss of support under moving trains, as seen in flash flood events that have historically caused multiple derailments with substantial damage.^[64] High winds, particularly crosswinds exceeding 50 mph on elevated or exposed sections like bridges in mountainous regions, can exert lateral forces sufficient to overturn or derail high-profile freight cars, with FRA records noting 26 wind-related incidents as primary causes between 1993 and 2002.^[64] Similarly, ice accumulation on rails, switches, and overhead wires during severe winter storms reduces traction and can freeze mechanisms in place, contributing to misalignment and derailments; FRA data identifies snow and ice as a primary factor in 22 accidents, with snow present in 131 total incidents.^[64] Sabotage and vandalism, including deliberate tampering with rails, switches, or signaling systems to induce failure, account for a small fraction of derailments, typically less than 5% of reported cases, though they can have severe consequences when undetected.^[65] In analyses of high-speed rail accidents, vandalism contributed to about 7% of incidents in sampled data, often through actions like placing obstacles or cutting signal wires.^[65] Geological events, particularly earthquakes in seismically active regions, can cause derailments by inducing ground shaking, fault rupture, or soil liquefaction that shifts or buckles tracks beneath trains. The 2004 Niigata-ken Chuetsu Earthquake in Japan, with a magnitude of 6.8, derailed a Shinkansen bullet train traveling at 200 km/h due to intense vertical and horizontal accelerations, marking the first such incident for Japan's high-speed network and highlighting vulnerabilities in non-quiescent periods.^[66] In the United States, the 1989 Loma Prieta Earthquake (magnitude 6.9) disrupted rail lines in California through track displacement and bridge damage, though no moving train derailments occurred; studies emphasize that such events affect 30% of global earthquake impacts on rail systems via direct derailment or operational halts.^[67]

Mechanisms

Wheel-Rail Interaction

The wheel-rail interaction forms the foundational interface in railway dynamics, where the conical profile of the wheel treads plays a critical role in maintaining lateral stability. The coning effect, characterized by a slight taper (typically 1:20 slope) on the wheel tread, ensures that when the wheelset shifts laterally relative to the track, the larger diameter on the outer wheel increases its rotational speed, generating a restoring moment that self-centers the wheelset without flange contact. This geometric feature, integral to standard wheel profiles since the late 19th century, minimizes wear and enhances straight-track stability by accommodating small displacements through differential rolling radii.^[68] Under operational loads, the wheel-rail interface experiences creepage, defined as the relative velocity difference between the wheel and rail divided by the wheel's rolling speed, leading to micro-slipping in the contact patch. Longitudinal creepage occurs during acceleration or braking, while lateral and spin creepages arise from curving or misalignment, with typical values ranging from 0.1% to 2% before gross slipping. These creepages generate tangential forces via friction, modeled by Kalker's linear theory for small values, where creep forces are proportional to creepages through material-dependent coefficients, ensuring controlled adhesion and preventing excessive slip that could precipitate instability. Beyond the linear regime, nonlinear theories account for saturation, where forces plateau at the friction limit, influencing traction and energy dissipation.^[69]^[70] Contact mechanics at the wheel-rail interface are governed by Hertzian theory, which describes the elastic deformation and stress distribution when two curved steel surfaces meet under normal load. Assuming non-conforming geometries approximated as ellipsoids, the theory predicts an elliptical contact patch with semi-axes determined by the load, principal curvatures, and reduced elastic modulus E^* (typically 1.1 × 10^{11} Pa for steel). More precise formulations yield A = \pi a b with a = \left( \frac{3 F R}{4 E^*} \right)^{1/3} ( R as reduced radius). This results in high localized Hertzian stresses (up to 1-2 GPa), concentrated in a patch of 1-2 cm² per wheel, which must remain below yield limits to avoid plastic deformation and fatigue.^[71] Lateral stability depends on the friction coefficient \mu at the interface, typically 0.3-0.5 for dry steel-on-steel contact, which governs the tangential resistance to lateral displacements. For small lateral shifts, the coning effect restores equilibrium, but if \mu is insufficient (e.g., below 0.2 on contaminated rails), slipping amplifies displacements, reducing the effective steering and allowing wheelset hunting oscillations. Conversely, high \mu (approaching 0.5-0.7 dry) can sustain larger lateral forces, but excessive values promote instability growth if combined with track irregularities, as the frictional shear resists but does not fully dampen perturbations. These interactions provide the physical basis for understanding derailment-prone dynamics, such as those leading to flange climbing under perturbed conditions.^[72]^[73]

Flange Climbing

Flange climbing occurs when excessive lateral forces cause the wheel flange to ascend the rail head, potentially leading to the wheelset derailing if the climb progresses unchecked. This quasi-static process begins with the flange contacting the rail's inner face, where the resultant force vector directs the flange upward along the rail profile. As the lateral force overcomes the stabilizing vertical load, the contact point shifts progressively higher on the flange until the wheel tread loses contact with the rail top, allowing the flange to override the rail.^[15] The primary theoretical framework for predicting flange climbing is Nadal's criterion, which assesses the balance between lateral (H) and vertical (V) forces at the wheel-rail interface, accounting for friction. Derailment initiates when the ratio exceeds the threshold: H/V > \frac{\tan \delta - \mu}{1 + \mu \tan \delta}, where \delta is the flange contact angle (typically 60°) and \mu is the friction coefficient (e.g., 0.5 for conservative limits). This yields a practical limit of approximately 0.66, though safety standards like the FRA's often use 0.8 to incorporate dynamic effects and angle of attack. This criterion assumes dry friction conditions and quasi-static motion, providing a conservative limit for safe operation.^[74]^[75] Flange climbing typically arises under high lateral-to-vertical force ratios, often exceeding 0.8 for standard wheel profiles, where the wheelset experiences sustained outward pressure against the rail. Such ratios commonly develop on curved track sections or during vehicle hunting oscillations, where the wheelset yaws and rolls, amplifying lateral inputs. Empirical validations of Nadal's limit confirm its accuracy in these scenarios, particularly at elevated angles of attack greater than 5 degrees, as the wheelset advances in a steady climbing motion.^[76]^[77] Contributing factors include excessive train speed relative to curve radius, inadequate track superelevation that fails to counter centrifugal forces, and track twist that unevenly distributes wheel loads across axles. For instance, superelevation deficiencies increase the effective lateral demand, pushing the force ratio toward the critical threshold, while track twist can induce sudden roll that initiates climbing on one wheel. Historical instrumented tests from the mid-20th century, including those evaluating wheel-rail dynamics under varying speeds and geometries, demonstrated that these factors could elevate lateral forces by 20–50% beyond nominal levels, confirming the role of geometric mismatches in promoting climb initiation.^[15]^[78] If the climbing process continues without intervention, the flange fully overrides the rail head, resulting in complete derailment of the wheelset and potentially the entire vehicle. This progression often unfolds over several meters of travel, with the initial climb phase lasting seconds before loss of stability, leading to lateral displacement and impact with adjacent infrastructure. Unchecked flange climbing accounts for a significant portion of low-speed derailments, underscoring its role as a critical failure mode in wheel-rail stability assessments.^[75]^[77]

Dynamic Effects

Dynamic effects in railway derailment encompass the transient oscillatory and impact phenomena that destabilize vehicle motion, often amplifying small perturbations into catastrophic events. These effects arise from the interaction between vehicle dynamics and track conditions during operation, leading to forces that exceed safety thresholds and cause wheels to leave the rails. Understanding these dynamics is crucial for predicting and mitigating derailment risks in high-speed and freight rail systems. Hunting oscillation represents a primary dynamic effect, characterized by sinusoidal yawing and lateral swaying of the wheelset relative to the track centerline. This self-excited motion occurs when the vehicle's speed exceeds a critical threshold, causing the wheelset to repeatedly shift between rails in a periodic manner. The phenomenon stems from the coned profile of railway wheels, which generates restoring forces that, at high speeds, interact with lateral stiffness to produce instability. The critical speed for the onset of hunting is derived from linear stability analysis of the wheelset's equations of motion, highlighting influences such as lateral stiffness, wheelset mass, conicity, and creep properties; above this speed, amplitudes grow, generating excessive lateral forces that can lead to flange contact and eventual derailment if damping mechanisms, such as suspension friction, are insufficient.^[79] Track irregularities introduce additional dynamic excitations through vertical bounces and twists that resonate with the vehicle's natural frequencies. These imperfections, such as corrugations or settlements, manifest as periodic perturbations with wavelengths that, when matching the vehicle's speed-induced excitation frequency, amplify vertical and lateral accelerations. For instance, vertical irregularities at wavelengths corresponding to the vehicle's bounce mode natural frequency of approximately 1-2 Hz can cause resonant oscillations, leading to wheel unloading and increased derailment risk on uneven sections. Twists in track alignment further exacerbate this by inducing roll motions that unevenly distribute wheel loads, potentially causing one rail to lift under dynamic amplification. Such resonances are particularly hazardous in high-speed operations, where even minor irregularities (e.g., 5-10 mm amplitude) can escalate forces beyond the 60-80 kN safety limits for wheel climb.^[80] In collision scenarios, dynamic effects manifest as sudden impact forces that propagate through the train consist, inducing whip-like oscillations or buckling deformations. Post-collision, the abrupt energy transfer generates longitudinal compressive waves that cause adjacent cars to accordion or override, with peak forces often exceeding 1-2 MN and leading to secondary derailments. This whipping action involves flexural modes of the carbody and coupler slack, amplifying lateral displacements and rail interactions; for example, in head-on collisions at 50-80 km/h, the dynamic buckling can displace wheels laterally by 100-200 mm within seconds, far surpassing static thresholds. These effects are compounded by the train's length, where wave propagation delays create out-of-phase motions that destabilize trailing vehicles.^[81] To predict and analyze these dynamic effects, multibody dynamics (MBD) models are employed, simulating the vehicle-track system as interconnected rigid or flexible bodies with contact nonlinearities. These models integrate equations of motion for translation, rotation, and wheel-rail interactions, often using software like SIMPACK or ADAMS/Rail to forecast hunting growth rates, resonance amplifications, and post-impact trajectories. By incorporating stochastic track inputs and parametric variations, MBD simulations enable assessment of derailment probabilities under operational conditions, such as speeds up to 350 km/h, providing insights into stability margins without physical testing. Validation against field data confirms their accuracy in capturing transient behaviors, aiding in design optimizations for suspension and track maintenance.^[82]^[83]

Prevention and Safety Measures

Infrastructure and Track Design

Infrastructure and track design play a critical role in preventing derailments by ensuring stability, proper load distribution, and resistance to lateral forces during train operations. Key design standards focus on rail profiles, horizontal curvature, and superelevation to minimize wheel-rail interaction risks. For instance, the UIC 60 rail profile, standardized under EN 13674-1, weighs 60.21 kg/m and features a head width of 72 mm, height of 172 mm, and base width of 150 mm, providing enhanced durability for heavy-haul and high-speed applications.^[84] This profile is widely adopted in European and international networks to support axle loads up to 25 tonnes while reducing wear that could lead to track irregularities.^[85] Horizontal curve design prioritizes larger radii to limit centrifugal forces, with radii exceeding 1000 m preferred for mainline tracks to reduce derailment potential from excessive lateral acceleration, particularly at speeds above 100 km/h.^[86] Superelevation, or cant, counters these forces through the formula e = \frac{G V^2}{127 R}, where e is superelevation in mm, G is track gauge in mm (e.g., 1435 mm for standard gauge), V is speed in km/h, and R is radius in m; this ensures equilibrium at design speeds while limiting maximum cant to 160-180 mm for passenger lines.^[87] These parameters are calibrated to maintain wheel-rail contact within safe flanges, preventing climbing or jumping derailments. Maintenance protocols are essential for sustaining track integrity over time. Ultrasonic testing detects internal rail defects such as cracks and transverse fissures, typically conducted annually or every 40 million gross tons (MGT) of traffic for higher-class tracks, using pulse-echo technology on rail flaw detection vehicles traveling at low speeds.^[88] Ballast tamping, which compacts the under-ballast layer to restore alignment and drainage, is performed every 1-2 years on high-traffic lines or as needed based on geometry degradation, employing automated tamper machines to lift and reposition sleepers.^[89] Geometry inspections utilize track recording vehicles to measure parameters like gauge, alignment, cross-level, and warp, conducted at least annually to identify deviations that could initiate derailments, with tolerances tightening for higher speeds (e.g., no more than 1.25 inches of misalignment for tracks supporting 80 mph operations).^[88] Track upgrades further enhance safety by addressing common failure points. Continuous welded rail (CWR) eliminates joints that are prone to loosening or batter, reducing vertical and lateral oscillations that contribute to derailments; its implementation has lowered maintenance costs and extended track life by up to 50% in heavy-traffic corridors.^[90] Guard rails at switches and crossings guide flanged wheels through complex geometries, maintaining minimum flangeway clearances of 1.5 inches to prevent overriding or dropping off, particularly in turnout areas where misalignment risks are highest.^[91] Regulatory frameworks enforce these practices through codified standards. In the United States, the Federal Railroad Administration's Track Safety Standards under 49 CFR Part 213 classify tracks from Class 1 (maximum 15 mph for passengers) to Class 9 (up to 220 mph), with escalating requirements for geometry, rail condition, and ballast depth to mitigate derailment hazards— for example, Class 5 tracks demand at least 12 crossties per 39 feet and rail/head wear limits of 0.25 inches.^[92] Compliance involves documented inspection plans and CWR procedures to address thermal expansion risks, ensuring infrastructure resilience across varying operational demands.^[93]

Vehicle and Equipment Standards

Vehicle and equipment standards for rail vehicles focus on enhancing stability, optimizing wheel-rail interaction, and minimizing dynamic forces that contribute to derailments. These standards, primarily developed by organizations such as the Association of American Railroads (AAR) and the Federal Railroad Administration (FRA), specify design parameters, material requirements, and maintenance protocols for rolling stock components to ensure safe operation across varying speeds and track conditions. By addressing potential failure modes in wheels, bogies, and load configurations, these regulations reduce the likelihood of instability-induced incidents. Wheel and axle specifications are foundational to derailment prevention, as they directly influence contact geometry and load distribution. The AAR Manual of Standards and Recommended Practices defines tread profiles, such as the AAR-1 and AAR-1B contours, which feature a 1:20 taper to promote self-centering of wheelsets and limit flange wear that could lead to climbing derailments. For new freight car wheels, the standard flange height is 1-1/8 inches (approximately 28 mm) to provide adequate guidance while avoiding excessive contact forces; the wheel is condemnable if the flange height reaches 1-1/2 inches (38 mm) or more to preserve stability.^[94] Axle bearings must undergo continuous monitoring via wayside acoustic and thermal detectors, as outlined in AAR's Wheel, Axle, Bearing, and Lubrication (WABL) standards, to detect defects like spalling or overheating that could cause seizures and subsequent derailments.^[95] Bogie designs incorporate advanced features to control vehicle dynamics and enhance curve negotiation. Active steering systems actively adjust wheelset yaw angles using actuators, reducing angle of attack and wheel-rail lateral forces by up to 83.6% in simulated high-speed operations, thereby improving stability and lowering derailment risks on irregular track.^[96] Suspension damping in primary and secondary bogie elements is calibrated to suppress hunting oscillations, with standards recommending nonlinear dampers that optimize energy dissipation; for instance, multi-objective optimization techniques ensure damping levels that balance ride quality and critical speed thresholds above 200 km/h.^[97] Load limits emphasize proper distribution to maintain equilibrium and prevent shifting under acceleration or braking. Center-of-gravity rules require the combined center of gravity of the loaded rail car to remain at or below 98 inches (approximately 2.5 m) above the top of the rail for standard freight configurations, restricting high-stacked loads that could amplify overturning moments.^[98] Securement protocols for lading, detailed in AAR Circular 42-N, mandate the use of blocking, bracing, and dunnage to immobilize cargo, with commodity-specific guidelines ensuring no more than 5% load shift under dynamic forces to avoid destabilization.^[99] Certification processes verify ongoing compliance through inspections and performance testing. FRA regulations under 49 CFR Part 229 require periodic mechanical inspections of locomotives and cars every 92 days maximum, encompassing visual and dimensional checks of wheels, axles, bogies, and securements to identify wear or defects preemptively.^[100] Since the early 2000s, crashworthiness standards from FRA and APTA, including full-scale collision tests per APTA PR-CS-S-034-99, evaluate vehicle structures for energy absorption and occupant protection, mandating deformable end frames to mitigate injuries in derailment scenarios.^[101]

Operational Protocols and Training

Operational protocols in railroads emphasize standardized procedures to mitigate risks of derailment arising from human error or procedural lapses, focusing on precise adherence to speed restrictions, braking responses, and communication safeguards. These protocols are enforced through Federal Railroad Administration (FRA) regulations, which mandate comprehensive training and operational guidelines to ensure crew competency and system reliability. By integrating rule-based decision-making with rigorous oversight, railroads aim to prevent incidents such as overspeed on curves or signal violations that could lead to flange climbing or dynamic instability. As of 2025, FRA has implemented new dispatcher certification rules (effective FY2024), and the proposed RAIL Act seeks to mandate two-person crews and boost inspections to further reduce human-factor derailments.^[102]^[103] Speed and handling rules are central to derailment prevention, particularly on curved track where excessive lateral forces can cause wheel climb. Under FRA Track Safety Standards (49 CFR § 213.57), maximum permissible speeds on curves are calculated based on the degree of curvature (D) and the sum of actual superelevation (Ea) and qualified cant deficiency (Eu), using the approximation V ≈ 38.9 × √[(Ea + Eu)/D], where V is in miles per hour and Ea and Eu are in inches (exact values from standards tables in Appendix A); for unqualified equipment, cant deficiency is limited to 3 inches, while qualified vehicles may operate up to 5 or 6 inches with FRA approval. This ensures that trains do not exceed balance speed, reducing unbalanced superelevation that contributes to derailments; for instance, on a 2-degree curve with 4 inches of superelevation and 3 inches cant deficiency, the maximum speed is approximately 73 mph. Emergency braking protocols require immediate full application of brakes upon receipt of a stop signal or detection of an obstruction, as stipulated in 49 CFR § 232.103, which mandates that train brake systems achieve an emergency reduction in speed of at least 20 mph per second initially and halt within specified distances based on track class, thereby minimizing impact forces in potential derailment scenarios. Crew training programs are designed to instill proficiency in signal interpretation and response, utilizing simulator-based simulations to replicate high-risk scenarios without real-world hazards. FRA's Training, Qualification, and Oversight requirements (49 CFR Part 243) compel railroads to develop approved curricula that include hands-on and virtual simulator training for locomotive engineers, emphasizing rapid reaction to restrictive signals to avert overspeed events; for example, programs often simulate curve negotiation under varying weather conditions to build muscle memory for throttle and brake adjustments. Fatigue management is equally critical, with hours-of-service laws (49 CFR Part 228) limiting train employees to no more than 12 consecutive hours on duty in a 24-hour period, followed by a mandatory 10-hour off-duty rest, and capping service at 276 hours per calendar month; these limits, updated by the Rail Safety Improvement Act of 2008, address circadian disruptions that impair judgment and reaction times, thereby reducing error-induced derailments. Dispatch and signaling protocols rely on strict adherence to block signal systems to maintain safe train intervals and prevent conflicting movements. Per FRA Signal and Train Control regulations (49 CFR Part 236), railroads must ensure that automatic block signals display aspects indicating track occupancy, with crews required to comply immediately to avoid rear-end collisions or siding misentries that could derail trains; non-compliance triggers mandatory reporting and retraining. Misrouting prevention incorporates double-check mechanisms, where dispatchers issue track warrants or authorities that crews verbally confirm and physically verify before proceeding, such as aligning switches and cross-checking lineup sheets against routing instructions, as outlined in industry safety guides to eliminate routing errors that lead to unintended track occupancy. Incident reporting protocols facilitate proactive safety enhancements by capturing near-misses, enabling pattern analysis to refine operational practices. The FRA's Confidential Close Call Reporting System (C3RS), established in collaboration with NASA, allows anonymous submission of near-miss events like near-overspeeds or signaling lapses, fostering a non-punitive environment for data collection that has identified recurring human factors in potential derailments; the National Transportation Safety Board (NTSB) has repeatedly recommended expanding such systems, as seen in investigations where unreported near-misses preceded accidents, urging railroads to integrate C3RS data into training and protocol updates.

Advanced Technologies

Positive Train Control (PTC) represents a significant advancement in automated rail safety systems, mandated by the U.S. Rail Safety Improvement Act of 2008 and fully implemented across required Class I railroads by December 31, 2020.^[104] This communications-based technology integrates GPS, wireless radio, and onboard computers to continuously monitor train locations, speeds, and signals, automatically enforcing temporary speed restrictions or applying brakes to prevent collisions, overspeed derailments, and incursions into work zones.^[105] By overriding human error in signal compliance and speed management, PTC has been credited with preventing numerous potential accidents, with Federal Railroad Administration (FRA) analyses indicating it addresses key causes of derailments such as excessive speed. Wayside detectors form a critical component of modern sensor-based monitoring, deployed along tracks to identify mechanical faults in passing trains that could lead to derailments. These systems include hot box detectors (HBDs), which measure bearing temperatures to detect overheating journals, and hot wheel detectors (HWDs), which identify dragging equipment or brake-related issues by sensing wheel surface temperatures exceeding safe thresholds, typically above 200°F (93°C). Wheel impact load detectors (WILDs) complement these by quantifying impacts from flat wheels or other defects, alerting crews to set cars out for repair and thus mitigating risks of track damage or derailment.^[106] Integrating artificial intelligence enhances this infrastructure through predictive analytics, such as ENSCO Rail's risk assessment algorithms that analyze detector data alongside track geometry to generate derailment risk scores, enabling proactive maintenance scheduling.^[107] The European Train Control System (ETCS), part of the broader European Rail Traffic Management System (ERTMS), provides a standardized automated protection framework across Europe, with Levels 1 through 3 offering progressive enhancements in derailment prevention since its widespread adoption post-2000.^[108] Level 1 uses intermittent balise transponders for position updates and continuous speed supervision to enforce limits and prevent overspeed; Level 2 employs continuous radio-based communication for real-time movement authority without fixed signals; and Level 3 introduces moving-block signaling with train integrity monitoring via GPS and onboard systems, further reducing collision and derailment risks by optimizing headways.^[109] Complementing ETCS, onboard derailment prediction systems leverage GPS for precise positioning and accelerometers to detect anomalous vibrations or lateral forces, triggering alerts or automatic braking when thresholds indicative of wheel climb or track irregularities are exceeded.^[110] Post-2020 innovations have accelerated the use of drones for non-invasive track inspections, enabling rapid assessment of remote or hazardous areas to preempt derailment causes like vegetation overgrowth or erosion.^[111] Equipped with high-resolution cameras and LiDAR, these unmanned aerial vehicles (UAVs) generate 3D models of infrastructure, identifying defects such as rail cracks or ballast displacement with sub-centimeter accuracy, as demonstrated in projects like the EU's Drone4Rail initiative launched in 2021.^[112] Machine learning further refines anomaly detection by processing vast datasets from track sensors and inspections; for instance, unsupervised algorithms analyze acceleration time-series to flag irregularities like uneven geometry, while hybrid clustering models on vision data from hi-rail vehicles achieve real-time identification of surface anomalies with over 90% accuracy in controlled tests.^[113] These AI-driven tools, often integrated into cloud platforms, prioritize high-risk segments for intervention, building on traditional monitoring to enhance overall predictive capabilities.^[114]

Statistics and Trends

Derailment Rates and Patterns

In the United States, the Federal Railroad Administration (FRA) documented 1,259 train derailments in 2022, marking a substantial decrease from higher levels in earlier decades, such as approximately 3,000 in 1980.^[3]^[16] This equates to an average of about three derailments per day, with the majority involving freight trains, reflecting the dominance of freight operations in the national rail network.^[8] The overall derailment rate has fallen by 82% since 1980, from 8.98 to 1.63 per million train-miles as of 2014, driven by improvements in maintenance and regulation.^[16] Updated FRA data indicate continued decline, with around 950-1,000 derailments in 2023 and 793 Class I railroad derailments in 2024.^[115]^[8] Analysis of FRA data from 2006 to 2015 reveals that infrastructure and equipment failures, including track geometry defects and mechanical issues, were leading causes of freight train derailments, while human factors contributed to a smaller share.^[116] These proportions highlight the prominence of track and mechanical problems over operational errors. Most derailments are minor in severity, with FRA records indicating that over 90% result in no injuries or fatalities.^[117] However, high-speed incidents incur costs more than 10 times higher than low-speed ones due to greater damage and disruption.^[16] Temporal patterns show seasonal peaks, with winter exhibiting roughly double the derailment rate of summer for causes like broken rails and wheels due to ice, while summer sees elevations from track geometry issues linked to heat expansion and storms.^[118] Advancements like Positive Train Control (PTC), fully implemented by 2020, have accelerated declines by preventing overspeed and switch-related derailments, contributing to a roughly 50% reduction in preventable accidents on equipped lines since rollout.^[119] Post-2023 regulatory enhancements, including FRA's focus on tank car standards and track inspections following incidents like East Palestine, have further supported safety gains.^[11] If current trends persist, annual U.S. derailments could continue declining toward lower levels by 2030, supported by ongoing technological and infrastructural enhancements.^[120]

Global and Regional Perspectives

Europe exhibits relatively low derailment rates compared to other regions, with 70 derailments reported in the European Union in 2023 according to European Union Agency for Railways (ERA) and Eurostat data, down 12.5% from the previous year.^[121]^[122] These low rates are attributed to widespread implementation of the European Train Control System (ETCS), which enhances signaling and automatic train protection. On high-speed lines, such as France's TGV network, derailment rates remain below 1 per billion train-kilometers, reflecting robust infrastructure standards and maintenance protocols.^[123] In Asia, derailment frequencies vary significantly by country. India recorded 48 consequential train accidents (including derailments) in 2022-23, with total derailment incidents higher but predominantly due to track defects and operational errors, as noted in government and CAG audits.^[124]^[125] In China, emphasis on high-speed rail safety intensified following the 2011 Wenzhou collision, which killed 40 people and prompted nationwide speed reductions, enhanced signaling, and rigorous inspections to minimize derailment risks on its extensive network.^[126] Recent expansions in China's high-speed rail continue with safety protocols as of 2025. Other regions face unique challenges that influence derailment patterns. In Australia, remote freight lines are particularly vulnerable to environmental factors and maintenance delays, as evidenced by incidents like the 2018 BHP iron ore train derailment in the Pilbara region.^[127] Africa experiences underreporting of derailments owing to significant infrastructure gaps and limited monitoring systems, with outdated tracks and signaling contributing to higher vulnerability in countries like South Africa and Nigeria.^[128] Comprehensive global estimates for annual derailments are limited due to varying reporting standards, but developed regions like the EU and US account for a significant documented share, while developing areas show disparities in infrastructure and enforcement.^[121] For context, U.S. benchmarks show higher absolute numbers than Europe's, underscoring variations in network scale and technology adoption.^[129]

Consequences

Human and Economic Impacts

Train derailments pose significant risks to human life, particularly affecting railroad employees, passengers, and nearby communities. In the United States, derailments account for a notable portion of railroad accidents, with an average of approximately 1,300 incidents annually over the past decade, representing 61% of all train accidents.^[3] Fatalities from these events remain relatively low compared to total railroad deaths, with only 144 derailment-related deaths recorded nationwide since 1975, averaging about three per year.^[3] Nonfatal injuries are more common, though specific derailment figures are limited; overall railroad employee injuries totaled 6,542 in 2024, a 3% decline from the previous year, with many linked to operational incidents like derailments.^[130] Globally, data from the International Union of Railways (UIC) indicates 114 significant derailments in 2022 across reporting members in Europe, Asia-Pacific, and the Americas, contributing to a rise in total railway fatalities despite a decrease in overall victims.^[131] Freight derailments, which dominate statistics at around 74% occurring in yards and 26% on mainlines in 2024, primarily injure workers rather than passengers, with employee on-duty fatalities declining 71% since 2000 to an all-time low in 2023.^[8]^[115] In the U.S., major incidents occur 1-2 times per decade, often involving hazardous materials and resulting in elevated injury counts, such as the 1,441 injuries from a single 2002 freight derailment.^[117] Economically, derailments impose substantial direct and indirect costs on the rail industry and broader economy. Minor derailments typically range from $1-5 million, while major events can exceed $1 billion, as seen in the 2023 East Palestine, Ohio, derailment, which is expected to cost Norfolk Southern nearly $2.2 billion in remediation and related expenses as of 2025.^[132] Indirect effects amplify these costs through supply chain disruptions and legal liabilities. The 2023 East Palestine incident, involving hazardous chemicals, halted regional chemical shipments and affected businesses, leading to significant operational delays and economic losses for affected industries.^[133] Under the Federal Employers' Liability Act (FELA), enacted in 1908 but strengthened by post-1970s safety regulations, injured railroad workers can pursue negligence-based claims for medical expenses, lost wages, and pain and suffering, excluding them from standard workers' compensation.^[134] These regulations, including Federal Railroad Administration track standards from the 1970s, have driven long-term declines in injury rates—employee casualties fell 27% since 2005—yet FELA claims persist, with 3,032 worker injuries reported in 2020 alone, often resulting in settlements averaging hundreds of thousands to millions depending on severity.^[115]^[135]

Environmental and Societal Effects

Derailments involving the release of hazardous materials pose severe risks to soil and water resources, often leading to long-term contamination that requires extensive remediation efforts. In the United States, approximately one in five derailments involves trains carrying such substances, resulting in chemical spills that infiltrate groundwater, rivers, and surrounding land.^[136] The U.S. Environmental Protection Agency (EPA) oversees cleanup protocols, which mandate containing spills to prevent further spread, excavating contaminated soil and sediment, and treating affected water bodies to mitigate persistent pollutants like vinyl chloride and butyl acrylate.^[137] For instance, following the 2023 East Palestine, Ohio, derailment, EPA-directed operations removed thousands of tons of contaminated material to restore site integrity and protect downstream waterways.^[10] These incidents also disrupt local biodiversity, particularly in ecologically sensitive or remote trackside habitats where spills can devastate aquatic and terrestrial species. Chemical releases have caused widespread fish kills and wildlife mortality, with toxins bioaccumulating in food chains and altering habitat viability for years.^[138] In the East Palestine case, Ohio authorities estimated over 40,000 animals perished shortly after the spill, primarily minnows and other stream dwellers, highlighting vulnerabilities in riparian ecosystems.^[139] Recovery operations exacerbate environmental strain through the carbon footprint of diesel-powered heavy machinery, excavation, and transportation of debris, though exact emissions vary by incident scale.^[140] On the societal front, derailments trigger evacuations and persistent health anxieties, especially concerning degraded air quality from volatile organic compounds lingering post-spill. Communities often face prolonged uncertainty, with residents reporting symptoms like respiratory irritation tied to airborne contaminants.^[141] These effects disproportionately burden marginalized groups, as derailments frequently occur in rural, low-income, or tribal areas lacking robust emergency infrastructure and recovery support, amplifying inequities in access to clean environments and health monitoring.^[142] In response to such incidents, U.S. policymakers introduced the Railway Safety Act of 2023, which aimed to strengthen hazardous materials oversight by mandating real-time electronic train consist information for emergency responders and enhancing inspection requirements for high-risk shipments; the bill did not pass but was reintroduced in 2025.^[143]^[144] As of 2024, Class I railroads reported 793 derailments, with industry-wide derailment rates down 40% since 2005, marking the second-lowest year on record.^[7]

Rerailing and Recovery

Techniques and Methods

Rerailing derailed railway vehicles involves a series of coordinated techniques to safely return the equipment to the tracks, minimizing further damage and ensuring operational integrity. These methods have evolved significantly since the 19th century, when recovery relied primarily on manual labor and rudimentary tools, to modern standardized procedures incorporating mechanical aids and engineering specifications. In the 1800s, wrecking crews used hand tools, timber cribbing, pry bars, and basic pulleys or mules to lift and reposition derailed cars, often requiring days of effort for even minor incidents.^[145] By the 20th century, the introduction of steam-powered derricks and later hydraulic systems established more efficient, protocol-driven approaches, as outlined in international standards like EN 16404, which specifies requirements for interoperable railway vehicles.^[146] The overall sequence of rerailing begins with site assessment to evaluate the derailment's extent, vehicle position, track condition, and potential hazards such as unstable ground or hazardous materials.^[147] Debris clearance follows, removing obstacles from the track to facilitate access and prevent additional complications.^[148] Alignment then repositions the vehicle toward the rails using supports and guiding mechanisms, ensuring wheels engage properly.^[147] Finally, stability testing verifies the vehicle's secure placement through visual inspections, load checks, and trial movements before resuming operations.^[148] Manual rerailing is typically employed for low-speed derailments involving lighter vehicles or isolated cars, where hydraulic equipment may not be immediately available. The process starts by securing the derailed vehicle with handbrakes and isolating it from other cars to prevent movement.^[147] Undercarriage support is established using cribbing—stacked timber blocks—to stabilize the frame and distribute weight, preventing structural distortion.^[148] Jacks, positioned at designated lifting points (at least four per vehicle, paired and separated by a minimum of 860 mm), gradually raise the vehicle to align the wheels with the rails.^[148] Pulling follows using cables or winches attached to an adjacent locomotive or anchor point; the vehicle is slowly drawn laterally, with workers monitoring wheel flanges to guide them onto the track head.^[147] This method demands trained personnel to avoid tipping or rail damage, and it is limited to scenarios where the derailment distance is minimal, often under 15 feet.^[147] Mechanical methods enhance efficiency for partial or more complex derailments, particularly those involving heavier loads. Rerailing ramps or wedges—metal devices clamped to the rails—provide inclined paths for wheels to climb back onto the track; the outer wheel contacts the ramp first, followed by the flange sliding into the inner rail groove as the vehicle is pulled forward at low speed.^[147] These are secured with clamps and wedges to ensure stability during the operation.^[147] For elevated support, hydraulic lifts are applied at jacking points located inboard or outboard of the running gear, at least 360 mm from the re-railing beam centerline, to raise vehicle ends or the entire underframe.^[148] Re-railing beams then translate the vehicle perpendicular to the track, allowing precise alignment before lowering.^[148] These techniques, standardized since the mid-20th century, reduce recovery time from days to hours compared to historical manual efforts.^[148]

Equipment and Procedures

Rerailing operations rely on specialized heavy machinery to lift and reposition derailed railcars and locomotives. Primary equipment includes wreck derricks and cranes with capacities ranging from 50 to 250 tons, allowing for the handling of substantial loads during recovery efforts.^[149] Rerailing frogs, also known as straddle rerailers, are steel devices positioned adjacent to the tracks to guide derailed wheels back onto the rails, particularly effective for minor incidents involving one or two cars.^[150] Air bags, often high-pressure pneumatic systems, provide controlled lifting for precise adjustments, with capacities up to 70 tons per unit, enabling safe elevation without excessive strain on surrounding infrastructure.^[151] Standard procedures begin with a thorough hazard assessment to identify risks such as fuel leaks, structural instability, or hazardous material releases, ensuring the site is secured before any lifting commences.^[152] Crew coordination involves specialized teams, including crane operators, signal maintainers, and safety personnel, who communicate via radio to synchronize movements and avoid secondary incidents.^[153] Following rerailing, comprehensive inspections of tracks, wheels, and undercarriages are conducted to verify integrity and prevent further derailments.^[154] Timeframes vary by incident scale: minor derailments affecting a single car can be resolved in hours using portable tools, while major events involving multiple cars or hazardous cargo may require days for full clearance and verification.^[155] Safety standards emphasize worker protection and environmental safeguards during these operations. OSHA regulations under 29 CFR 1917.17 mandate positive protection measures, such as barriers and chocks, to shield workers from moving equipment or unstable loads on railroad facilities within marine terminals.^[156] For general railroad operations, the Federal Railroad Administration (FRA) oversees safety protocols. Environmental containment protocols require immediate deployment of booms, absorbents, and diking to isolate spills, preventing groundwater or waterway contamination from leaked fuels or chemicals.^[140] Since the 2010s, innovations have introduced robotic aids and remote operation capabilities to address hazardous environments, reducing human exposure to risks like toxic releases. Remote-controlled hydraulic jacks and cranes allow operators to manage lifting from a safe distance, improving precision and response times in contaminated zones.^[157] These advancements, often integrated with wireless camera systems, have become standard in high-risk recoveries, enhancing overall operational safety.^[158]

Notable Incidents

Historical Examples

The Malbone Street wreck occurred on November 1, 1918, in Brooklyn, New York, when a five-car subway train of the Brooklyn Rapid Transit Company entered a sharp curve at approximately 30-40 mph, far exceeding the safe speed of 6 mph for that section. The inexperienced motorman, a 22-year-old replacement during a labor strike, lost control, causing the wooden cars to buckle and derail into the tunnel wall at Malbone Street station. This resulted in 93 deaths and over 250 injuries, primarily from the splintering of wooden car bodies and the compression of passengers. The disaster exposed critical signaling failures, as the curve lacked adequate speed enforcement mechanisms, and highlighted the dangers of undertrained operators ignoring track signals.^[159]^[160]^[161] A devastating illustration of infrastructure vulnerability took place on November 23, 1956, in the Ariyalur train accident near the town of Ariyalur in Tamil Nadu, India. The Chennai-Madurai Mail passenger train, carrying hundreds of passengers, derailed and plunged into the Marudaiyaru River after the railway bridge collapsed under it due to severe damage from torrential monsoon rains and flooding. The incident killed at least 142 people and injured over 110 others, with many trapped under debris in the river. Investigations revealed track maintenance deficiencies, including inadequate inspections of bridges in flood-prone regions, which allowed floodwaters to erode the structure without timely repairs or warnings.^[162]^[163] On July 31, 1967, the Thirsk rail crash unfolded in North Yorkshire, England, when the rear wagon of a northbound cement freight train derailed due to a fractured axle from metal fatigue and fouled the southbound track. The Talisman, an express passenger train from King's Cross to Edinburgh traveling at about 75 mph, struck the derailed wagon, causing multiple coaches to derail and overturn. Seven passengers died, and 45 were injured, with the impact demonstrating the consequences of undetected mechanical failures in freight operations. The official inquiry identified operational errors in routine wagon inspections and signaling coordination, as the derailed wagon was not immediately cleared from the main line despite proximity to passenger routes.^[164]^[165]^[166] These pre-2000 incidents collectively spurred advancements in rail safety practices worldwide, including the adoption of improved braking systems like air brakes with emergency features to prevent overspeeding on curves and the implementation of stricter speed regulations enforced by automatic train control signals. The Malbone Street wreck accelerated the phase-out of wooden rolling stock in favor of steel construction and mandated enhanced motorman training protocols in urban systems. Similarly, the Thirsk crash prompted rigorous axle and suspension inspections for freight trains, while events like the Ariyalur disaster emphasized mandatory flood-resistant bridge designs and routine structural audits in monsoon areas, reducing recurrence of maintenance-related failures.^[161]^[162]

Recent Derailments

One of the most devastating recent rail incidents occurred on July 6, 2013, in Lac-Mégantic, Quebec, Canada, where a Montreal, Maine & Atlantic Railway freight train carrying crude oil derailed after becoming a runaway. The train, left unattended without sufficient handbrakes on a mainline track with a descending grade, rolled uncontrolled into the town center, derailing 63 tank cars and spilling approximately 6 million liters of petroleum crude oil. The resulting fires and explosions killed 47 people and destroyed about 40 buildings, highlighting operational lapses such as inadequate securing procedures and human factors in the transport of volatile oil cargoes by rail.^[167] In the United States, the February 3, 2023, derailment of a Norfolk Southern freight train in East Palestine, Ohio, involved 50 cars going off the tracks, including 11 carrying hazardous materials like vinyl chloride and ethylene glycol monobutyl ether. The incident was caused by the undetected failure of an axle bearing on the 23rd car, which overheated due to a manufacturing defect and lack of timely detection by wayside monitoring systems; the bearing temperature exceeded 200°F but was not flagged by the previous hot box detector approximately 20 miles earlier. Approximately 1,600 residents were evacuated as a precaution, and a controlled burn of vinyl chloride was conducted to prevent an explosion, though long-term health and environmental monitoring continues. The NTSB's final report, released in June 2024, confirmed the defective wheel bearing as the cause. In May 2024, the U.S. government reached a $310 million settlement with Norfolk Southern to address environmental cleanup and community impacts. Positive Train Control (PTC) was operational on the line but could not prevent the mechanical failure, as PTC systems are designed primarily to avert collisions, overspeed events, and signal violations rather than detect equipment overheating or bearing issues.^[168]^[9]^[169] These incidents underscore ongoing challenges in rail safety despite technological advancements. Limitations in PTC, such as its inability to monitor mechanical components like wheel bearings or cargo stability, have been evident in post-2000 derailments involving freight loads, where human oversight and sensor gaps contributed to failures.^[170] In response to the East Palestine event, the U.S. Congress introduced the Railway Safety Act of 2023, which sought to mandate more frequent safety inspections, including for trackside defect detectors and hazardous materials routing, though it stalled in committee. A revised version, the Railway Safety Act of 2025 (H.R. 928), was introduced in February 2025 to advance similar reforms; meanwhile, the Federal Railroad Administration enhanced enforcement through increased track inspections funded by the Bipartisan Infrastructure Law. Gaps in hazardous materials monitoring persist, particularly in real-time temperature detection for bearings and chemical containment during transport, as systematic reviews highlight insufficient integration of advanced sensors and protocols to address rising volumes of dangerous goods on rails.^[171]^[143]^[172]

References

[1]
Rail Data Definitions - Data.Transportation.gov
Derailment: A derailment occurs when on-track equipment leaves the rail for a reason other than a collision, explosion, highway-rail grade crossing impact, ...
[2]
Derailments - an overview | ScienceDirect Topics
Derailment is defined as the event where a train goes off its designated tracks, potentially caused by factors such as track defects, equipment failures, ...
[3]
[PDF] Statistical Causal Analysis of Freight-Train Derailments in the United ...
Nov 21, 2016 · Table 1 shows that derailment was the most common type of accident on each track type, accounting for 72% of train accidents across all types of ...
[4]
Train Accident Cause Codes | FRA - Federal Railroad Administration
Oct 28, 2019 · 1. Track, Roadbed and Structure · 2. Signal and Communication · 3. Train Operation – Human Factor · 4. Mechanical and Electrical Failures · 5.
[5]
Leger Fernández Statement on Train Derailment in Northwest New ...
Apr 29, 2024 · SANTA FE, NM – April 26, 2024 ... “Every day in the U.S., an average of three trains derail with as many as half potentially carrying hazardous ...
[6]
[PDF] Train Derailments in Rural and Urban Pennsylvania, 2018 to 2022
On average, 4.1 rail cars derailed per incident. • Twenty-three percent of all Pennsylvania derailments involved train cars carrying hazardous materials. • ...<|control11|><|separator|>
[7]
Freight Rail Train Derailments | AAR
not on mainline track running across the country. ...
[8]
Failed Wheel Bearing Caused Norfolk Southern Train Derailment in ...
Jun 25, 2024 · A rail car's defective wheel bearing caused the derailment and subsequent hazardous material release in East Palestine, Ohio, last year.
[9]
East Palestine, Ohio Train Derailment | US EPA
At about 8:55 PM ET on February 3, 2023, a Norfolk Southern freight train derailed in East Palestine, Ohio, about a quarter-mile west of the Ohio-Pennsylvania ...Contact Us About the East... · Background · Operational Updates
[10]
FACT SHEET ON RAIL SAFETY | US Department of Transportation
Jan 16, 2025 · FRA is investigating an April 16 train collision and derailment involving a misaligned switch that resulted in serious injuries to crew members.
[11]
[PDF] Railroad Safety Strategy
During this period, train accidents also fell by 18 percent, casualties. (deaths and injuries) dropped 24 percent, and highway-rail grade crossing incidents.<|control11|><|separator|>
[12]
49 CFR § 225.5 - Definitions. - Law.Cornell.Edu
Train accident means any collision, derailment, fire, explosion, act of God, or other event involving operation of railroad on-track equipment (standing or ...
[13]
Why Are Rails Shaped Like That? - Practical Engineering
Oct 3, 2023 · We put flanges on the insides of wheels so they can keep a train from derailing even if one wheel lifts off the track. Let's put some flanges on ...
[14]
Flange Climb Derailment Criteria and Wheel/Rail Profile ...
Effect of wheel/rail profiles and wheel/rail interaction on system performance and maintenance in transit operations.
[15]
[PDF] Freight-train derailment rates for railroad safety and risk analysis
Notes: 1) Over the five-year period covered in this study there were a total of 1420 derailments and 17.5 trillion gross ton-miles of freight train traffic ...Missing: fatalities | Show results with:fatalities
[16]
There are about three train derailments per day. They usually aren't ...
Mar 9, 2023 · There were at least 1,164 train derailments across the country last year, according to data from the Federal Railroad Administration. That means ...
[17]
[PDF] Analysis of Causes of Major Train Derailment and Their Effect on ...
FIGURE 2 Number of freight train derailments by speed and accident cause on Class I main lines: (a) derailment speed 0–10 mph,. (b) derailment speed 10–25 ...
[18]
[PDF] Wheelclimb Derailment Processes and Derailment Criteria
Jun 6, 1984 · ~~he most widely accepted criterion for wheelclimb derailment defines an upper limit for safe operation on wheel/rail contact forces on the ...
[19]
Train Wrecks and Track Attacks: An Analysis of Attempts by ...
In this report, we examine the more than a thousand attempts to derail trains and to attack rail infrastructure to discern overall patterns and trends.
[20]
https://transweb.sjsu.edu/research/1794-Train-Wreck-Train-Attacks
[21]
Railroad - Early American, Steam Engines, Expansion | Britannica
Oct 16, 2025 · The earliest locomotives used in North America were of British design. In 1829 the Stourbridge Lion was the first to run on a North American railroad.Missing: strap failures
[22]
[PDF] The New Albany-Salem Railroad- Incidents of Road and Men
The ordinary pounding of the engines on this flat-bar track often loosened the flat-headed nails and the end of the bar springing up was called a snakehead.
[23]
Train Derailments and Collisions
Major Train Derailments in Greater Philadelphia. November 8, 1833: Hightstown Rail Accident, Hightstown, New Jersey. An overheated journal box caught fire ...
[24]
Derailment | Research Starters - EBSCO
Causes of derailments often include faulty equipment, track defects, excessive speed, human error, and weather-related issues. Historically, derailments have ...
[25]
1853 Norwalk Railroad Accident - New England Historical Society
In 1853, the Norwalk railroad accident claimed the lives of 50 people, making it the first American railroad bridge disaster.
[26]
Regulation of Railways Act :: The Railways Archive
The brake must be self-applying in the event of any failure in the continuity of its action; (iii.) The brake must be capable of being applied to every vehicle ...Missing: 1842 | Show results with:1842
[27]
Railway Regulation Act 1842 - Legislation.gov.uk
Railway Regulation Act 1842 is up to date with all changes known to be in force on or before 02 November 2025. There are changes that may be brought into force ...Missing: brakes | Show results with:brakes
[28]
Railroads In The Gilded Age (1880s) - American-Rails.com
Aug 22, 2024 · Uniform Track Gauge ... Perhaps the 1880s' greatest achievement was the adoption of a standard gauge; 4 feet, 8 1/2 inches. Railroads finally ...
[29]
Rail | Trains Magazine
Nov 3, 2020 · In 1880, about 30% of all track was laid with steel rails; by the turn of the century, steel had almost completely replaced iron. Steel rail ...
[30]
Standardisation | UIC - International union of railways
Oct 13, 2020 · UIC has been an SSO (standards setting organisation) since its creation in 1922, and technical harmonisation of the railway system remains one of its core ...Missing: founded | Show results with:founded
[31]
Agencies - Interstate Commerce Commission - Federal Register
The ICC, the first regulatory commission in US history, was established as a result of mounting public indignation in the 1880s against railroad malpractices ...
[32]
[PDF] historical industry and safety overview - Princeton University
This chapter presents a brief, historical over- view of the evolution of and factors impacting railroad safety. It provides a general summary of how the early ...Missing: standards | Show results with:standards
[33]
[PDF] Causal Analysis of Passenger Train Accidents on Freight Rail ...
Some accident causes related to human factors on train operations were identified to have high risk such as train speed violation and not obeying signals • ...
[34]
[PDF] Accident-Cause-Specific Risk Analysis of Rail Transport ... - Xiang Liu
Prior research found that over. 70% of freight train mainline derailments were caused by either infrastructure defects or rolling stock failures. (24). The ...
[35]
[PDF] Analytical Modelling of Rail Defects and Its Applications to ... - ROSA P
Broken rails, or rail failures, generally occur from fatigue cracks that form and grow in the rail steel as a result of cyclic forces caused by the repeated ...Missing: scholarly | Show results with:scholarly
[36]
Identification of factors contributing to broken and buckled rails
May 12, 2025 · These were, for example, trees falling on the rail infrastructure, train accidents at level crossings or malfunctions of rail equipment.
[37]
Risk Analysis of Freight-Train Derailment Caused by Track ...
Jun 10, 2016 · This paper develops an analytical framework for analyzing freight-train derailment risk due to track geometry failures.
[38]
Broken Rails Are Leading Cause of Train Derailments
May 13, 2015 · Broken rails and welds were more than twice as likely to have been the cause of train derailments than the second and third leading causes—track ...
[39]
Investigation on train dynamic derailment in railway turnouts caused ...
This study aims to explore the dynamic derailment behaviour caused by rail joint failures before the railway switch panel.
[40]
Influences of ballast degradation on railway track buckling
Ballast fouling play a significant role in undermining lateral track stability. Lateral track resistance can reduce by half when fully fouled ballast incurs.
[41]
Ballast Defects and Conditions-Importance of Identification and ...
Aug 26, 2015 · The concentrated wheel loads can cause rapid deterioration of track components and track instability, which can increase the risk of derailment.
[42]
[PDF] Prevention of derailments due to concrete tie rail seat deterioration
Thus, by increasing concrete tie spacing while maintaining rail, tie, and ballast stresses at acceptable levels, the initial research showed that fewer concrete ...
[43]
Recent Advances in Wayside Railway Wheel Flat Detection ... - NIH
Apr 12, 2023 · Wheel flats are the most common local surface defect of railway wheels and are one of the important causes of train derailment [4]. ... wheel ...
[44]
[PDF] An automatic method for detecting sliding railway wheels and hot ...
May 3, 2016 · One of the specific wheel defects is a flat wheel, which is often caused ... Analysis of causes of major train derailment and their effect on ...
[45]
[PDF] a holistic approach to remote condition monitoring for the accurate ...
Figure 14: Derailment due to axle bearing failure (courtesy of Mr. ... Causes, impacts, prevention, and mitigation measures,” Transport Research Arena,.
[46]
[PDF] Deliverable D 3.2 WP3 Report on AI approaches ... - European Union
wheel and bearing failures, which result in train derailment. ... axle bearing failure, wheel flatness, and wheel ... current research scope. AI could be one of the ...
[47]
[PDF] Annual Report 2007 - GOV.UK
Dec 31, 2006 · Three of these derailments resulted from carriage suspension issues on a single narrow gauge ... Research into the technical feasibility and ...
[48]
[PDF] major railroad accidents involving hazardous materials release ...
CAUSE OF THE ACCIDENT: According to NTSB:, the probable cause of the derailment was vandalism to track, resulting in the intentional displacement of a rail end ...
[49]
[PDF] 2020 Washington Rail Transportation Safety Study
Implementation of positive train control (PTC) and its potential for reducing accidents. • Electronically-controlled pneumatic (ECP) braking systems and ...Missing: "research | Show results with:"research
[50]
[PDF] Shipping Container Response to - Severe Highway and Railway
the Eggers database that 0.8% of the train derailment accidents involve train ... Other (cargo shift, etc.) 0.020. <1,000. 71000. 31. Fire only. 0.010. No load.
[51]
[PDF] A National Risk Assessment for Selected Hazardous Materials in ...
releases that occur as a result of a cargo shift, valve failure, corrosion-induced container ... occurred during a traffic accident or train derailment. The ...
[52]
Human Factors Overview | FRA - Federal Railroad Administration
Nov 13, 2019 · Human errors now account for more than one third of all train accidents in the U.S. railroad industry. Railroads depend on the adaptability ...
[53]
Role of Human Factors in Rail Accidents
Mar 16, 2007 · Accidents caused by human factors constitute the largest category of train accidents, accounting for 37 percent of all train accidents in the ...
[54]
Following railway signal indications
Sometimes, crews misinterpret, misperceive or miss a signal and, although the probability of an accident may be low, the resulting collision or derailment can ...Missing: misreading | Show results with:misreading
[55]
Denver train derailment caused by switch error, NTSB says
Sep 2, 2025 · A train derailment that trapped and seriously injured a Denver rail worker happened when a railroad switch was in the wrong position, causing ...
[56]
A Preliminary Review of Fatigue Among Rail Staff - PMC
There were 98 rail investigation reports found in the SPARK database, 23 of which identified fatigue as one of the contributory causes of the train incident or ...
[57]
[PDF] The Fatigue and Safety of Locomotive Engineers and Conductors
Jun 15, 2023 · The authors concluded exposure to fatigue elevated the risk of a human factors accident from 11 to 65 percent, and the economic cost of a human ...
[58]
[PDF] Human Factors Root Cause Analysis of Accidents/Incidents ...
This report presents findings from a human factors root cause analysis (RCA) of six train accidents/incidents—collisions, derailments, and employee injuries— ...
[59]
[PDF] Potential Impacts of Climate Change on Railroads
Warping of tracks due to uneven thermal expansion in the summer, or buildup of snow and ice on the tracks in the winter, can lead to decreased speeds and ...
[60]
[PDF] Safety of High Speed Guided Ground Transportation Systems
Track defects were the most common cause (24), followed by vehicle defects (12), human error (6), and vandalism (3). It is clear from this sample of accident ...
[61]
Train derailments in earthquakes - ResearchGate
In October 2004, a Shinkansen train derailed in Japan as a result of the Niigataken Chuetsu Earthquake. This was the first Shinkansen derailment, and was caused ...
[62]
Impact of earthquakes on California's Railways - ScienceDirect.com
Another notable instance is the 1989 Loma Prieta earthquake in California. The magnitude of 6.9 caused significant disruption to the Bay Area's transportation ...
[63]
[PDF] Wheel and Rail Profile Development | RISSB's
This friction force arises from the friction (coefficient μ) between the wheel flange and the rail gauge face. Figure 1: Illustration of forces in flange-climb ...
[64]
https://www.transportation.gov/sites/dot.gov/files/docs/rossetti_CC_Impact_Railroads.pdf
[65]
Wheel–Rail Creep Forces: Challenges & Progress
The creep forces between wheel and rail are dependent on longitudinal, lateral and spin creepages. The prevalent number of measurements consider the creep ...
[66]
(PDF) A Hertzian Contact Formulation for the Wheel-Rail Contact ...
In this work a Hertzian contact formulation is developed to calculate the contact forces that develop in the wheel-rail interface.
[67]
None
Summary of each segment:
[68]
[PDF] the wheel-rail contact friction influence on high speed vehicle model ...
Aug 19, 2015 · Significant influence of wheel-rail coefficient of friction µ on rail vehicle stability can be observed. Increase of µ from 0.3 to 0.5 means ...
[69]
[PDF] Application of Nadal Limit for the Prediction of Wheel Climb Derailment
The Nadal limit is accurate for high angle of attack conditions, as the wheelset rolls forward in quasi-static steady motion leading to a flange climbing.
[70]
Flange Climb Derailment Criteria and Wheel/Rail Profile ...
Therefore, the Nadal flange climb criterion can be relaxed based on the level of longitudinal force. The flange climb would occur at an L/V ratio above the ...
[71]
[PDF] society papers - ROSA P
This paper discusses wheel climb derailment criteria for rail vehicle safety, where wheels climb over the rail due to rolling motion and lateral force.
[72]
Study on flange climb derailment criteria of a railway wheelset
Aug 6, 2025 · The mathematical solutions show why Nadal's limit (Nadal, 1896) is the most conservative derailment criterion. They also provide the ranges ...
[73]
[PDF] A Study of the Factors Affecting Flange-Climb Derailment in Railway ...
Keywords: flange climb derailment, Nadal's criterion, wheel-rail contact forces, ... This paper focused on the analysis of the flange climb specific derailment.
[74]
Coupling effect of parameters on critical speed and hunting ...
Critical speed and hunting frequency are critical metrics for assessing running stability, with a significant impact on railway vehicle dynamic performance.
[75]
[PDF] Investigation of Derailments - iricen
1.10 Cyclic track irregularities and resonance. 1.11 Effect of track or vehicle twist on wheel off-loading. 1.11.1 Track Twist. 1.11.2 Effect of track twist.
[76]
[PDF] Proceedings of - ROSA P
Nov 10, 2006 · ABSTRACT. This paper describes a planar rigid-body model to examine the gross motions of rail cars in a train derailment. The model.Missing: whip | Show results with:whip
[77]
Numerical simulation of the post-derailment behaviour of a railway ...
May 13, 2024 · The aim of this paper is to introduce a non-linear multi-body (MB) model for the simulation in time domain of the post-derailment behaviour of a ...
[78]
https://www.ctresources.info/ccp/download/XDYNA81C5OSDRUOJ.pdf
[79]
Transport Rail 60E1 (UIC60) - ArcelorMittal
Rail profile 60E1 (UIC60) manufactured according European Standard EN 13674-1, mass 60,21 kg per meter.
[80]
Specifications of UIC 60 steel rail
The 60E1 (UIC60) rail model is manufactured according to the European standard EN 13674-1. It is used for railroad construction. This is a type T section ...
[81]
[PDF] Railway Curves - iricen
The focus, however, is to provide the reader with provisions in the manuals as well as maintenance tips to avoid problems in laying/ maintaining curved tracks.
[82]
[PDF] TRACK MODERNISATION CHAPTER V CURVES AND ...
gravity, R = Radius of the curve. In metric system. The equilibrium superelevation is given by the formula: E = GV2/127R. Where, e = superelevation in mm, V ...Missing: v² / | Show results with:v² /
[83]
[PDF] Review of Standards for Track Inspection and Maintenance
May 20, 2022 · A high proportion of track-caused derailments occur from track geometry, special trackwork (turnouts, crossing diamonds and rail joints on ...
[84]
How are railroad tracks maintained? - Tiannuo
Aug 27, 2025 · Tamping is the process of compacting the ballast around and beneath railway sleepers to ensure proper support and alignment. High-output tamping ...Missing: protocols | Show results with:protocols
[85]
Track Safety Standards; Inspections of Joints in Continuous Welded ...
Oct 11, 2006 · CWR refers to the way in which rail is joined together to form track. In CWR, rails are welded together to form one continuous rail that may be ...
[86]
[PDF] Why do passenger trains run through switches in the rail yard?
• Forgetting to return a switch to its previous position after changing it or failing to communicate that the switch position has been changed, causing another ...
[87]
49 CFR Part 213 -- Track Safety Standards - eCFR
This subpart prescribes minimum requirements for ballast, crossties, track assembly fittings, and the physical conditions of rails. § 213.103 Ballast; general.49 CFR 213.9 -- Classes of... · 49 CFR 213.113 · 213.233 Visual track inspections.
[88]
Track | FRA - Federal Railroad Administration
Mar 6, 2025 · Within 49 CFR Part 213, there are specific provisions for Continuous Welded Rail (CWR). Railroads with CWR must adopt and comply with a CWR Plan ...Missing: 1-9 | Show results with:1-9
[89]
Train Wheel Flange Wear: Impacts, Risks, and Maintenance Standards
Sep 28, 2025 · ... limit or the vertical flange height wear exceeds 15 mm. · Repair Process: If wear is beyond acceptable limits but has not yet triggered ...Missing: maximum | Show results with:maximum
[90]
AAR Technical Services
The WABL Committee's mission is to establish, improve, and maintain wheel, axle, bearing and lubrication system interchange standards and rules.
[91]
Analysis on Steering Performance of Active Steering Bogie ... - MDPI
The steering control at 100% level of the target steering angle can achieve the highest performance of 83.6% reduction in wheel lateral force, but it can be ...
[92]
Pareto optimisation of railway bogie suspension damping to ...
This paper presents the optimisation of damping characteristics in bogie suspensions using a multi-objective optimisation methodology.Missing: oscillations | Show results with:oscillations
[93]
[PDF] CIRCULAR NO. M-1 Car Loading Rules
in interchange, loaded cars who's combined center of gravity of a car and load less than or equal to 98 inches at top of rail (ATR), except for cars that do not ...<|control11|><|separator|>
[94]
[PDF] Circular 42-N
Circular 42-N provides general rules for loading closed cars, superseding previous circulars, to ensure safe transit and car inspection.
[95]
49 CFR 229.23 -- Periodic inspection: general. - eCFR
Except as provided in § 229.33 and paragraph (b) of this section, the interval between any two periodic inspections may not exceed 92 days. Periodic inspections ...Missing: vehicles | Show results with:vehicles
[96]
[PDF] 11. APTA PR-CS-S-034-99, Rev. 2 Standard for the Design and ...
The purpose of this document is to provide minimum structural standards to improve the crashworthiness of passenger rail vehicles. 2. References. This ...<|separator|>
[97]
Positive Train Control (PTC) | FRA - Federal Railroad Administration
Oct 10, 2023 · Positive Train Control (PTC) systems are designed to prevent train-to-train collisions, over-speed derailments, incursions into established work zones.Missing: effectiveness 73%
[98]
Positive Train Control Systems - Federal Register
Oct 28, 2024 · By law, PTC systems must be designed to prevent certain accidents or incidents, including train-to-train collisions, over-speed derailments ...
[99]
[PDF] An investigation into wayside hot-box detector efficacy and ... - UTRGV
Jun 28, 2019 · Wayside hot-box detectors (HBDs) are devices used to assess the health of railcar components including bearings, axles, and brakes.
[100]
ENSCO Rail Data Analytics | AI & Machine Learning
The ENSCO Approach: Use analytical models that can be trained and applied to a variety of track features to develop a risk assessment index algorithm to rank ...Missing: scoring | Show results with:scoring
[101]
ETCS Levels and Modes - Mobility and Transport
The levels and operation modes are fundamental concepts of the ETCS system (European Train Control System).
[102]
[PDF] European Train Control System (ETCS) vs Positive ... - ERTMS.net
PTC performs a similar function, but at significantly lower speeds than ETCS, enforcing safety measures to prevent overspeed and unauthorized movements. However ...
[103]
On-board accelerometers in railway track condition monitoring. A ...
The acceleration Root Mean Square (RMS) has emerged as a major metric directly related to the overall condition of train and track running, facilitating track ...
[104]
Drone4Rail for Plain Track | UIC - International union of railways
May 24, 2023 · UAV will help in assisting the transition to autonomous railway inspections, especially where these are conducted in remote areas.D4r-Pt · Project Description · Project Members
[105]
A Complete Guide to Railway Drone Inspection | SolDrones
Jan 20, 2025 · Learn all about railway drone inspection with this complete guide - how drones enhance safety, efficiency, and cost in railroad operations.Early Adoption Of Drones By... · How Are Drones Used In... · Best Drone Model For...
[106]
An unsupervised anomaly detection framework for onboard ...
A novel two-stage and AI-based approach is proposed for unsupervised anomaly detection of railway tracks using data collected from an in-service train. •. The ...
[107]
[PDF] Robust Anomaly Detection for Vision-Based Inspection of Railway ...
This was done to force the learning machine to learn to differentiate object categories by taking into account parts that are not common across object ...
[108]
Are train derailments becoming more common in the US? - USAFacts
Oct 25, 2023 · For the last decade, an average of 1300 trains derailed each year, accounting for 61% of all train accidents.
[109]
[PDF] Quantitative Analysis of Changes in Freight Train Derailment ...
Aug 31, 2020 · This paper presents a comprehensive statistical analysis of freight train derailment causes and rates using historical data for the. 10-year ...
[110]
Train Fatalities, Injuries, and Accidents by Type of Accident
This table includes train accidents for both freight and passenger operations, excluding highway-rail grade crossing accidents.
[111]
Statistical Analysis of Seasonal Effect on Freight Train Derailments
The modeling results show that it tends to have high derailment rates in winter due to broken rails and broken wheels (double that of summer), whereas summer ...
[112]
Positive Train Control (PTC) for railway safety in the United States
PTC is designed to prevent certain types of train accidents. This paper provides a review of the policy development, operational impact, cost-effectiveness, and ...
[113]
[PDF] Statistical Temporal Analysis of Freight Train Derailment Rates in ...
Rates of freight train derailment caused by broken rails or welds and track geometry defects declined by 6% and 5% annually, respec- tively; the rate of ...Missing: collisions | Show results with:collisions
[114]
Traversing railways across the EU and USA - Overhaul
The Bureau of Transportation Statistics recorded 54,539 derailments between 1990-2021, or an average of 1,704 per year compared to 500 per year across the EU.Missing: 2020s | Show results with:2020s
[115]
Fatal train accidents on Europe's railways: An update to 2019
Fatal train accidents per train-kilometre in Europe fell at the rate of 6% per year from 1990 until 2019. · There were 0.85 fatal accidents per billion train- ...<|control11|><|separator|>
[116]
Progress To Problem: China's High-Speed Trains - NPR
Sep 26, 2011 · Since the accident, 54 bullet trains have been recalled and new high-speed rail projects halted. Safety checks have been instituted and the ...
[117]
Ore train runaway and derailment highlights the importance ... - ATSB
Mar 17, 2022 · “As a result, BHP's trains configured for ECPB operation were potentially vulnerable to a runaway event should a unique combination of events ...
[118]
Underinvestment in Rail Leaves Africa Stranded
Dec 12, 2022 · Africa's underinvestment in rail infrastructure stands in the way of economic development, regional integration, and inclusive growth.
[119]
[PDF] Making Roads Safer - | Independent Evaluation Group - World Bank
More than 90 percent of the world's road fatalities occur in developing countries, and half of the accident victims are pedestrians, cyclists, and motorcyclists ...
[120]
Railroad Deaths and Injuries - Injury Facts - National Safety Council
Railroad deaths totaled 954 in 2024, a 1% decrease from the 2023 revised total of 967. Nonfatal injuries totaled 6542.
[121]
[PDF] UIC Safety Report 2024 - Significant Accidents 2023
The spike observed in 2022 was due to not only a high number of train collisions with obstacles (163 incidents) but also derailments (114 incidents), both of ...Missing: statistics | Show results with:statistics
[122]
How come passenger trains don't derail as often as freight trains?
Dec 25, 2005 · Here are my theories: First, Pasenger trains-generally-run only on well-maintained main lines. They are less likely to be on diferred maintence ...Missing: casualty | Show results with:casualty
[123]
Train derailments aren't uncommon, but damage can cost millions
Feb 17, 2023 · ... average, Norfolk Southern's cost per incident in the past decade was $1.2 million. But the financial services firm found six of the derailments ...
[124]
Derailment costs grow for Norfolk Southern but railroad's trains ...
Oct 25, 2023 · Norfolk Southern's costs related to the East Palestine derailment have grown to reach nearly $1 billion, but the railroad's service is improving.
[125]
Train Derailments: Annual Trends, Causes & Response Strategies
Apr 8, 2025 · The External Stressors. Weather and infrastructure age are now bigger contributors to derailment risk than ever before: Extreme heat → warps ...
[126]
Impacts of the East Palestine Train Derailment Mapped
Apr 4, 2023 · Disrupted supply chains cause significant damage to businesses. Many workers in the area are sick, have been evacuated, or are otherwise ...
[127]
Injured Railroad Worker Compensation Under FELA
The FELA requires that railroads pay injured workers for their pain and suffering, emotional distress, medical bills, and all of their lost wages while they ...
[128]
FRA 2023 Data Affirms Rail's Strong, Sustained Safety Record
Mar 4, 2024 · For all railroads, the derailment rates have dropped 30% since 2000. Per carload, the hazardous materials (hazmat) accident rate is at its ...
[129]
Don't Get Railroaded on Your FELA Claim - Jencap
Mar 8, 2022 · In 2020, railroad incidents resulted in 3,032 injuries to employees and 11 employee deaths. There are some similarities between FELA and ...
[130]
Interactive Rail Safety Map: See Derailments in Communities Across ...
Jun 1, 2023 · NLC's interactive train derailments map allows you to easily see the frequency of derailments in your city and Congressional district area.Missing: context | Show results with:context
[131]
EPA Orders Norfolk Southern to Conduct All Necessary Cleanup ...
Jan 12, 2025 · Containing and remediating contaminated soil, sediment, and water;. Remove and dispose of hazardous substances at EPA-approved disposal ...
[132]
Ohio train derailment could affect local ecosystem for years, experts ...
Mar 7, 2023 · The tens of thousands of aquatic life that have died as a result could potentially point to whether ecosystems are safe enough for human ...
[133]
Off the Rails: A Personal Reflection on Wildlife Impacts from the ...
Mar 9, 2023 · Ohio's Division of Natural Resources estimated that 40,000 individual animals died in the weeks immediately following the crash, mostly minnows ...
[134]
Freight Rail Hazmat Remediation - Association of American Railroads
Railroads follow strict laws and partner with agencies for hazmat cleanup. Experts monitor air, water, and soil for safe remediation. EPA ensures compliance and ...
[135]
A year after a train derailment in Ohio spilled hazardous chemicals ...
Feb 2, 2024 · Tests by the Environmental Protection Agency also suggest there's a low chance that dioxins were released. But more research is needed, ...
[136]
The Environmental and Health Fallout of Rural Train Derailments
Mar 14, 2023 · Train derailments overwhelmingly happen in rural and tribal areas where communities have fewer resources for response and recovery, Junod said.
[137]
Hazardous Materials: FAST Act Requirements for Real-Time Train ...
Jun 27, 2023 · PHMSA proposes amendments to its Hazardous Materials Regulations to require all railroads to generate in electronic form, maintain, and provide to first ...
[138]
Bipartisan Railway Safety Legislation Heads to Commerce ...
May 8, 2023 · The bill mandates a new requirement that all railcars have a thorough inspection at least once every five years to ensure all its components are ...Missing: enhancing | Show results with:enhancing
[139]
The Wrecking Derrick: Railroading's Unsung Hero
Nov 20, 2024 · Early versions of the derrick were rudimentary, often relying on manpower, mules, and basic pulleys.
[140]
https://www.aar.org/issue/hazmat-remediation/
[141]
How to rerail a freight car on a short line - Trains Magazine
Feb 1, 2022 · The best way to rerail the car was to use wheel ramps. The derailment occurred just short of a public crossing, and with permission from the crew, I had an ...
[142]
UP 900000 Series Derricks and Cranes - UtahRails.net
Jan 31, 2021 · 153 locomotive cranes; built between 1905 and 1990, with capacities from 10 tons to 60 tons. · 42 wreck derricks; built between 1899 and 1973, ...
[143]
https://www.congress.gov/bill/119th-congress/house-bill/928
[144]
Air Bag Jacks (70 Tons) - esco.net
Lifting capabilities range up to 70 tons · Made of aramid fiber consisting of five layers · ESCO airbags also come in kit form, which includes the air bag ...Missing: derailed trains railway
[145]
Emergency Railroad Services - Hoy Excavating
rerailing; clearing cars; stockpiling materials and commodities; roadbed ... We are equipped with GPS systems on grading equipment to insure efficient ...Missing: train | Show results with:train
[146]
[PDF] Railroad Emergency Preparedness Guide - CN Rail
The CN Railroad Emergency Preparedness Guide was developed to assist local emergency response organizations in their efforts to plan for and respond to railway- ...<|control11|><|separator|>
[147]
FM 55-20 Chptr 9 Wreck Crews and Equipment - GlobalSecurity.org
A wreck train consists of a locomotive, a wreck crane, tool cars, and enough bunk and cook cars for personnel required for a particular wreck. Wreck cranes and ...
[148]
Federal Railroad Administration's Final Accident Report on Norfolk ...
Jul 19, 2024 · FRA found that the derailment was caused by a roller bearing that failed due to overheating, consistent with the investigation findings of the National ...
[149]
[PDF] A TECHNICAL GUIDE ON DERAILMENTS - irtsa
Apr 3, 1998 · If speed is in excess of permissible speed, lateral forces on the flange increase and the formation may not be able to resist this increased ...
[150]
https://www.aldonco.com/product/bullfrog-straddle-type-rerailer-90-142-lbs-right/
[151]
Train Lifting Equipment – Portable & Heavy-Duty Solutions - Railquip
Railway lifting equipment includes hydraulic jacks, skid systems, and dollies designed to recover derailed ... It is hydraulically operated with a remote control ...
[152]
Rail Cranes | HoistCam
HoistCam supports rail and locomotive crane operations with wireless cameras that provide operators real-time visibility of loads, tracks, and work zones ...
[153]
The Malbone Street Wreck of 1918 - Smithsonian Magazine
Nov 1, 2018 · A confluence of circumstances led to the deadly disaster, 100 years ago today, in the New York subway that killed 93.
[154]
Death Beneath the Streets | American Experience | PBS
The Malbone Street wreck directly caused the deaths of at least ninety-three people and indirectly contributed to the death of the BRT, which fell into ...
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100 Years After New York's Deadliest Subway Crash
Nov 1, 2018 · An estimated 100 people died in the Malbone Street Brooklyn Rapid Transit disaster. Here's how the tragedy changed public transportation in America.<|control11|><|separator|>
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Nightmare in Ariyalur, a brave tale from 1956 - The Hindu
Mar 2, 2014 · It occurred on November 23, 1956, leaving 142 passengers dead and 110 injured. An estimated 200 people were buried in the debris. Many were ...
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India's worst rail disasters - Punch Newspapers
Jun 3, 2023 · On November, 23, 1956, a train plunged into the Marudyar river after a bridge was destroyed by flooding, leaving at least 154 dead and 115 ...
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Accident at Thirsk on 31st July 1967 - The Railways Archive
Accident at Thirsk on 31st July 1967. Location: Thirsk. Train Operator: British Railways (Eastern Region). Primary Causes: Track defect, suspension or bogie ...
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How the express dissolved in mid air – the Thirsk rail disaster 50 ...
Aug 1, 2017 · Seven people that day, though, were killed and 43 wounded, at least of them 15 severely. The accident had happened when a cement train ...
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Flashback: Yorkshire rail crash that left seven dead
Apr 14, 2015 · The Thirsk rail crash in July 1967 in which a passenger express was derailed after hitting a loaded cement wagon, killing seven people and injuring dozens.
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Railway Investigation Report R13D0054
63 tank cars carrying petroleum crude oil (UN 1267) and 2 box cars derailed. About 6 million litres of petroleum crude oil spilled. There were fires and ...
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[PDF] Norfolk Southern Railway Derailment and Hazardous Materials ...
Jun 25, 2024 · Abstract: This report discusses the February 3, 2023, derailment and subsequent hazardous materials releases involving Norfolk Southern ...
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[PDF] Information Guide on Positive Train Control in 49 CFR Part 236 ...
Dec 12, 2022 · In the case of FRA's PTC regulations, PTC must be designed to prevent train-to-train collisions, over-speed derailments, incursions into ...
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After Ohio train derailment, 2023 was the year that put rail safety in ...
Dec 16, 2023 · A fiery train crash sparked a push for rail safety this year. But as Frank Morris of member station KCUR reports, the Railway Safety Act of 2023 may have run ...
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Advancing hazardous materials transport safety: Systematic insights ...
This study systematically reviewed 2078 publications from 1970 to 2022, focusing on trends, challenges, and research gaps in Hazmat transportation safety.