Background
DuPont is a city of 10151 people (as of 2020) in the far northwest of the USA, located in the federal state of Washington 26km/16mi southwest of Tacoma and 18km/11mi east of Olympia (both measurements in linear distance).
DuPont lies on the Lakeview Subdivision (often referred to as the Point Defiance Bypass), a 23.3km/14.4mi single-track non-electrified branch line originally opening in 1891. With most of the US rail-system giving priority to freight trains the decision was eventually made around the turn of the millenium to refurbish the bypass to take passenger services off the overloaded Point Defiance Line. The refurbishment included mew tracks, signaling and support infrastructure at a cost of 230 Million USD/211.6 Million Euros (as of 2023) and was finished by 2016.
A neuralgic point in the line’s old routing had been a bridge over Interstate 5 near the city of DuPont, which saw the rail line describe a rather tight S-turn. Plans to replace the overpass with a new bridge containing a wider turn as part of the refurbishment were scrapped due to cost. Thus the section including the bridge (nicknamed the Nisqually Bridge, referring to a nearby river) retained the old routing, receiving a 48kph/30mph speed limit while some other sections, including the one immediately adjacent on the eastern side, allow speeds of up to 127kph/79mph. The refurbished rail line ends just 1km/3300ft linear distance west of the bridge as the Bypass rejoins the main line.
The train involved
The “Cascades” is a passenger service provided by Amtrak since 1971, connecting Vancouver (Canada) with Eugene, Oregon (USA) on a 752km/467mi journey. On the day of the accident the southbound service was operating as train number 501 and carried 77 passengers along with 6 crewmembers. Among the passengers was a number of enthusiasts likely riding on the train to witness the inaugural run on the new Point Defiance Bypass.
The train involved in the accident was pulled by Washington State Department of Transportation (WSDOT) locomotive number 1402, a Siemens Charger which had only been delivered a few months prior to the accident and was used by Amtrak for their Cascades-service under a contract agreement. The Siemens Charger-family of locomotives is a group of four-axle diesel locomotives based off the Siemens Vectron-family and is intended exclusively for passenger services. The first production unit was unveiled in 2016 and started service August 2017. The different versions are largely identical, but differ in fuel capacity and power-output. Each Charger measures 21.79m/71.5ft in length at a weight of 120 metric tons and can reach a top speed of 200kph/124mph thanks to a 95l/5800cubic-in turbocharged V16 diesel engine. Amtrak 1402 was a Charger SC-44, the midrange version putting out 3300kW/4400hp. The day of the accident was #1402’s 7th day in service, pulling its fifth train.
On the day of the accident the Cascades-train consisted of a Mark VI Talgo Pendular set, a permanently coupled 12-car passenger train consisting of first and second class cars along with two bistro cars and a baggage car. The Mark VI Pendular was introduced in 1980 and has a special suspension-system with a passive tilting concept (hence the “Pendular”-name). The cars run on shared single-axle bogies located between the train cars, which are attached to the roof of the car rather than the bottom. This means the body of the car essentially hangs between the wheelsets rather than sitting on them, allowing the cars to swing out up to 3.5° in turns from just their own weight rather than utilizing a hydraulic system for the motion as other tilting trains do. This tilting allows higher cornering-speeds than conventional train cars, with Talgo’s design being less complex and lighter than the conventional active tiling-systems. The first such trainset was introduced into US-service under the Cascades-brand in 1998, with each set named after a mountain peaks in the cascades-range. A separate set was originally intended for a route between Los Angeles and Las Vegas, being repainted, named “Mount Adams” and included in the Cascades-Fleet when those plans fell through. Each Cascades-Set can carry 304 passengers, so the one involved in the accident was at less than 33% capacity. The US-Market version of the Mark VI is distinctly recognizable by tall fins on the end-cars meant to match the roof-height of the locomotives.
The Mark VI Cascades-trains always ran with another locomotive at the back end, often using it as a cab-car rather than actual propulsion. On the day of the accident this role was fulfilled by Amtrak locomotive #181, a GE P42DC “Genisis”. The P42DC is a four-axle diesel locomotive from General Electric’s “Genesis”-series and a modernized version of the P40DC introduced in 1992. The locomotives measure 21m/69ft in length at a weight of 121.7 metric tons and can be easily identified by their relatively streamlined design compared to most American locomotives of their time. The P42DC is powered by a turbocharged V16 diesel engine with 175 liters of displacement producing 3170kW/4250hp for a top speed of 177kph/110mph.
The accident
On the 17th of December 2017 Amtrak Cascades 501 departs King Street Station in Seattle at 6:10am, 10 minutes behind schedule. Riding in the cab of the Charger were a driver and a qualifying conductor, referred to as such as he was riding along to learn the new route’s characteristics. Similarly, a trainee attendee was aboard the train learning from a lead attendee, bringing the total crew count to 7. The onboard cameras and voice recorder recorded the two men in the cab talking about the wayside signals and job-related topics as the train entered the Subdivision, eventually pulling into Tacoma Dome Station at 7:13am, 32 minutes behind schedule. The driver told the conductor in the cab that the trip was a learning experience for him too, mentioning that he had only done one round-trip over the new route and still had to learn what throttle-positions kept the train at the desired speeds throughout the journey.
Cascades 501 departed Tacoma at 7:17am in mild rain and, according to the report, a visibility of approximately 16km/10mi. The conversation between the two men in the cab shifted to future trips and job assignments, but according to the report the driver still appeared alert and focused on his surroundings. The train passed a warning-sign referring to the upcoming speed limit for the overpass at 7:32:16am, 3.2km/2mi ahead of reaching the Interstate overpass. In his post-accident interview the driver stated that he didn’t recall seeing the warning-sign, but that it was still too far ahead of the curve to be concerned about slowing down anyway. He was planning to start slowing down at control point (CP) 188, 1.6km/1mi ahead of the overpass. The train passed mile post 18 (MP 18) at 7:32:21am, and despite the inward-facing camera recording the driver looking towards the sign for the post he later stated that he didn’t see it.
34 seconds later the train passed the green signal at CP 188, which also carried a sign installed in front of a silver equipment shed. The report notes that the headlights of the train reflected off the wet metal, making it difficult to read the white sign’s lettering. By 7:33am the two men were talking about the qualifying conductor’s return trip arrangements just as the train passed MP 19. At this point, just 800m/0.5mi from the overpass, three double beeps sounded in the cab, leading the driver to lightly apply the brakes. Warning-messages appeared on both screens in the cab, informing him about the locomotive’s overspeed protection having cut traction power. This means the train was going faster than it was allowed to anywhere on the line. The driver looked at the display to his right, glanced forwards for a second, then looked at the right hand display for two seconds, and forward again. “I guess that happens when…” he started, but trailed off, looking around his desk some more.
At 7:33:34am the retaining walls on either side of the track ahead of the overpass came into the forward-facing camera’s view and the 48kph/30mph speed limit sign (MP 19.75) was visible. By 7:33:41 the inward-facing camera recorded the driver leading towards the screens, announcing “we just tripped the overspeed”. He later elaborated in his post-accident interview that he was unfamiliar with the new locomotive’s overspeed protection, as it hadn’t been covered in training and hadn’t been set off during his few previous trips in the type. As he stated having tripped it he applied full brakes, but not an emergency brake-application, took his hand off the brake handle and, after a moment’s hesitation, put it back on the handle.
He spotted the 30mph-sign at 7:33:44, called out, as the report puts it, “an expletive”, and resignedly announced “we’re dead” at 7:33:46am. The train entered the left-hand turn into the overpass at 7:33:50, travelling at 125.5kph/78mph rather than 48kph/30mph. The Charger immediately derailed upon entry into the curve, leaving the rails to the right and pulling the leading train cars along. The locomotive went down a wooded embankment onto the southbound lanes of Interstate 5, ripping off the train and rear-ending a passing car before coming to a stop. Several passenger cars followed it, ripping off each other and in some cases shedding their suspension system, with a few cars rolling over as they effectively blocked the southbound lanes of the Interstate. A handful of cars derailed on the destroyed tracks ahead of the overpass and headed left, falling onto the interstate. 2 cars remained on top of the overpass at 45° to the tracks while the rear locomotive remained on track as the sole vehicle of the train that didn’t derail.
3 passengers aboard the train died in the derailment, with 57 people on the train being injured, along with 8 people being injured when their cars were struck by pieces of the derailing train. All 3 fatalities occurred in car AMTK 7504 in the middle of the train (6th place), which suffered a loss of survival space on over 3/4 of it’s length as both floor and roof were caved inwards at the ends. 2 of the victims were found outside the car’s wreckage, being ejected when car 9’s shed wheelset tore a hole into the car’s floor, while the third had been fatally struck by that wheelset inside the train car. Another 5 passengers survived being ejected from different train cars as they rolled over, losing their windows.
Aftermath
Motorists who had managed to dodge train and debris coming down in front of them were the first people to render aid to the survivors, among them by coincidence 3 soldiers from a nearby base who possessed medical training. One of them, Mr. McCoy, later recalled that they saw one of the train cars dangling off the overpass, threatening to fall down onto ejected, injured survivors beneath. They managed to drag those survivors to safety before scaling a crashed semi to climb into the dangling train car, using the damaged interior like a makeshift staircase.
Several passengers were trapped in the mangled cars and had to be cut free once firefighters arrived with spreaders and cutting-tools capable of creating openings in the train cars. Ambulances took survivors to six different hospitals in the area, with most requiring medical care for broken bones or abdominal injuries. A state of emergency was declared within hours of the derailment, with the Washington Military Department’s emergency operations center located at the nearby military base coordinating the rescue and recovery effort.
Despite WSDOT #1402 suffering severe damage as it struck several trees during the derailment the two men inside survived the accident, getting away with broken bones and blunt impact traumas. The driver’s cab’s safety structures limited the reduction of survival space throughout the accident and even kept all doors operational. The damage was still sufficient to write off the nearly brand-new locomotive, sending it to the scrapyard once the investigation concluded.
After reviewing the recorded conversations, video footage and locomotive data the cause of the accident was about as clear to the investigators as it could be, with the driver neglecting to pay sufficient attention to the speed limits and thus entering the sharp turn at over 2.5x the speed limit. Amtrak subsequently fired the driver over violating safety guidelines. The conductor riding in the cab could have also observed the speed, having his own screen with a speedometer. However, after the screen had gone dark (as it is meant to without interaction) he had left it turned off, focusing on taking notes and learning the route rather than comparing the train’s speed to the local speed limits. The investigation noted that the Bypass was fitted with automatic train control (ATC), a system capable of autonomously stopping a train if it breaches local speed limits, but the system was not yet activated on the day of the accident as Amtrak claimed the installation and testing of it wasn’t quite finished. As such, with the conductor not being meant to observe the train’s speed, the task of ensuring proper speeds was left entirely to the driver.
The report notes that the locomotive’s overspeed warning was triggered as the locomotive exceeded the line’s overall top speed. The system, in contrast to ATC, was not capable of observing local speed limits. The driver had only operated one train on the line ahead of the accident, in the dark in the opposite direction, and thus was highly unfamiliar with the signage and landmarks intended to help drivers identify their location. In consequence the driver confused different mile post signage after missing selected signs, losing geographical awareness. Similarly, due to his inexperience and extremely scarce training on the new locomotive-type, he took almost 20 seconds to identify the overspeed-warning, likely being so preoccupied with the confusing alarms and display-messages that he failed to properly identify a sign he saw as he briefly looked outside. In summary, inexperience due to lackluster training caused the driver to lose track of his location and the local speed limits despite not being distracted from driving by other tasks (like talking on the phone, for example). In addition to that ATC being inactive meant there was nothing keeping the train from speeding into the tight turn at vastly excessive speed once the train driver lost track of his location and the speed limits.
During the investigation the investigators noticed that several of the cars had lost their wheelsets and suspension systems, with one wheelset being eventually identified as the direct cause of all 3 fatalities that occurred. This, along with structural damage to several of the train cars, led the investigation to question the Mark VI’s operational safety. The focus was drawn to the type’s odd suspension system, which saw one wheelset attached to the “suspension end” of each train car, hanging in a large U-frame attached near the roof, while the other end of the car rests on the adjacent car’s wheelset. It was this construction which enabled the tilting motion of the train cars, being attached to the wheels by the roof with the car-body essentially hanging freely between the U-frames and swinging like a pendulum when cornering pulled the body of the car outward. The only train cars to possess their own conventional floor-mounted wheelsets are the end-cars, which each have one shared and one non-shared wheelset.
During the accident a total of five wheelsets completely detached from the train, creating steel projectiles weighing 2 metric tons each. One of these dropped right into the path of a passing subcompact SUV (Kia Soul), causing extensive compression-damage as the car’s engine-block was forced inward, pinning the driver inside the car. The same wheelset subsequently struck the black Jeep pictured further up and below, which suffered a similar extent of damage. Luckily, both cars’ occupants only suffered minor injuries in the accident.
Fatally, one of the wheelsets penetrated the sixth car in the train (AMTK 7504), killing one occupant and causing the fatal ejection of two others. The report notes that the U-frames are connected to the cars on either side of them by six articulated connectors, four horizontal and two vertical ones, in addition to the cushioning-elements. These connectors are articulated and compressible, acting to dampen motions in between the cars and allow the necessary freedom of movement. All six of these connectors had to fail in order for the wheelsets to completely detach from the train.
Already skeptical of the type’s crashworthiness the investigators consulted Talgo, being told that the train cars were designed to meet UIC-556, a safety engineering guideline established in 1990. Talgo explained that the guideline gave requirements for the construction of the body and frame of each rail car, which their design fulfilled, and that it even surpassed the impact forces train cars had to be able to endure without deformation both laterally and longitudinally. However, the type did not pass a US -requirement in 1999, which demands that train cars endure 363 metric tons of pressure applied at coupler-level without permanent deformation. Amtrak had reacted by petitioning the Federal Railroad Administration (FRA) in October 1999 to “grandfather in” the Talgo-cars, which had started service a few months prior, asking the FRA to allow operation under special conditions on selected lines. The FRA eventually allowed use of the type in September 2000, with conditions including:
- Installation of safety-cables between the cars and their wheelsets able to resist a longitudinal force of 35 metric tons/77162 pounds.
- The cars are only allowed operation in dedicated, single-type train sets with no other cars mixed in and with the end-cars unoccupied.
- A locomotive or depowered-locomotive cab-car (a locomotive with the engines removed) has to run on both ends of the train.
- The operational speed is limited to 127kph/79mph.
- Operation is limited to a submitted list of connections/routes, with no random additions to the list.
The National Transportation Safety Board concluded in their investigation that the Talgo Mark VI Pendular cars were unfit for passenger service in the USA, contradicting the FRA’s 17 years old decision, and recommended their immediate withdrawal from service over safety-concerns. The recommendation was followed up on, with all remaining cars of the type being withdrawn from service in June 2020, being taken to the scrapyard. The destroyed Charger was replaced by a new unit (#1408) in August of that year, while the withdrawn train cars were substituted with “Horizon”-Type Amtrak passenger cars and loaned Talgo Series 8 trains (which do pass US crashworthiness requirements). In July 2021 Amtrak and Siemens announced that 48 new Siemens “Venture” train cars and 2 additional Chargers had been bought for the Cascades-service, expected to enter regular service in 2026.
Amtrak was sued by over 35 individuals relating to damages suffered in the accident, paying out more than 41.4 Million Euros/45 Million USD by April 2022 for injuries and injury-related costs alone. The driver of the train also sued Amtrak, claiming that the company failed to adequately train him and failed to safely operate the rail line by starting operations before the train control system was operative. Thus, he argued, Amtrak was to blame for his injuries. His claim was settled out of court, with the driver’s lawyer only publishing a short statement saying his client was “taken care of for life”.
The train control system went online on the Bypass in March 2019, with passenger services on the line resuming in November 2021. With Amtrak promising to improve training especially on new routes and locomotives and the train control system operational a repeat of the accident at the site is just about impossible. The replacement of the involved passenger car type also means occupant safety in case of an accident was drastically improved.
The lack of an automatic train control and signaling system which could override the driver’s input in an emergency is an ongoing problem that keeps coming up when a train has an accident in North America, although it appears that the situation is slowly improving. Modern rail traffic shouldn’t rely on the driver alone, and as accidents like this one show, even two men in the cab are not a guarantee for safe operations.
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A kind reader has started posting the installments on reddit for me, I cannot interact with you there but I will read the feedback and corrections. You can find the post right here.
