Background
Southall is a town of 69857 people (as of 2011) in southern England, located 17km/10.5mi south of Watford and 18km/11mi west of London, being officially considered a suburb of the British capital (both measurements in linear distance).
The town lies on the Great Western Main Line, a 190km/118mi double- to quad-tracked electrified main line running from Bristol in the southwest of England to Paddington Station in central London. Opened in its full expansion in June 1841 the line is mostly used for passenger trains at speeds of up to 201kph/125mph with the main operator, Great Western Railway (at the time called First Great Western), running everything from Intercity trains to regional commuter services on a network spanning over 270 stations. Occasional freight services use the line also, provided by various companies. One of the common destinations for freight services is the shunting yard at Southall, situated on the southern side of the tracks.
The trains involved
Travelling eastbound through Southall was the Great Western Trains (GWT) Intercity 125 service from Swansea to London Paddington. The Intercity 125 is a diesel powered high speed passenger train introduced into service in 1976. Despite appearing as a multiple unit the trains are not fixed combinations, instead each train consists of a British Rail Class 43 locomotive on either end of a row of Mark 3 passenger cars. The Class 43 is a four-axle high speed diesel locomotive purposely developed for the then-new Intercity service, evident in its asymmetrical design with a streamlined and a vertical end. Originally a small section on the vertical end also wore the same livery as the passenger cars, making the trains look more uniform. This was later extended to the whole locomotive’s livery matching the cars. Each Class 43 weights 70.25 metric tons at 17.79m/58ft in length and has a listed top speed of 200kph/125mph (giving the Intercity 125 its name) while 238kph/148mph have been reached in testing. At the time of the accident they were powered by a 79l/4800cubic inch Paxman V12 diesel engine producing 1680kW/2280hp at 1500rpm.
On the day of the accident the Intercity consisted of 8 first and second class Mark 3 passenger cars (called “coaches” in the UK). Introduced in 1975 each Mark 3 passenger car measures 23m/75.6ft in length and can carry 74 (second class) or 48 (first class) passengers at up to 200kph/125mph. The cars have an all-steel construction and weight 33.6 metric tons each with the exception of the buffet car (36 metric tons).
6V17 was a freight train from London to Southall Yard, consisting of an ARC-owned Class 59 and 20 empty four-axle hoppers, each weighing 22 metric tons. Introduced in 1986 the British Rail Class 59 is a six-axle diesel-electric freight train locomotive designed to haul heavy freight trains with rocks and other quarry-products. Each Class 59 weighs 121 metric tons at a length of 21.35m/70ft and can reach up to 97kph/60mph thanks to a 2460kW/3300hp. 6V17 was pulled by locomotive number 59101, named “Village of Whatley”, under the command of Mister Bricker.
The accident
On the 19th of September 1997 the HST-Service from Swansea to London Paddington departs Swansea station at 10:32am for the return trip to London Paddington, where it had originated early in the morning. The train was under the command of Mister Tunnock, who would hand it off to his coworker, Mister Harrison, at Cardiff Central. Being a return trip the train ran in reverse formation, with the leading passenger car being designated Coach G, one of two first class cars. Earlier in the day, when he took command of the train at Paddington, he had been made aware of two faults. Firstly, the buzzer used to communicate with the conductor was working unreliably. The buzzer was sounding nonstop in the London-end locomotive while working not at all on the Swansea-end. Secondly, and more importantly, after arriving at Swansea Mister Tunnock realized that the AWS (Automatic Warning System), the system notifying him of upcoming signals and their setting, was not releasing the train. Since the fault-repair-notebook on the train was full Mister Tunnock attached a handwritten note to the control desk to inform his coworker, Mister Harrison, of the fault. Workers also managed to fix the buzzer at Swansea. Mister Tunnock then disabled the AWS-System and departed eastbound with a minor delay.
After the short leg to Cardiff Central the train was handed off to Mister Harrison, who correctly adhered to several 160kph/100mph restrictions around Reading before speeding up to the scheduled 200kph/125mph. Approaching Southall from the west sees trains pass 4 signals, SN298, SN280, SN270 and SN254 over a space of approximately 3.2km/2mi. The final signal is located just ahead of Southall station. Shortly after 1:10pm the IC125 passes the first of the four signals, which shows green (full speed ahead). However, SN280 showed a double-yellow and SN270 showed a single yellow light, indicating that SN254 would be red (stop).
At the same time Mister Bricker is approaching Southall station from the east with his freight train, being meant to cross the main line before arriving at Southall Yard. By 1:13pm he was travelling at approximately 34kph/21mph. The red signal for the Intercity is meant to allow Bricker’s train, one of the rare freight services on the line, to cross in front of it. Mister Harrison would have had to start decelerating at SN280 in order to come to an orderly stop by the time he reached SN254. He failed to do so, however, and also failed to react upon passing SN270. At 1:14pm SN254 came into view, likely at the same moment as the freight train did. Harrison would later recall suddenly spotting the freight train’s locomotive “at a funny angle” before realizing that it was crossing his path. Harrison triggered an emergency stop, but a collision was about to happen regardless.
Mister Bricker later recalled seeing the Intercity in the distance, expecting it to stop but instead being alarmed by its speed and signs of a sudden brake-application that he could tell came too late. He immediately applied full throttle and the engine aboard the Class 59 roared to life, but at that point he was little more than a spectator to the unfolding tragedy. The freight train only gained 6kph/4mph before the Intercity, still travelling at approximately 125kph/80mph, reached it. The collision occurred at 1:15pm with the Intercity 410m/1345ft past the red signal. The leading locomotive of the intercity scraped along the seventh freight car before suffering a low-overlap impact on car 8, splitting the freight train as the Intercity locomotive’s right hand wall is shaved off the body. This derailed the Intercity to the left while the rear section of the freight train stopped almost immediately due to the severed brake lines.
Two seconds into the collision Coach H collides with one of the freight cars and is thrown onto its side, separating from the Intercity, and eventually slides to a stop to the left of the tracks, largely intact. Two people die aboard it as they are ejected from broken windows and end up beneath the following cars. Coach G suffers the worst fate, striking several freight cars which tear away most of the right hand side. One of the derailing freight cars strikes an overhead catenary support, lifting the car’s rear end off the ground long enough for Coach G’s forward section to be wedged underneath. Due to being struck by Coach F in the back Coach G is then bent into a U-shape, suffering a near-total loss of survival space. Four people die as the body of the train car folds inward on itself, a fifth later dies at the hospital. Coaches A and B come to a stop at the beginning of the wreckage less than 15 seconds after the initial impact, suffering minor damage and not even derailing, the applied brakes and various debris eating up their momentum. Ahead of the rear motor car six people are dead, one is dying and 139 have been injured. Mister Harrison survives with minor injuries, having retreated to engine compartment (luckily ending up on the left hand side) after triggering the emergency stop.
Aftermath
The first people on site are workers at the adjacent yard, along with surviving passengers from the back of the train. They’re met with a sight of utter carnage, except for the rear car and locomotive little of the intercity is left intact. The rail line to the east of the station is a chaotic field of debris, piling up the remains of two trains, the overhead catenary and the tracks itself. The responders start climbing into and over the wreckage trying to free surviving passengers while other witnesses keep shocked survivors from wandering off. Again and again the responders hear or see people trapped below pieces of the wreckage, but until heavy equipment reaches the site there is little they can do to help. Eventually, sixteen survivors will be freed from underneath the wreckage once cranes start picking the pile apart. By that time Mister Harrison has already been arrested.
Once the survivors were all taken care of investigators took over the scene, trying to figure out why the prestigious IC125 broke apart on the side of a freight train for seemingly no particular reason. They had already examined the signaling system and found it to be in perfect working order, same with the brakes on both trains. Climbing into the remains of the leading locomotive they soon stumbled over the first suspicious object. The master switch for the AWS, usually set to “on” and secured with a lead seal, was set to isolate the locomotive from the system, essentially disabling it and breaking the seal. This meant that the system was disabled at the time of the incident, and the driver would not be notified of signals, not having to confirm them either. At the time it was perfectly legal for trains in England to operate with AWS disabled, but this first finding at least explained why the train hadn’t obeyed the signals autonomously. The IC125 was also equipped with an additional train protection system (ATP) that could enforce speed limits, but the system was turned off as neither Harrison nor Tunnock were trained to use it. Investigators also found advanced corrosion on the ATP-system, meaning even if it had been turned on it may not have functioned properly.
Upon being questioned Mister Tunnock stated that he had notified both the operational supervisor at London Paddington of the faulty buzzer and AWS-system as well as calling GWT Control at Swindon, explaining that he was going to run the westbound service with AWS isolated (turned off) and expect repairs to be carried out at Swansea before the locomotive with the faulty system would become the leading unit for the return trip. The system had already failed the previous day, but workers had failed to replicate the error during nighttime maintenance, forcing Tunnock to isolate the locomotive’s system before departing London Paddington. He did not, as the rules required, notify the signal box crew, which could have arranged further protective measures for a train running with AWS off, such as leaving more space between the first yellow and a red signal.
Arriving at Swansea Tunnock found no workers waiting so he headed out onto the platform to call GWT control again. The call was taken by Ms. Hallett, the new information controller with just 3 weeks experience. While talking to investigators she admitted that she wasn’t yet familiar with “the railway jargon” and acronyms, but claimed that she made a note that a driver at Swansea had called about “isolating something”. She then recalled passing the information to either the service controller or the head of fleet maintenance, but both men don’t recall ever receiving any such information. By the time the information breakdown was somewhat sorted out the train was already heading east under the command of Mister Harrison, with the buzzer fixed but the AWS still disabled. Several people along the chain of command could have had the unit pulled from service or order a shunting crew to swap the locomotives with one-another ahead of the eastbound trip, but none did. Tunnock’s demand to have the train fixed ahead of the eastbound journey was unrealistic as such a repair requires work underneath the locomotive, impossible at a normal train station.
Harrison was a sufficiently licensed, educated driver for whom it wouldn’t have been characteristic to ignore signals willfully. He had only had two incidents on his record from the 1970s, passing red signals at low speed without severe consequence. A possible reason for his fatal error surfaced when the investigation acquired a transcript of the call Harrison made with the local signalman moments after the accident, having climbed out of his stricken locomotive and finding a trackside phone at a nearby signal (written record from the report):
Signal Box: Right, and your at a stand, and your ringing in from SN251, Driver are you okay?
Harrison: Driver I’m okay, yeah, I was just putting me stuff away in the bag the A…the A…the…the AWS has been isolated because some, some brake problem, I believe, so, I had no AWS so, I put me stuff away in the bag and the next thing I knew, I was coming up against red, up, such coming through, through… (trailing off)
Signal Box: Through Southall Station?
Harrison: Through Southall, yeah
During the call, which lasted until after the first police officers reached the site of the crash, Harrison mentioned twice that he put “stuff” in his bag (probably paperwork relating to the completed part of the journey), which likely caused him to miss at least one of the yellow signals (how long he was looking at his bag for could not be determined). It was during the call that Harrison also first learned of several fatalities aboard his train. It has to be noted though that he managed to somewhat keep control of his thoughts, giving precise information and ensuring, among other things, that all trains were stopped and the overhead wires were shut down. During the call the signal box crew handed their side of the call to a police officer, who noted down Harrison’s statement regarding placing something in his bag as he approached Southall.
At this point Harrison became anxious to recover his bag from the wreckage, but rather than keeping him where he was, restrained if necessary, the officer who arrived at Harrison’s side allowed him to climb back into the severely damaged locomotive to retrieve his belongings. The officer recalls Harrison immediately heading to the torn up right hand side and retrieving the bag by “reaching in” near the control desk. This sparked the rumor that he might have used to bag to hold down the dead man pedal and riding with his feet up on the desk. This possibility was supported by several witnesses who claimed seeing him pull into both Bristol Parkway station early in the journey and Swindon station with either one or both feet up on the desk. Harrison originally rejected the possibility, but later admitted that he couldn’t remember for sure and might have had one or both feet up during parts of the journey. It has to be noted that it was widely known that the Class 43 could roll at walking pace without anything pressing the pedal, so maybe he had them up at least at the stations and/or tried to keep the pedal down with his bag later, allowing higher speeds. Even if the feet up theory couldn’t be proven, it did cast reasonable doubt on the professionalism of his behavior.
With all the evidence at hand the fault for the accident was placed firmly on Mister Harrison, who soon found himself charged with manslaughter, but the charges were eventually dropped and he was never legally held responsible. GWT was fined 1.5 Million £ (3.03 Million £/3.57 Million Euros/3.65 Million USD in today’s money) for negligent handling of long-distance train operations, leaving both ATP and AWS disabled on a high speed train. The report was finally published in February 2000, containing 93 recommendations to improve operational safety. The main criticism was that AWS was seen as more of a “gimmick” in operation, rather than something that should be required to operate especially high speed trains. Both ATP and AWS were introduced as a measure to improve safety, especially after the end of two-driver train crews. The report urged British Rail to make the systems’ operation mandatory, no longer giving an alternative to pulling a locomotive from service if the system is found to be defective. Furthermore, the report criticizes that the maintenance crews released the train into service on the day of the accident after being unable to find, let alone fix, the defect in the AWS-system. The operational rules were changed accordingly, with one key difference. Operation of the IC125 remained legal with AWS inoperable, but only with a second fully capable and licensed driver in the cab or at speeds of no higher than 65kph/40mph to the nearest station were the required second driver can board the train.
Once the investigation finished Class 43 number 43173 became the first of its type to be retired from service and scrapped, meeting the same fate as the 8 passenger cars it pulled on the day of the accident. The rear locomotive, number 43163, had its very minor damage repaired and returned to service, being sold to ScotRail in 2018. As of summer 2022 it is still in service. The first non-accident related retirements of IC125-sets started in 2017, by 2019 they lost their operational permit for England’s national rail network due to not upholding new accessibility-regulations. Exceptions have been issued for Scotrail, who are working on modifying their sets, and EMT, who are dealing with delays in the acquisition of new trains. Thirteen Class 43 have been marked for preservation in different conditions while their jobs were largely taken over by Hitachi Class 802 units. The locomotives are outlived by the Mark 3 passenger cars, who won’t see full retirement before 2035.
Video
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The official report can be found right here if you want to look through its 312 pages yourself.
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