On 7 March 2015, a steam-hauled charter train passed a signal at danger and subsequently came to a stand across a high-speed mainline junction near Wootton Bassett Junction, Wiltshire, England. Another train, which had right of way, had passed through the junction 44 seconds earlier and no collision occurred nor was any damage done.
As a result of this signal passed at danger (SPAD), Network Rail banned the train's operator, West Coast Railways (WCR), from operating trains anywhere on the British railway network. The Rail Accident Investigation Branch (RAIB) opened an investigation into the incident, which it called a "dangerous occurrence". The incident was rated the most serious SPAD in the United Kingdom since December 2010. Following improvements made by WCR, the ban was lifted. A subsequent incident led to a further ban, which was later lifted.
In December 2015, the Office of Rail and Road initiated a prosecution against the driver of the train and WCR for offences under the Health and Safety at Work etc. Act 1974. The case was heard in June 2016. Both WCR and the driver of the train pleaded guilty. WCR was fined £200,000 plus costs. The driver received a sentence of four months' imprisonment, suspended for eighteen months.
In May 2016, the RAIB published a report on the incident, which largely blamed the incident on the train crew tampering with a safety system that would otherwise have safely brought the train to a halt.
Incident
At 17:25 GMT on 7 March 2015, a charter train approached Wootton Bassett Junction, where the Great Western Main Line and South Wales Main Line diverge at Royal Wootton Bassett, Wiltshire. In the approach to signal SN43, an Automatic Warning System (AWS) magnet was present in the trackbed, warning of a temporary speed restriction ahead. The line speed was . The temporary restriction of then in force did not apply to the train as steam locomotives are restricted to a maximum of on Network Rail (NR) tracks in any event. An emergency brake application occurred on the train after it had passed over the magnet because the driver failed to press the AWS cancelling button within 2.7 seconds.
The driver should have allowed the train to come to a stand and contacted the signalman, but he did not. Instead the AWS isolating cock was operated, releasing the brake after the train's speed had been reduced from to about . This had the effect of isolating both the AWS and the Train Protection & Warning System (TPWS), rendering them unable to apply the brakes. Although the driver was permitted to operate the isolating cock under certain fault conditions, he did not follow the British Railway Rule Book protocol or inform the signaller that he had done so.
The next signal, SN45, was displaying a red (danger) aspect. By the time the driver saw this, there was insufficient distance available to stop the train, which eventually came to a stand on the junction some past the signal. The service train that was being protected by the red signal had already passed through the junction and no collision occurred. As the points had already moved for the passage of the charter train, no damage was done to the trackwork at Wootton Bassett Jn. The line speed approaching the junction was for the service train. Before he was relieved from driving duties, the driver of the charter train claimed that signal SN43 had displayed a green (proceed) aspect. NR investigations showed that a single yellow (caution) aspect was displayed.
Following the incident, the driver was relieved at . There a new driver was supplied by West Coast Railways (WCR) who drove the train to , where the train was terminated.
The incident was rated the most serious SPAD since December 2010, rating 25 out of 28 on Network Rail's scale. Any SPAD rated at 20 or more leads to a mandatory investigation by the Office of Rail and Road (ORR). The scale is logarithmic, with each increment rated twice as serious as the previous; thus the incident was rated as nominally over thirty times more serious than this threshold. The December 2010 SPAD was rated at 26, and was at Uphill Junction, Somerset, on the Bristol to Exeter line when a passenger train overran a signal by . The month before that incident, a passenger train overran a signal at , Staffordshire, in an incident rated at 25.
RAIB investigation findings The RAIB investigation into the accident reported that the outward working, reporting number 1Z21, the 07:22 from to , had been fitted with a numbered plastic tie on the handle of the Automatic Warning System (AWS) isolating cock. The train was driven to Bristol without incident, although some misting of the driver's window was reported. The driver of that train was not the driver later involved in the SPAD at Wootton Bassett. During an empty coaching stock movement to St Philip's Marsh depot, the emergency brake applied because the driver did not cancel an AWS warning in the allotted time. The AWS isolating cock was opened, breaking the seal. On leaving St Philip's Marsh, a similar incident occurred, and the AWS isolating cock was opened again. There was a change of traincrew on arrival at Bristol Temple Meads, where the return working was designated 1Z67. According to the rulebook, the driver of the train should have reported the missing seal on the AWS isolating cock. The train should not have been allowed to depart until the cock had been sealed. The driver did not do this, and set off with an unsealed cock.
Due to misting and exhaust obstructing the driver's view through the window, the driver drove leaning out of the cab for much of the time. This made hearing the AWS sounder and observing the AWS reminder light harder. Approaching signal SN43, there was a temporary speed restriction of , which was warned of by a temporary AWS magnet in advance of the restriction, and indicated by a sign at the start of the temporary speed restriction. The train approached signal SN43 at and passed over the temporary AWS magnet. The driver failed to react to the warning given within the time allowed and the brakes were applied. Because the AWS isolating cock was out of reach of the driver, he instructed the fireman to open it for him. The train's speed had reduced by about when the brakes were released. The rules require that the train is brought to a stand and the signaller contacted in the event of an AWS brake application. Additionally the driver must inform the signaller whenever the AWS is isolated;"Driver: If it becomes necessary to isolate the AWS, you must: stop your train immediately tell the signaller not move the train until instructed to do so carry out the instructions given." The train then passed signal SN43, which was displaying a single yellow (caution) aspect. The driver acknowledged the AWS warning, but did not reduce speed. In the twelve seconds between brake application and brake release, the train passed over the fixed AWS magnet for signal SN43, which was displaying a single yellow (caution) aspect. This warning was cancelled in time. The train then passed over the TPWS+ overspeed sensor for signal SN45, which was displaying a red (danger) aspect. As the train was travelling more slowly than the trigger speed, no brake action was demanded from the train. The train then passed over the second TPWS overspeed sensor for signal SN45, this time at , which was in excess of the trigger speed. Consequently, a TPWS intervention occurred, but as the AWS isolating cock was open the brakes did not apply. When the driver saw that signal SN45 was at danger, he applied the brakes on the train. Due to there being insufficient distance to stop, the train overran the signal by and came to a stand across Wootton Basset Junction.
Then the driver reported to the signaller by radio, claiming that the signals had not sequenced properly (i.e. that SN43 had been green). During the time that he was on the radio, the fireman closed the AWS isolating cock. The signaller initially treated the event as a Technical SPAR (i.e., Signal Passed at Red due to an Irregular Signal Sequence) because there was no SPAD alarm provided for signal SN45 and the driver had claimed that the preceding signal was displaying a green aspect. Because this is not a safety-critical event he authorised the driver to take the train forward to . However, by the time the train arrived at Swindon, it was understood that signal SN45 had been passed at danger without authority and the driver was relieved of his duties. The driver was not tested for the presence of drugs or alcohol in his system, as is required by Railway Group Standards. The investigation found that there was no evidence of alcohol in his system. Prescription drugs that he was taking were assessed as not having an effect on his ability to drive the train. Fatigue was found not to be a factor.
The investigation found that crewing of the train was insufficient. There was no traction inspector on board. WCR had discontinued the use of traction inspectors by 2012. A traction inspector's duties include assisting the driver with the sighting of signals. Two members of the train support crew were also on the footplate of Tangmere, but they had no responsibility in respect of the operation of the train. No problems were found with the ability to sight signals SN43 and SN45. The locomotive and carriages from the train were tested separately following the incident; no fault was found with either, although some of the sensors were not being recorded by the On Train Data Recorder (OTDR). The RAIB were able to reconstruct the sequence of events from the data that was recorded by the OTDR.
The investigation found that the fixed AWS magnet for signal SN43 was incorrectly positioned. It was located from the signal, instead of the standard . The actual location of signal SN43 was closer to the junction than shown on signalling diagrams, which was at from London. These errors meant that the placing of the AWS magnet for the temporary speed restriction was also incorrect. Instead of being from the fixed AWS magnet, the temporary AWS magnet for the speed restriction was only from it. The installation of signal SN43 was in 1978, and the errors had remained undetected since then. An emergency speed restriction had been introduced in January 2015 due to the condition of the track, and had subsequently been converted to a temporary speed restriction. These errors were found not to have been contributory factors in the incident.
The safety culture at WCR was found by the investigation to be weak. This was evidenced by a number of factors, including the lack of traction inspectors, failure to test for drugs and alcohol, failure to download data from OTDRs to analyse individual driver performance, failure to maintain OTDR equipment correctly, failure to report missing seals on safety equipment where they were required to be fitted, failure to keep proper records, and failure to improve following the incident at Bell Busk (detailed below).
Trains
Charter train The charter train, reporting number 1Z67, was a steam-hauled passenger train, the 16:35 Cathedrals Express charter from to , Essex. The train was hauled by Battle of Britain-class locomotive 34067 Tangmere (TOPS number 98 767). Tangmere was hauling thirteen carriages, which were a mixture of Mk 1s and Mk 2s. The train was operated by WCR. There were 477 passengers and 39 staff on board the train.
Service train The service train was the 15:28 to , reporting number 1L76. It was operated by a First Great Western InterCity 125 "High Speed Train", and was carrying about 240 passengers.
Investigations