Abermule train collision

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The Abermule train collision was a head-on collision which occurred at Abermule, Montgomeryshire, Wales on 26 January 1921, killing 17 people. The crash arose from misunderstandings between staff which effectively over-rode the safe operation of the Electric Train Tablet protecting the single line. A train departed carrying the wrong tablet for the section it was entering and collided with a train coming the other way.

1 Background
2 The accident
3 Causes and lessons
4 See also
5 External links

[edit] Background

Single line operations were always rightly regarded as inherently unsafe. The Cambrian Railway, which traversed Wales from Whitchurch in Shropshire to Aberystwyth and Barmouth, via Dyfi Junction, contained a number of single line sections. The small station of Abermule (or Abermiwl), was a crossing station between two such sections. To the east was Montgomery (also known as Trefaldwyn), to the west was Newtown (also known as Y Drenewydd). The English names were in contemporary use, and appear in most reports on the accident.

To protect the single line sections, Tyer's electric tablet apparatus was used. Two linked machines were used, one at each end of the section. To allow a train to proceed into the section, a call button would be pressed on one machine, alerting the operator on the machine at the other end, who would then press a release button which allowed a tablet to be withdrawn from the caller's machine. The tablet (a metal plate inscribed with the name of the section, inside a weatherproof pouch) would then be handed to the driver of the train as proof of his authority to occupy the section. Until the tablet was replaced in one or other machine, another tablet could not be withdrawn.

This system had protected the Cambrian railway for many years. There was a potential weakness in that the electric tablet machines at Abermule were kept in the main station buildings, while the signals were worked from a separate signal box, and some of the points from a ground frame at the other end of the station. Regulations specified that only the stationmaster or signalman were to work the tablet machines, but it was common for both to be occupied with duties away from the station buildings, and it became accepted practice for any member of the station staff to work them. On the day of the crash, the regular stationmaster was on leave and a relief stationmaster was deputising for him, which may have contributed to the confusion.

[edit] The accident

Shortly before midday on January 26, two trains were approaching Abermule from opposite directions, and were due to cross there. These were a west-bound stopping train from Whitchurch, and an east-bound express from Aberystwyth.

The staff at Montgomery station requested clearance for the stopping train, and Signalman Jones pressed the release on the tablet machine for the Montgomery-Abermule section, to allow it to proceed. After checking with Newtown that the express was running to time, he then went to open the level crossing gates and attend to the signals. Meanwhile, Relief Stationmaster Lewis returned from his lunch. Without inquiring as the position of any trains approaching Abermule, he went straight out again to carry out some shunting in the goods yard.

Newtown station then requested permission for the express to proceed. Porter Rogers pressed the release on the tablet machine for the Newtown-Abermule section which allowed it to do so. He then went to the ground frame to set the points for it (which would require him to alert Signalman Jones as to what he had done and would also prevent the stopping train leaving the station), but was distracted when the stopping train arrived from Montgomery.

A trainee youth named Thompson collected the tablet from the driver of the stopping train, and was heading back to the station buildings to replace it in the tablet machine when he met Lewis returning from the goods yard. He gave the tablet to Lewis, saying that he had to go and collect the tickets. Lewis assumed that the tablet was for the Abermule-Newtown section, and handed it back to the stopping train's driver, who set off into the section. Jones allowed him to proceed, assuming that the express had been delayed or held at Newtown for some reason.

Lord Herbert Vane-Tempest, a director of the Cambrian Railways, killed in the accident.

The crew of the express were travelling at about 50 miles per hour and about to begin braking before arriving at Abermule when they saw the stopping train on the same track. Although they immediately braked, they could not stop in time, and the crew of the stopping train do not appear to have seen them. The crew of the express were just able to jump clear in time, although they were both severely injured. Fifteen passengers, and the driver and fireman of the stopping train were killed in the collision, including a director of the railway, Lord Herbert Vane-Tempest.

[edit] Causes and lessons

The obvious cause of the Abermule collision was the unauthorised working of the tablet machines by anyone who happened to be around, and the failure of the staff at Abermule to notify each other of their actions. A contributory cause was the failure of anyone to examine the tablet they received by removing it from its pouch and checking that it was the correct one. Since the system had worked faultlessly for years, it may have been taken for granted. Indeed for anyone to ostentatiously examine a tablet may have been a breach of etiquette, as it would imply that the person handing it over might not be competent or trustworthy.

Finally, the awkward layout of tablet machines, signals and points levers at Abermule meant that it was possible for conflicting movements to be made. The inquiry recommended that tablet machines be placed in the signal box, under the sole control of the signalman; and also that starting signals (which gave engines authority to leave the station) be interlocked with the tablet machines so that they could not be cleared until the correct tablet machine was locked.

The obvious, though costly, solution to the problems of working single lines would be to double the tracks. As finances allowed, the Cambrian Railway (and the Great Western Railway, which took over the Cambrian after the grouping of 1923) had been slowly carrying out the necessary work. Ironically, British Rail actually removed much of the doubled track and some of the crossing stations as part of the Beeching Axe.