The Rail Accident Investigation Branch (RAIB) is investigating a “dangerous occurrence” after a train passed a signal at danger (SPAD) on the approach to Wooton Basset junction in Wiltshire recently.

A steam-hauled special, consisting of Battle of Britain class locomotive Tangmere, its tender and 13 coaches, was on a service from Bristol Temple Meads to Southend using the Great Western main line through Bath. Just west of Swindon is Wooton Basset Junction where the main line is joined by the line from Bristol Parkway, the Severn Tunnel and South Wales.

A train had recently emerged from the South Wales line (the Badminton Up line) and signal SN45 on the main line was still at red, although the signalling system had already set the points ready for Tangmere.

Having passed the signal at danger, the train finally came to a standstill across the junction. This generated quite a bit of speculation in the Rail Engineer office. The locomotive was fitted with both AWS (Automatic Warning System) and TPWS (Train Protection and Warning System) so how hadn’t the driver realised what was happening? And why hadn’t the train been brought to a standstill automatically?

The RAIB website states: “Evidence shows that the driver and fireman … took an action which cancelled the effect of the AWS braking demand after a short period and a reduction in train speed of only around 8 mph. The action taken also had the effect of making subsequent AWS or TPWS brake demands ineffective.”

While there was again much comment on this, the RAIB investigation has to take its course. Meanwhile, Network Rail has issued a suspension notice to the train’s owner, West Coast Railway

Company Limited, stating that no services may run on any routes and requiring various actions be taken by 15 May at which time, if Network Rail is satisfied, the notice will be withdrawn.