Penmanshiel Tunnel
The tunnel was constructed between 1845 and 1846 by contractors Ross and Mitchell, to a design by John Miller, who was the engineer to the North British Railway.
Later it was determined that it would be too dangerous and difficult to rebuild the tunnel, so it was sealed up and a new alignment was made for the railway, in a cutting to the west of the hill.
[4] On the evening of 23 June 1949 a fire broke out in the tenth coach of an express passenger train from Edinburgh to King's Cross, about 2.5 miles (4 km) beyond Cockburnspath.
[6] The cause of the fire was thought to be a cigarette end or lighted match dropped against a partition in the corridor, the surface of which was found to have been coated with a highly-flammable lacquer.
[10] Shortly before 3:45 a.m. on 17 March 1979, the duty railway works inspector noticed some small pieces of rock flaking away from the tunnel wall, approximately 90 m (300 ft) from the southern portal.
[14] The 13 other people working inside the tunnel at the time of the collapse were able to escape successfully, but despite the efforts of rescuers (including a specialised mine rescue team) it was not possible to reach the two operators or to recover their bodies.
[23] Geotechnical investigations into the surrounding hillside found evidence suggesting fracturing of the rock overlying the tunnel, but similarly this was not thought to be sufficiently definitive.
[15] The existence of the anticline would almost certainly have never been confirmed without the excavation of the bypass cutting, and it was considered "most unlikely" that the "extreme complexity" of the geology could ever have been appreciated by investigation of rock exposed in the tunnel or though other routine investigatory techniques.
[27] Finally the report stated that—as the conditions leading to the collapse could not reasonably be foreseen—there were no grounds for finding any individual responsible for the accident.
[28] Despite this the British Railways Board was charged in the High Court of Justiciary at Edinburgh with breaching the Health and Safety at Work etc.
[3] This decision resulted in a total of around 1 kilometre (1,100 yd) of existing railway being abandoned and replaced by a new section of line constructed in an open cutting, approximately 40 m (130 ft) to the west of the tunnel.
[3][33] During the closure, some trains from King's Cross terminated at Berwick, with onward services being provided by a fleet of buses, some towing trailers for luggage.
Other InterCity services reached Edinburgh by diverting from the East Coast Main Line at Newcastle and travelling via Carlisle and Carstairs.
The memorial is adjacent to a road running over the hill and is marked on 1:50,000 and 1:25,000 scale OS maps, at grid reference NT 797670.
