The town of Morpeth in Northumberland, England, has what is reputed to be the tightest curve ( radius) of any main railway line in Britain. The track turns approximately 98° from a northwesterly to an easterly direction immediately west of Morpeth Station on an otherwise fast section of the East Coast Main Line railway. This was a major factor in three serious derailments between 1969 and 1994. The curve has a permanent speed restriction of . 1877 derailment On 25 March 1877, the 10:30 p.m. train from Edinburgh to London Kings Cross was derailed on the curve. It was travelling at only . The officer from the Railway Inspectorate who held the inquiry, Captain Henry Tyler, found that faulty track was to blame. He also commented perspicaciously "It would obviously be better if a deviation line could be constructed, to avoid the use of so sharp a curve on a main line". This "deviation line" has still not yet been built . 1969 derailment On 7 May 1969 a northbound Aberdonian sleeping car express train from London to Aberdeen derailed on the curve. The train in question consisted of Deltic locomotive The Royal Northumberland Fusiliers hauling 11 carriages. Six people were killed, 21 were injured and the roof of the station's northbound platform was damaged. The train had been travelling at . The driver had apparently allowed his attention to wander because he was thinking about an official letter that he had been handed when booking on duty, asking for an explanation of time lost on a previous journey. The investigation into this accident led to the implementation of alerts for major speed restrictions via the Automatic Warning System. However, despite the recommendation for this system stemming from the accident at Morpeth and the common reference to the 'Morpeth warnings', the gradually stepped speed restriction for the Morpeth curve did not meet the guidelines for this system and it was not installed until at least after the 1984 derailment. 1984 derailment The southbound sleeper service from Aberdeen to London was derailed at the same location on 24 June 1984. There were no fatalities but 29 passengers and 6 train crew were injured. Two houses narrowly escaped being demolished by the derailed carriages. The train was estimated to have been travelling at . The train involved was led by Class 47 locomotive number 47452, hauling seven British Rail Mark 3 sleeping