55006 (D9006) "THE FIFE & FORFAR YEOMANRY" pauses at Doncaster on the 16th March 1979 with the 1S17 09:00 King's Cross - Edinburgh service. Though the adverse weather of 16th-17th March caused problems and lengthy delays to ECML the route was to be thrown into absolute chaos on the 17th when the Penmanshiel tunnel tragically collapsed. The ECML had to be re-routed around the site of the tunnel and regular through services would not re-commence until August 20th. During the interim northbound services from King's Cross terminated at Berwick and shuttle services operated between Dunbar and Edinburgh - a coach service linking Berwick and Dunbar. Only overnight services ran throughout using the route via Carlisle from Newcastle to Edinburgh, though two day time services, the 1S12 05:50 King's Cross - Aberdeen and 1E26 16:30 Aberdeen - York, did also traverse the route via Carlisle. However, during the closure the 1S12 only ran King's Cross to Edinburgh and the 1E26 commenced from Edinburgh at 18:25.