The Quintinshill rail disaster was a multi-train rail crash which occurred on 22 May 1915 outside the Quintinshill signal box near Gretna Green in Dumfriesshire, Scotland. It resulted in the deaths of over 200 people and remains the worst rail disaster in British history.
The Quintinshill signal box controlled two passing loops, one on each side of the double-track Caledonian Main Line linking Glasgow and Carlisle (part of the West Coast Main Line). At the time of the accident, both passing loops were occupied with goods trains, and a northbound local passenger train was standing on the southbound main line.