On 22 May 1915, a troop train carrying men of the 1/7th Battalion Royal Scots crashed near Quintinshill Junction, near Gretna. A second collision and fire followed. The disaster killed 230 people and became Britain’s worst railway accident.

The men on the troop train were part of Britain’s war effort. They were being moved by rail through Scotland before travelling on towards the wider war. Their deaths came before they reached the front. That gives Quintinshill its grim force: soldiers in uniform, travelling under military orders, were killed by a failure on a railway line at home.

Railways were vital to wartime Britain. They carried troops, munitions, goods and ordinary passengers. That movement depended on routine. Signals, timetables and railway rules were meant to keep trains apart, even on a busy line. At Quintinshill, the system failed.

The immediate danger was a local passenger train standing on the main line. It should have been properly protected. It was not. Normal safeguards in the signal box were missed, and the troop train was allowed into danger. It ran into the standing train.

The first crash was already serious. Then another train struck the wreckage. Fire followed, spreading through the damaged carriages. The troop train’s wooden coaches made the disaster worse. Men who had survived the first impact were trapped in conditions that gave them little chance.

Most of those killed were soldiers of the Royal Scots. Others also died, and the disaster reached beyond the regiment into families, railway staff and the communities that had sent the men away. The scale of the loss was enough to stand beside wartime casualty lists, even though it happened on British soil.

Responsibility fell on the railway workers and human error. The disaster was not treated as a chance or an unavoidable accident. Railwaymen were later convicted for their part in the failure. Quintinshill was a tragedy of scale, but it was also a collapse of the ordinary discipline that made the railway system work.

The war gave the disaster its setting, but the cause lay in routine broken at a junction. A system built to move thousands safely failed in one place, on one morning. The result carried the weight of battle without being battle.