Casualty clearing station

A casualty clearing station was a medical unit of the British and Commonwealth armies, most associated with the First World War. It stood several miles behind the front, usually near a railway, and received the wounded from dressing stations. There they were sorted, treated, and either operated on, kept, or put on trains to base hospitals.

The units began the war as clearing hospitals and were renamed early in it. At first they were meant to pass casualties back quickly. As the Western Front settled into fixed lines, it became clear that many wounds, including abdominal wounds and badly contaminated limb wounds, needed surgery sooner than a base hospital could give it. Through 1915 and 1916 casualty clearing stations became the main place for urgent surgery, with operating theatres and nursing sisters.

Late in the war, some stations gave blood transfusions, including with stored blood.

1. Arrival. Motor ambulances brought the wounded from advanced dressing stations, often in large numbers after an attack.
2. Sorting. Medical officers decided who needed surgery now, who could travel on, and who was unlikely to survive.
3. Treatment. Urgent operations were done on site. Wounds were opened and dead tissue cut away to prevent gas gangrene.
4. Onward evacuation. Those fit to travel went by ambulance train to base hospitals, and some by hospital ship to Britain.