The RAMC and the Chain of Evacuation

If a patient needed further care, the RMO marked their forehead with a letter—such as an 'M' for morphine—and sent them back. The next stage was the Advanced Dressing Station (ADS) or the slightly further Main Dressing Station (MDS), both run by a mobile medical unit known as a Field Ambulance. These stations could hold roughly 150 men for up to a week before they were either returned to the frontline or evacuated further down the chain.

Casualty Clearing Stations (CCS) and Base Hospitals

Understanding how the military sorted the wounded explains why survival rates improved dramatically by 1917. If injuries were severe, casualties were moved 7 to 12 miles behind the lines to a Casualty Clearing Station (CCS). Medical staff used Triage to sort patients into three categories: those who could walk, those needing immediate surgery, and the moribund who had no chance of survival.

Crucially, the CCS became the primary site for life-saving operations. Instead of waiting for patients to reach the coast, surgeons performed rapid wound cleaning and advanced procedures right at the CCS to combat infection. For example, Harvey Cushing achieved a 71% survival rate performing brain surgery at the CCS, while Geoffrey Keynes used portable kits for early blood transfusions.

After emergency surgery, patients travelled via ambulance trains or smooth-sailing canal barges to a General Hospital or Stationary Hospital located near coastal ports like Étaples. These Base Hospitals provided specialist, long-term care for specific injuries, such as head wounds or gas poisoning. During transport to these coastal hospitals, survival rates for leg fractures soared from 20% to 82% thanks to the application of the Thomas Splint.

Medical Personnel: RAMC and Nursing Units

You might picture wartime doctors working alone in a tent, but effective medical care required a vast, coordinated army of diverse professionals. The Royal Army Medical Corps (RAMC) was responsible for all medical operations and grew from 9,000 personnel in 1914 to 113,000 by 1918. All doctors, surgeons, and medical orderlies belonged to this corps.

They worked alongside professional military nurses from the Queen Alexandra’s Imperial Military Nursing Service (QAIMNS), a highly trained group of women that expanded to 10,000 members by the end of the conflict. Volunteer groups provided crucial supplementary support alongside these professionals. The First Aid Nursing Yeomanry (FANY) were mostly upper-class volunteers who initially faced rejection from the British Army. However, from January 1916, they played a vital role driving British ambulances, operating mobile bath units, and running soup kitchens.

Meanwhile, Voluntary Aid Detachments (VAD) consisted of volunteer nurses who began by performing domestic cleaning tasks. Over time, as casualty numbers rose, VADs gradually took on more direct medical duties to assist the stretched QAIMNS nurses.

Case Study: The Arras Underground Hospital

Protecting medical facilities from heavy artillery fire forced army engineers to look directly downwards into the earth. In November 1916, British and New Zealand miners linked existing chalk tunnels and quarries to create a massive, protected medical facility known as Thompson’s Cave. Located just 800 yards from the frontline, this fully equipped underground hospital at Arras functioned essentially as an Advanced Dressing Station due to its proximity to the fighting.

Despite being incredibly close to the frontline, it boasted remarkable facilities. The 800-metre tunnel network included an operating theatre, electricity, piped water, a mortuary, and enough space for 700 stretcher beds. This innovative use of the underground environment successfully kept staff and patients safe from shellfire until May 1917, when the hospital was abandoned after a direct artillery hit destroyed its water supply.