The Field Ambulance was a mobile front-line medical unit (it was not a vehicle), manned by troops of the Royal Army Medical Corps. Most Field Ambulances came under command of a Division, and each had special responsibility for the care of casualties of one of the Brigades of the Division. The theoretical capacity of the Field Ambulance was 150 casualties, but in battle many would need to deal with very much greater numbers. The Field Ambulance was responsible for establishing and operating a number of points along the casualty evacuation chain, from the Bearer Relay Posts which were up to 600 yards behind the Regimental Aid Posts in the front line, taking casualties rearwards through an Advanced Dressing Station (ADS) to the Main Dressing Station (MDS). It also provided a Walking Wounded Collecting Station, as well as various rest areas and local sick rooms. The Field Ambulances would usually establish 1 ADS per Brigade, and 1 MDS for the Division.

The Field Ambulance had been born out of the Boer War in an attempt to speed up the evacuation of wounded men. It merged existing separate and previously independent units in order to increase efficiency. When it was at full strength a Field Ambulance was composed of 10 officers and 224 men. It was divided into three Sections. In turn, those Sections had Stretcher Bearer and Tented subsections. RAMC officers and men did not carry weapons or ammunition. ‘A’ Section (usually 65 men) was commanded by a Lt-Colonel with at least two other officers (one in command of stretcher bearers, the other in charge of the tented section), six NCOs and up to fifty privates who were primarily stretcher bearers. ‘B’ and ‘C’ sections (usually 128 men) were commanded by a captain were similarly staffed. All three sections were designed to work separately. The aim was to bring the wounded back from the Regimental Aid Post and give comfort to them while awaiting evacuation to the rear.

Walking wounded would be picked up, as they made their way back, at the RAP and accompanied to the Dressing Station. When wounded had to be carried back, four stretcher bearers per wounded man would be involved. The suggested time allocated per wounded man, one hour per stretcher carried, rapidly became unrealistic. Any records kept for these transfers were made at the ADS as only here that there were the men who had the time to write down what had been done. The sections were now responsible for the vehicles used to transfer the more serious cases from the ADS to a clearing hospital.

During the retreat from Mons in 1914, the system had to change so as to become more efficient, and modifications had to be made. The system carried on in similar circumstances until Sir Almoth Wright study of the Field Ambulance service in 1917. Wright was very critical of the system for a variety of reasons. He felt that the scale of the system was not adequate; that the casualties were not transferred quickly enough for surgical intervention to be efficient; and that the ambulance sections themselves were extravagant in medical personnel, that is the officer in charge of the stretcher bearers did not have to be a doctor.

The first major test of the Field Ambulance was the response to the casualties incurred on the First Day of the Battle of the Somme in 1916. The forward elements coped quite well although the trenches soon became congested with wounded. The evacuation of casualties (the Field Ambulance was moving 1,000 casualties in the first hour when 150 had been expected) did impede the movement of reinforcements but the major problem was experienced at the Casualty Clearing Stations (CCS) where the number of casualties was far in excess of what the doctors and nurses expected and they were soon felt overwhelmed. This can be attributed with the lack of ambulance trains required to transfer the wounded onto hospitals.

As the war progressed and the ground became more difficult to transport stretchers (running was prohibited as this jeopardised the stability of the wounded), the time taken to bring a casualty from the Regimental Aid Post to the Advanced Dressing Station increased to four hours on average. It was noticed by stretcher bearers that many of the wounded died during this transfer and the ground around the ADS would be taken up with blanketed bodies like Egyptian mummies labelled ‘Deceased awaiting burial’. To help the stretcher bearers in this transfer extra ‘posts’ were instituted in the chain of evacuation – ‘Collecting Posts’ and ‘Bearer Relay Posts’. These became important not only for resting the stretcher bearers but also created a chance to re-assess the injuries of the wounded and to create navigational landmarks for the evacuation.

These lessons were put into practice in April 1917 with the Battle of the Scarpe. To illustrate the Field Ambulance experience, Alistair concentrated his attention on three divisions, one territorial (56th ), one regular (3rd ) and one New Army (12th).

The 56th division attacked the Hindenburg Line at Neuville Vitasse, the ADS was at Achicourt with a series of bearer posts linking it to the front line. Unfortunately, the ADS was close to an artillery battery and suffered heavy shell fire as a result. As the attack progressed, the RAMC pushed forward establishing RAPs in the ruins of Neuville Vitasse. Records of the first day, 10th April, indicate that over 200 casualties passed through the ADS in the first 24 hours. As the front line moved, so did the Field Ambulance as the ADS moved closer to the front line. But the attacks of 14 & 15 April were less successful, there was little advance and casualties built up. They had to be carried three and a half miles back in place of the planned one mile. No longer could the Field Ambulance wait until dark to move casualties, trenches had to be dug to carry them during the hours of daylight.

The 3rd Division, attacking to the north of the 56th , was in the line to the suburbs of Arras. They had two ADSs, one centred in a girl’s’ school, the other in Thompson’s Cave. Their attack would take them across a strong German position called The Harp. With the initial success of the attack, casualties were rapidly removed, the first arriving at the girls’ school within 50 minutes of zero hour. As the day progressed the two ADS alternated in receiving casualties. As the Field Ambulance experienced little traffic congestion, there was no accumulation of wounded in any of the medical posts.  As the afternoon progressed the Field Ambulances moved forward but now experienced congestion. The use of German POW aided the evacuation of the wounded. In the early evening the ADS in the girls’ school closed having treated 160 of the 3rd Division’s 291 casualties.

The 12th Division also attacked from the suburbs of Arras, their objective being a line between Feuchy and Monchy. Four ADS were established in Arras, the main two being in a factory adjacent to the Cambrai road and one in a nearby abattoir. During the fierce fighting in the morning, two RMOs became casualties and their replacements were quickly found from the officers in the field ambulance. It was important to find doctors who were experienced in realities of trench warfare. As the advance slowed, the field ambulance established an aid post in an abandoned German dressing station. As evening approached there was a build of casualties. So as to avoid congestion in the chain of evacuation, a motor ambulance convoy was set up by the division. This had to be repeated at midnight due to a second build up.

The battle continued into May, divisions were rotated out of the line for rest and training then returned. Did the training of the field ambulance live up to pre-war planning? Before an answer can be given, one must ask about expectation of casualties. Pre-war expected casualty rates were estimated to be between 5% and 20%. In reality they were far greater in the major offensives. Not only that, the expectation that field ambulance units would provide care for the wounded was shown to be wrong. In reality, the major concern for the field ambulance was the rapid and careful transference of casualties from the RAPs back down the line to rear hospitals via the CCSs.

Report by Peter Palmer