A Field Ambulance is NOT a vehicle. It is a mobile front line medical unit. Most Field Ambulances came under the command of a Division and each had special responsibility for the care of casualties of one of the Brigades of that Division. A Field Ambulance was set up to have the capacity to deal with 150 casualties but in battle it needed to deal with far greater numbers. It 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 rearward through the Advanced Dressing Station thence to the Main Dressing Station. It also provided a Walking Wounded Collecting Station as well as various rest areas and local sick rooms. Field Ambulances would usually establish 1 Advanced Dressing Station per Brigade and 1 Main Dressing Station per Division.
A Field Ambulance at full strength composed of 10 officers and 224 men divided into 3 sections. Each section had Stretcher Bearer and Tented sub-sections. Each section had 36 privates who were Stretcher Bearers under the command of a captain or lieutenant.
As with all other units of this time Field Ambulances relied heavily on horses for transport. Each had 14 riding horses and 52 draught and pack horses. These worked the 23 wagons, 3 water carts, 3 forage carts, 6 general service wagons, 10 ambulance wagons and the cook’s wagon. It also had 1 bicycle, and by the end of 1914, 7 motor ambulances.