As regards the interior equipments, in most instances all that is needed is provision for readily fixing in place two or four stretchers as the case may be, and also for loading the stretchers on to and unloading them off the body without difficulty, and without unnecessary discomfort to the patient. The standard types of ambulance body approved by the British Red Cross Society consist of simple but stout wooden frameworks with all the joints reinforced by angle irons held by bolts through the wooden members, and not merely by wood screws, which are liable to work loose. Over this framework is stretched a cover of waterproof canvas that has been treated with rubber, while the front and back of the vehicles are covered in by waterproof curtains of similar material, capable of being drawn aside or raised quite easily so as to enable attendants, with the minimum of difficulty, to lift the loaded stretchers into the vehicles. Medical experts who have experience in the carriage of wounded men do not appear to be entirely in agreement as to whether the stretchers in a motor ambulance should be rigidly secured to the vehicle body, or should be carried by some form of springing supplementary to that of the car itself. In some examples of ambulances in regular use in this country, additional springing is provided by suspending the body from the chassis by means of semi-elliptical or complete elliptical springs. In many others, no springing other than that of the vehicle itself is interposed between the stretcher and the ground. One point at least on which there is universal agreement is that on no account must any rolling motion of the stretcher relative to the vehicle body be permitted, as motion of this kind causes acute discomfort to the patient, and often leads to physical effects similar to those occasioned by the rolling of a vessel at sea.
Probably side loading is the ideal method of getting stretchers on to an ambulance car, but it is difficult to realise the ideal in the case of a simple and fairly cheaply constructed body. Consequently, the system of end loading is far more common. In this case, the stretcher is generally slipped in along the floor of the vehicle, and when right inside the car, is raised to the necessary elevation to allow it to be secured in position. The lower stretchers are afterwards slipped in and similarly secured. A design in which this is possible is more convenient than one in which the upper stretchers have to be raised to their full height before the operation of sliding them into the car can be attempted.