THE CAISSON
The Caisson is made of metal throughout with the exception of the spokes and felloes of the wheels. The principal parts are the wheels, axle, pintle, lunette, apron shield, fuze setter bracket, frame, road brake, and ammunition chest.
Caisson, Plan
The wheels and wheel fastenings are interchangeable with those of the gun carriage and the limber. The caisson road brake is modeled after that of the gun carriage, all parts as far as possible being interchangeable. The frame upon which the ammunition chest rests, is diamond shaped, and consists principally of two steel side rails riveted to lugs on the axle, meeting in front to form the lunette for attachment to the limber, and in rear to form a pintle for attachment of another caisson in case it is desired to tow several caissons by one team and limber, as for instance in the ammunition train. In other respects the construction is similar to that of the limber excepting that the ammunition chest is much larger and has a capacity of 70 rounds. The front of the chest and the chest door are made of armor plate. A bracket for the fuse setter is also provided. An apron shield, similar to the one on the gun carriage is hinged under the axle, giving the cannoneers at the caisson full protection. A spare-pole body can be carried under the caisson frame, large end of pole to the front. On the sides and front of, and under the ammunition chest, suitable straps, brackets and connections are provided for securing all tools and accessories. To lock the caissons and limbers, a padlock is provided. These locks are interchangeable and can be unlocked by the same key. This key is marked “Ammunition.”