The tools used in military bridge work, like the structures built therewith, should be of the utmost simplicity. There should be an ample supply of the common tools, such as picks, mattocks, axes, saws, hammers, wrenches, shovels, cant-hooks, etc., with a few of the less usual tools that will occasionally be required. All should preferably be of commercial sizes; but, to meet emergencies, miniature tools, easily transported on a pack mule or on the person of the soldier, should also be available in case of need. There will arise situations in which the entire equipment of the bridge builder must be carried on pack mules.

Class of Labor Available

Military bridges must usually be built chiefly by unskilled labor. In every engineer organization there will be a number of skilled artisans of every class; but the majority of the men in the ranks of these organizations, as well as those from labor battalions and working parties from the infantry, will be of the class known as "unskilled labor." This fact has an important bearing on the design and methods of construction of military bridges.

Improvisation and Standardization.

The difficult situations encountered, the varied circumstances under which work must be performed, the emergencies constantly arising, and the necessity of adapting to his purposes whatever materials are available, will require the military bridge builder to be skilled in improvising structures to meet these conditions. Improvisation, in fact, is characteristic of all the operations of military engineering. It is a valuable means of developing ingenuity and resourcefulness; nevertheless it is a practice which results only from necessity, and it has the disadvantages that it consumes valuable time and that it tends towards lack of uniformity both in training and in actual construction.

Standardization, including standard designs, standard materials, and standard methods of construction and of training, is at least as useful and economical in military practice as in civil practice. It has the following important military advantages:

(a) A standardized structure can always be erected in less time than one in which extensive improvisation is necessary, especially by troops who have been trained in standardized construction. The saving of time results from both the fact that it is possible to use standard plans, and that loss of time from improvisation is eliminated.

(b) A further saving of time is effected by the fact that standardized materials may be prepared beforehand at the engineer depots, and sent to the front as needed. Lumber can be cut to exactly the required dimensions, bolts will be of exactly the right length, and special pieces of all kinds can be made up in rear, so that it will not be necessary to spend time in preparing them under difficult conditions at the front.