Besides, the boiler furnaces are small and not well adapted to burning wood.Īll in all, up to the advent of our own steam-electric driven dredge, the steam-driven dredge, containing a boiler with individual engines for the various units, was the most successful type of self-contained dredge. In a few instances the locomobile, which is an overmounted engine on a portable boiler, has been tried in combination with an electric generator but these engines being of the reciprocating type, do not lend themselves readily to the driving of the usual type of generator. Sooner or later fine grit is certain to work its way into the cylinders and bearings, eventually causing them to wear out. Furthermore, it is essential that these engines be kept free from dust and dirt, and this is practically impossible on a dredge. It is almost impossible to put foundations under these engines that are heavy enough to absorb the shock of the explosions. They are exceedingly heavy and the usual vertical type racks the hull in bad shape. Such engines are too delicate for the rough work involved in gold dredging. In order to obtain a self-contained dredge with its power plant on board, several attempts have been made by others in the past to use gas or oil engines, but these attempts have not proven very successful. Where such power is lacking and a self-contained steam driven dredge is required, then our steam-electric driven type should be used. There can be no question that the most efficient and economical method of operating a dredge is to have all the units electrically driven by individual motors and where electric power is available, the question of motive power presents no difficulty.

Portable electric gold dredge