There existed difficulties of two natures: The first of these related to the stability of boats such as this, having their engine, boiler, supply of coal, forty passengers who might all occupy one side of the vessel, a central superstructure, with roof; and, finally, all the weight centered on five feet of the deck, with nothing below to counterbalance it except the hollow hulls and two three-foot compartments, each placed toward the central portion of the hulls and designed as fresh-water reservoirs for the steam generator. The second difficulty was to obtain the best utilization possible of a screw placed in the current between the hulls and upon a shaft inclined toward the stern, that is, "stern" by analogy, for there is no distinction of fore and aft in ferry boats.
STEAM FERRYBOATS OF THE PORT OF MARSEILLES.
The conditions of the problem were finally fulfilled to the satisfaction of all concerned, and especially to that of the public.
The hulls, navicular in form and having a flat bottom, are constructed of one-tenth inch iron plate and 40x40 angle iron. Their dimensions are: Length, 33 feet; breadth, 3¼ feet; and depth, 5 feet. The internal distance between the two shells is 7¼ feet. These hulls, having absolutely water-tight decks, are connected below by tie bars of flat iron, and above by vertical stays 1 foot in length, which serve to support the floor-planks of the deck and boilerplate flooring of the engine-room. The engine-room, which is 19½ feet long by 5 feet wide, is constructed of varnished pitch-pine, with movable side-shutters of teak. The roof, of thin iron plate, is provided with a ventilator to allow of the escape of hot air.
The passengers, to the number of forty or fifty, can move about freely from larboard to starboard, or from stem to stern, or seat themselves on the benches running along the inside of the guard railing on the two sides of the vessel. They are protected from rain by a roof, and from the rays of the sun by a curtain extending along the sides.
Although the usual method of landing is fore and aft, gangways have been provided at the sides for side-landing should it become necessary.
The general appearance of one of these boats may be likened to that of a floating street-car. Finally, a small apartment, provided with benches, is provided for the use of those passengers who might be taken sick, or for office purposes, if need be.
The total weight of one of the boats is divided up as follows:
Forty passengers................ 6,200 pounds,
Engine and boiler............... 6,600 "
Ballast, water, and equipment... 9,900 "
Deck and superstructure......... 6,600 "
Hull and accessories............12,500 "
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Total...........................41,800 "