Holland submarine torpedo-boat.
John P. Holland
devised a submarine boat which met with the requirements of the United States Navy Department.
When submerged, the boat was propelled by electricity, and able to make 8 knots for six hours. Among the requirements were power to carry two tubes for automobile torpedoes; ability to reach a depth of 20 feet within one minute after being ordered to dive, the boat running light at full speed, and with smokepipe at full height; power to dive to a depth of 20 feet within thirty seconds, the boat before diving running at full speed with steam-power, and with 3 feet of water
over hull, and smoke-pipe up; with complete submergence and 3 feet of water over turret, the pilot to obtain a view with a camera-lucida in a tube projecting above the surface; a turret to rise 4 feet above the hull, with an armor cylinder of 8 inches thickness to protect the pilot's head; a complete double shell to extend
The Holland submarine torpedo-boat.|
about three-quarters of the vessel's length from the stem; ability to stand the water pressure at a depth of 70 feet; automatic arrangements for preventing a too deep submergence; automatic compensation for weights consumed, and independent mechanism for correcting variations in trim due to shifting weights; mechanical means for steering a fixed course; air to be supplied for crew either chemically or by storage under pressure in tanks; apparatus to cause the vessel to rise quickly to the surface; ability to maintain an approximately fixed position and definite depth of submergence without undue expenditure of power; provision for escape of crew in emergency.
Since the building of the first boat many improvements have been made, all tending to increase the practicability of submarine action.
writes of his boat as follows: