Nautilus (1800 Submarine) - Construction

Construction

Fulton built the first Nautilus at the Perrier boatyard in Rouen of copper sheets over iron ribs. It was 21 ft 3 in (6.48 m) long and 6 ft 4 in (1.93 m) in the beam. Propulsion was provided by a hand-cranked screw propeller. Her hollow iron keel was her ballast tank, flooded and emptied to change her buoyancy. Two horizontal fins on the stubby horizontal rudder controlled angle of dive — the origin of the diving planes used on all modern submarines. It resembled a modern research submarine in shape — a long teardrop with an observation dome we would call a conning tower. When surfaced, a fan-shaped collapsible sail, looking rather Chinese, provided propulsion. Air, other than that enclosed, was provided by a waterproofed leather snorkel tube.

It was always designed to carry a "carcass", as Fulton called his dragged mines. A device on the top of the dome drove a spiked eye into the enemy's wooden hull. The submarine then released its mine on a line that went through the eye. The submarine sped away, and only when the long line had paid out would the mine strike the target hull and explode by a detonator. The mines were nothing like a self-propelled torpedo: They were variously-sized copper cylinders carrying ten to two hundred pounds of gunpowder, triggered by a gunlock mechanism that went off on contact with the hull.

Nautilus was first tested, with constant success, in dives in the Seine at Rouen, in the Saint-Gervais dock, beginning July 29, 1800. As the river current interfered with some tests, Fulton took the boat to Le Havre to work in the quiet salt water of the harbor. He tested endurance with a candle lit, and found the flame did not challenge the air capacity of the snorkel. He tested the speed of his two men cranking against two men rowing on the surface, and Nautilus covered the 360 ft (110 m) course two minutes faster. During this time he changed the rudder, and the screw propeller to one with four vanes like a windmill.

Through friends like Gaspard Monge and Pierre-Simon Laplace, Fulton obtained an interview with Napoleon, but nothing came of it. However, the Minister of Marine was by Fulton's friends pushed into appointing a scholarly panel to assess the submarine, to consist of Volney, Monge, and Laplace.

On July 3, 1801 at Le Havre, Fulton took down the revised Nautilus to the then-remarkable depth of 25 feet (7.6 m). With his three crewmen and two candles burning he remained for an hour without difficulty. Adding a copper "bomb" (globe) containing 200 ft3 (5.7m3) of air extended the time underwater for the crew for at least four and a half hours. However, one of the renovations included a 1.5 in (38 mm) diameter glass in the dome, whose light he found sufficient for reading a watch, making candles during daylight activities unnecessary. Speed trials put Nautilus at two knots on the surface, and covering 400m in 7 min. He also discovered that compasses worked underwater exactly as on the surface.

The first trial of a carcass destroyed a 40-foot sloop provided by the Admiralty. Fulton suggested that not only should they be used against specific ships by submarines, but be set floating into harbors and into estuaries with the tide to wreak havoc at random.

The overseeing committee enthusiastically recommended the building of two brass subs, 36 ft (11 m) long, 12 ft (3.7 m) wide, with a crew of eight, and air for eight hours of submersion.

In September, Napoleon expressed interest in seeing the Nautilus, only to find that, as it had leaked badly, Fulton had her dismantled and the more important bits destroyed at the end of the tests. Despite the many reports of success by reliable witnesses like the Prefect Marine of Brest, Napoleon decided Fulton was a swindler and charlatan. The French navy had no enthusiasm for a weapon they preferred to think suicidal for the crews (though Fulton had no problems). Certainly, it would be overwhelmingly destructive for conventional ships.