The spars used in boats are generally arranged on a different principle from those attached to the bows or beams of high-sided vessels. Arranged to work in a swivelled sleeve with a martingale at the rear end to regulate the depth to which they shall sink, the spar is either launched or dropped over and is permitted to swing without guys, the operator watching and exploding it as it is brought abeam and into the desired position by the driving ahead of the boat.
Fitting for Heel of
Spar Ship-Torpedo.
Chafing-Plate for Heel
of Spar-Torpedo.
The spar used with the dynamite torpedo is an iron or steel bar of diminished cross-section in order to offer a minimum resistance to the water, with a hinged piece at its rear end bolting to the keelson of the boat and acting as a martingale.
TORPEDO VESSELS.
In several of the navies of the world gun-boats have been designed for the purpose of using torpedoes, either locomotive or spar, to the total exclusion of battery—or, in some cases, with a limited artillery—fire.
Pietro Micca (Italian).
This vessel, having a displacement of about 530 tons, is built very low in the water, with a curved deck or cover, and is not armored except as regards a deck under the curved cover and over the engines, intended to resist the penetration of plunging projectiles, and which is of laminated steel 2¼ inches thick. Her estimated speed is 18 knots, and she is provided with tubes for discharging Whitehead torpedoes ahead, abeam, and astern.