These two vessels are of the Krupp design, and have a submerged displacement of 300 tons. The horse-power of their heavy-oil surface engines is 600. The electric motors develop 200 H.-P. The surface and submerged speeds are 13 knots and 8 knots respectively. The surface range of action is 1,500 miles, and the armament consists of two bow and one stern tube with five 18-inch torpedoes. Their complement is fifteen officers and men.
U.5 and U.6.
(Completed 1910.)
These are submarines of the Improved Holland type. Their submerged displacement is about 316 tons; length 135 feet, and beam 13 ½ feet. The horse-power of the petrol engines is 600 and that of the electric engines 189. The speed averages 12 knots on the surface and 8 knots when submerged. The surface cruising range is 1,300 knots at 10 knots an hour. Their armament consists of two bow tubes with four to six 18-inch Whitehead torpedoes. Their complement is sixteen officers and men.
U.7-U.11.
(Completed 1914. Delivery doubtful.)
These five vessels are of the Krupp-Germania type, and are similar to those completed for the German Navy in 1912–13. They are large sea-going submarines with a submerged displacement of 800 tons. They are propelled on the surface by heavy-oil engines of 1,200 H.-P., and when submerged, by electric motors of 500 H.-P. Their speed is 14 knots and 9 knots, above and below, respectively. The surface range of action is 3,000 miles, and the submerged endurance 120 miles at economical speed.
Their armament consists of two bow and two stern torpedo tubes, with eight torpedoes, and one 14-pdr. quick-firing gun and two 1-pdr. high-angle guns, for defence against hostile destroyers and air-craft. Their complement is twenty-five officers and men.
One or two Austrian submarines are supposed to have been sunk by the Allied Fleet during the first few weeks of the war, but exactly which vessels they were is not known.
Several other submarines have been ordered in foreign countries for the Austrian Navy, but cannot be delivered while the war lasts.