Kaschalot Class.

(Completed 1909–12.)

These seven vessels are among the most modern submarines in the Russian flotillas. They are of the Holland-Bubnoff type, and have a submerged displacement of about 500 tons. Heavy-oil engines of over 1,000 H.-P. drive them at a maximum surface speed of 16 knots, and electric motors of 550 H.-P. give them a submerged speed of just over 10 knots an hour. Their surface cruising range is about 3,000 miles. Their armament consists of two bow and one stern tube with six 18-inch Whitehead torpedoes. They are also fitted with a small, quick-firing, high-angle gun for defence against air-craft. Their complement is 21 officers and men.