The K class pursued the idea of a cruising submarine with oil-fired steam propulsion. That machinery imposed substantial size, weight, and complexity, including two funnels passing down into the submersible hull. Diesel engines were already available in quantity, making steam an avoidable choice in this criticism. Contemporary submarines were still essentially submersible torpedo boats, but that operating pattern did not justify the machinery burden. Keyes, Jellicoe, and Beatty supported the class, while Fisher opposed steam propulsion for submarines in 1913. The last boat remained in service until 1931.
Chapter · 1:19:14-1:22:27
Steam machinery burdened the K-class submarines
Steam propulsion imposed a heavy machinery installation and two funnels on the K-class cruising submarines despite the availability of diesels.