Book excerpt: Originally printed in 1946, The Fleet Type Submarine series of technical manuals remains unparalleled. Contained in its pages and those of the companion texts are descriptions of every operating component aboard a fleet boat. Submarine Distilling Systems Navpers 16170, was originally written to acquaint crewmen with the mechanisms used to replenish the sub¿s supply of fresh water. These systems are important not only for providing water for cooking and drinking purposes, but because fresh water provides cooling for the Diesel engines, and serves as a vital agent for battery and steam boiler systems. This manual includes a description of how water is distilled, and discusses its use aboard the boat. It uses the Model S and Model X-1 systems as examples, detailing their operation, maintenance, and inspection.