K XIV-class submarine

The K XIV class submarine was a class of five submarines, built for the Royal Netherlands Navy. Used for patrols in the Dutch colonial waters. The class comprised K XIV, K XV, K XVI, K XVII and K XVIII. The submarines diving depth was 80 m. Three of the boats were lost in World War II.

Design
The K XIV class submarines were the last submarine design made by J.J. van der Struyff, at the time chief engineer of the Royal Netherlands Navy. They were a improved and englarged version of his previous K XI design. The submarines of the K XIV class were fully riveted and their pressure hull were made of 14 mm thick steel. To increase their seaworthiness the pressure hull was plated with 3 mm thick steel. As a consequence the K XVII was 200 ton heavier than the submarines in the previous class, the K XI class submarines. However, this did allow the submarines of the K XIV class to dive as deep as 80 meters, while withstanding the enormous water pressure. Between the plating and the pressure hull there was room for the ballast tanks, fuel tanks, anchor, torpedo tubes and more.

Armament
The primary armament of the K XIV class submarines consisted of eight torpedo tubes that had a width of 53.3 cm, which made the K XIV class the first Dutch K class that were equipped solely with 53.3 cm torpedo tubes. There was also room aboard for a total of fourteen torpedoes, with 8 being in the torpedo tubes and six for reloads. In addition, each boat was equipped with a single 8.8 cm deck gun and two 40 mm Vickers anti-aircraft guns.

Propulsion
The K XIV class submarines were equipped with two 8-cylinder four-stroke MAN diesel engines that could produce 1,600 (combined 3,200 ) shaft horsepower and drive the two screws of the submarine to a maximum surface speed of 17 knots. Besides the two diesel engines, the submarines also had two electric motors that each could produce 430 hp and 192 cells batteries with a capacity of 4740 Ah. This allowed the submarine to operate solely on electric power for 3 hours. The maximum underwater speed was 9 knots.

Sensors and processing systems
The submarines of the K XIV class were equipped with passive sonars made by the German firm Atlas-Werke. As part of this sonar system the boats had two rows of six hydrophones, with one row being placed at the stern and the other row at the bow. The K XIV class was also the first submarine class that were equipped with a retractable radio antenna, in Dutch called radioperiscoop, which was installed behind the two normal periscopes. The retractable radio antenna used the same mechanic as a normal periscope to move upward and downward.

Layout
The submarines were divided into six compartments. The first compartment at the front contained a room with four torpedo launchers which were loaded during wartime, while there were also four reserve torpedoes stored. The room also acted at the same time as sleeping accommodation, galley and mess for the crew. In the second and third compartment the batteries were stored, and also contained the sleeping accommodation for officers. The fourth compartment was the nerve center of the K XIV class submarines, since this was the place where all control panels, instruments and command tower were located. The command tower was made of thick and pressure-resistant steel. The fifth compartment contained the machine chamber and thus the diesel motor. The sixth, and last, compartment was located at the back and had two torpedo launchers and the electric motor. There was also space for two reserve torpedoes. To enter the submarines six water resistant shutters were built. The submarine also had one twin external trainable mount amidships that hosted two torpedo tubes.

Modifications
Between December 1942 and May 1943 the K XIV and K XV were refitted at the Philadelphia Naval Shipyard. During this major refit the bridge of both boats were reconstructed, which resulted in the loss of the forward 40 mm anti-aircraft guns. Furthermore, the mounts for the two external-traversing torpedo tubes were removed. As a result the sideview of the modernized boats showed a great resemblance with the boats of the O 21 class.

Boats
The boats were built by two different shipyards in Rotterdam. K XIV, K XV and K XVI were built by Rotterdamsche Droogdok Maatschappij and K XVII and K XVIII at the Wilton-Fijenoord shipyard.