Z-39

History

Z39 was a Type 1936A (Mob) destroyer built for Germany's Kriegsmarine during World War II. She was laid down in August 1940 and completed three years later. Her anti-aircraft armament was increased extensively during the war. She served with the 6th Destroyer Flotilla her entire German career, which she spent escorting transports in the Baltic Sea, laying mines, and bombarding land forces. She served with a total of three different countries: from 1943 to 1945 with the Kriegsmarine as Z39, from 1945 to 1947 with the US Navy as DD-939, and from 1948 to 1964 with the French Navy as Q-128.
Over her German career she laid numerous barrages of mines in the Baltic Sea, and bombarded Soviet forces several times. In the last months of the war, Z39 helped escort steamships, which were evacuating German soldiers and civilians from Eastern Europe to Denmark. She was damaged twice, once from Soviet planes, while in Paldiski, and the other time from British planes, while in Kiel. At the end of the war, she was transferred to the United States Navy, where she was experimented upon to test her equipment, especially her high-pressure steam propulsion plant. After the US Navy deemed her obsolete, she was transferred to the French Navy, where she was cannibalized for parts, and made into a pontoon for minesweepers.

Design

The Destroyers of the 1936 A class were the last class of Destroyers designed by Germany before the outbreak of World War 2.

Being slightly larger than the preceding 1936 class, they were designed to be more stable in the seas. The hull was more strengthened, and a bulge was installed at the bow to improve seaworthiness. Latter was removed however as it proved to have negative side effects onto the bow. A double rudder allowed better maneuverability than on the 1934 or 1936 classes.

The result was a 127m long and 12m wide hull with a draft of up to 4.65m. The displacement ranged between 2,600 and 3,700 tons depending on the loadout and her engines with a combined 70,000 shp would allow for a speed of 36 knots, however during speed trials up to 38.5 knots were achieved. The fuel capacity gave these ships a cruising range of up to 2500 nautical miles. The crew for a single vessel would consist of 11 Officers and 320 men.

What made the 1936 A class stand out from all Destroyers was their main armament. The 15cm L/48 was gun which was unique among other nations, and the biggest gun of it’s time that was mounted on Destroyers. Being tested on the 1934 class Destroyer Z-8 Bruno Heinemann, those guns were supposed to counter new French and British Destroyers, as well as allowing the 1936 A class ships to serve as scout units and to compensate for the always problematic lack of Cruisers. There were two mountings available on the 1934 A class, a single mount and a twin turret. Other than the number of guns in these mountings they also differed in terms of gun elevations. The single mounting allowed for 30° elevations, whereas the twin turret could elevate up to 65°! Planned for every ship were one twin mounting on the bow, and three single mountings at the rear of the ship with two being superfiring and the third one facing forward. The only exception for this layout being Z-28, which was intended to be used for fleet command and rather used four single mounts in two superfiring pairs, one at the bow and one at the aft. The Torpedo armament did not change with two quadruple 53.3cm Torpedo Tubes, and the initial anti-aircraft armament consisted of two twin 37mm Flakzwilling 30 and five single barreled 20mm FlaK 38.

Availability issues with the 15cm twin turret meant that during the first years only four 15cm guns in single mountings were installed. However, even the lighter armament showed that the bow was insufficiently designed and very wet in the rough seas, which were very common on the Northern Atlantic. When the twin turret was eventually installed in 1942 the issues with these guns became more noticable. With the twin turret weighting more than four times that of a single mount, the foreship was even more prone to being wet. As the turret was not properly designed to be waterproof the electrics would often fail in heavy seas and the fixed ammunition meant that a lot of physical effort was required by the gun crews to reload the gun, which would hamper the ability to maintain a high Rate of Fire during combat. With the threat from aircraft rising throughout the war, it was deemed as necessary to increase the anti-air-armament of all Destroyers, which resulted in the so-called “Barbara-program” which included additional AA-guns for almost all ships in 1944. The proposed changes for the 1936 A class ships was the removal of a 15cm single mount, and a completely new AA armament of twelve 37mm M42 and eighteen 20mm FlaK 38 guns, with the addition of 8.6cm AA rockets in four single launchers.