Design 1047 Battlecruiser - Design - Armament

Armament

The table of characteristics provided by Lt. Jurrien S. Noot for the 19 April 1940 design does not give any armament specifics, as these likely remained unaltered from the earlier 16 February 1940 drawing. This drawing provided the following: a main armament of nine 283 mm guns, a secondary armament of twelve 120 mm dual purpose guns, and an anti-aircraft defense consisting of fourteen Bofors 40 mm guns and eight Oerlikon 20 mm cannons.

Work on the main armament was contracted to Krupp Germaniawerft, which based its designs for the turrets, mountings, and guns of the 1047s on the 28 cm SK C/34 used on the Scharnhorst class. With a 315 kg (694 lb) APC shell, the guns would have had a muzzle velocity of 900 m/s (2,950 ft/s) and a maximum range of 42,600 meters (46,600 yd); 120 rounds of ammunition would have been stowed for each gun, and the rate of fire would have been about 2.5 rounds per minute. The guns would have been able to be elevated to a maximum angle of 45° and trained to 150°, while the loading angle would have been about 2°.

Secondary armament was planned to be twelve Bofors 120 mm (4.7 in) guns in dual mounts. It is unclear whether or not these were an older version of the gun (which had been mounted as the main armament on Dutch destroyers since the 1920s) or an entirely new version. However, the debate is academic as the new guns were developed in the 1940s during the chaos of the Second World War and were unavailable for warships until after the war's end. Detailed specifics such as range or rate of fire are also unknown; had the older gun been used it would in any case have been updated (including the use of dual instead of single half-shield mounts), and the more modern version did not see service until 1950, by which time it incorporated improvements from lessons learned during the war.

Arguably the best light anti-aircraft gun of the Second World War, the 40 mm Bofors was used for air defense both on land and at sea by many of the countries involved, including the Americans, British, Dutch, Japanese, and Swedish. Produced in the early 1930s, it first entered service with the Royal Netherlands Navy when the cruisers Java and Sumatra were refitted in 1934–35. Before the Second World War, Hazemeyer, a Dutch subsidiary of the German company Siemens & Halske, had devised "a very advanced triaxial mounting together with a tachymetric control system" for the 40 mm gun. When the Netherlands fell in 1940, this was brought to the U.K. aboard the minesweeper Willem van der Zaan, where it was copied and put into service as the British Mark IV twin mount. The description of the proposed fire control mechanism for the 1047s, discussed on 6 November 1939, mentions that the 40 mm weapons were "to be controlled autonomously from the gun positions"; this seems to describe Hazemeyer's system, but no direct link is made in sources.

The Dutch Navy had already acquired a quantity of the Hispano Suiza 20mm guns before the war for mounting in torpedo boats and other craft and 6 of these were mounted in the cruiser Jacob van Heemskerck when she made her escape to Britain in 1940. The Hispano fired similar 20x110 ammunition to the Oerlikon but had a higher rate of fire and slightly higher muzzle velocity. The Hispano Suiza however was to prove insufficiently durable for shipboard use and would find its niche as a highly successful aircraft gun.