Technological Showcase: Gier-class Sloop
Having the Batavian Navies Naval Staff settled on dividing destroyer types into defender (gun) and attacker (torpedo) variants, Secretary Comptroller Dumas decided that he wanted a general-purpose sloop, convertible between escort (ASW) and minesweeping. He asked Chief Constructor Van Haarlem for a combination of three types: colonial gunship, convoy escort and coastal minesweeper. Constructor replied that harbour and coastal minesweeping was incompatible with the other two because a ship designed to fulfill these would displace over 1,500 tonnes and draw more than 2.5m. However, if the ship was allowed to grow well beyond this figure, she could carry ASW gear and minesweeping gear at the same time, while also being able to perform as fast oceanic sweepers for the fleet. Commander, NEI, Admiral Garland requested to implement a new innovation he was sponsoring, experimental Siemens-Spyker active stabilizers, which promised to improve gunnery on small, lively platforms. The designers provided about 2.5m in length for this purpose. This decision in turn transformed into a cost spiral as the Staff took turn to add more innovative equipment that had been witheld from the austere destroyer construction of the late ‘20s. In July 1934 Comptroller allowed growth to a maximum of 2,000 tonnes and curbed the number of ships to three, in order to evaluate the equipment implemented before releasing it for future construction.
This convoy escort was by far the largest yet, and was to be powered by a steam plant using just one destroyer boiler feeding two turbines for a total of 6,000hp, for a design speed of 19 kn, considered necessary when pursuing a submarine (It was soon to be known that the latest Louisiainnean cruiser submarines could easily reach 20kn surfaced). She would end up displacing 1,960 t standard on 95m and 2,400 t deep. Standard displacement included two stern depth charge racks and a Y-gun (minimum ASW compliment for an escort) and also minesweeping gear (two paravanes). If required, she could land the minesweeping gear and ship additional depth charges and stick bomb launchers. The ship could not meet the minesweeping requirement because she drew 3.9m deep. Nevertheless, they were still earmarked to supplement destroyers on minesweeping duty.
The design was submitted in January 1935. A powerful 5.5” (14.2 cm) 50 caliber gun developed from the 42 caliber gun of the light cruisers was chosen, at least three guns would be installed. This new gun used a fully RPC mount that elevated to 65° for anti-aircraft fire. It had integral hoists served from a shell room below the mount, one for shells and one for propellant cases. The gun breech was served by a spring rammer that was cocked pneumatically and recocked by the gun’s recoil. The guns were directed by a Model 1933 director which was triaxially stabilized and included it’s own rangefinder. Concerns about the main battery’s ability to deal with aircraft at medium and short range prompted the addition of two twin 7.1cm/42 guns, these would eventually be replaced during construction by twin 3.9cm an 2.6cm autocannon, only a single 7.1cm gun left to fire starshell.
ODSI (SONAR) was clearly essential for the escort mission, and was provided for including an operator room below the bridge. The desired depth charge battery had increased to a six charge pattern, and could be achieved by adding lateral rails or a second Y-gun; provision for this was designed but no ship was ever fitted this way thanks to the implementation of newer ahead-throwing weapons.
Minimum performance was 7,500nm at 12kn with four months’ stores, with a new ideal speed of 20kn when operating against a submarine. The ship had to be able to maintain a speed of no less than 17kn for long periods, to give her a dash capability against a submarine. For good maneuverability the ship needed twin screws. Captain Martadinata of the Naval Staff objected to the low speed; he wanted more than 20kn, but Comptroller objected that treaty restrictions had to be considered still in effect. Consensus was achieved when internal combustion engines were chosen in order to provide quick acceleration, speed in excess of 20kn was to be kept by governing the engines. The ship was no longer considered as a cheap expendable escort or gunboat, and the design was now revised to be powered by four license-built Sulzer diesel engines of 2,000 hp, two on each shaft.
This 1936 Convoy Escort became the Gier
class. Three were built under the pre-war 1936 program. A modified version was ordered in 1938 mobilization programme, ten were laid down but one was cancelled once mass production designs started replacing previous, more expensive designs. First of class Rep. Sch. Gier
was launched on the 25th of November of 1936 and commissioned on the 29 of May 1937 by Marine Etablissement in Amsterdam. While on speed trials, the ship achieved 20kn on standard displacement while pushing 6,732 hp total, further acceleration was not recorded. Gunnery trials while under support of the active stabilizers showed increased efficiency over destroyer platforms, comparable rather with older open-mount light cruisers. After practice, Gier showed impressive accuracy while demonstrating its abilities to the Chairman of the Council of Guilds of the Netherlands, Dr. Axel Van Buren and his retinue. Later that year Gier would compete against the cruisers of the home squadron and beat Enno Doedes Star
by one point, earning it a gunnery efficiency R
badge, a first for an auxiliary or flotilla craft.
Gier was awarded to the Batavian Indies Navy and performed station duty at various locations starting in 1938 on the Nieuw Zeeland station. This plate depicts Gier
as seen in January 1940 while serving on trade protection duties while in the Formosa station. She is camouflaged in Dazzle Pattern 7B. She is equipped with a half ASW compliment of two depth charge rails with six bombs each, and two Y-gun with twelve bombs total. She also carries a half minesweeping compliment of four paravanes. Her foremast has a Klok-B air warning radar, her main battery director is fitted with Plas-C gunnery ranging radar and her 3.9cm gun mount has an integral Plas-B radar on a triaxially stabilized mount. The 7.1cm starshell gun, 2.6cm gun mount and 13.2mm machine guns weren’t slaved to directors but could receive orders from the target markers on the bridge wings next to the main battery director. Her anti-aircraft armament proved to be insufficient and she was sunk by bombers while operating off of Quelpaert in August 1940.