(De Ruyter ship image). The Tromp class began to be built in 1971 and had all the technical and electronic advances of the time. The hull and superstructure under the huge radome are made of steel and the rest of the ship is made of aluminum alloy. They were ships with excellent seaworthiness, and like the French Suffren-class destroyers, they had non-retractable fin stabilizers in addition to a large beam and a high free-board for service in the rough waters of the North Sea.(De Ruyter ship image). These destroyers incorporated a GOGOG-type propulsion system, consisting of the installation of four gas turbines in the style of the British ships of the time. Two of the turbines (Rolls Royce Tyne) were used for economy cruising speed while the two main ones (Rolls Royce Olympus) were used for speeds above 18 knots. Olympus turbines were down-rated to improve gas-generator life and reduce maintenance. These ships had double rudders with independent hydraulic steering gear for each one and although they operated electrically synchronized, they could also operate independently.(Tromp ship image). Special care was taken to reduce the acoustic signal of the ship, and for this the machinery rests on double silent blocks as well as silencers were installed in uptakes and intakes. All machinery is controlled from a highly automated room, located next to the operation room. Two “bifid” type chimneys were installed to reduce the effect of hot exhaust gases on the electronic equipment. In addition, they had independent air conditioning and ventilation equipment for each area of the ship and also had NBC protection.(Tromp ship image). These two ships had a modern electronic crew headed by the Hollandsee Signaal Apparaten (HSA) SPS-01 air/surface 3D exploration radar, which, like the French Suffren class destroyers, was installed inside a huge radome on top of the bridge, which gave them the same unique appearance. This system earned them the comical nickname “Kojak” in reference to a television series starring Telly Savalas. This radar had the ability to indicate the height of the detected object, something unique at that time. It also had the Dutch SEWACO-1 tactical data system that was in charge of data coordination and arms control.(De Ruyter ship image). In addition to the main radar, it also carried two Raytheon SPG-51C fire control radars, an HSA WM-25 aerial search radar, two Racal Decca 1226 navigation radars and a CWE-610 hull mounted active medium frequency sonar for search and attack. They also had extensive countermeasures such as an RPZO radar interceptor, a Ramses jammer, an AN/SLQ-25 “Nixie” decoy torpedo and four SBROC Mk.36 chaff dispensers.(Tromp ship image). These destroyers must have installed the British Sea Dart anti-aircraft system in return for the Royal Navy’s acquisition of HSA 3D radars for the Invincible-class aircraft carriers and their Type-82 Bristol class destroyers escorts. Finally the agreement did not take place due to the price and the enormous size of the system and it was decided to install in its place a single American Tartar/Standard Mk.13 launcher located aft together with 40 Standard SM-1 MR medium-range surface to air missiles housed in an under-deck magazine.(Tromp ship image). The armament was completed by an 8-cell Mk.29 launcher for Sea Sparrow short-range anti-aircraft missiles, of which it carried 16 missiles in magazine located forward, two quadruple Harpoon anti-ship missile launchers, a twin 120mm Bofors dual purpose automatic gun, two 324mm Mk.32 triple torpedo tubes for Mk.46 anti-submarine torpedoes and a WG-13 Lynx ASW helicopter. Later a 30mm seven barreled CIWS Goalkeeper was installed on the F-806 De Ruyter. The twin 120mm guns belonged to the D-811 Gelderland destroyer of the Holland class which had been scrapped in 1974. Of course, the guns were completely modernized and automated.(De Ruyter ship image). The main mission of these destroyers was to lead escort or anti-submarine groups, which is why these ships had supplementary accommodations for an admiral and his staff. Thanks to the great automation of the equipment, these destroyers had a crew of 305 people, 3 times less than the cruisers they replaced. In 1985 both ships received a modern SCOT 1D STACOM satellite communications system and Data Links 10 and 11 were installed. Both vessels provided excellent service and were highly appreciated by their crews, being retired in 1999 (F-801 Tromp) and 2001 (F-806 De Ruyter).
