Both Tromp-class frigates entered service in 1975/76. Their primary task was area air defence. They acted as flagships for the COMNLTG (Commander Netherlands Task Group). Because of their large radome (wich housed a 3D radar antenna) the ships had the nickname “Kojak” after the bald-headed actor in the famous action crime tv-series. Both Tromp-class frigates entered service in 1975/76. Their primary task was area air defence. They acted as flagships for the COMNLTG (Commander Netherlands Task Group). Because of their large radome (wich housed a 3D radar antenna) the ships had the nickname “Kojak” after the bald-headed actor in the famous action crime tv-series. The Tromp class guided missile frigates were the first highly automated all gas turbine propelled vessels in the RNlN and were considered as one of the most advanced designs of the mid-seventees aera. The prominent radome accommodates a for that time state-of-the-art Signaal multi-target 3D radar for long range surveillance and tracking of air targets. The Tromp Class AAW Command Frigates were built to serve as flagships for the RNLN's ASW squadron. Tromp, along with the British Type 42, were among the first guided missle ships built for the singular purpose of AAW.