sentences:  The third-batch S-class boats were fitted with either a Type 129AR or 138 ASDIC system and a Type 291 or 291W early-warning radar.HMS "Stonehenge" was a third-group S-class submarine and was ordered as part of the 1941 Naval Programme on 3 August 1941.She was laid down in the Cammell Laird shipyard in Birkenhead on 4 April 1942 and launched on 23 March 1943.