anchor. Much of the internal pipework was steel rather than copper. The first Group Three boat was P311, launched on 10 June 1942. Welding gradually replaced riveting and some boats were completely welded, which gave them an improved rated maximum diving depth of 350 ft (107 m). Nine submarines were ordered under the 1940 Programme; P311 (lost, probably to Italian mines, before her name Tutankhamen was formally assigned) Trespasser Taurus (to the Royal Netherlands Navy as Dolfijn) Tactician Truculent (sunk in collision on 12 January 1950) Templar Tally-Ho Tantalus Tantivy Seventeen submarines were ordered under the 1941 Programme; Telemachus Talent (P322) (to the Royal Netherlands Navy as Zwaardvisch) Terrapin Thorough Thule Tudor Tireless Token Tradewind Trenchant Tiptoe Trump Taciturn Tapir (to the Royal Netherlands Navy as Zeehond (2)) Tarn (to the Royal Netherlands Navy as Tijgerhaai) Talent (P337) "Teredo" Fourteen submarines were ordered under the 1942 Programme, but only five were completed; Tabard Totem (lost in accident on passage to Israel as INS Dakar) Truncheon (later the Israeli INS Dolphin) Turpin (later the Israeli INS Leviathan) Thermopylae The other nine were ordered but cancelled on 29 October 1945 following the end of hostilities: Thor (P349) (laid down at Portsmouth Dockyard on 5 April 1943 and launched on 18 April 1944. However, the war ended before she was completed and she was sold for scrapping to Rees Shipbreaking Co Ltd of Llanelli, Wales in July 1946. She would have been the only ship of the Royal Navy to bear the name Thor, after the mythological Norse god of thunder. Tiara (also launched on 18 April 1944 at Portsmouth but not completed) Theban (P341) Talent (P343) Threat (P344) also four unnamed submarines (P345, P346, P347 and P348). Transfers to Royal Netherlands Navy Four submarines were transferred to the Royal Netherlands Navy in the 1940s. Two were later returned in 1953. Tijgerhaai (ex-Tarn): transferred 1944 Zwaardvisch (ex-Talent): transferred 1943 Zeehond (2) (ex-Tapir): transferred 1948, returned 1953 Dolfijn (ex-Taurus): transferred 1948, returned 1953 Transfers to the Israeli Navy Three submarines were sold to the Israeli Navy in the 1960s. Totem, renamed Dakar, was lost in transit in 1968. INS Dakar (ex-Totem): sold 1965, commissioned 1967; lost January 1968. INS Dolphin (ex-Truncheon): sold 1968 INS Leviathan (ex-Turpin): sold 1965, commissioned 1967 Notes References Clayton, Tim (2011). Sea Wolves. London. Abacus. Mars, Alistair (1971). British Submarines at War 1939-1945. London. William Kimber. T