Israel's chronic lack of AFV's on one hand and it's phenomenal victory in the 1967 Six Days War on the other, brought the IDF to adopt captured enemy vehicles for it's use.
The Arab armies lost hundreds of fighting vehicles - mostly Egyptian T-54 and T-55 MBT's which were abandoned by their crews.
The first combat use of captured tanks by the IDF was in operation "Raviv" (8-9 September 1969) - an amphibious raid across the Suez channel. Three T-54 tanks and six BTR-50 apc's were used to wreak havoc behind the Egyptian lines (also see the "Operation Raviv" scenarios).
In order to allow for greater standardization in it's armor corps, the IDF initiated a conversion program. The captured tanks were re-engined and re-gunned (with the standard 105mm gun used in the Centurion and Patton MBT's). The converted tanks were named Tiran 4 and 5 (for T-54/T-55).
Tirans were used along Israel's borders -mostly at the Suez front. In the 1973 Yom Kippur war Tirans were used in combat in the southern front - against Egyptian T-54/55 (which caused a lot of confusion).
During the 1973 war the IDF managed to capture the newest Soviet MBT of the time - the T-62. Plans for conversion into Tiran-6 were made, but the realtively small numbers captured, together with the massive numbers of M-60 MBT's supplied by the US brought them to a halt (several prototypes were made, however).
During the early 1980's Tiran MBT's were withdrawn from active duty. Some were sold to foreign states (including, reportedly, to Iran during it's war with Iraq), some were given to Israel's allies in Lebanon and some were converted into the Achzarit APC.
Ironicaly, some of the Tirans supplied to the SLA (South Lebanon Army) militia fell into Hizballah hands after the Israeli withdrawal from Lebanon (June 2000). In a way, those tanks made a full circle...
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