norbitonflyer
Established Member
I've already covered sub-10 year lifespans. Slightly different, as we're talking about first withdrawal rather than extinction, but those which were still intact after 20 yearsThat was pretty standard for 50s and 60s diesel classes, of the 40 or so classes built in that period, probably 75-85% of classes had seen the first (non-accident related) withdrawal of a loco prior to it's 20th birthday.
The various pre-war LMS shunter classes (12xxx) existed for more than 20 years, the last variant (later Class 11) being introduced in 1945 and the first withdrawals being in 1967. However, as they were still being built in 1952, many of them had much shorter lives)
Shunters do tend to be long lived, but main line classes which were still intact twenty years after introduction are harder to find. Even Class 20, introduced in 1957 and still going today, had lost six members by the beginning of 1977. Class 31, also introduced in 1957, came close with only 31150 and eight of the non-standard pilot-scheme subclass gone by the beginning of 1977. The Deltics also came close, introduced in 1961, the class was still intact at the beginning of 1980, but three of them had been withdrawn by the end of that year.
Class 37 - Introduced 1960. With the exception of D6983 which was written off in an accident in 1966, the class remained intact until 1987
Class 43 (HST) Introduced 1976. The first withdrawal (43173) was in 1998, although that particular vehicle was only 17 years old)
Class 45 - Introduced 1960 - all except 45067 (withdrawn 1977) still in service in 1980
Class 47 - Introduced 1963 - Three examples - D1671, D1734 and D1908 scrapped in the 1960s but otherwise intact well into the 1980s
Class 50 - Introduced 1967 - first withdrawals (50006, 50011, 50014) in 1987
Class 70 - (SR Booster electric locos) Built between 1941 and 1948, withdrawn in 1968
Class 73 Introduced 1962 - E6027, 73115 and 73111 were scrapped after accidents in 1972, 1982 and 1991 respectively, but withdrawals only really started in 1998.
Class 76 - Leaving aside the 1941 prototype, the class was introduced in 1950. The first withdrawls (including the prototype) were in 1970, when the only iine on which they could operate lost its passenger services.
Class 81 - Introduced 1959. Two scrapped in 1968 following accidents, otherwise intact until 1984
Class 82 - Introduced 1961, one scrapped in 1971, otherwise intact until 1983
Class 85 - Introduced 1961, first withdrawal 1983
Class 86 - Introduced 1965, first withdrawals 1986
Class 87 - Introduced 1973, first withdrawals 2003
Post 1985, locos seem to be longer lived - I don't think there have been wholesale withdrawals of any of classes 57,59,60, 66 or 67, all of which have been around for over twenty years now. (35 for the Class 59s), and classes 90 and 91, both introduced in 1988, were still intact after thirty years. all
An exceptional case is the Class EB1 electric locos built for the North Eastern Railway in 1915. These were not withdrawn until 1950, although they did not operate in normal service after the line they were built for was de-electrified in the 1930s.