|Fowler 4F Loco Add-On|
|Availability||Currently available on Steam|
Designed by Henry Fowler, the 4F class of 0-6-0 steam locomotive was designed for medium freight work with the London, Midland & Scottish Railway (LMS). They accrued the nickname "Duck Sixes", derived from their wheel arrangement.
The 4F was based on the 197-strong Midland Railway 3835 Class of 1911, with only a few modifications, primarily the adoption of left-hand drive in favour of right-hand drive. They originally had been designed by Henry Fowler, who from 1925 became Chief Mechanical Engineer of the LMS.
Midland Railway locomotives were notorious for their short axle-box bearings, which were prone to overheating. Why this poor design feature was perpetuated is a complete mystery but, unfortunately, the LMS 4F inherited it.
The LMS constructed 530 of the locomotives between 1923 and 1928, numbered sequentially from where the Midland engines left off from 4027. A further 45 examples were reluctantly authorised by William Stanier in 1937 at the behest of the operating department. All entered British Railways stock in 1948, where 40000 was added to their numbers.
Withdrawals of the class started slowly in 1954 and began in earnest in 1959. The class was finally retired in 1966. and scrapped. Three LMS-built 4Fs survive, with the first-built LMS 4F No. (4)4027 being part of the National Railway Collection. In addition, one Midland 4F, No. (4)3924 has also survived.