In 1924 Charles
Collett responded to the Running Department's request for a more powerful mixed
traffic engine than the 43xx Moguls by rebuilding one of Churchward's 'Saint'
4-6-0s (No. 2925 'Saint Martin') with 6ft. diameter coupled
wheels. In 1928, after four years of extensive evaluation, the first of 258
production engines was introduced; they had several differences from the prototype
including increased boiler pitch, reduced bogie wheel diameter, outside steam
pipes and modified motion and frames.
which can be built without modification from this kit are Nos. 4901-5920,
5901-5920 an alternative set of coupling rods will be required which are
When built, the
first 20 engines, or so, were paired with second-hand 3500 gallon tenders of
standard Churchward design. Many,
but not all, from 4922 up to around 4958, were paired with new Collett 3500
gallon tenders and from 4961 onwards new 4000 gallon Collett tenders became the
norm, although some others had Churchward tenders.
Subsequently the Collett 4000 gallon tenders were standardised for the class,
although this process was very protracted some engines not receiving this tender
until after the second World War. Hawksworth tenders found their way onto a
number of the engines as tenders were exchanged in the late 1940s and 1950s.