1958 BR details:
BR Nos; 45500-45551.
Location; Main lines of the Midland Region, particularly ex-L.N.W.R.
Origin; L.M.S. Introduced; 1930 Designer; Sir Henry Fowler.
Driving Wheel; 6 ft 9 in. Bogie Wheel 3 ft 3 in.
Weight; 123 tons 9 cwt. Length; 62 ft 8 3/4 in.
Boiler Pressure; 200 lbs. sq. in. Cylinders [3]; 18 in. x 26 in. Tractive Effort; 26,520 lb.
Coal; 5 1/2 tons. Water; 3,500 gals.
Classification; 6-P.

Notes: The history of these fine engines encapsulates much of the history of LNWR and LMR engine development from pre-WW1 onwards. A 3-cylindered rebuild by Fowler of the old London and North Western 'Claughton' class which was introduced in 1913, most all were described officially as 'rebuilds' but were in fact new engines. Few original 'Claughton' parts were used, even in the first two engines. Some names, wheel-centres and whistles were transferred.
Between 1946 and 1948, 18 engines were rebuilt by H. G. Ivatt with Stanier 250lb boilers, smaller cylinders and double chimneys, resembling the rebuilt 'Royal Scot' class.
The 'Claughtons' had done some fine work on the LNWR and LMS but had some weaknesses in maintaining good work capacity between servicing, and required skilled crews for their 'best'. With the success of the 1927 'Royal Scot' class the need for effective general-purpose express engines was met by the new Claughton 'rebuilds' from 1930-on.
Like the Scots the new engines were very successful from new, and became known as 'Baby Scots'. After 1937 they became known as the 'Patriot' class after the re-naming of class leader No.5500.
Five more of the class were on order, but 5552-on were built as the first of the 'Jubilee' class. The whole Patriot class was well-liked, reliable and hard-working, being used on all types of trains, all 34 unrebuilt engines lasting until 1960, and the few last withdrawn late in 1962, some rebuilt versions lasting until 1964.
45503 was based at Crewe during her BR days, until withdrawal in August 1961.