The Merchant Navy class were a radical new design of Southern steam locomotive designed by Oliver Bulleid. They incorporated a number of novel features such as an all-steel welded boiler, chain-driven valve-gear, inside motion enclosed in an oil bath, ‘air-smoothed’ casing and a steam generator under the cab to power cab and headlights. With its 4-6-2 configuration and 6ft 2in driving wheels, the class were most suitable for hauling express passenger trains, but were officially designated as mixed traffic and during WWII it was not uncommon to see Merchant Navy Class locomotives hauling freight and military trains. It’s concession to wartime conditions were that the parts could be easily manufactured. The class were named after shipping lines, with the fifth being named after the Canadian Pacific Line.
Canadian Pacific is now the oldest survivor of the class. The locomotive was built in 1941 at Eastleigh Works, entering service on 13th January 1942. During its time on the Southern Railway, it was numbered 21C5, a unique numbering system for the UK introduced by Oliver Bulleid.
The numbering system works as such:
2: Number of leading bogie axis
1: Number of trailing bogie axis
C: 3 coupled axles
5: Engine construction number (it was the fifth Merchant Navy Class to be built)
Clement Attle’s Transport Act saw the big four (and various other smaller) railway companies in Britain amalgamate and nationalise to create British Railways that formed in 1948. This lead to a number of changes for Canadian Pacific including a new more conventional number - 35005. Aside from numerous livery changes, its biggest change was to come in 1959 when it was rebuilt to overcome numerous mechanical issues.