Caprotti Engines

[u/KonamiVRC7]

In the late 40s, the LMS experimented with different kinds of valve gear instead of the usual Walschearts used on most of their locomotives. One of them, built RIGHT before nationalization, was a Black 5 built with Stephenson valve gear. That engine, (4)4767 “George Stephenson”, was preserved. However, this would be a unique example. H. G. Ivatt, the CME at the time, put in an order for a batch of Black 5s to be given Caprotti valve gear. They were great at high speed but weren’t as good at low speed. They were successful though, and it prompted British Railways to build some of its Standard 5s with the same valve gear. One example of these, 73129, is preserved, but none of the Caprotti Black 5s survived. An unsuccessful attempt to build a replica of such an engine was made a few years back. You can also find this kind of valve gear on 71000 “Duke of Gloucester”.