Hi Sprid,

>Watching a repeat of a Fred Dibnah tour with his 1912 traction engine I was surprised to see when he had a problem with a front wheel that it ran on a greased axle with a phosphor bronze hub bush. Then it ocurred to me that I'd never seen a ball or roller bearing used anywhere on a steam engine or the running gear in spite of ball bearings being used on bicycle hubs since 1869.
>(I also don't recall noticing any being used on steam trains either).

Mmmm ... but it might've been a matter of scale - there might've been manufacturing problems scaling up a pushbike ball bearing to steam locomotive-size in the 1860's/1870's? Afaik, it was either just before or just after WW2 that certainly the British railway company CME's became interested in the widespread use of particularly roller bearings on locomotives and rolling stock, I suspect because their lower rolling resistance compared to greased bushes could make a significant-enough difference to running costs?

>Research on the web hasn't produced any specific references other than industry was slow to change

Again, bear in mind locomotives and rolling stock had a significantly-longer life - countries that didn't have the ignorant meddling fcukwits in government that this country had in the 1950's saw particularly steam locomotives built in the 1920's and 1930's not considered life-expired 'til the 1970's.

However, when money was available to BR in the early 1950's to construct new steam locos., they were built in existing long-established works and the priority was to get 'em built, not spend too much time incorporating 'new' technology.