Bulleid Wheels

A question (because I don't know the answer). What are the advantages of a Bulleid Firth-Brown wheel over a more conventional spoked wheel? On the face of it, it doesn't appear to be a lighter construction and is certainly a more complex pattern-making job. BR certainly didn't perpetuate the design into the standards.

 

One of its major advantages over a spoked wheel is the more uniform support provided to the tyre.

 

Was the BFB wheel pattern derived from continental practice? I can't cite any specific locos off the top of my head, but I'm sure there are many locos in other countries which used similar wheel patterns...USA, Japan...???

 

To all intents and purposes it was a development of the Boxpok wheel patented in the USA.

 

one other feature is that the 'pockets' on the wheel rim collect oil, rain water, sand , u -name ie whilst stood, (and then tip it out onto the motion later no doubt) and are a pain in the but to clean out...

 

You're not wrong there. The bogie, trailing truck and tender wheels are the worst to clean as the pockets are relatively small. Main drivers not quite so bad. Keeping some of our team busy at the moment though.

 

would the drilling of small hole into these (box) pocket(te)s close to the rim really compromise the strength of the wheel ?

This not withstanding surprised BR didnt adopt these wheels for the standards, apart from the fact that they didnt look LMS enough ? or perhaps they would have had to pay the patentees...

 

Some 01 Pacifics where also fitted with box pox wheels in Germany, don't know if there's any documented improvements.

 

According to that great font of knowledge (Wikipedia) 8 01.5s were fitted with boxpox wheels after cracks were found in the spokes of the driving wheels, but were then themselves replaced with spoked wheels due to poor castings.

 

Unfortunately the Bulleid Firth-Brown wheels turned out to be rather prone to cracking - more so, apparetly, than conventional spoked wheels. This may be due to the rather poor quality of the castings produced in the 1940s. The cracks tend to appear around the holes and the bosses, but are (usually) fairly easy to repair by welding. But drilling more holes may not be a good idea !

David



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Sure Dave, drilling more holes usually isnt. In the unlikely event that any more get cast perhaps its a mod that could be incorporated...