Coupled wheels - what if the wheels are slightly different sizes?

I never had the veracity of the story confirmed so glad you can put that one to rest.

 

The following Wikipedia page may help answer the question. Scroll down to the paragraph headed "Forces on wheels, creep"

https://en.wikipedia.org/wiki/Adhesion_railway

 

I think it was one of the LMS loco engineers who recalled seeing an American loco coming into a depot with a broken tyre, and having a new wheelset fitted in record time and out on the road again - no thought of matching the wheel diameter though!

Dave

 

Roland Bond, maybe? I seem to remember reading a chapter in a book of his about a tour round North America, in which he was by turns hugely impressed and absolutely horrified by various aspects of American practice.

 

There's a video of doing this on the loco, as shown in the still, but I failed to track it down when I searched. Plenty use of a sledgehammer to get the tyre on and G clamps to hold it in place whilst it cools.

 

I hate to think what the balance across the axles is. The SVR learnt that just changing a tender spring without re weighing can lead to a derailment. Any serious maintenance with the running gear and its over the weighing system