48151: Improved Balancing.

Seeing the images of 48151 at speed yesterday prompts me to ask if anyone happens to know whether 48151 was one of the engines with improved balancing of the reciprocating masses for working class E express freights in BR days, or whether the improved balancing has been applied in the preservation era by WCRC?

Thanks

46118

 

48151 was one of the engines that had the improved balancing.

 

From memory when 8151 was at Embssay it's first preservation home you could see a star painted above the number which was the indicator that the wheels/motion had, had the balancing improved so she could run at higher speeds.Whether Smiffy has restored the engine as such I'm not sure, be nice to think he has......

 

A question for those in the know, what was entailed by improving the balancing of 8fs? Thanks in advance from a luddite.

 

I think 48305 has the improved balancing too...?

 

I can only add a little by quoting from the Bradford Barton "Stanier 8F" book: "The star on the cabside denotes that 50 per cent of reciprocating weights were balanced, a modification latterly made to most of the class to allow them to work class E express freights (55 mph maximum) more smoothly by reducing substantially both fore and aft oscillation and the "nosing" tendency".

Over to the technical experts as to "how" this balancing was carried out. A "works" procedure?

My own recollection of BR steam days was somewhat different to that quoted above, I dont recall "most" of the 8F's I saw having the "star" on the cabside. The 8f's I saw were mainly Toton/Heaton Mersey engines engaged on the coal drags from the Erewash Valley to Manchester. Unless they were so dirty that the "star" was obscured!

 

48773 was 50 mph rated when she was on the mainline and I would imagine she also had the balancing to allow such a speed.

 

The balancing was done at main works, since sheds had no facilities to do this. It entailed adding more weight between the spokes of those engines fitted with large plates on their wheels (the plates were only covers, not the balance weights, which were added inside these but wouldn't occupy all of the plates' areas); it was more complex with those wheels which had the weights cast in instead of being added later. Provided that the wheels stayed with the engine, or that it received a similarly modified set of wheels, the 50% balance would be retained and the cabside star applied.

I can confirm that 8233/8773 had 50% reciprocating balance in BR days, which it carried through to preservation and still has today.

 

BR, 1967 pic here:

http://andrewstransport1960.fotopic.net/p56995963.html

Cheers

AN

 

Whereas coach wheels were balanced in a similar fashion to Kwikfit.
The wheelset was coupled to a machine then spun up.
A gauge then indicated weight required and at what position it was to be fitted.
Then out with the 1/2 inch drill, drill a hole under the disc rim and fit a Bolt, weight and nut then flatten the threads to secure the nut. Spin again to recheck.
Guess what I used to do at BREL York

 

Yes, but there are no reciprocating masses on a coach - unless something's gone SERIOUSLY wrong!

 

Would this mean that the hammer blow was increased? Presumably there must be a downside?

 

Yes, it would. But the hammer blow rises with the square of the rpm. with an 8F, 50 mph eqates to 297.5 rpm; a Black Five at 80 gives 336 rpm so the hammer blow was probably less.