4472 wheelsets

I'm surprised that no-one has mentioned the report in this month's "Heritage Railway" that one of 4472's wheelsets has been found to have a "wobble" in its back to back measurements- this is quopted as being up to 1/4", which seems a lot to me but according to reporter Geoff Courtney's "industry source" it would not have been a cause for concern in BR days. Presumably there must have been a specified tolerance then (and now)- can anybody on here say what it as? If it is out of tolerance - and the fact that the NRM are concerned would suggest it is - and ran like that for 22 years since it was last re-tyred it would seem to be a bit of an indictment of both the previous enginnering team and whoever re-tyred the wheels.

 

Visit the National Railway Museum thread on this forum. Plenty of discussion there. Also a few off-topic posts on the huge 6100 Royal Scot thread.
Hope you have a free weekend handy.

 

As said, most discussion on this subject is on the 4472 thread in the NRM section. However, to answer your specific query about limits for wheel 'wobble', Railway Group Standards lay down a maximum of 0.4mm (0.015") for locomotives (see: http://www.rgsonline.co.uk/Railway_...ck/Railway Group Standards/GMRT2466 Iss 2.pdf - page 20) I've been unable to find any info on allowable limits in 'steam days' in the documentation I have..

 

I must admit I'd missed the discussion in the NRM thread, but I've had a look now and found very little in the way of intelligent comment there, the whole thread is mostly about the tired old livery debate.

I find it hard to believe that standards have been tightened by a factor of 15 since BR steam days!

 

A bit puzzled over this one. I was under the impression that replacement tyres were fitted to the wheels, then the whole wheel/axle assembly put in a lathe and the tyre treads machined to the appropriate profile. That way the the tyres cannot help but be parallel with one another. In these circumstance it would be virtually impossible to be anything other. Possible causes in this case - tyre shifted or bent axle?

 

In theory, yes you are correct. What happens if one of the axle centres is damaged or has some grot in it? You will get "wheel wobble".

 

... but the oposite wheel would then be running out of true and I'd have thought 1/4" out would be visible. Regardless of that, though, it doesn't say much for the quality control of whoever was responsible for the error, or for those who accepted the work.

 

if it is only previlent on one side then it must have happened when the tyre was fitted but it would have been noticed when machining the tyre flange or you would think so, so what happened ? did it get sent back to the loco without the restoration team knowing? but surely it would have been noticed , or did the management behind the work know about this and decided to carry on regardless mostly because at the time it wasnt thought of as being a serious enough issue to mean dropping the wheel set back out? but one thing that stands out very clearly is that project management and quality control does not appear to have been very high up on the list of things and have not improoved over the last 22 years i think that the ordinary workers at southall have been badly let down by those suppossed to be in charge is it poor facilities, ie worn out machines, so that turning is hit and miss? or bad management?

 

Without knowing any real detail we are all speculating on the cause and when it happened. If you want further possibilties, it could be that a wheelset has been lifted using short slings around the rim/tyre instead of a cradle or beam and this could quite easily be the cause. Easily done if you don't know. As a matter of interest, when were the tyres last turned?

 

If I understand correctly, the tyre is not quite square on the wheelset, therefore I have another question - how did the LNER secure tyres on the wheels? Presumably not with gibson rings as wouldn't the lack of squareness have shown up when the Gibson rings were fitted?

 

LNER TYRES ARE FITTED WITH HOT RIVETS ,THERE ARE NO GIBSON RINGS FITTED TO TYRES?

 

I believe that one of the Ivatt 2's running on the Severn Valley in years gone by had a driving wheel diameter discrepency of 1" from one side to the other, it had a terrible reputation for not running properly for years, until the wheels were put on the wheel lathe during an overhaul and the error came to light! How many other locos are running with similar issues which are very difficult to spot when on the loco but easy to see when set up for turning? I would hazard a guess that it's considerably more than we think. I know of at least 2 where side rod bushes have been machined off centre to correct axlebox alignment issues.

 

Can some one explain then how the hell you rivet a tyre in place then i dont actully see that one working at all

 

Jordan, can I suggest you arrange a visit to Search Engine at the NRM and have a look at the appropriate drawing from the Doncaster Works Drawings archive.

 

is that all that secures the tyre to the wheel then, i always thought that all tyres were heated then shrank onto the wheel if you have to line up rivet holes whilst fitting a red hot tyre it sounds very easy to get something wrong, how was tornados tyres fitted? do you re use the old holes or weld up and drill new? can someone who has actualy done this explain how you do this?

 

Believe it was called the Beattie fastening. basically the tyre is machined with a very deep lip on the outside and to be a shrink fit on the wheel centre. The wheel centre is lowered into the heated tyre until it abuts the outer lip of the tyre and the tyre shrinks onto the centre. Once cooled the tyres are drilled through from the transverse rivet holes through the rim of the wheel centre and rivets are fitted. Should the shrink fit ever give up, the rivets prevent the tyre from coming off the outside of the rim. they also prevent sections of tyre being thrown, should a tyre break in two places. This fastening was widely used on the LNER and on the LMS Fowler loco's.

 

Crewe Hall has explained it very well. There are quite a few LNER locos going round with such fastenings. It was also quite common practice to bolt tyres to the wheels, in addition to the usual shrinking on. Bolts, or sometimes studs, were fitted radially through the tyre to secure them. My own loco, a Hunslet 'industrial', has these. Manning Wardle 'Sir Berkeley' used to have them but Ian Riley used more modern methods when he re-tyred it. Mind you, he couldn't understand why there were fitted spacers in the wheel rim, which fell out when the old tyres were removed! Sorry, Ian!

 

i dare say thats true but how come then tyres still slip? surely the said rivets should stop that happening at all?

 

I recall someone telling me that Scotsmans driving wheels were stored in an outbuilding during the overhaul at Southall under Tony Marchington's ownership. One night intruders broke in and pushed one of the wheelsets into a pit. That's why one of the wheelsets became bent. It's not something that dates back to BR days. Such a defect would have been picked up last time the tyres were turned.

 

So was the damage spotted at the tme but not felt to be worthy of correction, or was it not noticed I wonder?