Fitting Steel Tyres to Locomotive Wheels

[Norman LortonParticipant @normanlorton75928]

shrink on or adhesive?

[Norman LortonParticipant @normanlorton75928]

There is a nice article in another magazine this month by Ian Jefferson describing the cutting and fitting of steel tyres. He describes the standard practice of heat shrinking for the final fitting from 300-400 degC and the use of 6 to 8 riveted pins for security.

What is not mentioned, and what occurs to me, is whether there is any experience with the use of appropriate loctite. You would have to machine a location shoulder and suitable gap for the loctite, and would finish off with the same rivet security.

I have seen loctite hold onto main bearings in a racing motorcycle engine with a loose journal so I cannot see that the expected pressures, vibration and temperature will be a problem; there is a massive surface area as well.

Norm.

Edited By Norman Lorton on 15/04/2013 12:22:54

[Trevor WrightParticipant @trevorwright62541]

Norm,

Loctite 603, wonder stuff.

Make the joint a good running fit and it will never come off…..unless heated with an oxy torch and drifted.

Used to make extended drills for work by drilling a long bar and then turning the drill round and loctiting into the hole. Still have them except for the drills that have snapped……

Trevor

[MICHAEL WILLIAMSParticipant @michaelwilliams41215]

Hi Norman ,

You can use a proper shrink fit or you can use Loctite but PLEASE don't use the pins .

A locomotive tyre is z shaped in cross section ie the main part which is the actual tread , an outgoing flange at the back to engage the rail and an ingoing flange at the front which abuts the cast wheel centre . Basically copy real world practice on this and you won't go far wrong .

Full size engines had a retaining ring rolled into a circular groove on back of tyre to prevent tyre disintegrating if it cracked while running but you won't have that problem on a model engine .

MikeW

[David TaylorParticipant @davidtaylor63402]

The steel tyres on my loco are loctited to the cast iron wheels with no pins etc. One of them came loose once in about 5 years. Seems to work well enough.

[Neil WyattModerator @neilwyatt]

Make it a close push fit – the better the fit, the stronger the loctited joint. The myth that you need a 'thou' for the adhesive has been dispelled several times on this forum and elsewhere by reference to the maker's own advice notes. Loctite will work even when the joint is force fit (about 25% stronger than when a running fit), but is best (by about 5%) with a very tiny gap.

Neil

[vintagengineerParticipant @vintagengineer]

When I used to do full size tyres we used to allow 1 thou per foot diameter and heat shrink them on.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Neil Wyatt on 24/11/2014 10:51:43:

Make it a close push fit – the better the fit, the stronger the loctited joint. The myth that you need a 'thou' for the adhesive has been dispelled several times on this forum and elsewhere by reference to the maker's own advice notes. Loctite will work even when the joint is force fit (about 25% stronger than when a running fit), but is best (by about 5%) with a very tiny gap.

Neil

.

But don't be tempted to produce a 'mirror finish' on the parts … some micro-roughness does help.

Yes … it's in the documentation.

MichaelG.

[mechman48Participant @mechman48]

Posted by vintagengineer on 03/12/2016 21:40:35:

When I used to do full size tyres we used to allow 1 thou per foot diameter and heat shrink them on.

​Ditto… when I was crane fitter; I used to heat the trod wheel tyres up in a gas ring set up very similar to the methods used in the old steam rail movies, with the addition of painting white lead onto the wheel before placing the tyre on & allowing to shrink fit.

George.

[Nick_GParticipant @nick_g]

.

Not applicable to ME (but I suppose the principle is the same)

Interesting video of tyres being fitted to a full size wheel. Go to about 11 mins in if you don't want to watch the whole thing.

Nick

[duncan webster 1Participant @duncanwebster1]

I think the above 2 contributors mean 1 thou per inch. This needs 76 C difference in temperature to just expand the tyre to wheel size, you need a fair bit more to ensure that you can get it on before it's cooled down, otherwise it is well and truly stuck. Don't ask how I know!

The modern way of fitting rail wheels to axles is to use liquid nitrogen to shrink the axles. I suspect this means less radiant heat transfer between axle and wheel, and no chance of changing heat traetment of wheel by heating. No the domestic freezer isn't cold enough.

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