Question re pre grouping locomotive flange depth

[Timber]

I am having some tyres machined for my 3D printed wheels.  It appears that pre-grouping the flange depth was 1 1/8".   It also appeared that when the wheel became worn by more than 2" in diameter it was replaced.

 

But given the wheel tyre must wear more than the flange would it be a correct assumption that on well used engines the flange depth would often be deeper than 1 1/8.

 

Someone told me that the wheel would have to be re-profiled if the flange of depth became greater than 1 1/2" but I am not sure if that is based on any facts.

 

Anyone who is more expert in prototype matters have a POV on this?

 

Thanks in advance.

Edited August 14, 2023 by Timber

[Wickham Green too]

It won't actually WEAR by 2'' but it'll be reprofiled - including the flange - when worn to an unacceptable ( maybe hollow ) profile ....... so the flange depth will  not generally vary by a huge amount.

[JimC]

Yes indeed, but flange wear was a major problem too. Especially on tightly curved lines leading and trailing flanges would wear thin and a horrendous amount of tread depth needs to be removed to get flanges back to required thickness. But for your purpose you can assume flange depth to be pretty much constant. 

Edited August 15, 2023 by JimC

[Jeremy Cumberland]

Just in case the previous replies aren't clear enough, when a wheel wears beyond acceptable limits (which might be hollowing of the tread, side wear on the flange, or flats, for example), then the entire wheel, including the flange, is reprofiled. It is thus restored to an as-new profile with a smaller diameter. This might happen more than once.

 

If reprofiling would make the wheel smaller than the 2" allowance (or whatever it was), then a new tyre or wheel would be needed.

 

I seem to recall one of the finescale societies adopted a protoypical worn wheel profile as their standard to get sufficient a flange depth for reliable operation.

[Compound2632]

The details of flange and tyre profile and limits to acceptable wear no doubt differed from company to company so it would be best to consult an original drawing for your prototype. There was debate between Clayton of the Midland and Emmett of the LNWR over the profile and back to back for the 1887 RCH private owner wagon specification.

[JimC]

In Cook's 'Swindon Steam' he states that maximum allowable flange depth was 1 1/2 inches. Also that under Collett the GWR increased the minimum depth to 1 5/16 from 1 1/8 which was standard across the big 4.

[t-b-g]

Duplicate post

 

Edited August 15, 2023 by t-b-g
duplicate post deleted

[t-b-g]

7 hours ago, Jeremy Cumberland said:

Just in case the previous replies aren't clear enough, when a wheel wears beyond acceptable limits (which might be hollowing of the tread, side wear on the flange, or flats, for example), then the entire wheel, including the flange, is reprofiled. It is thus restored to an as-new profile with a smaller diameter. This might happen more than once.

 

If reprofiling would make the wheel smaller than the 2" allowance (or whatever it was), then a new tyre or wheel would be needed.

 

I seem to recall one of the finescale societies adopted a protoypical worn wheel profile as their standard to get sufficient a flange depth for reliable operation.

 

I think your last sentence is a reference to the Manchester EM standards.

 

There is some interesting information, including dimensions of the "Manchester EM" wheel profile, which is based on a prototype wheel with the maximum permitted wear on the tread.

 

https://www.mmrs.co.uk/technical-articles/making-wheels/

 

I am currently building a layout to run stock with these wheels and they are an entirely practical prospect in EM gauge (using the original 18mm gauge that the Manchester people kept to). With an adjusted back to back, they should work on P4 as well.

[Compound2632]

52 minutes ago, JimC said:

In Cook's 'Swindon Steam' he states that maximum allowable flange depth was 1 1/2 inches. Also that under Collett the GWR increased the minimum depth to 1 5/16 from 1 1/8 which was standard across the big 4.

 

But with what degree of confidence can one project that back to the pre-grouping period? The OP has given us no hint as to company, date, or prototype. For all we know they could be building some L&Y engine of the 1860s...

[Timber]

This is great information - thank you.   Does anyone know where I can get a copy of the "British Standards Institution’s specification that related to full size railway wheels" that was used behind the Manchester Profile....

 

Thank you to everyone for your help!! 

[Miss Prism]

A copy of BS276 can be obtained from BSI.

[Jeremy Cumberland]

The standard is BS 276:1927 Contours for Locomotive Tyres for British railways (4 ft. 8 1/2 in. Gauge)

 

I haven't found an online copy of the standard, and I no longer have a BSOL subscription . Apparently there is more than one profile; both the S4 and S7 societies reference Profile A as being one that was in use before 1927, but the MMRS web page talks about a "dimension in the BSS which were listed for wheels that had reached maximum allowable wear and were due to be re-profiled", which is probably a different profile.

 

There is a hand-drawn copy of the BS276A profile here: http://www.norgrove.me.uk/history_files/sep70/sep70.htm

 

3 minutes ago, Miss Prism said:

A copy of BS276 can be obtained from BSI.

I'm not sure that it can. The BSI web page says it is "subscription exclusive", and subscriptions are expensive. However, you can always ask them, I suppose. Here is the page for the standard: https://knowledge.bsigroup.com/products/contours-for-locomotive-tyres-for-british-railways-4-ft-8-in-gauge/standard/details

[Miss Prism]

I wasn't aware that a subscription is now required.

 

I'll send you a copy of its main drawing (the BS276A profile). Don't forget it is a spec for new tyres. Wear profiles were usually checked with custom templates.

 

[Wickham Green too]

As a slight diversion off topic - but not totally irrelevant - when did British railways ( small 'r' ) standardise on 1:20 rail inclination rather than 1:40 ( commonly used elsewhere ) or something different entirely ?

[roythebus1]

My son is a rolling stock engineer and I had this sort of chat with him a while ago. There's a number of different profiles and standards these days and I would suggest the same applied in bygone days. It depends on the vehicle, maximum speeds, weight of said vehicle etc. 

[roythebus1]