9F why does not having a flange on the centre wheels stop it being mainlined

If I’m remembering correctly a flangeless tyre is wider than a normal tyre so could actually ride up onto the check rail.

 

Back to back dimension is identical.

 

I seem to remember that the main issue is, in the days of steam the top of the running railhead and the top of the checkrail were in the same plane. Today the check rail is 1/4" higher that the railhead.
If you have ever been on a train which went over a penny or joint that was just slightly out you will know about it. Imagine hitting something three times as big at speed and the jolt it will inflict. The flangeless wheel by nature will tend to 'cut the corner' so be right over the zone of the checkrail. That is why flangeless wheels are not acceptable as they would impact the checkrail.

 

I am fairly sure the tyre is wider. But the check rail is adjacent to the running rail on the inside of the curve, where the middle driving wheel is further away from the centre of the track, nowhere near the check rail. None of this makes sense to me.

 

I have a vague memory of hearing it was something to do with check rails on crossings not curves, and that there weren't vast numbers of affected crossings. But my memory is not what it was.

 

It's the checkrails on the points that are the issue.

 

I'm think that the tyre is no wider in itself, but the tread is wider because it includes the area where the flange would be if it were there. Does that make sense to you?

Peter

 

The leading and trailing Wheel tyres were ARLE profiile A at 5½" wide, the intermediate wheel tyres were ARLE profile E at 5½" wide and the centre flangeless ones were ARLE profile X at 511/16" wide. RCTS BR Standard Steam Locomotives Vol.4

 

Ah, that does make sense to me. Thank you.

 

Yes, I thought that that was the case. It explains everything. I wonder why they built it with flanges. Perhaps because they were only expecting it to run on short straight lengths of track.

 

Note the same problem occurred with diesel locomotives on a rigid lengthy 1Co-Co1 bogie (i.e. Classes 40 / 44 / 45 / 46) hence their being banned from Glasgow Central where derailment caused major access / exit problems.

 

I might be wrong, but I didn't think the bogies on those locos were rigid; rather they are in essence a form of 2-6-0 design with the non-driven axle being in a pony truck. Certainly that was the case on the Bulleid-Raworth diesels, and I thought that the later BR designs basically took the Bulleid design largely unaltered.

Tom

 

Wjj hi ildd sad t on the subject of flangeless wheels, they were quite common on industrial ax coupled locos but how many ‘main line’ locos had them? I can only think of the 9F’s, austerity 2-10-0’s and Super D’s. Any more?

 

Don't know what happened with my previous post, which was meant to say "Whilst on the subject....." I've tried to edit it but I get a message saying "Forbidden. You don't have permission to edit posts." This is the second post I've tried to edit today with the same result. Am I the only one having this problem?

 

Haven't had that precise problem, but have seen what I suspect is a related issue saying that I don't have permission to see alerts. From a rough guess of the site architecture I have a hunch at the reason but I suspect that very few people really want a discussion about authentication tokens and whether load-balanced connections are sticky or not ... Bottom line is "it's the site, not you" (IMHO).

Tom

 

I have had similar, Steve.

 

Not only the 5AT & the continuing Advanced Steam Traction Trust but Chaplelon & Porta both developed piston valves driven by Washaerts and large light weight piston valves fairly hollow through the body of the valve which - with conventional outside admission - gave you effectively more steam chest volume just where you needed it near the steam ports. Chapelon was particularly interesting because he also used poppet valves driven by Walchaerts valve gear before he settled on the same gear and piston valves.

 

Very interested that there is no mention of cast Vs in point work by the frogs in this. I strongly remember - presumably just after when Liverpool Street was rebuilt apparently all the new points has these. Looking within the last ten years they seem to have gone.

Are they now rare? And would it be possible to readily set up the Network Rail track survey to pin point exactly where they are - or enable that sort of survey on any other train?

Check rails listed at 4 " Prohibited from curves of 10 chains radius or less, where there are guard rails more than 1 inch above running rail and 2 and five eights from running edge of outer rail" This seems pretty detailed but to confirm the the clearance form the running rail seems generous, would that be the clearance over bridges rather than through points?

 

In the back of my mind I thought I had a good example for you Steve, but turned out not. In the mid 1860s, Avonside made a pair of outside cylinder 0-8-0T tank engines for the Vale of Neath Railway. Being impressed, Sturrock on the GNR ordered a pair of similar locos, with condensing gear for working the goods yards around Kings Cross / Faringdon. Those locos had all flanged wheels but with considerable side play on the leading and trailing wheels.

In 1866, the LCDR needed motive power for its own extension over the "widened lines" through to Faringdon, and having seen the GNR locos, Martley ordered a similar pair from Avonside for the LCDR. There were proposed detailed differences, of which the most significant was that the two centre wheel sets were proposed to be flangeless. It appears, however, that after a few months in service, experience of the GNR pair was that they were prone to derailing on sharp curves in the goods yards, and accordingly the LCDR cancelled their order. Avonside wanted £180 per loco for work undertaken, which suggests that they were not very far advanced (or that some parts made could be readily reused in other locos); it's unclear whether the LCDR ever paid, as the correspondence seemed to peter out without conclusion after a year or so.

These were the GNR locos: https://www.gnrsociety.com/locomotive-class/avonside-0-8-0-tank-engines/ Apparently they lasted until 1880; presumably the worst faults were ironed out though whether that was track improvements or loco modifications I don't know. (14 years is also not a very long life even for that era: clearly they weren't complete duds, but presumably not greatly successful either).

Tom

 

That seems to mean that the problem is not only at turnouts but on curves in plain track, which doesn't make sense to me, as I said at #144.