Trailing Coupled Wheels: Flange Wear

There have in the past been comments about excessive wear on the trailing coupled wheels of some locomotives used on heritage lines due to running tender first.

How do heritage lines cope with this issue? Trackside flange lubricators are presumably one way of dealing with this issue, but I noticed today that 9F 92203 on the Glos-Warks is equipped with a piece of kit comprising a spring-loaded graphite rod shaped and angled to rub exactly on the tyre/flange interface of each trailing coupled wheel. The driver said that the flange wear is checked regularly with a profile guage.

What do other heritage lines do to minimise this wear on their larger locomotives?

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The 7F 53809 had a similar device fitted when it visited the Bluebell last winter. I seem to recall one of the MRC guys saying they had fitted it recently and were monitoring it to see whether it made a difference to flange wear, so presumably they were also concerned at the problem. Notably, the 7F (like the 9F) is another engine with a long fixed wheelbase and no pony truck to guide it into corners when running backwards.

Tom

 

Sounds like the same design of flange lubricator stick that is fitted to London Underground trains - I know the 1996 Tube Stock on the Jubilee Line has them fitted.

Regards,

Dan

 

Excessive flange wear occurs on locomotive and coaches on preserved railways becuase the permanent way departments, supported by board of directors or whatever they are called, think that third hand rail is ok. "Because we only run at 25".
The fact that the rail can be wide, or tight to gauge; can have so much wear on the top that the inside edge is a knife edge, does not matter. When the Engineering Dept. complain, the standard Pway response is, "the rails are being damage by engines and coaches with flats". The fact that the wheel flats are caused by: bad driving, guards leaving handbrakes on, everyone not pulling strings when BR locos replace GWR locos - is ignored.

 

Where on earth do you get this idea from? Such a critical statement as this needs either qualifying or withdrawing.

 

Not at all. 9F's, like WD 2 10 0's have flangeless centre driving wheels, ie they are effectively 2 4 2 4 0's. Eight coupled locos are far more rigid.

 

The KESR use the flange lubricators you have described on the leading and trailing wheelsets. There are quite a few others that use them, as well. The NYMR prefers the track mounted flange lubricators that squeeze a small amount of grease onto the running edge of the rail before each (sharp) curve and rely on the vehicle wheels to distribute the grease but even this does not fully solve the problem.

Flange wear is always a problem and became a major one for the WSR last year after a rail-reprofiling exercise. It is not just the Heritage Railways which experience it. The West Highland line is a good example of where flange wear it a problem on the Big Railway, affecting the steam locos that are allocated to that service.

 

The graphite sticks are fitted to all steam locos at the Midland Railway Butterley, including 6233 Duchess of Sutherland, and it is apparently very effective.

 

The driver of 92203 said that the main reason for the installation on that particular loco was to provide some lubrication through points and crossings. The Glos-Warks, being a former "main line" is relatively free of sharper curves, unlike for instance the NYMR, the SVR and the WSR. Also, as the driver of 92203 mentioned, if they needed to reprofile the rear drivers on Black Prince, then they would have ten in total to do, so some incentive to reduce the wear in the first place!

Re the earlier poster's comments about track quality, I suspect some C & W people would dispute what was said. Many Heritage lines hiring in tamping and lining machines after relays.

Increasingly now you find new relaying is with flat-bottom rail that is not suitable for Network Rail use, but still perfectly fine for a 25 mph railway. The Severn Valley I am sure now has sections of track relaid with this rail since the flood, and the Glos-Warks I recall goes a step further, having it continuous-welded. Does the NYMR now relay in good secondhand FB as well?

What must now be increasingly scarce bullhead rail being reserved for station areas, to preserve "the look".

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That applies to all coupled wheels of any locomotive, even a 2-4-0! You can't have one set of wheels a different size, and so trying to rotate at a different rpm, to others to which they are firmly coupled! Thats why the 8F on the SVR went through a set of brand new (in 1966) tyres in preservation service; it's only the trailing set that wears as they have no guidance into curves, but all have had to be turned down to match. To a lesser extent, this applies to pony and bogie wheels too.

 

The SVR now has a length of CWR and an increasing amount of new f/b rail on modern steel sleepers so the comment re 3rd hand rail does not fit here. (is there anywhere which REALLY does this??)

Nobody has mentioned turning the locos to at least distribute the flangewear. Most of the lines which were secondary routes have a significant curve or two (which it has to be said makes them a little more interesting) but these cause undue flange (as opposed to tread) wear in a particular direction.

SVR locos are periodically turned at Kidderminster for this purpose & the usual facing direction for that period is posted on the SVR website. This is not infallible as locos may be turned short term for other purposes.

 

LMS2968: I appreciate they all have to be turned to the same diameter at the same time!! The point the driver of 92203 was making was that putting ten through the wheel lathe is that much more expensive than say four or six drivers.

No doubt on those lines that dont have a turntable ( to turn locos and stock to equalise flange wear) there are some interesting calculations of the "net effect" of the line on both locos and stock. In other words one "side" wears more than the other if stock is not turned.


Anyway, thanks for the responses. An interesting discussion.

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Not quite true. Some modern thinkers believe that the driving wheels should be turned to a slightly larger diameter than the coupled wheels in order to minimise the effects of micro slip. (They tend to like high adhesion tyre profiles too)

 

That's an interesting theory. I suppose this is effectively creating a creep condition which gives a much higher coefficient of friction, similar to the GM Super Creep control which, I believe, drives the wheels round at a rate slightly faster than the loco is actually travelling. Not being a diesel man, I'm not too well up on this but I did carry out some tests on mining locos with a lubricant that had the same effect. In exactly the same way as the flange lubricators we've been talking about, a lubricating stick was applied to the tread of the wheel. This put down a minute layer of the material on the rail head and locos could climb gradients with much bigger loads than previously. The wheels rotated slightly faster than the actual rail speed and the system really did work. The only trouble was that, if you stopped on the gradient, the loco & train slowly slid backwards and there was nothing you could do about it!

 

The last major relayings on the NYMR were done with new FB rail on new concrete sleepers.
Bullhead rail is still rolled as far as I am aware. I think that London Underground is a customer. They tend to wear out rail in the tunnels before the sleepers require replacement and replace like with like as full scale renewal is much harder in the tunnels. Anybody know better information?

 

I agree the statement is groundless and implies that those who run preserved lines don't care. This is far from the truth.

 

Cn you explain that in a bit more detail please? I reckon I know what you mean by miscroslip - that at the point of maximum adhesiipon a wheel is travelling slightly faster (or if braking slower) you would expect from the speed. So far so good. But why should the effect be different on the driving pair as opposed to the wheels coupled to them? Even if there are effects due to flex in the rods etc, isn't that going to be taken up as the vehicle is accelerating so the force is equal on all wheels?

 

The last major relay (2007 - 8) on the NYMR at Beck Hole actually used 2nd hand F27 sleepers and New 60ft FB113 rail. With new Fishplates, pads and insultors this resulted in a very smooth finish following tamping with no dipped joints.

New BH 95 lb rail is still available. It can be seen in many locations on the big railway, and is most frequently to be seen in the new welded transition rails between existing Bh track and new FB relays. 60ft lengths are also still being installed where required.

 

Renewals on the Jubilee, Northern and Piccadilly have used flat bottom rail as far as I am aware. The Jubilee Line Extension was laid with this in the late 1990's.

Regards,

Dan