Wheel reprofiling

[strange6]

On average, how long can wheels be in service before they need reprofiling? I would imagine for somebody like Northern, this would be a more frequent task compared to say, Virgin, due to the increased amount of poor quality track Northern trains run over.
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Not got many wheel experts on here then!

 

[es373]

On average, how long can wheels be in service before they need reprofiling? I would imagine for somebody like Northern, this would be a more frequent task compared to say, Virgin, due to the increased amount of poor quality track Northern trains run over.
--- old post above --- --- new post below ---
Not got many wheel experts on here then!

Its not so much wheel profiling that's done, its more wheel exams.
We do wheel ovality tests, flange thicknesses, flange height, metal migration, etc. Should a wheelset fail this then it will be sent to the wheel lathe.
Also if flats are reported its done. There's a bunch of other stuff but its early and I can't think straight haha.

 

[strange6]

Its not so much wheel profiling that's done, its more wheel exams.
We do wheel ovality tests, flange thicknesses, flange height, metal migration, etc. Should a wheelset fail this then it will be sent to the wheel lathe.
Also if flats are reported its done. There's a bunch of other stuff but its early and I can't think straight haha.

What kind of lathes do you have?

 

[es373]

What kind of lathes do you have?

Not sure of the name. Its some automated expensive thing where axles don't need to be removed. Set can drive on and when its completed drive off.
I think there's a vid on you tube. Search temple mills bogie drop or wheel lathe. Can't remember what its called.

 

[rail-britain]

I would imagine for somebody like Northern, this would be a more frequent task compared to say, Virgin, due to the increased amount of poor quality track Northern trains run over

The checks will be based on mileage, so it is more likely Virgin rolling stock will be examined more throughout the year than Northern

Given how infrequently rolling stock visits lathe shops now I would say it is well into two or three years
As above, inspections will be recorded at regular intervals typically weekly for most rolling stock, but for some this could be as long as a month
Equally, with maintenance schedules many wheel tyres will be replaced as part of the bogie swap

 

[captainbigun]

You just have to hope that your lathe man doesn't chop the flanges off!

Alstom hold new wheelsets of varying sizes so that a straight swap, maintaining parity, can occur without having to send the whole set to the lathe. The downside of that is you ending up turning a brand new wheelset to last turn just to have it on the shelf.

 

[driver9000]

Wheel lathe visits can increase during autumn leaf fall as trains slide about gaining wheel flats.

 

[es373]

The checks will be based on mileage, so it is more likely Virgin rolling stock will be examined more throughout the year than Northern

Given how infrequently rolling stock visits lathe shops now I would say it is well into two or three years
As above, inspections will be recorded at regular intervals typically weekly for most rolling stock, but for some this could be as long as a month
Equally, with maintenance schedules many wheel tyres will be replaced as part of the bogie swap

Another thing to add is that its mostly done on mileage. I think our ones are done every 210,000km. Can't remember though.

 

[The Crab]

Talking of wheels, when did wheel tapping finish? I seem to remember being tapped in Sheffield about 1980.

 

[es373]

If you mean hitting the wheel with a hammer...

That was "ruled out" (may still happen on some loco's) when the single piece monobloc wheel came around.

Old wheels used to consist of the web and the tyre.. It was common that the tyre would come away from the web and cause slipping. That's why you sometimes see 2 white lines painted/sprayed on the tyre/web as if these lines come out of straight. You'll know the tyre has slipped.

 

[rail-britain]

Another thing to add is that its mostly done on mileage. I think our ones are done every 210,000km. Can't remember though.

er, that's what my post states...
The checks will be based on mileage
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If you mean hitting the wheel with a hammer...

I understood this was undertaken to determine if there was a fault with a wheel and/or bogie, including the tyres separating from the wheel and binding brakes

A train I worked on was very slow due to a binding brake
We were then held whilst the entire train had all the wheels tapped
The brakes were then found to be binding in the third coach after the loco and so they were isolated
The same coach appeared a few weeks later and I could clearly see it had had new brake shoes fitted on both bogies

 

[es373]

er, that's what my post states...
The checks will be based on mileage
--- old post above --- --- new post below ---

I understood this was undertaken to determine if there was a fault with a wheel and/or bogie, including the tyres separating from the wheel and binding brakes

A train I worked on was very slow due to a binding brake
We were then held whilst the entire train had all the wheels tapped
The brakes were then found to be binding in the third coach after the loco and so they were isolated
The same coach appeared a few weeks later and I could clearly see it had had new brake shoes fitted on both bogies

Sorry, I misread the post.

Can't say I've heard of that though as the brakes are a different system to the wheelsets. Sounds like a sticky disphragm/hollow stem in the distributor or relay valves. May also be a sticky cylinder/mechanical linkage.

The hammer is struck against the wheel as if the tyre has separated from the web, you'll get a low thud rather than a ringing 'ting'

 

[strange6]

Wheel lathe visits can increase during autumn leaf fall as trains slide about gaining wheel flats.

And that's the last thing you need on a train - flat-spotted wheels.

 

[ralphchadkirk]

And that's the last thing you need on a train - flat-spotted wheels.

It depends how serious the flat is. Sometimes it's just an inconvenience, other times it can damage the track.

 

[strange6]

It depends how serious the flat is. Sometimes it's just an inconvenience, other times it can damage the track.

And the suspension and braking performance. If it was down to me, any detectable trace of a flat and the wheels would have to be worked on.

 

[wheel tapper]

to answer your question on re profiling wheels at our depot its done on mileage it depends upon whether its a trailing wheelset or a motor coach if there is no flats, cav's, thin flange, high flange or hollow tread to name a few they will be turned to try and catch the rcf building up. if this can be done correctly then a small amount of m/t can be removed to regain the profile if it is done to late then to remove the damage under the rcf a lot m/t will have to be removed. therefore wheel management is important to make the wheel sets last longer. Also a point note at various places along the track there are wheel check sensor that check for the wheel impact upon the track so if there is a large flat or cav this is highlighted and the depot is sent the report the unit is booked in for lathe work and wheel cheeks. (rcf = rolling contact fatigue)

 

[strange6]

to answer your question on re profiling wheels at our depot its done on mileage it depends upon whether its a trailing wheelset or a motor coach if there is no flats, cav's, thin flange, high flange or hollow tread to name a few they will be turned to try and catch the rcf building up. if this can be done correctly then a small amount of m/t can be removed to regain the profile if it is done to late then to remove the damage under the rcf a lot m/t will have to be removed. therefore wheel management is important to make the wheel sets last longer. Also a point note at various places along the track there are wheel check sensor that check for the wheel impact upon the track so if there is a large flat or cav this is highlighted and the depot is sent the report the unit is booked in for lathe work and wheel cheeks. (rcf = rolling contact fatigue)

Thanks for that, Mr reaper

 

[rail-britain]

The hammer is struck against the wheel as if the tyre has separated from the web, you'll get a low thud rather than a ringing 'ting'

It was a massive Scotland - South Coast Polmadie set with Class 47
We were delayed 40 minutes whilst a rolling stock engineer was sent from Polmadie and by that time I was stood on the opposite platform whilst the train was inspected, from front to rear, and every set of wheels gave off the expected ting noise
He then walked back along the set repeating the test and performed several on the third coach, comparing it to the second and fourth
There was a very slight difference in sound, he then put his hands near the brakes presumably to feel how hot they were
Then finally he put the brake into the isolated position, spoke to the driver, and I handed him the train reporting book
"Possible binding brake in coach [number], requires inspection, brake isolated"
He had also advised the driver to place a note in the cab for the remainder of the trip (including any loco swaps en-route)

 

[es373]

I presume that would be because if the brake is applied and the block contacts the active surface, it would make the tyre even more loose which has potential to derail the train.
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to answer your question on re profiling wheels at our depot its done on mileage it depends upon whether its a trailing wheelset or a motor coach if there is no flats, cav's, thin flange, high flange or hollow tread to name a few they will be turned to try and catch the rcf building up. if this can be done correctly then a small amount of m/t can be removed to regain the profile if it is done to late then to remove the damage under the rcf a lot m/t will have to be removed. therefore wheel management is important to make the wheel sets last longer. Also a point note at various places along the track there are wheel check sensor that check for the wheel impact upon the track so if there is a large flat or cav this is highlighted and the depot is sent the report the unit is booked in for lathe work and wheel cheeks. (rcf = rolling contact fatigue)

RCF is metal migration isnt it?

Where you get a little lip form on the outer edge of the active surface?

 

[AlterEgo]

It depends how serious the flat is. Sometimes it's just an inconvenience, other times it can damage the track.

Highland Sleeper train passed MKC this morning with a very audible wheelflat on one of the MK3 sleeper coaches. It must have been a right pain in the rear to listen to that for the best part of twelve hours....

 

[wheel tapper]

I presume that would be because if the brake is applied and the block contacts the active surface, it would make the tyre even more loose which has potential to derail the train.
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RCF is metal migration isnt it?

Where you get a little lip form on the outer edge of the active surface?

no this is known as tyre roll over,
http://www.am.chalmers.se/~anek/research/fatigueintro.html
try the abve web as rcf is a long subject.

 

[The Crab]

Can I revise my question slightly? Does anyone know when routine wheel-tapping at major stations ceased?

 

[es373]

Can I revise my question slightly? Does anyone know when routine wheel-tapping at major stations ceased?

Due to the wheel being redesigned and the monobloc wheel being introduced.

 

[Barrett M95]

Wheelset life is also determined by the relative geometry on a given axle or vehicle. For example even if neither wheel on an axle is excessively worn as an absolute value, it may be that the delta (difference in diameter) between one and the other on that axle exceeds the standard for that profile or vehicle, then the wheels will need turning back into spec.

The time or distance taken for this or any other work to be needed totally depends on the duty the wheelset has had (including factors such as the track geometry it has covered, speeds involved, railhead conditions...etc....)

 

[Peter301184]

On average, how long can wheels be in service before they need reprofiling? I would imagine for somebody like Northern, this would be a more frequent task compared to say, Virgin, due to the increased amount of poor quality track Northern trains run over.
--- old post above --- --- new post below ---
Not got many wheel experts on here then!

Wheels will need reprofiling if any defect is found on exams.
I can't remember actual mileage, every TOC will be different depending on speeds, mileage, loadings etc.

Theres exams where just visual checks of the tread is ok, Looking for pitting, falt spots etc, Then another exam where each axle is jacked up and spun with a dti gauge against it measuring the 'runout' on the tread. There was 3 different tolerances iirc. one was passed the other if it was between .20mm - .30mm then the wheel had to be reprofiled within x amount of days and if over .30mm then the wheel had to be reprofiled straight away. Then we also took measurements using a 'back to back' gauge. This measured the behind of the flanges from wheel to wheel on an axle. Then there was 3 way gauging which measured flange thickness, flange height and flange gradient (qr).

We also measured wheel diameter but not for every wheel.

This was exams for class 373's. I am no longer with the company so can't give more specifics like mileage etc.

 

[Barrett M95]

qR is something that SNCF are very interested with, particularly on TGV stock (hence your experience with 373), however it is something that is rarely discussed in traditional BR rail dynamics.

 

[rail-britain]

Highland Sleeper train passed MKC this morning with a very audible wheelflat on one of the MK3 sleeper coaches

This is very common and has not changed over the years, although less frequent now
It was always put down to the amount of times the coaches were split and joined, and the variety of coaches used (although not as many now as it used to be)

Ironically, the noise is not really that audible and there is normally not much vibration either, as the sleepers use a heavier version of the BT10 bogie
Equally, it is not until the train is running at high speed (above 80mph) that the noise and vibration is more noticeable within the cabins above the affected bogie even though the noise can clearly be heard with the window open

I will need to have a look at the wheels on the Mark 2 and 3 coaches on the sleeper, as well as the Mark 4 coaches
Presumably it is these monobloc wheels that create the chirping noise at high speed (100mph and above) that was not present with the previous (traditional) arrangement

 

[Peter301184]

qR is something that SNCF are very interested with, particularly on TGV stock (hence your experience with 373), however it is something that is rarely discussed in traditional BR rail dynamics.

The OP did not specifiy whether he just wanted to know about 'traditional BR rail dynamics' or not. 373 does infact run on BR lines.

One thing i did forget to mention is that also ultrasonic testing is carried out periodically to test for cracks etc (although this work is contracted out to Serco).

 

[Barrett M95]

The OP did not specifiy whether he just wanted to know about 'traditional BR rail dynamics' or not. 373 does infact run on BR lines.

You have misinterpreted my post. I was not declaring your comment as irrelevant or dismissing it. Just the opposite in fact - pointing out that the parameter you raised (qR) is something that SNCF depots are very concerned with yet has never really featured in BR. It is interesting to see the different approaches to wheelset maintenance, which I thought was relevant.

For those who care to know what we are discussing, qR is a dimension taken between two datums looking at a wheel profile as it sits on the railhead. One datum is Xmm above the wheel flange tip, and the other is Ymm below the wheel-rail contact (tread) datum. The values of X and Y depend on the rolling stock, profile and conicity of the wheel. For a typical TGV wheelset the value of X will be ~2mm and Y~10mm to give a nominal qR of between 10 and 12mm (which itself has wear tolerances).

On a typical BR P8 profile, the standard makes no such reference or definition. The 68 degree flange angle is given, along with the 30mm nominal dimension from the tread datum to the flange tip. The rest of the geometry is controlled with the flange root and tip radii.

 

[The Crab]

Due to the wheel being redesigned and the monobloc wheel being introduced.

Yes but the change from tyred to monobloc was over a period. What I am wondering is when the balance between the types meant that a decision was made to stop routine tapping.