Another Wheel Flat Question

[dangie]

If a wheel has to be machined to get rid of a wheel flat, does the opposite wheel on the same axle also have to be machined as well? Otherwise both wheels will be different diameters. Thank you.

 

[Cliveblackpool]

If a wheel has to be machined to get rid of a wheel flat, does the opposite wheel on the same axle also have to be machined as well? Otherwise both wheels will be different diameters. Thank you.

They would be turned as a pair.
Blackpool Tramway has this equipment as posted by WatcherZero. Rail should be similar.

The new depot has a programmable autolathe that works on both the heritage trams and the new flexities. It turns the wheels of a new tram in 7 hours and a heritage tram in 4 hours, the heritage tram wheel turning used to take four weeks as they had to be dismantled first.

http://www.dailymotion.com/video/xnlpgn_blackpool-starr-gate-wheel-lathe_tech

 

[No Fault Found]

If a wheel has to be machined to get rid of a wheel flat, does the opposite wheel on the same axle also have to be machined as well? Otherwise both wheels will be different diameters. Thank you.

Most certainly. The tolerance between wheel diameters on the same wheelset is +/- 1mm

 

[Ploughman]

Also on a bogie vehicle there is a limit to the permitted difference between the wheelsets in the bogies.
Can't remember the figure but there was a limit I used to have to work to in York BREL on the wheel lathe.

 

[Smudger105e]

I believe it used to be 12 mm difference between wheelsets in a bogie, and 25mm between bogies. I will check on the tolerances there days tomorrow...

 

[millemille]

Most certainly. The tolerance between wheel diameters on the same wheelset is +/- 1mm

No it isn't.

Ex lathe tolerance is 0.25mm parity across the axle.

There is no in-service tolerance.

Tolerances between axles on a bogie and axles on a vehicle depends on the class of the vehicle, it's not a tolerance defined by GM/RT2466.

 

[TGV]

Most certainly. The tolerance between wheel diameters on the same wheelset is +/- 1mm

While it's possible this is applicable to a specific type of rolling stock, it's not a general rule. As said above, it is different from type to type.

On TGVs there is a broadly similar rule for all wheelsets. On a given axle the wheels should be within 2mm of each other. There is a tolerance band that allows re-profiling within a couple of weeks and if it is greater than 3mm then it requires immediate re-profilling.

There is NO limit on the differences between two axles on a bogie.