Failed train Twyford 2330 hrs Sunday 21st November

[Rambler2978]

The axle is lifted by jacks so that the wheels are clear of the rail and the jacks are supporting the weight of the vehicle, then the skate is assembled around the wheels and the side plates are clamped against the front and back of the wheel and then the jacks are lowered and the skate is now taking the weight of the vehicle. The train can now move, very slowly, with the small wheels of the skate running on the rail and the axle of the train not rotating.

Skates are used where the wheel, primary suspension, axle bearings etc. are damaged or are suspected of being damaged and the risk of driving the train normally, even at reduced speed, to a repair location is too great.

When I was an on-call FTO I'd attend incidents like this - a derailment on points in a yard - several times in each turn on the roster and that's without operating incidents on the line..

Many thanks for the photo! Much clearer now!!

Many thanks for the photo! Much clearer now!!

 

[Pshambro]

The axle is lifted by jacks so that the wheels are clear of the rail and the jacks are supporting the weight of the vehicle, then the skate is assembled around the wheels and the side plates are clamped against the front and back of the wheel and then the jacks are lowered and the skate is now taking the weight of the vehicle. The train can now move, very slowly, with the small wheels of the skate running on the rail and the axle of the train not rotating.

Skates are used where the wheel, primary suspension, axle bearings etc. are damaged or are suspected of being damaged and the risk of driving the train normally, even at reduced speed, to a repair location is too great.

When I was an on-call FTO I'd attend incidents like this - a derailment on points in a yard - several times in each turn on the roster and that's without operating incidents on the line..

Fascinating - thanks for the photos and explanation.
Do the train wheels sit in the skates on the same surface as they interface the railhead or does it sit on the flanges (presumably not as they are not designed to take the train’s weight ?

 

[millemille]

Fascinating - thanks for the photos and explanation.
Do the train wheels sit in the skates on the same surface as they interface the railhead or does it sit on the flanges (presumably not as they are not designed to take the train’s weight ?

The wheels are supported on the tread on a pair of curved blocks, one either side of the wheel. You can see them in the photo with the clamping bolts sticking through.

 

[rower40]

And just as certain vehicles are flagged as "may not operate track circuits" (due to reasons of low electrical conductivity between rail, wheel, axle, other wheel, and other rail), vehicles on wheelskates cannot be relied upon to count in/count out correctly to/from axle counter sections. This is because the axle counter head works by counting fluctuations in the magnetic environment - and the wheelskate may look like 1 axle, or two, or three. So there are all sorts of additional software and procedures to move a wheelskated train through axle-counter-signalled areas.