Grayrigg Pendolino

[millemille]

All those different theories about what exactly causes it... I wonder if anyone has examined whether the use of LWRT is a factor - think of the flexing the rails will get as the train moves round the hundreds of curves between the steel mill and the worksite? Then think of what happens if you flex a small piece of metal backwards and forwards in your hands...

RCF is the result of metal on contact, nothing to do with any movement within either of the metals. If you introduce shear force into the contact it is worse - so for track, if it is canted and/or it is in a position where trains would generally be accelerating or braking. This is exactly the circumstances of the track that failed and caused the Hatfield crash.

You get RCF on the train wheel metal as well as gauge corner cracking on the rail itself.

RCF only becomes an issue when the propagation rate of the sub surface cracking exceeds the wear rate of the surface and the cracks reach the surface and cracked material starts separating from the parent material.

My experience of RCF is from the rolling stock side and how to manage, on certain fleets, the wheel re profiling regime to strike a balance between preventing RCF reaching the surface and not turning too often and wasting pan material. I co-authored a paper with a colleague from a ROSCO on this very subject which was presented to WRISA many years ago.

 

[Peter Mugridge]

RCF is the result of metal on contact, nothing to do with any movement within either of the metals. If you introduce shear force into the contact it is worse - so for track, if it is canted and/or it is in a position where trains would generally be accelerating or braking. This is exactly the circumstances of the track that failed and caused the Hatfield crash.

You get RCF on the train wheel metal as well as gauge corner cracking on the rail itself.

RCF only becomes an issue when the propagation rate of the sub surface cracking exceeds the wear rate of the surface and the cracks reach the surface and cracked material starts separating from the parent material.

My experience of RCF is from the rolling stock side and how to manage, on certain fleets, the wheel re profiling regime to strike a balance between preventing RCF reaching the surface and not turning too often and wasting pan material. I co-authored a paper with a colleague from a ROSCO on this very subject which was presented to WRISA many years ago.

But has anyone examined whether the flexing of the rails on delivery has any long term effects on them? i.e. whether it can make the rail more susceptible to deterioration once other forms of fatigue - such as RCF - set in?

 

[sprinterguy]

So how was the loss of a whole rake of MK4's absorbed into operations, were there sufficient spares around to make up a replacement set?

There were originally thirty three each of both mark 4 restaurant vehicles and TSO(E) vehicles as well as thirty two DVTs, though I don't know that there was ever any more than thirty one full mark 4 rakes. At any rate, the loss of two restaurant vehicles (Great Heck and Hatfield) and one DVT (Great Heck) means that there are now thirty complete mark 4 rakes worked more intensively than the mark 4 sets were in Intercity days.