Confederation Line (Stage 1) | In Service

[Richard Eade]

As more, and more, axles are being looked at, after traveling 100,000 kilometres, RTM and OC Transpo will start to get a better idea of how prevalent the problem is. Right now, I don’t think that they are getting enough done, fast enough to know if there are, on average, only one in 30, for example, bearing races exhibit any spalling (or fretting, for that matter). To me, that is one of the biggest draw-backs of such a slow process. They just don’t have an adequate sample size yet – and won’t for a long while.

All that said, the pervasiveness of spalling is something that needs to be known – and that statistic will emerge as more axles are inspected/replaced – but, perhaps an even more important thing to know is the rate of decay that the bearings undergo.

Picking random numbers here, but, if 80% of bearings show spalling at 100,000 kilometres, that is one thing. Not a good thing, but one thing. If the rate at which the bearings spall is quite slow, those bearings, despite showing wear at 100,000 km, might show little increased wear by the time they travel 250,000 km. If so, then it might not be much of a safety risk to stretch the replacement interval to 200,000 km, or more.

By forcing all the bearings to be changed at 100,000 km, they lose the information about what happens after that point. This will make it very difficult to provide valid safety information to extend the allowable travel distance for bearings.

In fairness, I don’t know why the 100,000 km limit was chosen. It might be that by that point bearings are already showing severe degradation. Meaning that 100,000 km may already be the upper limit. I don’t suspect that we will ever know the whole story.

PS Why does RTM seem to be doing the tear-down and inspection of every bearing themself? Why do they not have a subcontractor who assembles complete axles that can be swapped into the bogies without having to have RTM mechanics open the bearing cartridges to inspect them? Yup, it might be a bit more expensive, but right now, there is a huge cost to having mechanics work over-time to do both inspection and replacement.