In the course of my work, I pass close by a marshalling yard where some traditional shunting still takes place frequently. I've noticed that some wagons (mainly the 2 axle non bogied ones), get de-railed quite frequently.
What aspect of shunting causes this, or is it down to the track quality?
"Traditional Shunting" as a definition, is probably more related to an individuals experiences, memories, than a set method that has remained the same. From my point of view, "traditional shunting" is a thing of the past and revolved around the principle outlined by "furnessvale".
What occurs today is basically the breaking up, and reforming of blocks of wagons. Wagon load revenue traffic is history. The nearest thing you will find is the working of Infrastructure traffic in Network yards.
The greater regard to safety today, and the much reduced volumes (along with other factors) has evolved into the current practices on the national network. Very simply, wagons remain attached to the locomotive with the auto brake in use.
Derailments have a number of causes, and it is quite often a combination of factors that come into play. Track, human, wagon defect, wagon type, loading etc.
As a wagon type, 2 x axle vehicles are more prone to derailment due to poor track/loading than bogie wagons. The shorter the distance between axle centres, the more susceptible to derailment.
The worst wagon I used to deal with was the ZBA Rudd. Short wheel base with a stiff wagon frame, which if badly loaded off a worksite would soon find any bad track twists in a yard. Now long gone from the network. The longer wheel base 2 axle wagons, such as OBA, OCA are much better at coping with poor track.
Unless things have changed over the last few years, MHA Coalfish and similar, were the most likely victims. Quite often, poor loading was a major contribution to the derailment in combination with other factors.
