Are skids the same as wheel skates ? (Forgive me I'm a suburban driver - Freight activities are a bit of a mystery
).
We use skates regularly as our DC motors have a habit of seizing solid when they 'die'. Fortunately the whole motor coach only weighs about 40 tons, so the skates seem to cope. To begin with the RSTs always cautiously tell us to keep the speed down to 5 mph, and then after about half an hour on the main line they change their minds and decide that actually '15 is fine'. Time is money nowadays.
FP