Fire Risk

At least equal in my question was wondering whether there is scope to relax the formal type competencies on diesels

 

I suppose the answer to that, in part, is how onerous it is to assess and pass someone once they have a ticket for 25, say, for a 33? Plus variants of sub class?!
I'm sure its possible to do some serious damage by being unaware of a small but significant facet, especially at the prep stage. Even some 08s are different from each other for example.

 

Understood, and accepted. But given the discussion about steam types, I'm struggling to understand the principle for why they're treated so differently (as distinct from "because they've always been")

 

Becuase that principle is why steam locomotives are allowed on the main line. Imagine trying to present the safety case for a steam loco ab initio
"so we put the large pressurised vessel on a really heavy chassis, fuel it with a very inefficient, highly polluting fuel source, have a drive system that magnifies the rotational force (for track damaging purposes) and doesn't respond automatically or even predictably to the controls... and then we put the crew in a position of minimal visibility and direct exposure to live steam escape and blowback. So can we run them please?"

There was some logic to it when it started, as nobody had the basic fault-finding experience, and every diesel had things that would render the unit inoperable for simple things (eg fuses, cut-outs etc). With no base experience, the drivers had to know exactly what to do in terms of eg starting procedures and re-setting, which had to be done on a class-by-class basis.