The question is, why was there ever such a notion that it was required? Sounds like a union-driven job creation scheme to me, and counter-productive as these shemes often are. Two in the cab when there's really only a job for one can easily lead to distraction for the one who has a job to do, by the other who hasn't.
I am unaware of high speed operation in steam days perhaps you will enlighten me ?Despite what OT says it was the reason ASLEF negotiated it, there was plenty of experience of high speed driving from steam days. The public reason isnt always the same as the private reason and you will find most history books taking a more cynical view.
As it was for the GW loco that exceeded 100 mph but I remember the first 100 mph sign going up on the GN main Line well after steam was on its way out. There was no high speed running at or above 100 mph in the UK on a regular and sustained fleet operation. Whilst some trains may well have reached this speed it was not done through the medium of a timetable.110-plus was well inside the performance envelope for a Gresley A4 and the Stanier Duchess/Coronations, that's steam-age HS running.
110-plus was well inside the performance envelope for a Gresley A4 and the Stanier Duchess/Coronations, that's steam-age HS running.
The only time I've known an accident occour with 125mph stock is when 110mph stock would have suffered exactly the same fate anyway...
That's why all non-steam cabs now, high speed or not, are single-manned.
It's not rocket science to work out there'd be one man with a job to do, and a spare man with nothing to do except to chat and thereby distract the one with the job to do - ergo, two man operation in those circumstances is less safe than single-man operation.