class 57 question

[randyrippley]

Why was the class 47 used as the donor for the class 57 project??
At the time there were enough redundant class 56 machines lying around, which would have had bodyshell and bogies that were ten years newer, it seems perverse not to have used those.
Even if the problem was that the traction motors were geared too low, surely they could have grafted 47 bogies onto the 56 body?

 

[Cowley]

Why was the class 47 used as the donor for the class 57 project??
At the time there were enough redundant class 56 machines lying around, which would have had bodyshell and bogies that were ten years newer, it seems perverse not to have used those.
Even if the problem was that the traction motors were geared too low, surely they could have grafted 47 bogies onto the 56 body?

Was it because when the first ones were converted for Freightliner in 1997/98 the 56s were still hard at work?
Perhaps class 47 bodyshells were much easier to come by at that time.
Once 57601 had been converted things like the ETS system must have all been designed in using I assume some of the standard 47 route for the cabling, along with the general experience gained in service.
Perhaps this along with using 56s and swapping bogies to make a hybrid with all the associated paperwork etc just wasn’t worth doing compared to using ex 47s?

It’s interesting to note that the first class 57 conversions were twenty years ago now, and there’s still talk of more 1960s/70s traction (more 73/9s and the class 69s) being re-engineered even now.

I think the fact that a locomotive is thirty years old compared to forty years old in some ways doesn’t matter because you’ll have to do corrosion repairs on both of them anyway.

 

[43096]

Why was the class 47 used as the donor for the class 57 project??
At the time there were enough redundant class 56 machines lying around, which would have had bodyshell and bogies that were ten years newer, it seems perverse not to have used those.
Even if the problem was that the traction motors were geared too low, surely they could have grafted 47 bogies onto the 56 body?

Ownership was a large part of it. The initial 57s were converted for Freightliner and used existing Freightliner 47s for the first batch. EWS owned the 56s and at that time most were still in use and EWS was not selling on second-hand machines at that time and was even less interested in helping their competitor.

During the conversion programme, ownership changed and Porterbrook financed them - of course they had a large number of 47s that came off lease as Virgin stopped using them.