Why not upgrade Class 91s to AC traction motors?

[JonD]

Hi all,

I was looking at the stalwart IC225 while passing the East Coast Main Line last week, and it occurred to me that things had moved on a fair bit in railway traction since the days of the APT (IC225's heritage), yet the design was clearly a very good one.

Given recent major re-engineering programs to the HST fleet, is there any reason why it there has not been a move to replace the DC traction motors on the class 91 fleet with modern, more efficient AC units with IGBT control?

Is it just a case of insufficient return on investment?

Best regards
Jonathan

 

[asylumxl]

I'm not sure of the technicalities, but the British rail industry seems to not be willing to make any long term investments, despite their large profits.

 

[Royston Vasey]

All sorts of reasons

1) They are 10-15 years younger than the HSTs and don't need life extension yet
2) They are working fine, by and large, whereas the original HSTs were failing unacceptably often
3) Thinking of cradle to grave efficiency, would the benefits of operational efficiency (not sure to what extent this is true) justify throwing away an operational and non-life-expired piece of equipment and building and installing another? I can't see it.

So yeah, the last part of your post sums it up, little or negative return on investment.

I'm not sure of the technicalities, but the British rail industry seems to not be willing to make any long term investments, despite their large profits.

Err... FGW and XC reengined and refurbished their HSTs didn't they? Virgin bought Pendolinos. And the DfT controls much of the investment process. Don't think it's entirely fair to pick on TOCs, despite recent bad publicity regarding certain franchises.

 

[mbonwick]

It's hardly surprising TOCs don't want to make long-term investments, by the time the benefits are starting to appear, the franchise will have changed!

 

[JonD]

> 1) They are 10-15 years younger than the HSTs and don't need life extension yet


Indeed, and it was because of the apparent intention for the IEP to replace them early that I wondered whether it wouldn't be more sensible to upgrade a successful loco instead.

However, I can see what you mean. Thanks for the replies.

Best regards
Jonathan

 

[Shinkensgone]

Around 2004-2006, GNER gave all the cl 91s had a heavy grade, back to chassis refurbs including traction motors, as a result they were more reliable and performed better. Even the cab got a nice makeover.