Class 50 Design Process

[Parham Wood]

Someone asked a question about Class 50 reliability on a closed thread here. This article may be of interest.

Why the ‘50s’ triumphed in class struggle

Half a century has passed since the Class 50s’ entry into service. DAVID CLOUGH explores the factors that led to the English Electric D400 Type 4 order in 1965

www.railmagazine.com

 

[randyrippley]

I've seen that document before and was always gobsmacked by this little bombshell

Prior to this approval and also in April, BR had made a comparison between the 3,300bhp Class 55 ‘Deltic’ and Class 47 for the WCML north of Crewe and concluded the balance of advantage lay with the former for reliability and scheduling

OK we all knew the 47s had the major crankcase issues, but the Deltics more reliable? If so it just shows there were some bad purchasing decisions being made at BR. Clearly the later 47 batches should have been Deltics

 

[Helvellyn]

I've seen that document before and was always gobsmacked by this little bombshell



OK we all knew the 47s had the major crankcase issues, but the Deltics more reliable? If so it just shows there were some bad purchasing decisions being made at BR. Clearly the later 47 batches should have been Deltics

But BR didn't want twin engine locos, which is one of the reasons DP2 was built. Now if EE had been allowed to effectively do a production run of those before having to add all the extras BR wanted...

 

[Clarence Yard]

Don’t forget the considerably higher daily diagrammed mileage would have skewed the reliability figures in favour of the Deltics. If you did the mean time (in days) between casualties, that would have been a different story.

 

[Richard Scott]

But BR didn't want twin engine locos, which is one of the reasons DP2 was built. Now if EE had been allowed to effectively do a production run of those before having to add all the extras BR wanted...

Believe in terms of miles per casualty the 47s and 50s were fairly similar (post refurb for 50s) but 50s tended to fail with more expensive issues. Seem to remember an article on Waterloo to Exeter route that gave reliability figures and they were comparable.

 

[Cowley]

Believe in terms of miles per casualty the 47s and 50s were fairly similar (post refurb for 50s) but 50s tended to fail with more expensive issues. Seem to remember an article on Waterloo to Exeter route that gave reliability figures and they were comparable.

I guess that 50s failing on the single line sections of the West of England route also caused the failures to be more noteworthy due to the disruption caused.
It’s a shame that the class wasn’t fitted with alternators during the refurbishment process as I think they would have settled down as a great fleet on the workings that they were allocated.

 

[Richard Scott]

I guess that 50s failing on the single line sections of the West of England route also caused the failures to be more noteworthy due to the disruption caused.
It’s a shame that the class wasn’t fitted with alternators during the refurbishment process as I think they would have settled down as a great fleet on the workings that they were allocated.

I know it was down to cost but still can't believe that the biggest issue with the class i.e. the generator wasn't replaced at refurbishments. To be fair I used to do the 50s most weekends in early 90s and never had a total failure with one. Biggest delays I had were caused by two locos refusing to multiple work with each other!

 

[Cowley]

I know it was down to cost but still can't believe that the biggest issue with the class i.e. the generator wasn't replaced at refurbishments. To be fair I used to do the 50s most weekends in early 90s and never had a total failure with one. Biggest delays I had were caused by two locos refusing to multiple work with each other!

Yes I must admit that being at one end of the route I was generally waiting for a 33 to drop, so although I didn’t see many completely failed 50s, I certainly reaped the rewards if it happened (“We are sorry to announce that the 12xx service from Waterloo is running 80 minutes late. This was due to a locomotive failure at…” ).
I do have a bit of a soft spot for the 50s though. Imagine what they’d have been like with a class 56 style alternator fitted? I don’t think there would have been much that could’ve beaten them Type 4 wise.

 

[Helvellyn]

Given how much else was done during refurbishment it is surprising, but were they considered too new? The only locos fitted when refurbishment started were the 56s and HST power cars. The Class 37 refurbishment that saw generators replaced with alternators didn't start until the Class 50 programme was complete.

 

[43096]

Given how much else was done during refurbishment it is surprising, but were they considered too new? The only locos fitted when refurbishment started were the 56s and HST power cars. The Class 37 refurbishment that saw generators replaced with alternators didn't start until the Class 50 programme was complete.

The Western Region wanted them fitted with alternators at refurbishment. It was ruled out on the grounds of cost.

It’s one of those “what ifs” but had they been converted, they would have been ideal for Cross-Country in place of the long range Duffs and would have lasted until Virgin’s Voyager shambles displaced them.