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GBRF class 66 re-gearing

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Richard Scott

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hwl said:
Not quite I have amended. The power is limited by what comes out of the alternator terminals albeit the voltage/current combination thrown at the TMs by the alternator will be slightly different resulting in the need to do a bit of relearning for driver which is probably what is giving DB nightmares at the moment (and FL staff breaking out the popcorn).
I may do an explainer with graphics and data on this at some point if I get the time.

Mostly agreed but due to subtle difference in the voltage and current supplied by the alternator to the TMs at a given speed compared to 75mph geared locos the TE deliverable at low-medium non-adhesion limited speeds is slightly better (small single digit %) due to very slightly better motor efficiency.
The solution to the back EMF issue is three phase motors driven by VVSD operating at a high voltage as possible with gearing that is vaguely appropriate for the max top speed, the tolerance on gearing ratio choice is much wider.

The parallel to series-parallel switch over speed is also lower on the 65mph geared locos to align with the different V/I characteristics.
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Thanks but am aware as someone with an electrical engineering degree but I try to keep it so all can access. Not the easiest topic to make accessible to everyone (hope that doesn't sound patronising as not supposed to be).
 
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The_Train

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Are all 3 of the GB re-geared sheds now back in service?

Also, does anybody know if 66687 has kept its "Annette" name that it carried as 66777 please?
 
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hwl

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Richard Scott said:
Not the easiest topic to make accessible to everyone (hope that doesn't sound patronising as not supposed to be).
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Completely agreed and there isn't a good online resource to point any one to with sufficient detail.
 
Alex62319

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The_Train said:
Are all 3 of the GB re-geared sheds now back in service?

Also, does anybody know if 66687 has kept its "Annette" name that it carried as 66777 please?
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From photos I've seen online 66687 has kept its nameplate.
 
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Spaceship323 said:
Half of them are 66/6's anyway so just need renumbering? All DB's 60's were for sale - obviously GBRf didn't want them
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Bit of an exaggeration there. I think it was four of which couple are hired to Colas aren't they ? 66793-66796 were delivered to 65mph spec.

My impression is that GBRf will continue to operate the 60s they currently have, until they either break or become due heavy overhaul, then maybe hand them back if they are leased. In the next eighteen months or so GBRf should receive another twenty eight 99s and they will displace 66s. More 66s can then be regeared as necessary to replace 60s. Class 60 is now around 35 years old in terms of age and structure, although none of them have put in 30 years continuous service. Pity they were never fitted with AC drivetrain, but are still rugged enough if the Mirrlees can be maintained.
 
43096

43096

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Wyrleybart said:
Bit of an exaggeration there. I think it was four of which couple are hired to Colas aren't they ? 66793-66796 were delivered to 65mph spec.
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Those are the four delivered with that spec, but none were hired to Colas. That was 66790-792, all of which are now back off hire.
 
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wickham

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Harlequinuk said:
Why are GB regearing them? Wont DB sell anymore 60`s?
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Although Class 60s have a higher Tractive Effort than the standard 66, they are far less reliable. Not much seems to stop a Class 66 that a "reset" wont solve, but you can't reset a Class 60 !
 
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wickham said:
Although Class 60s have a higher Tractive Effort than the standard 66, they are far less reliable. Not much seems to stop a Class 66 that a "reset" wont solve, but you can't reset a Class 60 !
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True but believe a 60 is more fuel efficient? Probably doesn't offset extra maintenance costs, though.
 
Nym

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wickham said:
Although Class 60s have a higher Tractive Effort than the standard 66, they are far less reliable. Not much seems to stop a Class 66 that a "reset" wont solve, but you can't reset a Class 60 !
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Then what's that big on/off switch and/or electronics reset pushbutton in the clean air room for?
 
Loadhaul60059

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Does anyone know what the situation is with 66693 please? It seemed to enter service for a bit after being re-geared/re-numbered, but it's been at Longport since the beginning of September.
 
Rob F

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Is this a relatively easy and inexpensive conversion?

If so, I wonder if similar was ever considered for the class 67s, re-gear them to 100 mph and you might have a locomotive that could pull some of the skin off a rice pudding and be more suitable for the work they ended up doing.
 
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Wyrleybart

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Rob F said:
Is this a relatively easy and inexpensive conversion?

If so, I wonder if similar was ever considered for the class 67s, re-gear them to 100 mph and you might have a locomotive that could pull some of the skin off a rice pudding and be more suitable for the work they ended up doing.
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Sounds like a good rational idea but ......

The 67 was only really intended as a fast passenger / mails locomotive ordered for a purpose which disappeared in 2004. Personally, I don't think they every really lived up to the EMD mantra of reliability, because they actually weren't an EMD design, apart from the power assembly and traction motors. too heavy for the track and too light for freight work.

OMHO the UK DBC operation wouldn't invest in such a small fleet, and I suspect the only reason 67s are still running are :
A) Royal Train
B) Belmond Pullman
C) TfW Mk4 contract

A) is more or less over and I wouldn't be surprised if TfW consider trials with the redundant class 68s which DRS are probably handing back - 68016-68018
 
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50002Superb

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I noticed that a couple of 66/7s went to Longport today (66730 and 66760 with 66308), are they next for conversion?
 
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