The AC Electrics: Classes 80-85, 86, 87

[xotGD]

Am I right in thinking that two different locos were numbered 86501 at different times?

 

[Richard Scott]

It’s amazing how different that looks, very continental!

Slightly OT, but doesn’t deserve a thread on its own: what causes the clicking you hear on electric lines, as heard hear at 3:58 -

Clicking is the spirax valve on the loco

 

[Mag_seven]

Am I right in thinking that two different locos were numbered 86501 at different times?

86258 and 86608

 

[xotGD]

86258 and 86608

Thanks. I had 501 for haulage in August 89, so I guess that must have been 258.

 

[NorthWestRover]

Did you have it as 258?

 

[Helvellyn]

Thanks. I had 501 for haulage in August 89, so I guess that must have been 258.

86501 (ex-86258) and 86501 (ex-86608, ex-86408, ex-86008).

 

[xotGD]

Did you have it as 258?

Yes - in Jan 88.

 

[Inversnecky]

Interesting video of the tap changer in action:

From this, it appears the tap changer wasn’t a feature of the first two classes:

Class History - AL6 / 86 - The AC Locomotive Group

We are the UK's only dedicated AC electric locomotive preservation society.

www.aclocogroup.co.uk

 

[GRALISTAIR]

If you look at the 87 in second picture that one also has one. Have seen other pictures of 87s with that type of pantograph.

I have a photo of them all with that pant then another with them all fitted with the high speed Brecknell Willis pant.

87009 ran around with a Stone Faiveley type for a while:

(photo by "Jamerail" on Flickr)

87009 [JC1-116]

87009 speeds through Nuneaton station on a Northbound passenger service. Unsure of exact date, but sometime in week 4th-8th July 1983.

www.flickr.com

forgot about that

 

[jfollows]

From this, it appears the tap changer wasn’t a feature of the first two classes:

The AL1-AL5 all had tap changers, however on these earlier implementations the tap points were made on the low voltage, high current side of the transformer. The AL6 design changed to using the high voltage, low current side of the transformer for the tap points. The experience with the earlier design presumably led to the design and implementation of the high tension tap changer in the AL6 as something that was more reliable and this seems to have been borne out by the fact that some of them are still in operation today with high tension tap changers.

EDIT - However, the article you posted tells us that the AL2 had a high tension tap changer from the start, which was something I didn't know until now. So this was a design feature of the AL2 which proved itself presumably from the start and was therefore selected for implementation in the much larger AL6 class later on.

What's interesting to me about this story, the history of the development of these locomotives, is that they represent the implementation and development of new technologies which mirror my timeline (I was born in 1961). Some of the early implementations were basic and unsubtle to say the least (such as the early rectifiers) and then, gradually, we see the implementation of high power semiconductors to replace and improve - so 87036/87101 was the only one of the set under consideration here which didn't have a tap changer from the start. But they all had DC motors, which were completely tried and tested technology, and although the idea of AC motors and regenerative braking all existed in 1961, it's only much more recently that it's become possible to implement with 25kV AC overhead supplies and become the new normal.

FURTHER EDIT - I've seen it mentioned elsewhere that the AL4 also had a high tension tap changer, but I can't find an authoritative source for this. I've learned something new today!

 

[GRALISTAIR]

87036/101 Thyristor control

 

[Richard Scott]

87036/101 Thyristor control

Wasn't there something fitted meaning it could only be driven as a thyristor loco with a special key? In normal service it acted like a tap changer loco, or have I made that up?

 

[Taunton]

Once the rectifiers were changed on 82/84 in the early 1970s, what were the continuing issues with them?

It does seem the development of the supply side, lineside substations and wiring, was about a generation ahead of the motive power side. Don't forget the various issues with the EMUs as well.

 

[billh]

Around 1980 I saw two class84s in a scrap yard at Hyde,near Manchester . They must have arrived by road. The carcase of one of them was heaped onto a pile of its own innards, transformer, switchgear and the likes, quite sad to see it like that.
I have a feeling they may have come from Metro-Vic/AEI at Trafford Park, which was in the process of downsizing or closing at that time and there was a lot of redundant machine tools etc from there also in the yard.

 

[CW2]

84002 and 84010 were sold to GEC at Trafford Park for use as generators. Once the useful electrical equipment was removed they were moved by road to a "Stockport scrap dealer."
Info from "The Power of the AC Electrics", details above.

 

[Inversnecky]

Yes, sad to see their end.

From hero to zero, from beacon of a modern, electrified future, to the scrap heap.

 

[jfollows]

Wasn't there something fitted meaning it could only be driven as a thyristor loco with a special key? In normal service it acted like a tap changer loco, or have I made that up?

I believe you're right, that it had two modes of operation, in "normal" mode it was driven as if it had a tap changer whereas in "advanced" mode it was driven to take advantage of the technology.

 

[hexagon789]

The AL1-AL5 all had tap changers, however on these earlier implementations the tap points were made on the low voltage, high current side of the transformer. The AL6 design changed to using the high voltage, low current side of the transformer for the tap points. The experience with the earlier design presumably led to the design and implementation of the high tension tap changer in the AL6 as something that was more reliable and this seems to have been borne out by the fact that some of them are still in operation today with high tension tap changers.

EDIT - However, the article you posted tells us that the AL2 had a high tension tap changer from the start, which was something I didn't know until now. So this was a design feature of the AL2 which proved itself presumably from the start and was therefore selected for implementation in the much larger AL6 class later on.

What's interesting to me about this story, the history of the development of these locomotives, is that they represent the implementation and development of new technologies which mirror my timeline (I was born in 1961). Some of the early implementations were basic and unsubtle to say the least (such as the early rectifiers) and then, gradually, we see the implementation of high power semiconductors to replace and improve - so 87036/87101 was the only one of the set under consideration here which didn't have a tap changer from the start. But they all had DC motors, which were completely tried and tested technology, and although the idea of AC motors and regenerative braking all existed in 1961, it's only much more recently that it's become possible to implement with 25kV AC overhead supplies and become the new normal.

FURTHER EDIT - I've seen it mentioned elsewhere that the AL4 also had a high tension tap changer, but I can't find an authoritative source for this. I've learned something new today!

82s and 84s had HT tap-changers.

And E3100 was originally equipped with an experimental transductor non-electronic control, stepless tap changer. This permitted much finer control of tractive effort and thus greater haulage capacities. While successful it was converted back to a standard Class 83 between August and October 1970.

The PKP locos took certain design elements from the experimental E3100.

Wasn't there something fitted meaning it could only be driven as a thyristor loco with a special key? In normal service it acted like a tap changer loco, or have I made that up?

Yes, in advanced mode it operated like a Class 90 with the controller setting a tractive effort and a seoerate control used to set the desired speed. The locomotive then accelerates to the set speed at a rate corresponding to the set tractive effort.

There was also a tractive effort "boost" button which allowed uprated performance for short periods, the higher TE would be held either until the set speed was obtained or maximum motor voltage reached.

In 'normal' mode it behaved exactly like a standard 87, notches and all.

Once the rectifiers were changed on 82/84 in the early 1970s, what were the continuing issues with them?

It does seem the development of the supply side, lineside substations and wiring, was about a generation ahead of the motive power side. Don't forget the various issues with the EMUs as well.

On 82s the transformer cooling oil levels and underpowered tap changer motors (causing tap changer failures) may have continued to cause issues after the rectifiers were changed; on 84s the issues appeared to be continued diverted switch flashovers and excessive gearwheel drive arm wear.

 

[Cricketer8for9]

On books you can also add Sparks, A celebration of British AC electric Locomotives by Charles Buchanan, published by Triangle Publishing, ISBN 0-9550030-1-6 in 2006 and Electric Trains in Britain by B.K Cooper, published in 1979 by Ian Allan, ISBN 0 7110 0972 4. The latter is not just about the AC engines, it does have some third rail stuff, and indeed 1500 volt DCN the former does what it says on the tin.

 

[hexagon789]

On books you can also add Sparks, A celebration of British AC electric Locomotives by Charles Buchanan, published by Triangle Publishing, ISBN 0-9550030-1-6 in 2006 and Electric Trains in Britain by B.K Cooper, published in 1979 by Ian Allan, ISBN 0 7110 0972 4. The latter is not just about the AC engines, it does have some third rails stuff, and indeed 1500 volt DCN the former does what it says on the tin.

My book of reference is "AC Electric Locomotives of British Rail", Brian Webb and John Duncan. Published by David & Charles, Newton Abbot. ISBN 0 7153 7663 2

Wealth of technical details on AC electrification, prototype Class 80, production Classes 81-87, experimental variants and a section on foreign exports of British equipment

 

[Ken H]

worth noting that Cl 86/87/90 were fitted with RCH jumpers for multiple and push pull working. Cl 81 - 87 also had high level jumpers from new for multiple working. I think it was theoretically possible for a Cl 81 to work in multiple with 87010.
The RCH jumpers carried time division multiplex (TDM) signals to pass control messages.

The Cl 86 was a flawed design. They decided that fully sprung motors were too expensive. They spent the lives of the class trying to fix a bad design decision. But they managed to make a 100mph design able to work at 100mph.

I remember my first go on an AC train from Lancaster to Carlisle. The acceleration as we left Lancaster was so much better than the stuff I was used to east of the Pennines. Over the years had some good journies on the loco hauled WCML trains. But not making a 125mph loco to go with the Mk 3's was another bad BR decision. APT blight?

 

[edwin_m]

I remember my first go on an AC train from Lancaster to Carlisle. The acceleration as we left Lancaster was so much better than the stuff I was used to east of the Pennines. Over the years had some good journies on the loco hauled WCML trains. But not making a 125mph loco to go with the Mk 3's was another bad BR decision. APT blight?

Despite being so much better than what preceded them, the performance of an electric loco-hauled set was a long way short of what today's multiple units can achieve with much more power and more motored axles (adhesion was the weak point of the AC electrics). It's questionable how much a 125mph non-tilting formation would have gained over a 110mph equivalent, especially as with the technology of the time the loco would probably have had to be higher-geared which would affect its acceleration at the lower end of the range. The Pendolinos changed all that, but now we're hearing that the 80x being ordered by Avanti can get close to those timings without the need for tilt.

 

[hexagon789]

worth noting that Cl 86/87/90 were fitted with RCH jumpers for multiple and push pull working. Cl 81 - 87 also had high level jumpers from new for multiple working. I think it was theoretically possible for a Cl 81 to work in multiple with 87010.
The RCH jumpers carried time division multiplex (TDM) signals to pass control messages.

The original push-pull system used with the DBSOs was designed to work with Class 81s which were at one point going to be transferred to the GEML Norwich services. Every control function that the 47/7s had controlled from the DBSO had a Class 81 equivalent. Engine start/stop were pan up/down for example though it was never used with 81s and they never had the necessary push-pull equipment installed.

The Cl 86 was a flawed design. They decided that fully sprung motors were too expensive. They spent the lives of the class trying to fix a bad design decision. But they managed to make a 100mph design able to work at 100mph.

It was more they felt axle hung motors motors were more reliable, less complex and they had better experience of them with the diesel-electric fleet. What wasn't appreciated was the D-Es ran at 100mph much less than the 86s would and on less trafficked lines.

But not making a 125mph loco to go with the Mk 3's was another bad BR decision. APT blight?

Given it took 10 years after the introduction of the 87s for the WCML to go to even 110mph running I'm sure BR probably considered it not worthwhile to upgrade a few short sections of the WCML to 125mph in addition to procuring 125mph locos hence the tilting APT-P project to allow higher speeds on the WCML.

If BR considered it worthwhile I'm sure they would've made the WCML 125mph without tilt.

Despite being so much better than what preceded them, the performance of an electric loco-hauled set was a long way short of what today's multiple units can achieve with much more power and more motored axles (adhesion was the weak point of the AC electrics). It's questionable how much a 125mph non-tilting formation would have gained over a 110mph equivalent, especially as with the technology of the time the loco would probably have had to be higher-geared which would affect its acceleration at the lower end of the range. The Pendolinos changed all that, but now we're hearing that the 80x being ordered by Avanti can get close to those timings without the need for tilt.

The 110mph workings did not surpass the fastest bookings in the original Electric Scot 1974 timetable for some years, indeed they were usually a few mins slower at best. Even after they speeded things up, 110mph saved 17 mins on the Royal Scot schedule in 1992 as compared to the original 5 hours in 1974 and that was as much due to the higher speed as to cutting recovery margins and station dwells.

 

[43096]

worth noting that Cl 86/87/90 were fitted with RCH jumpers for multiple and push pull working. Cl 81 - 87 also had high level jumpers from new for multiple working. I think it was theoretically possible for a Cl 81 to work in multiple with 87010.
The RCH jumpers carried time division multiplex (TDM) signals to pass control messages.

Classes 81-86 didn't have multiple working jumpers from new, only the 87s did. The 86/0/3/4 sub-class(es) were re-fitted with them before later getting TDM equipment. Classes 81-85 never had any form of multiple working as far as I know.

 

[hexagon789]

Classes 81-86 didn't have multiple working jumpers from new, only the 87s did. The 86/0/3/4 sub-class(es) were re-fitted with them before later getting TDM equipment. Classes 81-85 never had any form of multiple working as far as I know.

Class 81s were going to get the same RCH two-wire push-pull system the 47/7s/DBSOs had at one point but the plan was never implemented.

 

[LNW-GW Joint]

BR did have the intention in 1985 to order 25 class 91/Mk4 sets for the WCML and included this in the procurement options for the ECML build of IC225s.
But eventually gave up on the idea and went with the cheaper option of class 90 and existing stock.
That was followed by the IC250 plan for the WCML, before eventually (with privatisation) opting for tilting Pendolinos with Virgin.

 

[43096]

BR did have the intention in 1985 to order 25 class 91/Mk4 sets for the WCML and included this in the procurement options for the ECML build of IC225s.
But eventually gave up on the idea and went with the cheaper option of class 90 and existing stock.
That was followed by the IC250 plan for the WCML, before eventually (with privatisation) opting for tilting Pendolinos with Virgin.

The 91+Mark 4 for West Coast was revived when BR was allowed to lease some stock just before privatisation. The competition was between Network SouthEast for more Networkers and InterCity for around 15 Class 91+Mark 4 sets. NSE won the day, with the 41 Class 365s being the result.

 

[Taunton]

The 110mph workings did not surpass the fastest bookings in the original Electric Scot 1974 timetable for some years, indeed they were usually a few mins slower at best.

Right from the word go there had been high speeds on the WCML. Apparently a little competition developed to do Euston to Coventry (94 miles) in under an hour. You are not going to achieve that sticking to 100mph. And in fact management tolerated up to 110mph. With 1960s layouts and vacuum brakes.

Experiences in the 1974 "speed up" were similar.

 

[Bald Rick]

The 91+Mark 4 for West Coast was revived when BR was allowed to lease some stock just before privatisation. The competition was between Network SouthEast for more Networkers and InterCity for around 15 Class 91+Mark 4 sets. NSE won the day, with the 41 Class 365s being the result.

Indeed - that lease arrangement was designed by Governement specifically to enable more units to be built for NSE and keep York Works open. When InterCity West Coast waded in other the proposal for IC225s, there was much consternation at both DfT and Treasury. Especially as the ICWC proposal had (allegedly) a better financial case.

Right from the word go there had been high speeds on the WCML. Apparently a little competition developed to do Euston to Coventry (94 miles) in under an hour.

In the late 90s I often use to catch the 2115 off Euston which, unusually, was first stop Cov, always a Mark II set and almost always an 86. Quite often managed it in (just) under the hour. Of course this is before Weedon was eased and a few other changes made - and I suspect OTMR wasn’t as universal as it is now.

 

[Taunton]

In the late 90s I often use to catch the 2115 off Euston which, unusually, was first stop Cov, always a Mark II set and almost always an 86. Quite often managed it in (just) under the hour. Of course this is before Weedon was eased and a few other changes made - and I suspect OTMR wasn’t as universal as it is now.

Quite so. But what I describe was 1967!