1970-1974 WCML Weaver Jct -Glasgow electrification

edwin_m said:

The amount of damage per axle was probably less, but the Brighton line would have a lot more motored axles passing over per hour than the WCML.

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Though lower speeds too.

Until the early-80s, IIRC the Brighton Main Line was still 75mph maximum until it was resignalled and linespeed was then increased to 90.

GRALISTAIR said:

In this one taken at Euston I have Class 86 with and without Flexicoil

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Interesting that both locos have cross-arm pantographs - out of the 100 built, only 10 were originally fitted with those, the rest had single arm Stone-Faiveley pantographs.

edwin_m said:

Flexicoils (or to a lesser extent resilient wheels) reduce the unsprung mass, which hammers the track with a large force wherever there is a slight imperfection. This tended to make the imperfection worse and ultimately pulverised the ballast leaving a patch of mud that "pumped" every time a train went over. The 81-85 had the traction motors attached to the bogie frame and driving the axles through a flexible drive, so they were not part of the unsprung mass. The 86s tried to make this simpler/cheaper this by adopting nose-suspended traction motors with a non-flexible gearing to the axle and the other end of the motor attached to the bogie frame by a pivot. Thus, the motor had to move up and down with the axle, pivoting at the other end, and much of the weight of the motor was therefore unspung. Southern EMUs had the same arrangement, but at lower speed and with less weight on the axle so weren't as bad for track damage.

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As the 86s were rated at around 1000hp per axle, the motors were doubtless rather heavier than e.g. those fitted to contemporary diesels (which were half the power per axle). BR hadn't had similar track damage issues with the Deltics despite those running at 100mph with nose-suspended traction motors (IIRC the track forces of a Deltic at 100mph became a de-facto benchmark for what was acceptable).

As well as track damage/higher track maintenance costs, the poor riding of the 86's at 100mph produced a lot of complaints from drivers and was causing reliability issues with the motors and other equipment on the locos due to excessive shock forces and vibration. So something had to be done...

While the resilient wheels reduced the unsprung mass considerably (from around 4.5 tons to around 1.5 tons) and halved the dynamic track forces at 100mph, that alone didn't fix all the issues, so various experiments were done and the Flexicoil system (I assume) proved to be the best upgrade (albeit expensive, needing new bogie side frames and loco body modifications).

It would be interesting to know how much the whole saga cost BR, versus the cost savings from not using frame mounted motors and flexible drives in the first place?

(Comments above based on info from 'AC Electric Locomotives of British Rail' by Brian Webb and John Duncan - pretty much the seminal book on them, up to the cl. 87).

Taunton said:

Resilient wheels had a long history even then, they first came to prominence in the USA-designed PCC tram design of the 1930s, of which many thousands were built, running on into rapid transit cars with the same technology, and I never heard of any issue with them. Something tells me they were originally patented by a Swedish manufacturer. Didn't Dowty or another have the UK patent rights?

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Mansell composite wheels were still in use on LMS design 1st class sleeping cars until the 1970s, I believe.

ac6000cw said:

As the 86s were rated at around 1000hp per axle, the motors were doubtless rather heavier than e.g. those fitted to contemporary diesels (which were half the power per axle). BR hadn't had similar track damage issues with the Deltics despite those running at 100mph with nose-suspended traction motors (IIRC the track forces of a Deltic at 100mph became a de-facto benchmark for what was acceptable).

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Though Deltics as Co-Co had an almost 30% lower axle loading - 16 tons, 10cwt vs 21 tons, 7cwt for an 86.

matchmaker said:

Mansell composite wheels were still in use on LMS design 1st class sleeping cars until the 1970s, I believe.

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would you count wheels with a timber infill instead of spokes in this category? I bet some of the preserved railways have antique coaching stock with"wooden" wheels...
https://www.igg.org.uk/rail/4-rstock/04arstock2d.htm says

Wooden centred, metal tyred 'Mansell' wheels, developed in the 1860's, continued in use on non-passenger coaching stock, horse vans and the like, up to the 1950's. These had a steel centre hub with a hardwood body and a steel rim and tyre.

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hexagon789 said:

Though Deltics as Co-Co had an almost 30% lower axle loading - 16 tons, 10cwt vs 21 tons, 7cwt for an 86.

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Agreed, but most of that weight is 'sprung' (the bogie frames via the primary suspension, the rest via primary plus secondary suspension). AFAIK, it's the unsprung mass that is more important at high speeds - which with axle-hung motors is effectively the wheelset and final drive plus roughly half the motor mass (as the other side of the motor is pivoted on the bogie frame).

As an extreme example, in the USA and Canada, the Siemens Charger 125mph diesels have frame mounted motors and 30 tonne axle loads. The 125mph US Siemens ACS-64 electrics are nearly 25 tonne axle load, and their predecessor AEM-7 were around 23 tonnes.

USA locos have always had axle loads well beyond UK limits, principally to give them adhesion to move their substantial loads. New locos were commonly weighed down with concrete or scrap steel from the factory. This is despite the sometimes poor quality of USA tracks (or some would argue the latter is because of it). Recent times have brought some technical advances, like Creep Control.

From back in diesel-hydraulic days, the Warships, 2,200 hp and 4-axle, I think the most powerful B-B on BR, could be notably slippery starting away from Taunton in the rain, in a way the 2,700 hp C-C Westerns, with less power per axle, were not. Generally it was just the front bogie that was slipping, and engine racing, as the two were not mechanically connected.

Back to the WCML - however did we get to something built in California? .

ac6000cw said:

As the 86s were rated at around 1000hp per axle, the motors were doubtless rather heavier than e.g. those fitted to contemporary diesels (which were half the power per axle). BR hadn't had similar track damage issues with the Deltics despite those running at 100mph with nose-suspended traction motors (IIRC the track forces of a Deltic at 100mph became a de-facto benchmark for what was acceptable).

As well as track damage/higher track maintenance costs, the poor riding of the 86's at 100mph produced a lot of complaints from drivers and was causing reliability issues with the motors and other equipment on the locos due to excessive shock forces and vibration. So something had to be done...

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hexagon789 said:

Though Deltics as Co-Co had an almost 30% lower axle loading - 16 tons, 10cwt vs 21 tons, 7cwt for an 86.

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All consequences of adopting four-axle mixed traffic design. The original AC electrification didn't have much freight operation on severe gradients so it probably didn't matter too much thn, but adhesion would have become much more significant when Shap and Beattock were electrified. I guess they could have gone for something more heavyweight for the Class 87, but would have lost the benefits of a mostly interchangeable fleet (vacuum brake and later 110mph excepted).

Catch points were removed on the northern WCML with electrification, and any freight not fully fitted had to go via the Settle-Carlisle and Glasgow and South Western. I wonder if one contributory factor was that the electrics would have had difficulty braking an unfitted freight on those gradients.

edwin_m said:

Catch points were removed on the northern WCML with electrification, and any freight not fully fitted had to go via the Settle-Carlisle and Glasgow and South Western. I wonder if one contributory factor was that the electrics would have had difficulty braking an unfitted freight on those gradients.

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I remember being told that the catch-points were removed for the APT trials. The catch-points were apparently motor-worked (presumably by a treadle on the approach) but they couldn't be closed quickly enough for the planned APT speeds.

edwin_m said:

All consequences of adopting four-axle mixed traffic design. The original AC electrification didn't have much freight operation on severe gradients so it probably didn't matter too much thn, but adhesion would have become much more significant when Shap and Beattock were electrified. I guess they could have gone for something more heavyweight for the Class 87, but would have lost the benefits of a mostly interchangeable fleet (vacuum brake and later 110mph excepted).

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I suspect BR were basically following what had become common practice in Europe i.e. using mostly (cheaper to build and maintain) four-axle electric locos, but they seemed reluctant to embrace the idea of double-heading when necessary (e.g. AFAIK no MU capability on the 81-86's as-built). AFAIK none of cl. 81 to 86 were even fitted with sanding equipment originally, but it was later added to at least the 86s and fitted as standard to the 87s onward.

Getting back to the main topic, I think the big thing about Weaver Junction - Glasgow electrification project was the 'total route modernisation' aspect - BR took 200+ miles of basically steam-age railway and largely rebuilt/updated/replaced/re-aligned/re-signalled it all, in a timescale that seems almost fantastical these days.

A year or two after it was complete, I went on a BR excursion from Birmingham to Edinburgh, the first time I'd travelled north of Weaver Junction I think. That ride behind an 86 in a train of Mk1's (with the sliding ventilator windows open, of course) was one of the most exhilarating train rides I've ever had, arriving at least an hour early at Carstairs. I got the impression that the drivers were determined not to get looped to allow something faster to overtake... Yes, a modern train can do it faster but riding in an air-conditioned tube isn't the same wind-in-the-hair experience . A few years later I had an early 1960's throwback experience over the northern WCML - a BR excursion from Manchester to Edinburgh in Mk1s again, but hauled both ways by a class 40

ac6000cw said:

Getting back to the main topic, I think the big thing about Weaver Junction - Glasgow electrification project was the 'total route modernisation' aspect - BR took 200+ miles of basically steam-age railway and largely rebuilt/updated/replaced/re-aligned/re-signalled it all, in a timescale that seems almost fantastical these days.

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I totally agree. In every single way it was a game changing project.

I seem to remember that back in the early 70's there were also tentative plans - which never came to fruition - for a 6,000 hp Co-Co class 88 freight locomotive. I'm sure that there was an article about them in Modern Railways at the time....complete with a photo of how they would look - with two smaller windscreens and two-row four character headcode panel between them.

So given some of the issues mentioned with Bo-Bo AC electrics why did BR never pursue the Class 89 Co-Co design? I know it lost out to the Class 91 on the ECML but if I am recalling correctly it was looked at again for the WCML, either passenger or freight, but ultimately not taken forward.

ac6000cw said:

That ride behind an 86 in a train of Mk1's (with the sliding ventilator windows open, of course) was one of the most exhilarating train rides I've ever had, arriving at least an hour early at Carstairs. I got the impression that the drivers were determined not to get looped to allow something faster to overtake...

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It was an AC lines thing. The Plymouth to Liverpool via Hereford day train in the early 1960s changed locos at Crewe, setting off was quite a revelation, I'm guessing that they attained 100mph by Winsford. It certainly FELT like that. "Showed that Warship thing what for, we did ...". Incidentally, brakes then hard on to stop at Hartford!

D6130 said:

I seem to remember that back in the early 70's there were also tentative plans - which never came to fruition - for a 6,000 hp Co-Co class 88 freight locomotive. I'm sure that there was an article about them in Modern Railways at the time....complete with a photo of how they would look - with two smaller windscreens and two-row four character headcode panel between them.

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May have been a different thing but I recall it as an electric version of the 58, which would put it in the 1980s.

Very fond memories as a young man , doing a Swansea - Glasgow excursion (which left at 0400 !) for £5 return - first ever trip to Scotland and we even managed an odd-on to go over the Forth Bridge as well. (to Inverkeithing I think) , much to the amusement of the booking clerk at Central (a long way to see a bit of water !) - we had a couple of pints of heavy before the return which was a very bad move. Stupid o'clock stand at New St , - bright lights and glaring tiles - but we were glad we had done it.

Some years later there was a supervisors dispute at Gushetfaulds and I caught the night shift , and nearly re-rerouted an 86 into a non wired route - but the excellent driver dropped the pan and I had to use the depot 08 to correct the road and pull the loco back under the wires. I was very careful after that. Experience all right. 5x12 hours shift for no extra money - but to be fair I got an ex-gratio payment. Coming south I was determined to stay awake , closed my eyes at Newton and was woken up at Euston !

Helvellyn said:

So given some of the issues mentioned with Bo-Bo AC electrics why did BR never pursue the Class 89 Co-Co design? I know it lost out to the Class 91 on the ECML but if I am recalling correctly it was looked at again for the WCML, either passenger or freight, but ultimately not taken forward.

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It's complicated... BR's prime aim was APT for West Coast passenger services. There was a fallback plan to use an electric HST power car variant if the APT power cars were delayed. So they had four different types of 125mph AC traction in development: APT, electric HST, Class 89, Class 91. Conclusion was it was a waste of resources having four such projects, so the decision was made to concentrate on Class 91.

D6130 said:

I seem to remember that back in the early 70's there were also tentative plans - which never came to fruition - for a 6,000 hp Co-Co class 88 freight locomotive. I'm sure that there was an article about them in Modern Railways at the time....complete with a photo of how they would look - with two smaller windscreens and two-row four character headcode panel between them.

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I also seem to recall that there were very tentative plans to convert Woodhead to AC and to use the 88s on that route.

43096 said:

It's complicated... BR's prime aim was APT for West Coast passenger services. There was a fallback plan to use an electric HST power car variant if the APT power cars were delayed. So they had four different types of 125mph AC traction in development: APT, electric HST, Class 89, Class 91. Conclusion was it was a waste of resources having four such projects, so the decision was made to concentrate on Class 91.

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The 89 came out of the electric HST, whilst the 91 came out of the APT (sort of). There were never four in development in parallel.

GRALISTAIR said:

I totally agree. In every single way it was a game changing project.

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Preston division totally rebuilt over 100 single track miles from Coppull to the Scottish border in 12 months working only at weekends.

Ballast, sleepers, CWR, destressing and even sand blanketing the wet spots as discussed above.