Inter City 125 / HST

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Discussion

2xChevrons

3,159 posts

79 months

Monday 17th May 2021
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yeager2004 said:
Interesting thread. Never really considered until now how tough the railway environment is on diesel engines.

One things I've always wondered is why the train engines are left idling for such extended periods. Presumably there's a technical reason why the engines are not just shut down if the train is not going to move for again, say within the next 15 minutes? (at major stations or depos, where external power could be connected up to power the coaches)
For various reasons, locos/units were left idling because the cost of doing so (in both fuel and any maintenance issues arising from doing so) were less than the hassle of starting them up again when they were needed. Leaving them idling means the loco is warmed up with its air tanks full and its batteries charged. Shutting them down opened up a world of 'what ifs...' for getting them going again. Those old EE and Sulzer engines were designed to run virtually continuously. Cold starting performance was not a consideration in the 1930s when these engines were designed and they could take a lot of effort to start from cold.

Most of these engines didn't use anti-freeze either, so the engines would be left idling in cold weather to stop the water freezing, which also helps keep various auxiliary systems working. With a loco engine needing several hundred gallons of coolant, the logistics of supplying anti-freeze for filling and topping up, mopping it up when it leaked and getting rid of it when it was changed wasn't worth the fuss.

Again, take the example of the EMD 2-stroke engines which were designed from a blank sheet for rail traction duties. They were intended to run continuously between 30-day inspections, needing only topping up with fuel in between those times. They were (and probably still are) designed so that you check the oil and water levels with the engine running. The EMD engines were not assembled from cast parts - instead the block(s) and crankcase are assembled from either flat beams or rolled/formed forgings which are welded together to create what is essentially a frame into which the cylinder liners and crank bearings are hung. This was done because any decent railway workshop of the 1930s had the technology to gas-axe out a section and weld in a new one, so even cracked blocks, crankcases, bearing webs and other major parts could be changed 'on site'. The downside was the engine was very prone to internal coolant leaks. Which was fine so long as the engine was running as the small amount of coolant that found its way into the cylinders or crankcase would just boil off. But if the engine sat for more than a few hours it could cause a hydrolock. And that was also why they used 'straight' water without anti-freeze - plain water wouldn't hurt the oil in the crankcase so long as the oil was hot enough to boil it off, but glycol-based antifreeze would erode the faces of the bearings and pit the cylinder liners.

Of course these days when engines are more sophisticated, batteries more dependable, fuel is more expensive and people, passengers and employees much more vocal about permanent clouds of diesel exhaust and noise you see less long-term idling, auto stop/start systems and the like.

As I mentioned in another thread where this came up, I don't mind mechanical/engine noise but I was once kept up all through a calm, still, muggy summer's night when I lived in Bristol by the "ying-ying-ying-ying-ying-ying-ying" of an idling Class 66 and by about 3am the noise was setting my teeth on edge. I think if it was a regular occurence even the delightfully lumpy loping 3/4-time idle of an old English Electric would wear thin very quickly.

Arnie Cunningham

3,758 posts

252 months

Monday 17th May 2021
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Ah. And that explains on the EMD startup videos that (I suspect) too many of us watch at bedtime they spin open the compression valves first before cranking them to get any water out before closing them back down and starting the motor.

I did wonder why they needed to do that when similarly sized other makes didn't.

Diesel Engine Startup videos at bedtime. FML.

2xChevrons

3,159 posts

79 months

Monday 17th May 2021
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Arnie Cunningham said:
Ah. And that explains on the EMD startup videos that (I suspect) too many of us watch at bedtime they spin open the compression valves first before cranking them to get any water out before closing them back down and starting the motor.

I did wonder why they needed to do that when similarly sized other makes didn't.

Diesel Engine Startup videos at bedtime. FML.
Indeed. I believe that big EMDs used for mains electricity/back up power when they're required to start instantly and may well be in automated plants started up remotely or automatically use two-stage air starters where the starter is fed low pressure air, enough to turn the engine through a compression stroke on all cylinders but not enough to put any rod-bending force on a hydrolock if it's present, and then switches to full air pressure to spin the thing to start. Of course such engines are usually plumbed into coolant and oil heaters so they're always at operating temperature which greatly cuts down the internal leaks and the tendency for condensation to form in the cylinders, which for a loco shut-down and stood outside in an American climate is not the case.

In Big Diesel Cold Start video terms, EMDs have the most interesting procedure pre-start but they're usually too reliable and quick to start once the button is pushed. A big English Electric waking up cylinder by cylinder, puffing smoke rings, maybe blowing the occasional flame and then hunting up and down through a couple of hundred RPM at 'idle' as the treacle-like oil squeezes through the governor is where the real entertainment's at.

Arnie Cunningham

3,758 posts

252 months

Monday 17th May 2021
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I have watched all of them and am well into the reruns of the reruns. smile

yeager2004

240 posts

90 months

Tuesday 18th May 2021
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2xChevrons said:
For various reasons, locos/units were left idling because the cost of doing so (in both fuel and any maintenance issues arising from doing so) were less than the hassle of starting them up again when they were needed. Leaving them idling means the loco is warmed up with its air tanks full and its batteries charged. Shutting them down opened up a world of 'what ifs...' for getting them going again. Those old EE and Sulzer engines were designed to run virtually continuously. Cold starting performance was not a consideration in the 1930s when these engines were designed and they could take a lot of effort to start from cold.

Most of these engines didn't use anti-freeze either, so the engines would be left idling in cold weather to stop the water freezing, which also helps keep various auxiliary systems working. With a loco engine needing several hundred gallons of coolant, the logistics of supplying anti-freeze for filling and topping up, mopping it up when it leaked and getting rid of it when it was changed wasn't worth the fuss.

Again, take the example of the EMD 2-stroke engines which were designed from a blank sheet for rail traction duties. They were intended to run continuously between 30-day inspections, needing only topping up with fuel in between those times. They were (and probably still are) designed so that you check the oil and water levels with the engine running. The EMD engines were not assembled from cast parts - instead the block(s) and crankcase are assembled from either flat beams or rolled/formed forgings which are welded together to create what is essentially a frame into which the cylinder liners and crank bearings are hung. This was done because any decent railway workshop of the 1930s had the technology to gas-axe out a section and weld in a new one, so even cracked blocks, crankcases, bearing webs and other major parts could be changed 'on site'. The downside was the engine was very prone to internal coolant leaks. Which was fine so long as the engine was running as the small amount of coolant that found its way into the cylinders or crankcase would just boil off. But if the engine sat for more than a few hours it could cause a hydrolock. And that was also why they used 'straight' water without anti-freeze - plain water wouldn't hurt the oil in the crankcase so long as the oil was hot enough to boil it off, but glycol-based antifreeze would erode the faces of the bearings and pit the cylinder liners.

Of course these days when engines are more sophisticated, batteries more dependable, fuel is more expensive and people, passengers and employees much more vocal about permanent clouds of diesel exhaust and noise you see less long-term idling, auto stop/start systems and the like.

As I mentioned in another thread where this came up, I don't mind mechanical/engine noise but I was once kept up all through a calm, still, muggy summer's night when I lived in Bristol by the "ying-ying-ying-ying-ying-ying-ying" of an idling Class 66 and by about 3am the noise was setting my teeth on edge. I think if it was a regular occurence even the delightfully lumpy loping 3/4-time idle of an old English Electric would wear thin very quickly.
Thanks for that; very insightful. Now you mention it, I have noticed at Reading station those new cross-country trains starting up on the platform. Doesn't seem to apply to the Reading-Guildford trains though! Guess this stock is a lot older.

I've read regular letters from locals in Reading living near Reading depot complaining about engines being left running all night.

Southerner

1,392 posts

51 months

Tuesday 18th May 2021
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yeager2004 said:
Thanks for that; very insightful. Now you mention it, I have noticed at Reading station those new cross-country trains starting up on the platform. Doesn't seem to apply to the Reading-Guildford trains though! Guess this stock is a lot older.

I've read regular letters from locals in Reading living near Reading depot complaining about engines being left running all night.
Idling near to residential areas is an increasing issue on the railway, understandably. The CrossCountry stuff you mention (the dreaded Voyagers) are routinely shut down between trips; despite being universally unpopular amongst the punters for various reasons, they're consistently amongst the most reliable diesel fleets in the country. Quite impressive considering the abuse they get. The GWR diesel fleet up that way is early 90s ex BR, in fairness with the Covid timetable they do get shut down more often, with long layovers particularly on the Basingstoke runs. Away from Covid though the usual few minutes between most journeys makes it hardly worthwhile switching them off.

Interesting* (*sort of) fact about diesel multiple units (DMUs) is that once the driver takes their key out, it'll run for a set period of time and then shut itself down automatically. About 20 minutes or so for the old BR clobber, probably varies wildly on newer stuff. In the case of a lot of services the time between journeys is sufficiently short that another driver turns up and keys in before the train reaches the auto shutdown point. You can shut them down manually as well, of course.

More interesting* wibble; when drivers change over mid-journey, the outgoing chap usually leaves his key in and the incoming bloke gives him his to take away. So, at a lot of operators, drivers' keys are continuously circulating around the network (I did say sort of interesting biggrin ). I've always found that mildly fascinating for some odd reason!

Dashnine

1,287 posts

49 months

Wednesday 19th May 2021
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itcaptainslow said:
Anyone with an interest in HST’s-the Haynes manual written in conjunction with the 125 Group is a worthy way of spending hours on the bog.
...while sitting outside and dumping it on the pavement for the full effect! yuck

I can't believe that even when HST was new that it was thought acceptable to dump the toilet contents on the track! I remember seeing a documentary years ago when a maintenance guy was doing something underneath and there was bog roll and we all know what else all over the bottom of the carriage.

Psycho Warren

3,087 posts

112 months

Wednesday 19th May 2021
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GliderRider said:
That explains why the engines on which I worked were often referred to as Paxman SSKs. I thought they were for back up generators on nuclear subs, whereas they were actually for the diesel electric Upholder/Victoria class.
Plenty of Valenta's have been in use in Marine applications. The Vanguard Class SSBN's have paxmans but not sure off top of head if they were valentas, was like 15 years ago when I was last on one.

Yertis

18,016 posts

265 months

Wednesday 19th May 2021
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anonymous said:
[redacted]
I live quite near a gradient on the Bristol–Exeter line, I can always tell what's going up by the sounds they make. Saw a couple of HST sets passing each other just this morning which was nice. HSTs still sound nicest even without the Valentas. Best sounding of all, ever, was a late running Black Five with a heavy excursion, on a hot summer evening. cloud9

SlowcoachIII

304 posts

220 months

Wednesday 19th May 2021
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Caught the train into Penzance yesterday on one of the refurbished GWR sets which was absolutely filthy. On one hand, it was sad to see the slam doors go but relief as there was no chance of getting a dirty sleeve.

I didn’t have much time to look but does anyone know which carriages were retained for the 4 car set?

Stedman

7,213 posts

191 months

Wednesday 19th May 2021
quotequote all
anonymous said:
[redacted]
It's only a rumour for the moment, but it seems those 'new' 769s wont be using the juice from Reigate/Redhill down to Gatwick. I should find out soon enough

Vickers_VC10

6,759 posts

204 months

Thursday 20th May 2021
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Stedman said:
anonymous said:
[redacted]
It's only a rumour for the moment, but it seems those 'new' 769s wont be using the juice from Reigate/Redhill down to Gatwick. I should find out soon enough
I'll be driving them on that route ...

The last I heard is initially they won't be using the third rail...having had a nose around on the depot I'm not sure in this day and age of ergonomics, how the hell the union signed them off.

Potentially they 'could' run third rail from Reading to Wokingham, then diesel to Aldershot South junction, back onto third rail from this point right through to Shalford junction where they will tackle the bulk of the Surrey Hills on asthmatic diesel engines. Back on the juice rail at Reigate and run them to Redhill and Gatwick this way. That is a lot of changeovers for a train not designed for it.

Imo these will be running diesel ALOT if not all of the time. Certainly the entirety of the Basingstoke route. Maybe OLE into the depot lol.

MattyD803

1,690 posts

64 months

Thursday 20th May 2021
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Vickers_VC10 said:
I'll be driving them on that route ...

The last I heard is initially they won't be using the third rail...having had a nose around on the depot I'm not sure in this day and age of ergonomics, how the hell the union signed them off.

Potentially they 'could' run third rail from Reading to Wokingham, then diesel to Aldershot South junction, back onto third rail from this point right through to Shalford junction where they will tackle the bulk of the Surrey Hills on asthmatic diesel engines. Back on the juice rail at Reigate and run them to Redhill and Gatwick this way. That is a lot of changeovers for a train not designed for it.

Imo these will be running diesel ALOT if not all of the time. Certainly the entirety of the Basingstoke route. Maybe OLE into the depot lol.
Spotted a class 769 sat outside Reading just last week actually...? Is this all part and parcel of this?

Having grown up on the Thameslink line backwards and forwards from Mill Hill into London, I had wondered what it was doing there in it's new livery...

Vickers_VC10

6,759 posts

204 months

Thursday 20th May 2021
quotequote all
Tbh they are a fair while off service.

No one is even trained to drive them, I don't think there is a package put together as far as I'm aware and then it would require the driver to enter a training bubble with a competent person ( and there aren't any of those yet). I'd be surprised to see one turn a wheel in service this year.

Southerner

1,392 posts

51 months

Thursday 20th May 2021
quotequote all
SlowcoachIII said:
Caught the train into Penzance yesterday on one of the refurbished GWR sets which was absolutely filthy. On one hand, it was sad to see the slam doors go but relief as there was no chance of getting a dirty sleeve.

I didn’t have much time to look but does anyone know which carriages were retained for the 4 car set?
The "Castle" sets, as they've decided to name them (nice reference to the original GWR steam locos), have an original TGS (Trailer Guard Standard) - an ordinary carriage but with the Guards van at the far end - at one end behind the power car, with the Guards van door remaining an orginial slam door (justified on the basis that the public have no access to it between stations). This would have been Coach A in the 'proper' HST formations. There's a former Coach C with a disabled access toilet in each set, and then two other standard trailers.

Stedman

7,213 posts

191 months

Friday 21st May 2021
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Vickers_VC10 said:
I'll be driving them on that route ...

The last I heard is initially they won't be using the third rail...having had a nose around on the depot I'm not sure in this day and age of ergonomics, how the hell the union signed them off.

Potentially they 'could' run third rail from Reading to Wokingham, then diesel to Aldershot South junction, back onto third rail from this point right through to Shalford junction where they will tackle the bulk of the Surrey Hills on asthmatic diesel engines. Back on the juice rail at Reigate and run them to Redhill and Gatwick this way. That is a lot of changeovers for a train not designed for it.

Imo these will be running diesel ALOT if not all of the time. Certainly the entirety of the Basingstoke route. Maybe OLE into the depot lol.
They don't train your lot to use the short circuit bar, do they? Or maybe i'm thinking of your guards.

What's the issue with the cabs?

IJWS15

1,830 posts

84 months

Saturday 22nd May 2021
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C2Red said:
It wasn’t really the engine design that was the problem; but the application as you also suggested.
I’ve built, tested and rebuilt a few , quite a few returns from BR.
From memory the trains cooling systems weren’t up to the task.
We had some rebuilt and running on the testbeds at over 110 degrees on the water jackets, just to try and replicate the BR issues.
It’s true, we had a few unexpected crankcase ventilation mods.... but not that many.
Treated properly, and not left idling for hours on end in the sheds would also have helped, having witnessed the BR sheds and operations, I’m confident they as in BR simply didn’t know what they were expected to do with them.
One of the issues was the water cooled inlet to the turbo, it bolted across the two exhaust manifolds. The manifolds each covered six cylinders but not one bank - six at the free end and six at the drive end. The slight differences in manifold thickness stressed the aluminium casting and it would crack, fine when the engine was running as any coolant went straight out of the exhaust but, being a v12, when the engine was stopped there is always an exhaust valve open.

There was a case in the 80s which led to an out-of-court settlement between GEC and BR.

My brother was a submariner and laughed when I told him they would have problems with the Valenta in the diesel boats, he didn’t laugh long.

BTW the HST is unusual in having no field weakening (effectively low gear for a DC motor) so they have poor acceleration at low speed.

uk66fastback

16,457 posts

270 months

Thursday 27th May 2021
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I remember going on one of these muthas every day for four years from Didcot to Swindon from 1978-82. Always filthy at the front with those orange seats for first class and bright blue for second. It looked like no other train I'd ever seen - and in that original livery shown on this thread.

Occasionally we'd run up the steps and jump on a train in the station at Swindon and end up at Paddington as it was the first of two trains close together (this one didn't stop). As it was in the station we'd not heard the announcements ...

In those days if the guard asked for your ticket we'd just tell him what had happened and he'd say 'catch the next one back then'.

StefanVXR8

3,603 posts

197 months

Tuesday 1st June 2021
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Their Australian cousins are still going strong too!


TommoAE86

2,659 posts

126 months

Tuesday 1st June 2021
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C2Red said:
Flying Phil said:
Yertis said:
Sounds like the Triumph Stag of locomotives - sounds great, wonderful when it works, but underdeveloped and tricky to maintain.
....Yet still in frontline service after 40+ years......not too underdeveloped and tricky to maintain I would have thought!
They weren't underdeveloped, trust me. I apprenticed there, spent many a year on build and test.

If you want flakey, then NM 55B & 59K deltics would be your weapon of choice.
I'm sure people on this thread are already aware but I've read this and I really liked it gives good insight into maintaining the the ECML sets;

ISBN-10 : 1473838037
ISBN-13 : 978-1473838031

About the Author said:
Born in Leeds in the mid-1940s, Roger Seniour spent the first eleven years growing up around the vast array of railway lines and depots in the Leeds area. At fifteen, he began a seven-year apprenticeship as an Electrical Engineer, learning how to repair electric motors, transformers, and industrial wiring. In 1968 he found employment within the railway, and was eventually promoted to Technical Riding Inspector, which lasted for sixteen years, before finishing up as the Resident Engineer for the MK1V fleet of vehicles.