BR’s most successful DMU?

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WesternLancer

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Yes, lovely and comfortable. Still miss em on the Marshlink.
I always preferred the main line ambiance of the Hastings line DEMUs - I'm not old enough to recall them with buffet cars which must have been nice (tho the longevity of the Hampshire's is a very good call).
 

yorksrob

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I always preferred the main line ambiance of the Hastings line DEMUs - I'm not old enough to recall them with buffet cars which must have been nice (tho the longevity of the Hampshire's is a very good call).
Yes, they are something special, although there was only one left that cropped up on the Marshlink by the time I was using it in the late 80's. The Hampshires were rather more abundant in my youthful travels and had a very good innings though !
 

Taunton

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Ironically, the Leyland engines were later fitted to the class 115 DMUs for whose service duty they were much more suited.
One of the issues was that, consistently it seemed, BR would standardise on a Leyland/AEC engine shortly before it went out of production. This started with the very first Derby-built dmus, and worked right through to the Pacers.
 

WesternLancer

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Yes, they are something special, although there was only one left that cropped up on the Marshlink by the time I was using it in the late 80's. The Hampshires were rather more abundant in my youthful travels and had a very good innings though !
Absolutely right. I recall a few enjoyable trips on the Hastings line before electrification, including trips up to sample the Eridge - Tonbridge service before closure.
Of the 'suburban' style DEMUs I always like the design of the 3D (Oxted units?) front end a bit more than the 3H units.
 

yorksrob

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Absolutely right. I recall a few enjoyable trips on the Hastings line before electrification, including trips up to sample the Eridge - Tonbridge service before closure.
Of the 'suburban' style DEMUs I always like the design of the 3D (Oxted units?) front end a bit more than the 3H units.
Yes, the 3D's were quite a good design. I'm surprised that they didn't put vestibule connections in earlier than they did, as you would have had a completely walk-through unit which would have been very handy for revenue collection, toilet access etc.

I always knew them as "Oxted" units.
 

Mitchell Hurd

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I'm wondering if the Turbos have been the most successful DMU - a while back I was told they were the most reliable diesel trains in the UK (2018 I think it was).

Then there's SWR's Class 158 / 159's - the 159's won the most reliable former British Rail train or DMU I believe in 2016 / 2017.

I'm wondering if these are the most successful still.
 

matchmaker

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One of the issues was that, consistently it seemed, BR would standardise on a Leyland/AEC engine shortly before it went out of production. This started with the very first Derby-built dmus, and worked right through to the Pacers.
Really? The Leyland O680 was a very long lived engine which was developed into the TL11. It was used in many applications apart from rail. No sure about the AEC A220.
 

notadriver

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156 for me - a bit noisy and draughty particularly since the internal doors were removed.

But you can fill them with luggage all day long, apart from the doors sticking they tend to just keep going. Great medium distance Regional trains. I've only ever failed outright with one once when the door interlocking had an electrical fault.

158 could have been a lot better than it was. The right ideas but 5 or 6 years too early for them to be implemented reliably. Everything tech wise on them doesn't work properly. The internal partion doors when they go on the blink are an all day job to take to bits. The air con has been useless for 30 years and while some attempts have been made no one has really sorted it. The toilets and vanity units are crap and prone to appalling smells. The door systems are temperamental both electrically and mechanically. They're underpowered. They leak where the GRP vehicle ends meet the main body of the vehicle. The cabs are like greenhouses. They have the most ridiculous design of thermostat and stink of diesel fumes, the 1980s micropack for controlling the air con is about as user friendly as a video recorder of the same era and when it is playing up drives the driver mad constantly banging in and out of one state or another. The tilt profile renders the overhead racks largely useless and TOCs have a habit of shrinking the ground level stacks to get more seats in so there is little luggage space. As designed the bike space could hardly squeeze a bike into it.

I could go on - I've spent very many miles on 158s in my working life and if you get a rare good unit all around they aren't bad - until the train gets busy when their shortcomings become obvious.
158s underpowered ? When introduced were they not the fastest DMU with the most powerful engines ?
 

LowLevel

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158s underpowered ? When introduced were they not the fastest DMU with the most powerful engines ?
They have the most powerful engines of the 15x series but they also have a comparatively large electrical load and a not particularly capable alternator. They're not exactly slugs perhaps but they certainly don't have ample power for all the demands on the engine.

That's another of their faults while I remember. Vomiting their hydrostatic oil all over the track causing the alternator to fail and a total loss of electrical power to the vehicle
 

Cowley

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They have the most powerful engines of the 15x series but they also have a comparatively large electrical load and a not particularly capable alternator. They're not exactly slugs perhaps but they certainly don't have ample power for all the demands on the engine.

That's another of their faults while I remember. Vomiting their hydrostatic oil all over the track causing the alternator to fail and a total loss of electrical power to the vehicle
I must admit that I did chuckle reading the faults with them that you listed in your earlier post. :lol:

Quite a few of those problems made me think of the same era lorries that I worked on as an apprentice in those days that seemed like real cutting edge stuff back then but if you got into one now they’d seem incredibly dated.
I think that to a certain generation of us the 158/159 has a modern look to it that seems to have aged pretty well? But really it’s decades old technology, that’s still being asked to work hard...
 

yorksrob

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I think that to a certain generation of us the 158/159 has a modern look to it that seems to have aged pretty well?
That is certainly true. They still look and feel modern to me. The only thing that hasn't aged well are the controls and hand dryer in the loo !
 

notadriver

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I must admit that I did chuckle reading the faults with them that you listed in your earlier post. :lol:

Quite a few of those problems made me think of the same era lorries that I worked on as an apprentice in those days that seemed like real cutting edge stuff back then but if you got into one now they’d seem incredibly dated.
I think that to a certain generation of us the 158/159 has a modern look to it that seems to have aged pretty well? But really it’s decades old technology, that’s still being asked to work hard...
Interesting. If a train is refurbished inside to a high standard, I doubt the average passenger could tell if it was new or not.
 

LowLevel

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I must admit that I did chuckle reading the faults with them that you listed in your earlier post. :lol:

Quite a few of those problems made me think of the same era lorries that I worked on as an apprentice in those days that seemed like real cutting edge stuff back then but if you got into one now they’d seem incredibly dated.
I think that to a certain generation of us the 158/159 has a modern look to it that seems to have aged pretty well? But really it’s decades old technology, that’s still being asked to work hard...
I don't think there is any question they look pretty good for their age and can easily pass for a more modern train with a good refurb.

Most of their problems are more obvious to those working on them and critically bar some electrical gremlins that might be due to age have been there since day one anyway so as far as the passenger is concerned, they aren't bad. Certainly I've had people ask if they're new trains before when compared to Old Northern's offering or a 153.
 

Revaulx

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Growing up in Manchester I was extremely familiar with lots of terrible first gen DMUs. The 104s (Buxton, Blackpool) and 110s (Calder Valley) were particularly awful. The Cravens units that we encountered on spotting trips to Sheffield and Doncaster were even worse.

The 115s (4-car Derbys to us) that ran the CLC Manchester-Liverpool expresses were dull but decent. Their doors-at-every-bay layout felt wrong for a supposedly inter-city service, and the interiors were terribly dreary, but they rode well. didn't feel ready to fall apart at any moment and had good acceleration and a pleasingly throaty exhaust.

The Trans-Pennine 124s were great when I first travelled on them c1970, and were the one first-gen design that looked good in blue and grey with all-yellow ends. I'm not sure if they were deliberately neglected or just run into the ground, but they didn't age well and the hybrid 124/123s that ran on Sheffield services around 1980 were sad relics.
 

Journeyman

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The Trans-Pennine 124s were great when I first travelled on them c1970, and were the one first-gen design that looked good in blue and grey with all-yellow ends. I'm not sure if they were deliberately neglected or just run into the ground, but they didn't age well and the hybrid 124/123s that ran on Sheffield services around 1980 were sad relics.
I think prolonged high speed running had a tendency to knacker the rather basic first-gen DMU drivetrain very quickly. It seemed to cope very well with sedate stopping and suburban services, but couldn't take intensive thrashing. The Swindon InterCity DMUs on the Edinburgh to Glasgow fast services lasted fifteen years, and were in too poor a state to find use elsewhere. The slightly later batch used in Ayrshire had a more sedate existence, and they lasted quite a lot longer.

The preserved unit at Bo'ness is one of the Ayrshire sets, and it's a seriously gorgeous example of fifties design.
 

notadriver

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I think prolonged high speed running had a tendency to knacker the rather basic first-gen DMU drivetrain very quickly. It seemed to cope very well with sedate stopping and suburban services, but couldn't take intensive thrashing. The Swindon InterCity DMUs on the Edinburgh to Glasgow fast services lasted fifteen years, and were in too poor a state to find use elsewhere. The slightly later batch used in Ayrshire had a more sedate existence, and they lasted quite a lot longer.

The preserved unit at Bo'ness is one of the Ayrshire sets, and it's a seriously gorgeous example of fifties design.
Interesting regarding high speed wear and tear. Didn’t this also affect 321s on the London midland route ? The 350s seem better suited to high speed running.
 

Revaulx

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I think prolonged high speed running had a tendency to knacker the rather basic first-gen DMU drivetrain very quickly. It seemed to cope very well with sedate stopping and suburban services, but couldn't take intensive thrashing. The Swindon InterCity DMUs on the Edinburgh to Glasgow fast services lasted fifteen years, and were in too poor a state to find use elsewhere. The slightly later batch used in Ayrshire had a more sedate existence, and they lasted quite a lot longer.

The preserved unit at Bo'ness is one of the Ayrshire sets, and it's a seriously gorgeous example of fifties design.
Interesting. I understand there was a lot of interest in preserving at least one of the fabulous looking driving cars of a 124 but the asbestos put people off.
 

Journeyman

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Interesting. I understand there was a lot of interest in preserving at least one of the fabulous looking driving cars of a 124 but the asbestos put people off.
Yeah, it was a real problem on the Swindon InterCity family of DMUs. The only surviving set - the 126 at Bo'ness - had to be stripped back to bare metal to get all the asbestos out. It destroyed all the original panelling so it had to be reproduced from scratch.
 

jimm

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I feel the opposite, the WR didn't know what to do with them. There was some internal politics which led to them being authorised, just 5 8-car sets. They were hand-built in the carriage plant, not on a production line, the Swindon dmu line having been closed down a while before, and the jigs disposed of.

Significantly underpowered compared to say Trans-Pennine units, they only had two cars out of four powered, compared to two out of three with the latter. Being of heavyweight steel construction, their power to weight ratio was poor. They were on B4 bogies but these were wasted as the transmission could not handle more than 70mph.

When new I would see them growling out of Taunton late morning on the through Cardiff-Plymouth service, notably slow acceleration, other dmus would see them off. Apparently performance over Dainton led to them being withdrawn from the route, and Hymeks substituted.

Like other WR dmus, the buffets were a waste of space, hardly used, but these were actually scrapped very early on.
The fleet as built was made up of 10 four-car sets, five with buffet cars and five without. The buffets were removed in 1970 (with one reused in a Class 309 emu), with those five sets running as three-cars after that until they were mixed and matched with the 124s from 1977.

They had less power than the TransPennines because they weren't intended to spend their working lives climbing over the Pennines day in, day out, a job that the Class 124s were purpose-built for.

The use of 123s to Plymouth seems to have been a bit of an afterthought, as they were ordered to work services between South Wales and the South Coast, but ended up on the routes to the Midlands and Crewe when they entered service.

So what if they were limited to 70mph. Why wouldn't you fit a new and better design of bogie to the 123s if one was now available to use three years after the 124s were built? Railcar.co.uk notes that those sets had seen a fair bit of work done on the design of their bogies, presumably to try to improve the ride from the earlier Swindon-built 120s and 126s.

As for being a success, probably not, as they were too few in number to make a mark but you could make a case that they and their Swindon-built cousins pioneered the concept for various longer-distance unit types of train built more recently.
 

hexagon789

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Interesting. I understand there was a lot of interest in preserving at least one of the fabulous looking driving cars of a 124 but the asbestos put people off.
Yes, the NYMR strongly considered it but was put off by the exorbitant cost of asbestos removal and then having to effectively rebuild the unit.

One only has to look at how long the 126 at Bo'ness took to be brought up to its present fantastic condition and that required lottery funding as I recall.
 

Wyrleybart

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The 170 is post privatisation and off topic: the question was about BR DMUs.

For me, the 158/159 is the clear winner. I’ve never understood the 156 love-in.
I guess it really is an individual thing. I do like the 158 environment, and feel it is the BR solution to Express regional trains, but.....
Has anyone successfully got the air con system to work properly ? Of course these features are more for speeds between few stops, and are not suitable for rush hour commuting.

Success, the pacers weren't. The 141s and 142s in particular had new doors, engines, gearboxes, brakes etc, but I think the 143s and 144s retained their as-built doors.

These days the 143s and 144s seem more reliable but need a healthy supply of wheelsets for swapping, particular in Autumn and Winter.
 

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