More Swindon And Derby DMUs

[multiprinter]

79083 - 90  were new to (officially) St Margarets, on loan, between 9/56 and 12/56 and returned to (officially) Swindon in 4 and 5/57.

 

79083 was officially at Ayr 10/59(From Swindon) to 9/61, 1/62 to 1/70 and 5/71 to 11/71 (At Leith Central between those dates.) This is likely to be the vehicle 59401 mentions having cine film of on Ayrshire duties in his post.

 

79440/1 both spent a while at Ayr from late 59 to early 62, having been returned from WR to Leith Central initially.

[Sc59401]

You're welcome Brian and thanks for the information Multiprinter.  Now-preserved 79443 was at Ayr for a few months in 1960 so it's quite possible that it worked with cars from the preserved three-car unit.  After Stranraer line buffet services ceased it became common to see 5xxxx leading cab ends (which did have jumpers but no rubbing plates) buckeye coupled to other Class 126 units as through access in a six-car set was no longer required.  I didn't mention earlier that 79441 was preserved for a while at the Strathspey Railway and named "Glenfiddich" after the sponsoring whisky company.  It was used as hauled stock but was scrapped around the same time as 59098 and 59099.

 

Another unusual working was a six-car 79xxx set which was tried out north of Inverness after its withdrawal from the Edinburgh-Glasgow service, as there was still some life left in these units (they were only 15 or 16 years old).  Nothing came of the experiment but four cars lasted for many more years at Ayr, particularly 79088 and 79470 which made it almost to the end.

 

The DMU in landfill was 116 391 and it's mentioned here: http://www.scot-rail.co.uk/page/Class+116

 

I believe there's also a heavily stripped Class 27 locomotive and a railbus body (which was used as a bothy) in there to puzzle future archaeologists.

 

We have a comprehensive set of (legal) copies of original works drawings for the Inter-City DMUs at Bo'ness so if you have any specific questions please let me know.  I have cut out most of the new bodyside panels for 79443 using these for reference and the drawings have been an invaluable resource during the many years of restoration.  The lavatory window size took us by surprise as all our spares are 5xxxx Class 126 (too small) or Mark I (too big and toughened so they can't be cut).  We have no idea why Swindon changed it.

[pete_mcfarlane]

There's a flooded qurry in Northern Ireland that's full of asbestos contaminated Irish Rail and NIR DMU vehicles. That's definitely one to give future archeologists headaches - why did 20th Century man offer so many of his metal transport machines as an offering to the water gods?

[Brian Kirby]

I've been checking out this toilet window size business, i can see the difference now between the 5xxxx and 79xxx DMS vehicles, the toplights are certainly two distinct shapes. I hope Sc59401 is sitting down, because i've also found two different styles of cab window on the full-cab 5xxxx DMBSs! If you have a copy of Brian Morrison's DMU book (IA 1998), take a look at Sc51035 on page 207 and Sc51037 on page 208, they have tapering centre bulkheads that are much wider at the bottom, than the usual. Perhaps built like that, maybe a later modification or accident damage? Also on 79xxx full-cab DMBS, some have lower handrails on the cab front, some don't, some never did!

 

Here's some progress on the cab fronts, first the full cabs, 5xxxx on the left, 79xxx on the right. Followed by Intermediate half-cabs, again 5xxxx on left, 79xxx on right. BK

 

[Brian Kirby]

These six 126 DMU bodies have slowly evolved from when i marked out and cut the first 79xxx sides, which were followed by the three pairs of 5xxxx sides. By the time i'd done the 5xxxx sides, i'd realized to my horror that i'd made the 79xxx window openings about 1mm too deep. The whole project had been an exercise in "guesstimation", since the only drawing i had, apart from the Cheona book, was a floor plan for the original 79xxx series. I couldn't totally trust the Cheona book, furthermore some of the window frame sizes change from car-to-car within these drawings, i never fully trust drawings anyway, good side-on photos are far more reliable.

 

So it was a case of working out the size of the main windows and their vertical position on the sides. I pressed on with the 5xxxx and made them into bodies using roofs and ends from a DC Class 120 kit, which didn't get any further than that. I realized that to build extra units was going to need more DC spares, then suddenly i found myself with a quantity of redundant Southern Pride roofs and chassis. So these are what this second incarnation are based on, and the Class 120 roofs and ends went back to being a Class 120.

 

To correct this annoying window cock-up, has involved first adding a backing strip of plastic, at the correct bottom height, to the inside of each window, followed by an oversize strip in front of this, creating a temporary "window sill" effect, which when hardened, can be filed back flush with the bodyside and some filler added to the corners. All very tedious and time-consuming, but satisfying to correct the earlier mistake. Eventually, when painted, the Replica windows can be plugged in, but each one of these will also have to be cut down to the smaller size. Let's hope it looks right. You can see in last pic, where i've even ignored my original horizontal ink lines, having compared with more photos. BK

 

[Sc59401]

Brian, thanks for the photo-update and information about the 5xxxx leading cab windows.  There was a crash at Ayr station in the 1960s where one of these cars collided with an oil train and was quite seriously damaged, however it was repaired and put back into traffic.  It might have been one of the two you mention.  Preserved Sc51043 has of course been extensively re-plated but the cab end glass and some of the steel framework sections are original.

 

Another 79xxx leading DMBS detail difference apart from the handrails is that the roof ventilator above the cab was not in the same place on all cars.  I've studied a lot of photographs and concluded that it was on the second man's side on 79091 to 79094 and 79096 to 79104 while it was on the driver's side on 79106 to 79111.  I need to see a photograph of 79105!  79095 was an intermediate DMBS and it had a minor variation in underframe equipment layout around the EP valve boxes.  Perhaps I should get out more ...

Edited February 10, 2014 by Sc59401

[Brian Kirby]

Hi John (59401),

I agree, mostly likely the odd cab/s were from crash or corrosion damage. Donning my green anorak with cream lining, wasn't 79095 the odd early Intermediate DMBS (i.e with brake behind the cab) that Scottish Region inherited, prior to receiving the secondhand WR iDMBS? The Scottish Region obviously preferred the DMS arrangement.

Thanks for the tip about the cab vent, i vaguely recall something similar when investigating the Swindon Cross-Country sets. No new piccies tonight, i'm still correcting the 79xxx windows.

 

Cheers, Brian.

[Sc59401]

Thank you Brian.  I need to check my books again but I have a feeling that 79095 was new to Scottish Region along with the other later 79xxx Inter-City cars, which might explain why it was the only intermediate DMBS in the series 79091 to 79111.  There's a photograph of it at Leith Central in Jim Grindlay's book about DMU allocations.

Edited February 12, 2014 by Sc59401

[Brian Kirby]

Here's a bit more progress, i've corrected the 79xxx windows, and now that we have more informaton, i need to slightly alter the loo windows on the 5xxxx unit. This is the DMS (Driving Motor second) before, and then after with plasticard strip added, a bit more is needed in two of the corners, so they can be rounded out.

 

 

Instead of narrowing the loo windows on the 5xxxx TFK, i've decided to create a new body, and put the existing TFK to one side, for use in another 79xxx unit. When i made the sides sometime back, i also cut and drew a pair of blanks for a 79xxx DMS, which i haven't used thus far, so i did wonder about converting these to another TFK, starting from the common end door.

 

 

In the end, i've decided to keep the 79xxx DMS for later, and in the meantime started marking out some extra sides. First is a very exciting pic of a lump of plasticard with eight score lines. This sheet will yield nine coach sides, which added to the spare DMS plus one more new side, will create two more three-car units eventually, although one pair will be borrowed for the replacement 5xxxx TFK. BK

 

[Brian Kirby]

Now the new donor sides need the bottom curve, or tumblehome, rolling into them. Like many other DMU classes, the Swindon builds had straight slab sides on their upper half, thus with flat windows, and a curved bottom section, very similar, and no doubt influenced by Hawksworth coaches. To achieve this, you don't need to buy expensive rollers, just dig out the DIY Workmate from the shed. Opening the jaws of the Workmate very slightly, place the bottom 3mm of a side between them, then clamp it securely, using a straight edge, like a steel rule to check that all is level, re-adjust if necessary.

 

 

With the side tightly clamped and dead level, you can then grab the side and straight edge, with both hands holding either end, and start flexing the side towards you to create the lower bend, then repeat towards the middle of the side, to achieve an even tumblehome. It will be all rather hit and miss at first, but eventually you get a feel for what is required. If not perfect first time, you can just re-insert it and try again. Also make sure the Workmate jaws are clean and smooth, otherwise the soft plastic sides may be damaged. In this photo only one working BK hand is shown, because obviously the other BK hand was busy taking the piccy!

 

 

Fingers crossed and it should come out like this, but don't worry too much, the real things seemed to vary slightly. Notice my left hand is perfectly in focus, and the object is faintly fuzzy, but you get the idea. A strip of 30 thou plastic strip is glued to the inside of the curve, to maintain the shape. The last pic shows the first pair sketched out as the replacement 5xxxx TFK with the narrower loo windows, the body above will now become a 79xxx TFK with the earlier wider loo windows. Next is the boring job of opening out all the windows and filing to shape, before the new body is created. BK

 

[Sc59401]

Very interesting Brian - and sorry to give you extra work regarding the loo windows!  I'm off to work on the real Sc79443 for a few days now but I look forward to further updates.

[Brian Kirby]

While i'm busy cutting out and filing more windows, a couple of questions for the cognoscenti. Were the differences between the 79xxx buffets and the two 5xxxx buffets, just the different toilet windows, the different roof vents, the different shades of green livery and the different internal decor? The Cheona book states that the 5xxxx buffets were one ton heavier, is this correct? We know most DMUs were of semi-integral construction, how the chassis was reinforced has always been a mystery to me, although i can see the shadowy outline of a longitudinal spine, in some low-angle pics. Not knowing the dimensions of this section, i'm tempted to ignore it for now, but could always add this later. Any helpful comment would be appreciated.

 

Cheers, Brian.

[Sc59401]

Hello Brian, I think you've got it just about covered regarding differences between the 79xxx and 5909x buffets.  I have to admit I can't confirm the 1 ton difference at the moment.  This picture shows some underframe details not normally seen:

http://sdps.org.uk/2012-focus-buffet-car-rebuild/

[Brian Kirby]

Many thanks John,

    That underframe picture does confirm the lower centre section, but it's not that much deeper than the solebars. Your colleagues seem to be doing a good job restoring the 79xxx buffet. Stuart Mackay states in his DMU book, that all the Buffet Firsts were 34 Tons 9 cwt, so maybe the Cheona data is a misprint or wrong? (again). We know the original 79xxx were delivered in a bright shade of green and the last two buffets were delivered in olive/dark green, but were the main batch of 5xxxx vehicles delivered in the bright shade or something halfway between the two? I note the current shade on your preserved three-car.

 

                                                                   Cheers, Brian.

Edited February 20, 2014 by Brian Kirby

[Sc59401]

Thank you Brian.  The lowered section in the photograph sits on top of the bogie.  The Swindon Inter-City and Cross-Country cars all had integral construction with substantial solebars and underframes and importantly no trussing, which left more room for engines, gearboxes etc on power cars.  Despite its superficial resemblance to the Mark I design, the Inter-City DMU structure was the direct ancestor of the Mark II and prototype Mark II FK W13252 was built on the same jigs at Swindon.  We had extensive discussions about the shade of green for the three-car but went for the bright shade on the basis of paint fragments found during rubbing down.

 

I’ve dug out a few books and some photographs I took at Goathland in 1987 so here goes:

 

Firstly the weights in the Cheona book are not all correct.  I have one of the data plates from 79443 at home for safe keeping and it clearly shows 34 tons, so the 1 ton difference between 7944x and 5909x buffets is wrong.  The Cheona book also shows the weight of the 794xx trailer firsts as 38 tons, which is where a power car tips the scales.  In the absence of cast iron evidence it is reasonable to assume that they weighed a similar amount to the 59xxx firsts and composites (preserved 59404 is 33 tons according to its data plates) and indeed several Ian Allan ABCs show the 794xx firsts as 33 tons 9 cwts.  Stuart Mackay knows his stuff and has done a lot of work on all four preserved Inter-City cars.

 

Regarding differences between 7944x and 5909x buffet cars, I would issue a word of caution regarding the underfloor equipment layout.  As you are no doubt already aware, there are substantial differences in placement of certain equipment between 79xxx and 5xxxx cars, for example fuel tanks (diagonally opposite on 79xxx, both at cab end on 5xxxx with balancing pipe between), heaters (near centre line on 79xxx, more accessible from one side on 5xxxx) and battery boxes (compartment side on 794xx firsts, corridor side on 59xxx firsts/composites).  The 79xxx power car underfloor equipment layout (reservoirs, electrical boxes etc) has more in common with the Swindon Cross-Country cars than the ‘Ayrshire’ 126s, which kind of makes sense considering the order in which they were introduced.

 

Unfortunately I have been unable to trace a clear photograph of 59098 or 59099 to compare with a 7944x buffet.  There is a 5909x car on page 80 of ‘Diesels on Scottish Region’ (Bradford Barton 1975) but the part of the vehicle where the heater might be is obscured tantalisingly by a signal post.  What is visible (corridor side, first class end) looks similar up to and including the gas bottle cabinets but I would recommend trying to find better evidence.  My photographs of 59098 and 59099 are similarly inconclusive.  The Cheona layout is completely wrong below the floor as it is identical to the trailer first/composite diagram and even that is not correct for either batch!

 

There is also a difference in the method of fitting the aluminium window frames to the bodysides between the 79xxx and 5xxxx cars but this should not affect your model.  The earlier design is considerably more difficult to remove and replace, especially now that they are 57 years old. 

 

I would be pleased to show you around the preserved vehicles if you fancy a trip to Bo’ness to examine them at first hand.

[Brian Kirby]

Hi John,

     Thanks for the pre-warning about the underframe equipment, I didn't know a lot about that either, although I haven't even considered that stage yet. Many thanks for the invite, but i'm afraid i'm over 400 miles away in London, cor blimey stone the crows guvnor and no mistake don't ya know? Replacing the TFK shell has prompted some additional sides construction, as previously stated the TFK being replaced will be re-used in another three-car 79xxx unit, which I always intended to add anyway, to create a WR six-car set. I've made the new sides for the replacement 5xxxx TFK, with the narrower toilet windows, plus I plan to actually finish it as a TCK instead, to add more variety. I did also plan to make a WR middle set with intermediate cabs both ends, but I've never seen a pic of a WR nine-car formation, plus I can rustle one up by re-marshalling half the cars in the eventual WR six-car. For this reason, the first three-car has the motor bogie in the Intermediate DMBS, the second set with have a motor bogie in a full-width cab DMBS, which means the latter could also run with a DMS. (Is everyone still with me on this? ! )

 

Adding to the above, i'm also making a 79xxx DMS, a 5xxxx Buffet First and an additional 79xxx fw-DMBS.

So I should end up with:

 

                                   WR 79xxx DMBS/TFK/iDMBS + iDMBS/TRBF/DMBS

                                  ScR 5xxxx DMBS/TCK/DMS + ScR 79xxx DMS/5xxxx TRBF/79xxx DMBS.   (12 vehicles)

 

All the above can be mixed and matched to create alternative formations, I thought light green for the WR six and the second darker green with yellow panels for the ScR vehicles, thus giving yet more variety? I can't do everything in the same shade, since we now know the two later buffets started in dark green. Here are pics of the 5xxxx TFK/TCK and 79xxx DMS sides, the close-up shows a few test windows plugged in.

 

                                                                      Cheers, Brian.

 

[Brian Kirby]

Hi Everyone,

      Apologies for not updating for a few days, but I have been busy cutting out and preparing the extra sides, which will broaden out the range of types. When I was informed that the 5xxxx series had narrower toilet windows, it was time for a re-think. I decided to convert/correct the 5xxxx DMS loo window, to save altering the cab front, whereas the TFK could be reserved for another 1956 set unaltered (no loo on the 5xxxx DMBS). So this prompted the need for a replacement 5xxxx TFK/TCK, plus another 79xxx DMBS and iDMBS to go with the spare 79xxx TFK. Now as already shown, I had also previously prepared sides for a 79xxx DMS, so i've added another 79xxx DMBS, plus a 5xxxx buffet to create a fourth 3-car set and offer yet more variety. There is also limited potential to shuffle odd vehicles between sets. So for six extra cars, that's twelve new sides, each side takes best part of an hour to create, so time is the limiting factor. Here's a pic showing the new 5xxxx buffet sides, compared to the existing 79xxx buffet body, the difference is the narrower toilet windows on the former. The second pic shows what will be the new 79xxx DMBS/5xxxx TRBF/79xxx DMS set. The third pic shows what will become the second 1956 79xxx set, which re-uses the part-built TFK, and will give me a WR or E&G six-car set. I believe the other two sets can be used together to provide an ad hoc Ayrshire six-car option, please correct me if I'm wrong? If anyone spots any errors, please let me know, before it's too late. BTW, looking at my pics, I can assure you the sides are dead straight, but my dodgy camera has given things a faint fish-eye curved effect.

 

                                                                                                 Cheers, Brian.

 

Edited March 1, 2014 by Brian Kirby

[Sc59401]

Looking great Brian, you have been very busy!  There was a fair bit of shuffling between Ayr and Leith in the early years but (and I'm prepared to be corrected) I don't think Ayr ever had 79xxx 'leading' cars, as the lack of jumper sockets at the cab ends would have been a considerable operating inconvenience.  The Ayr fleet operated in three-, six- and even occasional nine-car sets while the Edinburgh-Glasgow service was usually a six-car formation.  I've contacted our society archivist as I believe that there might be a BR official photograph of a WR nine-car set in the collection.  I understand that Bo'ness is a bit far away for you but if you need something measured please let me know.

[Brian Kirby]

Quite right John/59401,

    I agree, you wouldn't normally see a leading full-width cab 79xxx DMBS on the Ayrshire lines. My 4th unit was inspired by reading about the extra cars constructed with the 5xxxx batch, some of which were to be coupled with the few spare 79xxx cars, to create extra complete 3-car units. I believe i'm right in saying, that the two 5xxxx buffets started life on the Stranraer service, but later on the catering service here was withdrawn. Then the buffets were transferred to Leith for the E&G service and perhaps were included in 79xxx formations? Did the two DMBS and two iDMBS vehicles, previously attached to the buffets, remain at Ayr/Corkerhill? So the picture on page 51 of the Kevin Robertson DMU book, showing a mixed 5xxxx/79xxx six-car formation at Kilwinning, seems to be 5xxxx DMS/TCK or TFK/DMBS + 5xxxx or 79xxx DMS/5xxxx Buffet/79xxx iDMBS?

I can still convert the latest 79xxx DMBS to iDMBS, it's not too late. Many thanks for your help, it is appreciated.                                       BK

Edited February 28, 2014 by Brian Kirby

[Sc59401]

That's right Brian, the 5909x buffets had a relatively short working life on the Stranraer line and were transferred to Leith where they worked with the 79xxx cars on the E&G service.  They were built after all the other White Circle cars and normally would have worked with DMBS and iDMS cars from Ayr although probably with the occasional iDMBS.  Formations at Ayr were always variable and the power cars would soon end up in other sets as formations were changed with cars requiring attention.  I can remember seeing a three-car set at Troon with gangways at both ends; this would have had a 79xxx intermediate DMBS at one end.  The RCTS coaching stock books from the 1970s show most DMUs in 'as-delivered' formations (although subsequent transfers meant that many were no longer running as such) but the Ayr White Circle cars are listed in batches by car number as they were not kept in fixed sets  Detailed observations from the late 1970s show that vehicle changes were frequent, probably more so as reliability became an issue towards the end of their careers.

Edited March 3, 2014 by Sc59401

[Brian Kirby]

Looking at Jim Grindlay's (TPL) DMU allocation book, the aforementioned 59098/99 buffets seem to have been put to work on the E&G service in the early 60s, with the two ex-WR buffets 79440/41 sent to Ayr instead, Perhaps Scottish Region preferred to use their two new buffets on the more important service, but this appears to have been reversed by 1965, then as previously reported, by 1967 all buffets were based at Leith Central for the E&G? Intermediate DMBS 79083 was at Ayr from at least 1965, until at least 1968, as was 79085 from at least 1962, until 1967. Oddly, full cab DMBS 79099 is listed as being allocated to Ayr from 1967?

 

I have progressed with the 5xxxx cars, fitting roof vents and door detail, the smaller windows on the full-cab DMBS did need some extra work making them slightly narrower, i didn't realize earlier that this vehicle does actually have a toilet, oddly right next to the guard's van, perhaps to keep second-class bottoms off the nearby first-class loos? The affected windows are temporarily marked by pencil crosses, the loo is marked by a 'T'. I've added toilet pipes, but not the exhaust pipes thus far, I assume they'd be the same as found on Class 120?        BK

 

[Brian Kirby]

Here's the 5xxxx DMS for the other end, with it's bits on. In later years, during the plain blue period, an additional handrail was added low down on each of the doors nearest the cab, to aid access. This model will be green, so I have omitted them.     BK

 

Edited March 8, 2014 by Brian Kirby

[Brian Kirby]

Here's a bit more Class 126 action, first the TCK (Trailer Composite) for the 3-car 5xxxx, now with roof and door detail.

 

 

Next up is the 79xxx buffet for the first half of the WR or ScR 6-car set.      BK

 

[Sc59401]

The second batch (5xxxx) power cars had steel mesh covers over the exhausts, Class 120 style, however the earlier cars had a different arrangement when new.  We have a copy of an official works photograph of a 79xxx power car inner end which appears to show the exhaust pipes wrapped in insulating material and fitted with leather (?) covers.  I'm not sure whether or not they acquired the mesh covers later but one of my preservationist colleagues might know.  A word to the wise - I think you need to check the position of the buffet car fan hood.  On Sc79443 it is offset to one side and there is a steel top hat framework section running along the entire centre line of the roof.  Looking good though and you're certainly making great progress.

[Brian Kirby]

Thanks for the details 59401,

      Do you mean a mesh collar around the top of the exhaust pipes?  Pics of the back ends of power cars are very rare, but i'm sure I've seen a scrapyard pic of the back of a Class 120, showing a boxed-in vertical duct, rather than pipes, that went around the outside of the buffers? Regarding the buffet hood, i was at the mercy of the Cheona drawing, so many photos are too angled to tell otherwise. I suspect a lot of the Cheona drawing detail has been guesstimated from photos, which would account for the mis-interpretations. Perhaps I should pull the vent and flue towards the buffet counter side slightly? Does that mean the position would be o.k. for my forthcoming 5xxxx buffet? You were right about the 79xxx power car roof vent layouts, the two do differ at the cab ends, but the rest is the same for both, unlike the Cheona drawing, which is only correct for the Intermediate DMBS. Pics of these to follow.       BK