This no frills site, simply records progress on John Down's three-car Class 117 Diesel Multiple Unit, which lives on the Pontypool & Blaenavon Railway. There are (or at least, will be), some photos, especially as and when the unit looks a bit more presentable. Although the site has some buttons, these are simply for navigation within the one large page, whilst the 'back' buttons return you here, to the top. There are a few links to other sites, and these are shown conventionally within the text. For reasons of operational simplicity (and cost!), it is attached to the PBR website, and can be accessed therefrom. The page was written in 800 x 600 resolution and is probably best viewed that way.

Although it is expected that many people will visit the main PBR site, this page is really for the railfan. Within this group probably less than half are diesel freaks, with an even smaller proportion being true DMU devotees, many of whom will be subscribers to TRA newsletter. This page is directed mainly at this small group, so some of the pages will get a bit specialised - sorry! Also, as long as the number of images is small, they will load directly, ( being JPEGs of about 0.5Mb), with the time penalty that this imposes. If the number of images gets large, and assuming I can find the time to find out how to do it, I will precede these with thumbnails.

Quite the best general history of the class prior to preservation is to be found in the Railcar Association site at

I have determined the following sketchy information regarding allocations from 'Rail', together with Ian Allan and Platform 5 publications. It looks as if all three cars were allocated to Reading (81D) until 1985. Not until 1986 can I find evidence of set numbers (though, generally, set numbers were used from the early seventies). 1993 sees 51351 allocated to OOC, but, judging by the presence of vinyl maps above the luggage racks, its last turn of duty was in the Far West. No doubt based at Plymouth (Laira). Incidentally, 51397 has London area maps, and Brummies clearly know where they're going, because 59520 has none. 51397 seems to have been with Reading until the end of its 'big railway' days in March 94, but 59520 has had a more varied history. To Bath Road in 1986 and at Tyseley by 1990 (just when, not known). By May 1994 it was at Penzance carrying the set number 117418, though by March 1997, still at Penzance, the set had been reduced to two cars. Quite apart from being painted in Brown and Cream, the roof finish is entirely different from the driving cars. Needless to say, if anyone can help 'fill the gaps', I'd be very grateful.

Other snippets:
Jul 90 51351,51397 noted in NSE livery
Jul 90 51368,51410, 59520 noted in GWR livery
7 May 94 set 117305 noted at Falmouth
3 Dec 93 51351 RG > HQ NWXX Spare
3 Dec 93 51397 RG > HQ NWXX L718

It looks like the two motor cars were brought, privately by Alan and Tracy Lear, for preservation around 1994. At that time the two motor cars were in NSE 'toothpaste' livery, whilst the trailer (which looks as if it might have been bought a little later) remained from the 117 set painted by Tyseley in pseudo-GWR Brown and Cream in order to celebrate the GW150 happening. Initially they worked on the Chinnor and Princes Risborough Railway until after Christmas 1995 when they were placed in secure store at MoD Long Marston in early 1997. Unfortunately the area in which they were secured was not particularly secure, being that part of the site leased to the nascent Stratford and Broadway Railway. The people there are a smashing bunch, who really deserve to succeed, Anyway the unit suffered from the ministrations of the self-styled 'urban artists' who covered the vehicles in graffiti.

There is little doubt that over five years in the sun and rain did little for the vehicles, and, coupled with a defective design around the guttering meant that the cars suffered badly. As a result of the defective guttering, lots of rainwater entered the cars, causing extensive failure of the inside cladding, especially below the waist level where most of the hardboard had bulged outwards, several window frames were rotten, a large number of seats were mildewed beyond redemption and most of the lino was lifting, at least along the edges. In one or two areas the outside metal skin was parting company with the body frame, and this has caused large gaps to appear around the windows. Additionally there is evidence of tinworm, though most of this is localised in 51351. Most of the rust problem can be dealt with filler in the short to medium term, but welding is expected to be needed in the longer future. The sun had also done its bit degenerating the fabric of the moquette, which had become very fragile where the sun had caught it. The cars also provided homes to any number of birds which had done what birds do. Altogether the insides were smelly, dirty and depressing.

Early days (from Spring 2002 'Top Line')

28 June 02- Both engines on 51397 started, the capacity of the No1 engine to throw oil out of its filler cap was quickly traced to a pair of blocked breathers, and soon solved. Both engines start immediately on almost no throttle and run very steadily and quietly. Early problems with No2 engine were traced to a duff tacho PCB which drives the SIR relay (start isolation relay). At present the relay is frigged. Initially the No1 engine would not bar. On seeking advice it was suggested that there might be a coke build up on the top lands of the cylinder. Accordingly, some clever tricks with two metres of fish tank hose saw me sucking white spirit out of its container and squirting it into Nos 3 and 4 cylinders. After about a fortnight the engine turned OK - but the white spirit tasted horrible!

11 July 02 - Work on the roofs of both motor cars is now essentially complete thus:
(a) all loose and fragile bitumen-like material scraped off, to leave only a few patches still covered.
(b) weld seams and rust patches cleaned down and painted with red oxide
(c). all exposed galvanised steel etch primed
(d) roof painted in a silver grey vinyl loaded micaceous iron oxide paint. Horrible stuff, will NOT brush out, ruins brushes, needs two gallons per roof - and if it fails in the next seven years I'll go round and kick the supplier's door in!

Work remains to paint the roof domes white, and to make a better job of some temporary repair work at the cantrail level where the dome joins the roof.

15 July 2002 - With both engines running so well on 51397 and with air pressure up to its limit and reservoir vac well on its way, it seemed a good idea to tinker in the cab. The throttles appear to work, but track badly. I suspect that one throttle motor is missing a step. The horns work - very well! I've even managed to get the brakes to come off - but at the expense of frigging the DSD relay (there is obviously a contact problem here, which I'll look at in the next few days).

The cab of 53197 looked really tatty with flaking paint, damp and corrosion everywhere. With the damp problem largely contained (see report elesewhere), and rain preventing progress on the roof, I was bored and idly tinkering and tried scraping the desk with a Skarsten scraper. Once half a dozen layers of black and blue paint were removed a clean smooth material emerged underneath which looks like SRBP (synthetic resin bonded paper). A bit of wire brushing and scraping round the controls removed flaking silver paint and all at once things started to look a zillion times better - and with it, the hope that from the mouldering remains of the cab, something really smart can be realised.

December 2002 - Late 2002 has unfortunately found it necessary for me to take over a very much more responsibility on the railway than I had planned, with the inevitable result that progress on the 117 has suffered. Even further, involvement in my friend Charles James rescue attempt of 1896 Dean Brake First Open has made the situation worse. However a dry September saw work turning to painting the east side of 51397 and extending some of the roof sealing work. In terms of painting a side, quite the most irksome part of the work is painting the door edges and jambs - the outside panels are real luxury by comparison. The jambs and door edges are now complete, but with the gnawing realisation that the colour I have been using is wrong -see new Technical Bulletin 'Getting the right green'. I suspect in the fullness of time they will have to be re-done (as well as the complete east side of 51351), so perhaps it's a blessing in disguise that work has been delayed whilst the slow process of research grinds to a conclusion.

 1 May 2003 - Progress has been slow but steady. The centre trailer 59520 has been extracted and the remaining motor cars coupled as a power twin. Outside the east side of 51397 has now been painted in dark green 'B2' (see Technical Bulletin), as has the front of 51351. I am far from happy with the surface finish and there is little doubt that further rubbing down will be needed. Both end have their roof domes now have their roof domes painted white - it's likely a second coat will be needed. Inside 51397, replacement of the lower hardboard panels, with new plywood panels, treated with Barretine, and painted with Antique Pine 'Sadolin' has greatly improved the ambience. Even the best of the original panels were warped, and those that had a rexine covering were coming adrift. Damage was particularly severe at the front end which was leaking badly. The panels had all but fallen off and everything was covered in green algae and slime (except the seats which were covered in white mildew - these have been replaced). The original panels were secured at the bottom by a low skirting. Self tapping screws passed through these and through the panels into a metal upstand. A deeper skirting has now been fitted employing brass screws which sit higher, and pass over the upstand into the wooden noggins - a design that permits much easier removal for maintenance. Additionally the top end of the panels sits up under the window frames and is thus captive - the original panels were just crudely butted up. At the far end of the car the design of the bar area is essentially complete and material ordering is imminent. This will not simply be a counter, but will take its inspiration from the RMB type design

13 December 2004 - Golly - is it really that long since I last put something on the site!
Most of the internal work has been concentrated on 51397, whilst most external work has been done on 51351. Both units have seen electrical work completed. Regettably, during March 2004, , there was a break in to 51397 by means of breaking a droplight in one of the doors in the rear saloon. Several other vehicles on site were also ransacked

On 51397, all of the internal lower waist panels have now been replaced. This really was rather a longer job than I had anticipated. It took much longer to remove the old panels, since it involved removing the trims alongside the doors, and the narrow trims alongside the windows below the upper panels. In nearly all cases the steel screws had corroded and 'welded' to the aluminium. These are now being systematically replaced with countersunk slotted head stainless steel screws which not only improves appearance but hopefully will avoid further corrosion problems. The small trims are being replaced with hardwood equivalents for a variety of reasons. Some trial scrubbing of the floors has revealed clean blue lino, and it has become clear that a wholesale effort will be needed to scrub the entire floor, which, on the basis of the trial patches dramatically improves the overall appearance of the saloon. Perhaps most important has been the completion of most of the bar which is illustrated below.

On 51351 lining has been completed on one side, and around the cab, lining and whiskers applied, together with the necessary blue coupling square. For no other reason than I like the look of it the modern 'Thames' insignia has been retained, but it may go if howls of protest are heard. Numbering remains to be applied. The upper lining has been applied to 51397. I am pleased with the general profile of the whiskers, which compares well with pictures I have seen, and I am particularly pleased that they clear the central headlamp with no apparent distortion. Work continues on both cars to seal leaks in the window rubbers, and most of the leaks seem now to have been controlled.

There has been considerable work on the electrical front. On 51397 a completely smashed jumper receptacle has been rebuilt. It's not entirely pretty, but it functions so far as I can tell. The complete unit has been mains wired with shore connections at the front of 51397 (for use when the vehicle is berthed overnight) and below the guards footstep on 51351 (for use when the unit is at our station, Furnace Sidings). This has necessitated the fitting of two inter vehicle jumpers. On both cars the Halon cylinders have been removed, and connections modified so that the cylinder integrity sensor is fooled into thinking that the cylinder is still there. On 51351 a wire corroded off close to the engine and powering the shutdown solenoid has been bypassed, though its final connection has not been made. Batteries on 51351 despite appearing to initially revive now appear to have finally died, though we have a few more tricks to try. On 51397 a burnt out Water Level Relay (in a box on the side) has been replaced by a modern plug-in type, and festooned with jumbo 10mm LEDs so immediate diagnostics can be made when an engine won't fire up. At the same time the Start Relay (which was unreliable,and in the same box) was similarly replaced. Due to the flat batteries (and the non-functioning shutdown solenoid), neither engine has run on 51351, though both have run sweetly on 51397. There appears to be a crack on one of the NRV castings and this results in failure to generate sufficient air on 51397.

My Chairman has insisted that return to traffic of the unit is now a high priority and late summer 2005 appears to be realistic. With a few more diesel loco drivers coming through the pipeline, it looks, at last, as if I am going to have the time to prepare the unit, so watch this space.

On the Smiths Heater front, attempts to run 51351s heaters in early 2002 met with SOME activity. The RHS unit ran and smoked a hellava lot, but didn't seem to be doing much heating. The LHS unit failed to run. A similar experiment on 51397, in late June 2002, was more interesting. The RHS heater appears to function,. The LHS heater was run for about 15 mins before I realised that the car was filling with smoke. Outside the unit was whirring fit to bust and throwing out flames! No panic, I thought, just throw the BIS. No chance! The bloody thing just carried on belching forth smoke and flame, and it wasn't till I pulled out the Jones plug that the wretched thing finally stopped - who said DMUs were boring? Since then I've pored over the circuit diagram, but the drawing was clearly drawn by a draughtsman, not an engineer, so glimmers of understanding are coming only slowly.