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Hitching a Ride - A GWR Diagram M2 Shunter’s Truck from a Seven Models kit

The appearance of a choice RTR pannier tanks surely creates a need for accompanying vehicles

Chris Gwilliam builds and describes something a little different

I have loved these tiny beauties ever since my boyhood, when I used to perch on an old airraid shelter watching a 57xx pannier with an attached shunter’s truck bustling about the yard at Newport East Usk, with shunters clutching their poles and dangling dangerously from its running boards. There was a high casualty rate for this grade of employee and I can fully understand why. I bought the kit for £25 when it was first released under the Seven Model Designs label but as is often the case life, including emigration, intervened and about ten years elapsed before I could make a start on it. I believe it’s now marketed by Scorpio but I don’t have a current price.

A little bit of history first. If you want to build the kit using only the parts supplied in the bag, there are some limiting dates if you wish to be authentic. The first batch of wagons were built in December 1908 on Lot 611, but as new, they had rectangular buffer bodies with oval heads and 3-link couplings, none of which are supplied in the kit. All were eventually given the self-contained round-head buffers and Instanter couplings as supplied by Seven Models, and the earliest known s/c buffer modification was in August 1912. An excellent illustrated article by John Lewis in the issue 26 of the Great Western Railway Journal (Spring 1998) lists allocations and withdrawal dates for almost the whole batch, and many of the modifications, so you can select an example which is correct for your period and area. Other photos are quite hard to find. The Great Western Trust has a distant photo of one with number indecipherable at work at the Didcot Provender Store in the mid 1920s in modified condition. Mine is going to be numbered 41746, though the exact date of fitting s/c buffers is not given in the table in this instance. I chose this number as it was allocated to Newport Dock St; the model will spend its life shunting Monmouthshire private owner wagons, of which I have a substantial hand-lettered collection.

The Scorpio half-cab pannier tank to which the shunter’s truck will be coupled has yet to be built; like the truck it has sat in its packing for some years now.

There is an alternative approach if you fancy the later diagram M3 instead. Conversion would be a fairly simple matter by substituting slanted and tapered hand-rail supports from brass L-section for the vertical round stanchions supplied, and using shorter lower handrails which do not wrap round the ends. Many of both diagrams survived well into British Railways days. There are various in-service alterations to be aware of. Those which worked carriage sidings frequently had vacuum through-pipes, some had steam heating pipes as well, and later pattern lamp-irons were retro-fitted to various examples, sometimes one at each end of the toolbox, sometimes two on each endsheet; none of these fittings are in the kit. As always it’s best to work from a photo if possible, though sadly that was not possible for mine as I have failed to locate a picture of it, so there had to be an element of guesswork. It would have been used for shunting the extensive freight and mineral sidings at Newport Docks, so my guess is it was not vacpiped.

Hindsight is a wonderful thing

If I were to build another I would make significant changes to the suggested build sequence. The instructions are brief, though the exploded drawings are a great help. The lower hand rails are easier to fit before the stanchions and upper hand rails are in place. With a wheelbase of only 7 ft, and the complex Dean-Churchward type III brake rigging to contend with, there is very limited space to work with below the deck, so I would also suggest you add the handrail stanchions at an early stage so that their locating spigots can be soldered from underneath. I recommend fitting the toe protector plates behind the W-irons before you add the wheel-sets, and that you add the stirrupshaped brake safety loops to the brake push-rod castings before they are fitted to the floor. All of these things caused me a headache when I built in the suggested sequence.

As per instructions I punched out all the bolt heads while the parts were still on the mother-etch. At the same time I also drilled all the V-hanger holes 0.95mm, (see below for my comment on the gauges of wire you will need). The W-irons have been folded down and the wheels test-fitted. Some adjustment was needed to get the axles parallel.

Photographs of M2 wagons show a hole in the solebar above the V-hanger for rope shunting by horse or capstan, but I did not spot this until after I had finished building the kit, so I must live with the discrepancy. My kit lacked one of its four cast white metal back-stops for the hinged lid; I carved a replacement from a lump of scrap white metal.

The main body structure

The etching cusp at each corner of the floor panel need filed off otherwise the sides will splay out when the one plank sides are folded up. The rebates on the solebar ends to allow clearance for the upper lip of the headstocks need enlarging slightly. The head-stocks themselves need to have slots cut in the lower lip, into which the DCIII Vhangers fit. I used a slitting disc in a mini-drill for this. The holes for the buffers also needed reaming out a little. The slots and tabs which locate the deck and the sole-bar/W-iron assembly together are a slack fit, so ensure solebars and wagon sides are parallel before seaming up. With the W-irons folded down and Slaters 8-spoke wheels and bearings in place I found that the axles were not quite parallel and when allowed to roll on a level surface the wagon veered to the left instead of rolling in a straight line. I removed the offending axle, and filed an oval hole for the bearing, leaving the bearing unsoldered and free to float a little. The other three bearings were soldered in place.

This cured the problem. I found I needed to insert one washer between each bearing and the W-iron to avoid end-slop on the axles. I omitted the halfetched W-iron keeper plates as they were impossible to remove from the etch without distortion; their absence will not be noticed once the running boards are in place. The deck and underframe have been united. It’s easier to add the toe protector plates behind the solebars before inserting the wheelsets and bearings. Assembling the buffers with shortened springs and test-fitting them to the headstocks.

Brake-gear

The kit includes 0.7mm brass wire, which is fine for the handrails, but for the brake rigging 0.9mm is needed for the sturdy rods between all the V hangers, and some 0.45mm for the finer DCIII linking rods. A useful drawing shows where all the bits fit on the GWR’s ludicrously complex DCIII brake-gear, but the brake-shoe push-rod castings are omitted from the sketch for clarity. It’s important to ensure the castings are orientated correctly. Viewing the wagon right way up and with the widely-spaced DCIII V-hangers on the right, the push-rods should be arranged so that the right hand one is above the left. On the far side the opposite applies, i.e. the right hand one is below the left. The 0.9mm rod between the large central V-hangers needs to be threaded through five holes; in order these are the nearside V, the nearside brake push rods, large crank, far side brake push-rods, far side V. I added almost all the adjustment clasps to the 0.45mm longitudinal rods, but omitted two that should attach to the two small brackets that fold down from the floor, as it gets very crowded indeed, and I did not want to risk melting the white-metal brake shoes. The missing clasps would have been hidden behind a wheel so their absence will not easily be noted.

The DCIII V’s at the right-hand end of each solebar will slightly obstruct the hole for the buffer body, even if they are tightly mounted against the rear of the solebars, so a little more reaming will be needed. They also present a problem when one attempts to fit the sprung buffers, as there is insufficient clearance to add the 8BA nut which retains the buffer shank, so only two of the four buffers on my example are sprung. The instructions point out that the internal springs provided need to be halved to fit. The buffer heads and shanks are lost-wax castings. One of mine had a deformed thread and needed attention to the thread before it would accept its nut.

Final details

The toolbox is slotted in such a way that you cannot mount it on the deck the wrong way round - a thoughtful touch. It’s easier to add the lampirons before adding the box to the deck; I did it the other way round and found it fiddly. I opted to use some spare Blacksmith angled lamp-irons rather than the early pattern supplied. The hinged lid is meant to be two layers sweated together, but I omitted the lower layer. Note that the cast backstops are mounted with their curved face towards the back of the toolbox, not the hinged side. I got that wrong as well and had to do it twice. Upper handrails, stanchions and brake castings. The back stops for the hinged lid of the tool box have been mounted back to front and need to be re-set.

The axle-box/spring castings were added with superglue rather than low-melt. It proved impossible to remove the springs from their casting sprues without breaking several of the spring hanger brackets, so the damaged ones had to be fitted to the lower flange of the solebars as separate items. The running boards caused me some puzzlement until I realised that there’s a numbering error on the exploded drawing - they are in fact parts 2, not parts 9 (parts 9 are the solebars). It’s easier to make the long 180 degree fold in the running board first (i.e. the one where the half-etched fold line is to be folded outwards), and then do the three shorter folds, which fold inwards.

Strictly speaking the suspension brackets for the running boards should be angle iron, not flat, but I can live with the slight lack of detail. I found some little eyelets that are supplied by Slaters for fitting safety chains to their 4-wheel GWR coaches, and used them as handrail clips for the lower handrail, instead of just using bits of brass wire as shown on the drawing, and I think the result is neater. The slots for the coupling hook in both the headstock and the coupling pockets needed opening out a little to accept the hooks. The coupling links are lostwax castings, and I broke two as the metal is very brittle and snapped when I attempted to bend it. Nickel silver wire replacements were fitted. Soldering completed, the wagon is ready for painting.

Livery

In GWR days I assume they were grey overall, though there is some suggestion that as departmental vehicles they might have been black. They look grey in all the photos I could find, so I went with airbrushed Humbrol 67 matt tank grey, and white letters and numbers. I believe that as built the handrails were grey, but from c1914 were painted white for better visibility in wartime. In British Railways days the one I used to watch at Newport, which I think was an M4, was certainly in black Departmental livery, with yellow letters and numbers, and the running number preceded by a DW.

In my childhood OO modelling days I once cobbled together a (not entirely convincing) likeness of it using a Triang single-bolster wagon and a Weetabix packet! Others in the nationalised era may have been in freight pale grey from 1948 onwards. There’s a good photo of an M3 in c1955 black livery at Pontypool Road in John Drayton’s book Across the Footplate Years (Ian Allan 1986).

Lettering was a somewhat painstaking process. ‘NEWPORT’ is available on the guard’s van section of the HMRS GWR wagon transfer sheet: I used the 4mm version as the 7mm letters are too large. ‘DOCK ST.’ had to be built up one letter at a time from other allocations. The planked floor and the running boards were painted in a brew of four parts matt light grey to one part desert sand, and when dry were washed with a very thin solution of Humbrol 98 matt chocolate, then the whole truck was given an airbrushed coat of matt varnish to which a couple of drops of 98 had been added, just to tone it down a little. When that was dry a very light weathering with powders was applied. The finished model with a little light weathering.

The kit goes together very well, the fit of the parts is mostly accurate, and there is evidence of some clever thinking behind the design of such a cramped little vehicle. I much enjoyed the build and the challenges it presented. Would be builders will need decent soldering skills and more than a little patience, but a fine model can be achieved.

gazettearchive/gazettevol20/gwrshunttruck.txt · Last modified: 2021/09/22 14:16 by 127.0.0.1