Constructing P.O. Wagon Sully No. 21

This all started from a need for more wagons for my layout "Moretonhampstead". I had built the society wagon kits, and wanted some more variety. I had never before scratchbuilt a wagon (or anything else) in either styrene or etched brass, but the results have encouraged me to go on to more complex things, which some of you may have seen at Newbury. The problem was, I had no drawings of any suitable wagons. I believe the old OPC drawings are now at the NRM but I have no idea how one would go about getting hold of them, and the Eddie Brown datasheets only cover very early and late wagons.

I decided therefore to look through some photos, and try to come up with my own drawing. There are very few decent pictures of broad gauge wagons, and the best bet seemed the Swindon dump photos. The most obvious example was the private owner wagon "Sully No 21" which is reproduced in the Waters book, and was enlarged on the front of Broadsheet 38. It is a lot easier to produce a drawing from a larger picture as it is easier to measure! The break van on the centre pages of Broadsheet 34 also tempted me, but it seemed that a simple four wheeled wagon would be a better bet for a first attempt at scratchbuilding. More of these enlargements would be useful please Mr Editor!

Sully No. 21 at Swindon Dump

The first step in producing a drawing is to establish known dimensions to scale from. The dimensions to use, seemed to be the wheel diameter, which would seem to  be, by comparison with the convertible four plank wagon next to it, 3' 1", the buffer spacing 5' 10" and the buffer height (varies 3' 0" - 3' 1").  Note that the later convertible stock used a different buffer height and spacing. Scaling the photo then gives the following dimensions :

Wheelbase 9' 0"
Length 14' 4"
Height 4' 0"
Width 9' 0"

This compares well with Mike Jolly's estimates on the next page of the Broadsheet, which I only noticed after having come up with these figures myself. Establishing the width of the wagon was not quite so simple as the other dimensions, because of perspective, but the result looks about right. Having established these dimensions, the drawing proceeded fairly quickly, the only real problem being the ride height of the wagon above the wheels, which can't be easily scaled from the photo. The buffer height is known, which enables us to make a reasonable estimate of this, the position of the buffers is again difficult because of perspective.

4mm Scale Drawing of Sully No. 21

So, with the drawing complete, now all I had to do was build some wagons! Styrene sheet seemed to be the obvious way to go, having watched a demonstrator at Expo EM a few years back making it look ever so easy. The main body was constructed from 40 thou sheet, which scales to about 3 inches for 4mm scale. This is possibly a little on the thick side, but I wanted my wagons to be fairly robust, thinner sheet deforms far too easily.

All the cutting and marking was done using a "Skrawker" and a metal ruler, which makes life so much easier than trying to use a scalpel. This cuts a V shaped groove in the plastic using very little pressure. Three or four passes are required, and then the plastic is snapped, giving a nice clean edge, which just needs a few strokes of a file to square up the edge. The plank grooving is produced in the same way but without snapping the plastic. Be careful here as the grooves are on both sides and it is easy to cut right through. To ensure that the planking all lines up, all the sides and ends are grooved in one operation - Fig 1. The sides can then be seperated from the ends and the sides reduced in height, before separating from each other. Each pair of sides and ends can then be clamped together, and the edges filed square. This ensures that both sides and both ends are identical even if your marking out was not quite accurate (mine never is), and helps to ensure the wagon has nice square corners. Assemble with the ends inside the sides. I find the easiest way to get a nice square corner is to lay one of the ends on a nice flat surface (not the best dining table without some covering please), line up one of the sides against it, and then push together with a small engineering square whilst applying liquid poly to the inside of the joint - Fig 2. A floor can be made similarly from 40 thou plasticard with planking scribed across. To clear the wheels you will need to cut clearance slots through the floor and cover with rectangles of 10 thou plasticard - a prototypical solution.

The corner plates can then be added from 10 thou plasticard, using plenty of polystyrene cement to soften the corner and prevent the plasticard from snapping. When set the corner can be rounded off a little with a few strokes of the file. The end stanchions are then added from 40 thou square microstrip, and the side door ironwork from 10 X 40 thou microstrip. Side door hinges can be added from 20thou plastic rod. The rivets were individually formed from tiny offcuts of plastic rod placed with the point of a scalpel, and then flooded with polystyrene cement. As can be imagined, this is a very time consuming process, but the results are effective.

The horse hooks are added from small staples of 0.45mm brass wire. Etched coupling hooks are from Ambis, W irons were cut from D&S models GCR W iron etches and superglued to the inside of the sides. The grease axleboxes and RCH 5 leaf springsare whitemetal castings from D&S models.  I could find no suitable buffers so took a set of ABS Models No. 723 LMS & LNE standard self contained buffers and cut off the buffer heads and shanks. The bodies were then filed into a truncated cone, and drilled to take Alan Gibson wagon buffer heads (4950), springs and bushes (4952).

Wheels are Alan Gibson 12mm open spoke variety (P4 profile) with new longer axles cut from 2mm silver steel rod. To support the wheels I cut down more D&S models GCR W irons to make inside bearing units. I had to reduce the height of these by 1mm to get the correct ride height for the wagon.

Livery is a pure guess, but I happen to like it and rule 1 applies. Later Sully wagons used an all over black livery, but to me the ironwork does not look the same colour as the wooden body in the dump photo. Transfers are Broad Gauge Society sheet F094. It's a shame there aren't more alternate numbers on the sheet.

Completed Model of Sully No. 21

Page updated : 19 Dec 2015