Cooper-Craft 4mm open wagons – an introduction

by Graeme Pettit


This range of kits are excellent fodder for the beginner. They have been well thought out, and have simple instructions and support diagrams. I particularly like the softer plastic from which these kits are moulded. A selection of my Cooper-Craft Opens are illustrated below, along with a few notes.

As you may gather from some of the photos, the buffers are prone to breakage. I recommend fitting cast types from ABS or similar. Alternatively I believe some of the MJT buffer offerings may be suitable, but have not tried many of the range, so am unable to comment further. If you find some on another kit, try approaching the supplier of the kit, and asking if parts are available separately – most suppliers are willing to oblige at a price, and some are better than others.

Watch too, how you build the brakes on these wagons. Work from photographs if possible. The kits below were built before I had expanded my library to cover GWR items to the extent I have now, and so the configuration of brakegear is not entirely correct on all the wagons.

GWR 5-plank OPEN A Diag O4 (Kit 1001)

This represents wagons built from 1903, and fitted with a Williams patent sheet rail (folded down and out of view on this model). The sheet rail was later removed when wagons of the type were not returned to the GWR after the RCH wagon pool was developed during WW1 – see kit #1005 below. Originally fitted with Dean Churchward brake, many were, once in the RCH pool, fitted with the standard brake lever system used by other companies.

GWR 4-plank open wagon – Diag O5 (Kit 1004)

During early experiments to try to ascertain the most useful size of wagon for general purpose use at the beginning of the 1900s, 200 of this design of wagon were constructed and placed into use for assessment against other types. The 4-plank design was not adopted as the standard due in part to the limited side height, and the 5-plank to Diagram O5 found favour instead. No further 4-planks of this type were built after the initial 200.

This wagon has been fitted with the only spare set of buffers I had left at the time – they are LBSCR pattern, and will be replaced by cast items at some future date when I rebuild the kit with the brake gear the correct way around, and fit the door springs which are missing. Can't the camera be cruel!

5-plank open RCH wagon Diag O4 (Kit 1005)

This kit is the same wagon as kit #1001 but in its later, 1925 guise after inclusion in the Railway Clearing House wagon pool. It was found that many of the sheet rail fitted wagons did not return to the GWR as other companies found them so useful, so the GWR removed all sheet rails from Comon User or Pool wagons to ensure their return more frequently. The kit comes supplied with the option to build either the Churchward brake system, or the later, lever type of brake. My example here is fitted with single-sided DC Brakes, and needs cross rodding to finalize.

GWR 7-plank open – Diag O2 (Kit 1006)

Between 1905, and 1907, approximately 1500 of this design of wagon were constructed. The intent was to use them for general merchandise rather than mineral use, and the extra height afforded by the two extra planks over the 5-plank allowed larger volumes of lightweight goods to be carried, which could be kept dry via use of the provided sheet rail. Many survived well into the 1950s and beyond.

GWR Provender Wagon – Diag Q1 (Kit 1011)

With a strong emphasis in the early years on the use of horse drawn transport, the GWR developed a central depot at Didcot for the distribution of animal feed throughout its network. 'Provendor' actually refers to the term then used to describe hay and bedding straw – a lightweight, yet very bulky material, which proved awkward to move in quantity using the existing wagon fleet. The GWR, therefore, developed these highly specialised wagons strictly for the purpose of conveying this traffic where needed. Two batches were built – one in 1888, and a further batch in 1903.

The kit represents the later batch, with an 11' wheelbase, 18' long, 8'6" wide. They could be found anywhere where horses were used, and often ran supported by Diagram O2 wagons (kit #1006), which carried heavier feedstuffs to the same locations. Loads on both would frequently be covered with tarpaulins if inclement weather was expected between loading and unloading. No. 37000 above represents the kit built as supplied with no modifications. It is an easy kit to construct, and recommended as a beginners project. It makes into an unusual, but fairly common prototype.

You can see more examples of the Cooper-Craft open wagons in the Showcase section.

Suggested reading:

  • Atkins, Beard & Tourret: 'GWR Goods Wagons', Tourret Publishing 1999

  • Geoff Kent: "The 4mm Wagon, Part 1: Opens, Minerals and Hoppers", Wild Swan 1991


Please note: The author has no affiliation with Cooper-Craft.