A Beginner's Guide to GWR iron/steel loco coal and mineral wagons

by Jim Champ


This article covers Loco Coal and the closely related mineral wagons built by the GWR. It does not cover the coal hopper wagons. There were also some wooden Loco Coal wagons, most notably Diagram N7 1, 4-plank wagons which preceded the iron wagons and N33, which were a batch of about 100 purchased from the Bute Supply company which were basically of standard private owner specification. There were others too – there is always an exception when it comes to GWR practice. One of the main design points to be aware of was the style of brake employed. This will be covered in a separate article on this site. At the turn of the century iron wagons were constructed with rolled corner plates, giving a distinctly curved profile to the corners. Later on they became square cornered and generally more conventional.

Diagram numbers

GWR wagon designs 2 were allocated diagram numbers. Loco Coal, Mineral and Coal Hopper wagons were allocated in the "N" series. This system commenced around 1905. When the system was created the newest and biggest wagons were given the lowest diagram numbers, but thereafter new diagram numbers were allocated when required, whether for new designs or for old or absorbed stock that required a new diagram. This means that, at this distance, there is little logic in the number sequence at all!

10T Loco Coal

The first iron loco coal wagon built in significant numbers was the N6 3. These started off as 7T or 8T wagons with quite low sides, but were converted to 10T with a distinctive continuous top panel and no stanchions. There were something like a thousand of these, built between 1889 and 1893. In their later days N6 appear to have been frequently used for transporting firebox ash. This wasn't just a waste material – it was often used for building up ground level during building works.

The N6 were followed by four subsequent diagrams, with evolving specifications. Successively these were DCI brakes/round corners (N13 – 289 built between 1905 and 1907), DCIII brakes/round corners (N19 – 250 built in 1912/3) 4, DCIII square corners (N20 – 300 built 1915/16) and Morton/Square corners (N30 5 – 200 built from 1935 to 1937). This sequence of design changes was typical for all the iron mineral wagons. N19 and onwards had a slightly wide side door – 5'4" rather than 5' of the earlier wagons, and the N30 wagons were 21'6" overall length, 6" longer than the earlier ones. The 10 ton wagons would have been used mainly for deliveries for the smaller sheds and stabling points – somewhere like Brixham might only use 1 ton of coal a week, and it might even be loaded directly from wagon to locomotive 6.

12T Loco Coal

Apart from a single prototype, which was based on N19, there was just a single diagram of metal 12Ton loco Coal Wagons. This, diagram N21 7, was essentially the same as N20 but with taller sides and slightly uprated axleboxes for the increased weight. 200 of these were built between 1918 and 1920, but no further 12T Loco coal wagons were built. An odd feature about both diagram N21 and the related N20 10 ton wagons is that the V hangers for the brakes were not on the centre line, but offset slightly. Apparently this was due to the wagons being built from condemned older wagons. However when you look at photos of these wagons as built, with the latest style buffers and brake gear, obviously new bodies and the rest of it its hard to imagine that very much was secondhand. Was this another example of the GWR juggling money between capital and revenue funds? 8

20/21T Loco Coal/Mineral

The early 20T loco coal wagons were 20' long. The first design, later allocated diagram N4 9 had massive 12" deep solebars, and was followed by diagram N3, with a more conventional 10". N4 preceded N3. N4 were built with the short-lived Thomas brake, but later converted to DCII or DCIII. These wagons didn't have external stanchions, and had rolled iron corners. There were over 200 of each of these, and they seem to have survived to post 1948.

From 1903 the N2 10 was produced, lengthened to 21', and with stanchions to support the sides, but still with the rolled corners. Some of these were vacuum brake fitted, as were some of the N4 when they were converted from the Thomas brakes. All vacuum brakes were removed by 1934. Earlier lots had DCII brakes, later ones DCIII. Nearly 1000 were built, the last in 1913.

N22 (1922/3) was a development of N2, all with DCIII brakes, some differences in underframe construction and self-contained buffers, but otherwise still with the rolled corners.

Something of a step change came with the "Felix Pole" Mineral wagons: these and all subsequent 20/21T wagons were 21'6" long and 8'4" wide. The square cornered wagons seem to come in bewildering variety, but some general principles can be observed.

Wagons built for Loco Coal were almost always two door, with no end doors. This seems logical, since they were normally unloaded by hand onto the coaling stage. Wagons built for mineral traffic were a mix of two and one side doors, initially with two end doors, but later designs had only one end door. Presumably the single side door wagons were intended for customers who usually unloaded the wagons by end tipping.

The panels were in two basic layouts – one side door wagons had a wide central panel, and smaller end panels, and two side door vehicles a narrow central panel and wider end panels. The doors were narrower than on the single side door wagons.

Until regulations intervened the tendency from this period seemed to be that Loco Coal wagons, which were GWR internal use stock, tended to have DC brakes and GWR self contained buffers. One assumes they were regarded as superior. Mineral wagons, however, which presumably would have more frequently ventured out of GWR hands, were fitted with the national standard RCH buffing gear and Morton brakes, for which parts and skills to repair would have been more widely available. Freight wagons had a very hard life indeed, and damage was not uncommon.

The first of the Felix Pole wagons were the single door N23s 11, built from 1923 to 1925. 760 were built, with a mixture of Morton and DCIII brakes. They had RCH type buffers rather than GWR. It seems somewhat unusual for the GWR not to have issued a separate diagram for the alternative brake type. 190 two door N24 followed from 1924/5, all with Morton brakes. The loco coal equivalent was N27 12, 635 built from 1925/38 with GWR self-contained buffers and DCIII brakes. Diagrams N28 13 and N29 14 were single door N23s converted between 1934 and 1937 to have three side doors and used for loco coal. These were the only loco coal wagons to have end doors. N28, of which there were 149, had Morton brakes, N29 (51 rebuilt) had DCIII brakes.

The last diagrams built under the GWR were the N32, which was a mineral wagon with a single end door and Morton slotted link brakes, and N34 15, the matching loco coal wagon without the end door. There were no less than 5,000 N32 built from 1933 to 1936, all by external companies. They were leased out to various private owners. There were 300 of the N34s, the last of which came out of the shops in 1949 under BR ownership. Further batches of mineral wagons similar to N32 came out under BR ownership 16.

40 Ton Loco Coal Wagons

The history of these is remarkably complicated for so very few wagons 17. Too complicated to include here! There were rebuilds, renumberings, reuse of old numbers and goodness knows what. Some were loaned to the war office for use in armoured trains in WWI. The fundamental dimensions were all very similar: the various diagrams mostly covered variations in braking and bogie position, although the first batch, uniquely for GWR built mineral wagons, had side hinged swinging doors above the main ones. In all 27 were build to diagrams N1 18, N11, N14, N15 and N17 between 1904 and 1910. In the end there was little advantage over the 20T wagons, and no more were built after that. Four were converted into garrison trucks for armoured trains during WWI.

Modelling the wagons

I think it useful for modellers to note how many were built of each diagram. Some were built in very great numbers, others, especially prototypes, very few. This should affect the choice of wagons to run on your railway, although unless you are building from scratch the practical consideration is what diagrams the manufacturers supply – surprisingly not always the most numerous.


10T wagons

These are no problem with three of the more common types available, and a bit of hacking and chopping serving to provide others. David Geen provided the early N6 in whitemetal, Cooper-Craft the N13 in a plastic kit, and Cambrian the N30, also in plastic. An important note about the Cooper-Craft model is that the wagon assembles with square corners. You need to round these off to represent the correct rolled corners of the N13 – but carefully so as to leave enough structure for strength. Then the inside radius also needs to be modelled, presumably with a filler such as Milliput. Some careful hacking will provide approximations of the N19 and N20 – Cooper-Craft provide the correct body length and Cambrian the correct door width: take your pick. Be aware of the offset brake hangers on the N20 too. See this article for more thoughts on modelling the 10T wagons. There were probably 1000-1500 10T loco coal wagons available to the 20thC GWR at any time.

12T wagons

They are not to my knowledge available ready to run or in plastic kit form, but they only represented about about 7% of the available stock.

20/21T wagons

4mm modellers (other than those who can build etched kits) are poorly served for the long wheelbase wagons. There would have been more than 2,000 of these large capacity wagons in use at any time, so they were the predominant type, yet there is no satisfactory 20/21T GWR Loco Coal Wagon available. A model of a BR prototype which is basically similar to the last mineral wagons, but with a more heavily reinforced end door and extra stanchions at the corners is available from Parkside-Dundas, but because the door sizes and spacing are so different it would be quite a challenge to convert. Hornby and Dapol produce what looks to me like an N32 mineral wagon, but is often badged as Loco Coal. How much this would have happened in GWR days is perhaps debatable – I suspect it probably only happened post war after the private owner wagons had been pooled.

40T Loco Coal

To my mind its a curious protoype to pick, with so few having been built and probably only a dozen or so in service at any time but nevertheless Cambrian (and Ks before them) provide a model. Sadly the door arrangement is quite different from the 20/21T wagons, so there is little scope for kit bashing into 20 or 21T. Similarly the sides of the 10T wagons are too low to make them a basis for a 20T.


Doubtless any number of etched kits are available, but these are the available models I can identify for the solder phobic.

10T Wagons

Cooper-Craft also do the N13 in 7mm scale.

20/21T Wagons

Parkside-Dundas do both the single door 20T N23 mineral and the same wagon in its three door 'converted to Loco Coal' variation as N28. The web pages show them with Morton brakes but if the DC parts are not included in the kits then they should certainly be readily available from etches. That would make the three door wagon N29 of course.



The only model I can trace is the Parkside-Dundas N24 (twin door) Mineral.


1  N7 photo: p46, Great Western Wagons Appendix, JH Russell, 1974, Oxford Publishing Co, SBN 0 902888 03 X, (RWA)

2  The main reference throughout is "A History of GWR Goods Wagons", Atkins, Beard, Hyde & Tourret, Combined Edition, 1986, Book Club Associates/David & Charles, ISBN 0 7153 8725 1 (ABHT).

3  N6 photo: RWA p47

4  N19 photo on Paul Bartlett's website.

5  N30 photo: p43, GWR Wagons before 1948 Vol1, R Tourret, 2005, Cheona Publications, ISBN 1 900298 29 5 (W1948)

6  ABHT, p136

7  N21 photo: RWA p43.

8  Expansions to the railway's equipment had to come from the capital fund – effectively money from shareholders, but replacement equipment was to be funded out of revenue – income. There is some evidence that the dividing line between the two could be blurred if money was available in one but required in the other.

9  N4 photos RWA p38/9, shewing both Thomas and DC brakes.

10  N2 photos RWA p40.

11  N23 photo: p42, W1948

12  N27 photo on Paul Bartlett's website (British Rail Wagon photographs by Paul Bartlett)

13  N28 photo: p108, A Pictorial Record of Great Western Wagons, J H Russell, 1971, Oxford Publishing Co, SBN 902888 01 3

14  N29 photo, p143, ABHT.

15  N34 photos here (British Rail Wagon photographs by Paul Bartlett) and here (Great Western Society)

16  BR built GWR style mineral wagon photos (British Rail Wagon photographs by Paul Bartlett)

17  ABHT p144 on.

18  N1 photo: p34, W1948