Since reading Part Three of the RCTS "Locomotives of the Great Western Railway" series, I have become fascinated by the first standard-gauge locomotives to run on the GWR. I shared some of my findings in a forum thread: GWR Absorbed Engines 1854 - 1921
My interest has gradually become focused on GWR No.184, which was built by E.B.Wilson and Company for the Oxford, Worcester, & Wolverhampton Railway in 1853. It was photographed several times, showing how it acquired a more modern appearance through at least two re-builds at Wolverhampton works. This engine appealed to me, because it continued in service throughout the rest of the 19th century, ending its life working local trains in the Oxford area, where my current layout is set.
There are several problems to be overcome before I can consider building a model of this engine and I intend, in this blog, to document my approaches to solving these. This post is, therefore, the first of what I expect to become a series. I have a "suck it and see" approach to modelling and, at the moment, cannot guarantee that a model will ever see the light of day but I hope that my methods will be of some interest to others. So, to begin at the beginning......
Before starting on a model, I need some reasonable outline drawings to work from. It may be that the originals of No.184 exist somewhere but I am going to work from the information that I have to hand. Part 3 of the RCTS series I referred to above has a line drawing of the original (1853) form of the engine (Fig.C62). It also provides me with the key dimensions of the wheelbase and boiler. While there are photographs of both the 1871 (Fig.C61) and 1893 (Fig.C63) re-builds, there are no drawings of these later versions in these books. There is, however, a drawing of a very similar E.B.Wilson engine, No.192, as re-built in 1874, with later modifications (Fig,C86), so I decided to see if I could adapt this drawing, to provide a fair outline of No.184, as it appeared towards the end of the 19th century.
My usual method, which I have described in earlier posts, is to make photocopies of the drawings and then to overlay them in the computer, to show the similarities and differences. The outside frames were not changed during the rebuilds, so my task was to 'graft' the new boiler and cab from the drawing of No.192 onto the frames and wheels of No.184. In making the overlay shown below, I had to reverse one of the images, since the drawing was of the opposite side of the engine.
The overlay shows that the two designs have very similar overall dimensions, so I did not find it difficult to synthesise a single drawing of No.184 from the two overlaid drawings: Both engines had the same overall wheelbase of 15' 6", equally divided in the case of No.192 (when re-built) but 7'6" + 8' 0" for No.184. I was also able to check many details against the various photographs of No.184.
Combined with the following information from the RCTS description of the re-built '182 class' :
Boiler Group 35 (Type R3) Code TJ with raised casing:
Barrel 10' 0" long X 4' 2" diameter
Casing (firebox) 5' 1" long
Wheels 3' 8" leading, 5' 8" coupled
I believe that there is now sufficient information here, for me to prepare some 4mm model drawings of the engine.
Next job will be to design a matching tender, which is rather more difficult, since there is much less information available, regarding wheelbase and other dimensions, for these early vehicles. That will be the subject of my next post.