Usually I don't tip my hand and show the 3D models I'm designing until I've got at least the first prototype print in front of me. This time though I gave the game away in my previous post so you already know that I'm working on a model of the open wagons used on the Sand Hutton Light Railway so I may as well give you the odd progress update.
As I mentioned before I'm basing the model on the drawings in the RCL Publications book on the railway. The book actually contains two sets of drawings as well as a description of the major components. The first drawing is a copy of the original P & W Maclellan Limited works drawing. While works drawings are nice they tend not to reproduce well in books, especially not when scaled down to fit a single page (all the measurements become difficult to read and obscure the details). Fortunately the second drawing is a modern set produced (I assume) for the book by Roy C Link.
Given that the drawings have big copyright statements all over them I'm not going to risk reproducing them here so, unless you have a copy of the book to hand, you'll just have to take my word for what follows. The modern drawings take up the top half of one page and show three views; a side on view, an end on view, and a view from above. Together these give most of the details and those that are missing can easily be gleaned from the copy of the original works drawings. The bottom half of the page is an old photo of a single wagon. The strange thing is that the photo and the drawings don't match! Now I'm not talking about a minor detail like the placement of a bolt or something. No, the main problem is that the planks making up the end walls of the wagons are in the wrong place on the drawing. Now I must admit that it is a fairly easy mistake to make, as I misinterpreted the works drawing initially as well, but when the drawing is placed next to the photo it is obvious. There are other problems, but I think they mostly stem from the fact that all the wagons I've seen in photos so far don't fully match the works drawing.
When I design a model based on a real prototype I strive to make it as accurate as I can although clearly issues of gauge and the available materials force some changes to be made. The point to remember is that while scale drawings are really very useful there is no replacement for looking at the thing you are trying to copy. In this case no wagons remain, but there are plenty of photos that show many of the important details and it is always worth taking a long look at these to see what you might have missed.