The process of CAD modelling starts with digitizing blueprints of the original rolling stock. The faded, degraded detail of many original documents can often be retrieved by using photographic processing techniques of the digital images.

One problem with using the blueprints is finding all the information for each specific model, sometimes this can only be found from different sources. Another problem is the variation in quality across a single blueprint, often the corner with the legend and reference measurements has been exposed to light and substantially faded. Ink can also be faded away on fold marks and critical measurements lost.

The blueprint we photographed showing the assembly of the GY wagon contained examples of several problems in the retrieval of information, however, because it was so common it is worth modelling for a train simulation. It also makes a good trial model as it is not as complex as a locomotive.

This is the unprocessed RAW photo of part of the blueprint.

This is the same photo after post processing.

The detail can now be seen clearly and is usable for creating new drawings and models. This is one of the most degraded blueprints we have photographed to date.

The Victorian Railways GY wagon was one of the most common examples of rolling stock on the tracks. This wagon was primarily used to haul grain after the wheat harvest but also variations were used for other purposes. When carrying wheat a tarpaulin was erected over the top.

This GY wagon was the first attempt our project manager, David, made at modelling in 2009, without using modern CAD software. The only information he had was a basic drawing.

We are re-creating the GY wagon using our new production pipeline.