Engineering Drawings Steam Locomotives

I would like to ask the members about engineering drawings for steam locomotives of the Big 4. My understanding is that these are all held at the NRM. Is this correct. Are these drawings being digitised and if so how far has this work progressed?

 

Have a look at http://www.nrm.org.uk/researchandarchive/archiveandlibrarycollections and you will see that there are collections of drawings and papers from the Railway Companies and a separate collection of drawings etc. from the manufacturers and others. I am aware that the NRM is concentrating on digitising the photographic collection first. Bearing in mind the specialist equipment needed to digitise large drawings and the restraints of the last decade or two on places like the NRM, I doubt if much progress has been made in digitising the drawings - but I'm sure an enquiry to their 'Search Engine' may produce the information you require. From experience, if you can visit York they are very good at digging out things from the archives, given a bit of notice.

 

The NRM is certainly the place to start & if a drawing there is not digitised it is possible to get it digitised. Their holdings are much better for some railway works than others and some drawings - especially Great Western ones - cannot be accessed because of fragile paper.
However, if a locomotive was built by a contractor there are surviving collections e.g. the North British Locomotive Company in Glasgow, the various companies that the
Hunslet locomotive company acquired as well as its own, and there are such drawings in the NRM. Useful indexed drawings were published in The Engineer and
Engineering.
Various specialist societies can be very helpful: Didcot have drawings. Anybody who has repaired, built or rebuilt a locomotive may well have drawings or know where they are.

 

To make matters worse - for GWR drawings at least - some of the scanning isn't altogether satisfactory. Many of the ones I've seen were scanned in black and white, not grayscale or colour, and the result is that smaller lettering - most notably fractions of an inch - can be very difficult to read. And then GWR drawings really need to be scanned in colour because alterations were marked in colour, but of course once you start doing that equipment costs arise and so does storage space. Not so much of an issue now, but a very big issue a few years ago.