Give up on the internet except to look for companies who might take pity on a poor student and help out.
Which are the signalling equipment supply and installing companies? e.g. Westinghouse, Plessy, GEC (must be more modern ones)
Which are the key Journals in S&T ?
This lot might help............
http://www.irse.org/
The Institution of Mechanical Engineers has always been very helpful to me...even though I'm not a Member.
Speaking as a fool who has done two Research Degrees in my time.......eventually there is no alternative to getting out of the armchair and going to meet people, and librarians are generally embarissingly helpful and have spent hours helping me out. (except for the Library Dragon at the NRM
)