A few from my neck of the woods in or near Manchester:
Museum of Science and Industry
http://msimanchester.org.uk/collection
Sort-of-free (you will be asked for a donation), massive collection from steam engines (some working, including the only reciprocating steam generating set left in the world (Ferranti), apparently) through machine tools to electricity generation equipment, scientific apparatus etc etc etc. A great opportunity to marvel at how recently we used to make an awful lot of things in the NW. The sections for electrical generation and telecoms are harder to find but worth seeking out.
Anson Engine Museum
http://www.enginemuseum.org/
Cheshire's version of the 'Internal Fire' museum in Wales referenced up-thread. Loads, and loads, and loads of diesel engines of all sizes. Refreshingly amateur, lots and lots to see.
East lancs railway
http://www.eastlancsrailway.org.uk/
Travel in style from Bury to Rawtenstall. DMUs and steam, not cheap but a good day out, esp with kids
I'll think of more but that will do for now!