What is the approximate number of operational heritage or privately owned (i.e. not part of the national network) standard gauge railways in England?

In the 1960's, when Dr. Beeching published his report on the future of the railways in Great Britian, it sounded the death knell for many branch lines and some main lines. Even before the closures which followed, there sprang up many voluntary groups whose aim was to preserve those lines and stations which were closed, or due to close, in their respective areas.

Now proving to be popular tourist attractions, there are currently around 70 such lines in operation in England, I cannot be exact with the figure as there are one or two under construction, and possibly more than one in serious financial difficulty, which may have to cease operations.

This figure does not include narrow gauge, tramway, or miniature gauge railways, of which there are many more.