Many years ago I was boating somewhere south of Birmingham, I thought it was on the Worcs and Birmingham canal and went through a very long tunnel, no towpath and at the halfway point it was impossible to see either end portal. It gave a lasting impression of being buried alive. I thought I remembered it to be Tardibigge Tunnel but this is only 580metres. Wast Hill Tunnel, further north could fit the bill but I recently read that it is possible to see from one portal to another. Can anyone shed light on which tunnel this may be? It was many years ago when I went through it but I am sure I was not dreaming.