The magic moment when you go under the great Forth Bridge

There are times when I think that a great bridge is the noblest work of man. I recently had the thrilling experience of travelling under the famous Forth Rail Bridge on a 52,000-ton ocean liner. I was up on the top deck before 7 a.m. to see this remarkable event, which had to be timed exactly to coincide with the right tide. At high tide the clearance of the bridge is 44 metres, and as the liner’s mainmast is 46 metres, its captain has to come in on mid- or low tide. Even so, the clearance is only a few feet, and the magic moment when the vast ship moves into the steel jaws of the structure is vertiginous; the distortions of perspective make you certain a horrible crunch is bound to occur. The new road bridge, a little further up the Firth, has a higher clearance, but even so the feat of negotiating it without a smash appears impossible.