This year sees the 50th anniversary of the iconic Forth Bridges spanning the Firth of Forth between North and South Queensferry.
Most people will assume that the only way across the water is by bridge or boat, very few are aware of a 50-year-old secret tunnel which was built to connect two coal mines.
The subterranean passage, at a depth of 500 metres below the sea, was built in 1962 and officially opened on April 30, 1964 connecting Kinneil and Valleyfield collieries.
The almost forgotten crossing permitted miners from both the Lothians and Fife to walk the entire length of the Forth using the three mile tunnel - albeit in complete darkness.
The route was never intended to be a pedestrian access however. As the Valleyfield collieries processing plant continued to age, it was not only expedient, but made good financial sense to haul coal south to be processed at the more modern processing plant at Kinneil colliery.
Alistair Moore, 82, a resident of Bo’ness recollects clearly the day in 1962 he received the call to report to the Kinneil pit. He had been working as a mining surveyor over in Fife when he was tasked with taking charge of, what was at the time, a unique and unheard of project - a tunnel crossing the Forth.
He recollects the 18-month digging project, undertaken by two teams of hard-working men, in the worst conditions imaginable. It was back-breaking work.
He said: “The problems we faced were, it felt at time, insurmountable, inching towards each other the teams were forced to face death on an almost daily basis.
“The geology was uncertain, and unlike today where those working on projects like this have unlimited resources to turn to, we had no such benefits.
“I knew I wouldn’t get a second chance at this - it’s fine getting the directional alignment of the tunnels right, but a much greater challenge getting the correct depth - there was always the question, will it meet up in the right place and at the right depth.”
Alistair recounted how the possibilty of errors were vast, one simple measurement or calculation being wrong could have ruined the whole project. Without the benefits of modern computers, geological surveys, laser guided theodolites and satellite imagery, Alistair was forced to depend on his own mathematical prowess as a surveyor, local Ordnance Survey registered waypoints, and endless manual soundings made by dropping weighted piano wire into shafts to register depths.
Alistair recounted: “The day we broke through the sandstone into the Valleyfield pit was a huge relief for me, the culmination of many sleepless evenings worrying if I’d made the right calculations.
‘‘As it was I had - the two bores matched up almost perfectly, well, almost, we were actually five centimetres out!”
Alistair, not being one for hogging the limelight, decided to take a well-earned holiday, after all it had been cancelled on more than one previous occasion, leaving the company management to smile widely for the many cameras who attended the official opening ceremony.
Unfortunately no trace of the tunnel exists now, with the exception of some archive paperwork and plans.
The two collieries which the tunnel linked are long since gone, along with the industry they served for many a year. The mine shafts were backfilled once the collieries had no need of the tunnel any longer and were then capped with concrete.
So, while there may be no physical trace of the engineering marvel left, it remains, to this day, an testament of what man can achieve without the whizz-bang technology we have become so used to.