When a tunnel ran under the Forth

The Forth Tunnel, complete with girders, in 1964
The Forth Tunnel, complete with girders, in 1964
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THE deafening roar of the drill stuttered and finally stopped. It was early morning, the last stage of a remarkable job was nearly done and now, deep under the Forth, choking dust in the air and with rubble underfoot, two men wiped the beads of sweat from their brows, the grit from their eyes, and shouted a friendly, sing-song “Helllloooo” at each other.

Bathed in the dim glow of miners’ lamps, this was surely among the most remarkable of greetings.

For this was almost 50 years ago, and the final task in an astonishing engineering mission had just been achieved – to chisel a winding tunnel beneath the Forth.

Meandering under the estuary, from Bo’ness on the edge of West Lothian to Valleyfield in Fife, two years in its execution, the underwater tunnel did what many had long dreamed of doing.

It created a shortcut linking the south side with the north. Yet while thoughts today turn to the forthcoming celebrations to mark 50 years of the road bridge – a triple whammy that also reflects fondly on its older railway sister and welcomes the new, perhaps slightly less photogenic, crossing – it’s likely that few will even be aware of a fourth Firth of Forth ­connection at this end of the estuary.

I put my mouth near the hole, as close as possible and I shouted ‘Helllloooo’ and got back this ‘Helllloooo’ from the other side. For while the tunnel through rock beneath the water was ground-breaking in more ways than one, it was never intended for public use.

Today, sadly, anyone trying to use it – indeed, even attempt to find it – will be sorely disappointed. Just like the once thriving coal industry it served, the tunnel is now a fading memory, the shafts which led to it filled in and capped, the iron props which supported it inside almost certainly collapsed.

By now the grey waters of the Forth will have claimed ownership and the crossing which once linked Kinneil Colliery in Bo’ness with Valleyfield pit in Fife, enabling its engineer Alistair Moore to shout his friendly greeting to his Fife neighbour and eventually coal trucks to pass to and fro, is no longer passable.

Work at the Valleyfield side was halted and a Sunday shift of Kinneil workers battered through the last remaining stretch. Alistair raced to work at 6am next morning, April 30, to make his way to the scene of the final push.

“The boys were working with a big jack hammer which used compressed air. You couldn’t hear a thing,” he said in 2015. “I’m watching them and all of a sudden they were crashing in and there was a wee hole, just three inches in diameter and the drill went shooting through. We were in.

“I put my mouth near the hole, as close as possible and I shouted ‘Helllloooo’ and got back this ‘Helllloooo’ from the other side.”

The tunnel was the idea of the National Coal Board, designed to make use of the modern coal preparation facilities at Kinneil in favour of the outmoded plant at Valleyfield which was so dated that it was under threat of closure for health and safety reasons. If joining two stretches of tunnel together sounds straightforward, this was a task that ­involved not only getting the two ends to arrive at the same point, but also to ensure their levels were spot on.

As it was, they connected with a mere six inches difference – an incredible achievement given the then 32-year-old Heriot-Watt graduate’s calculations had been worked out with brain power, pencil, paper, plumb lines and the trig pillar situated on top of Arthur’s Seat.

These days, lasers and computers would be used to ensure pinpoint accuracy. Alistair and his engineering colleagues’ tools were far more basic. For a start, they had to correlate the mines and underground workings to the Ordnance Survey National Grid, using established pointers, such as the trig pillar on Arthur’s Seat, church spires and, for underground measurements, piano wires hung with 150lb plumb weights.

Steel bands used in the process were, incredibly, measured using two brass plaques at the foot of The Mound which are precisely 100ft apart. And even then, when the heat underground stretched the bands, Alistair’s calculations would have to be redone, again and again.

The first small breakthrough joining Fife with West ­Lothian having been made, the two mine managers were called to the scene along with union ­officials, the provost of Bo’ness, and, naturally, a reporter from the Edinburgh Evening News and Dispatch to witness the next stage.

A 23-year-old Kinneil miner called Martin ‘Tiger’ Shaw was enlisted to do the honours, while on the Fife side, Valleyfield miner Andrew Drysale, 34, waited patiently.

“The drill in the hands of Tiger Shaw began biting through the thin sandstone shell, the last barrier in the tunnel link at 10.30am,” ­reported the paper later that day.

“Three minutes later, the lamps of the Valleyfield squad blinked through the gap in the rock and Shaw and Drysdale were face to face.”

The pair are said to have “grinned dustily at each other” before moving aside so the two pit managers, David Archibald of Kinneil and Norman Wallace of Valleyfield, could reach through the hole in the sandstone rock to shake hands. “I hope you have plenty of coal for me,” said Mr Archibald, thinking forward to the locomotives that would pull Valleyfield coal to his Kinneil plant.

As far back as the 1600s attempts were made to link the south of the Forth with the north side. Sir George Bruce of Carnock employed new drainage technology at Culross in Fife to have men chisel 40ft down into the coal seam and a mile out creating an arch-shaped tunnel, tall enough for a man to walk upright and big enough for three horses.

King James VI was invited to see it for himself in 1617. Unfortunately he was so spooked that he accused Sir George of luring him into there to kill him and threatened him with treason. The tunnels were later flooded. In the 1790s, the notion of a tunnel to link the two Queensferry communities was discussed but shelved with the discovery of hard whinstone.

By 1805, however, successful coal mining operations towards the west revived the idea for two tunnels, one to go and one to come back , connecting a point near Hopetoun House with Rosyth. The plans were priced at £160,000 but were scrapped. In 1891, the Kirkcaldy and District Railway Bill was approved at Westminster giving the go-ahead for an extension of the Kirkcaldy to Grangemouth train line that would involve a tunnel beneath the Forth.

Again, it never got off the drawing board. In 1954, there was talk of a £5.3 million “Forth Tube”, in which traffic would pass through a 2800ft reinforced concrete tube. It was declared a brilliant idea, but was scrapped in favour of the Forth Road Bridge.