Secret Scotland

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Walk the Clyde Tunnel on its 50th

Clyde Tunnel 50 years

Assuming nothing happens to see the opportunity being cancelled, Sunday, July 7, 2013, should see the first guided walking tours of Glasgow’s Clyde Tunnel take place.

Via Clyde Tunnel guided tours for 50th anniversary – Transport – Scotsman.com

See also 50 years of the Clyde Tunnel – Dumbarton Road Corridor Environment Trust (DCRET)

The northbound tunnel opened on Wednesday, July 3, 1963, (opened by the Queen) and is 762 metres (2,500 ft)  long, spanning a 123 metre (404 ft) wide section of the River Clyde. The tunnel is 5.3 metres (17.5 ft) high. The southbound tunnel followed in March 1964. The gradient is approximately 6% or 1:16.

Glasgow Corporation plans for the crossing began in 1947, but financial constraints meant that construction did not begin until 1957. The cost was £10.5 million.

The new tunnel would follow that at Finniestion, which had used hydraulic lifts to raise and lower traffic from ground level to the tunnel itself. Not bad for Victorian times.

Initial estimates indicated that the tunnel would have to carry 13,000 vehicles per day – by the time it reached its 50th anniversary, that figure had reached an average of 65,000.

Although generally referred to as the Clyde Tunnel, it actually comprises two tunnels, one northbound and one southbound, each also having a cycleway and a pedestrian path.

With the river overhead  – about 6 metres (20 ft) above – the tunnelling operation was complicated by variable ground, with the soft silt under the river lying atop a base of hard rock.

Construction used a tunnelling shield backed by compressed air, a method intended to keep the surrounding soft material from collapsing into the works.

It seems the methods of working under such conditions were not fully understood or developed, and the required decompression periods were not always observed, with many worker not prepared to submit to the long decompression period needed to allow the gasses which had been absorbed by their bodies to slowly dissipate as the pressure within a decompression chamber was slowly reduced over time. Many cases of decompression sickness were reported, with at least two fatalities recorded.

Work on the tunnel halted on one occasion, when the air pressure in the tunnel caused a breach in the river bed, causing a massive fountain to appear in the river above.

The eventual completion of the tunnel was tinged with a little irony. Having been driven by the need to install a crossing as far up the river as possible, the tunnel was chosen in order to avoid interfering with the free passage of shipping up the river toward the various ports and berths near the city. By the time it was completed, such facilities had moved further down river to the deeper waters of the Firth of Clyde, while improvements in building technology had allowed structures such as the Kingston Bridge (up river) and the Erskine Bridge (down river) to be built, and be tall enough to avoid interference with modern shipping. Although the Erskine Bridge has had its moments, as large structures have had to be very careful when passing below.

Back in 2008, plans for a concert involving 1,000 singers were scrapped by the council, apparently amid security fears. According to the event organiser, the main reason the council changed its mind about the choral event in the road tunnel was because it was thought terrorists might infiltrate the choir. (Really.) The piece composed for the event was performed at Kelvingrove Art Gallery and Museum: Tunnel Echoes – March 13, 2009.

Souvenir Booklet

The Souvenir Booklet which accompanied the 1963 opening has been placed online, and can be seen here:

Clyde Tunnel 1963

The 50th anniversary was also accompanied by a memorial publication:

ClydeTunnel_50yrs_Brochure

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June 9, 2013 - Posted by | Civilian, Transport | , , ,

1 Comment »

  1. […] In addition the Souvenir Booklet which accompanied the 1963 opening has been placed online, and can be seen here Clyde Tunnel 1963 (Source: Secret Scotland website) […]

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    Pingback by 50 years of the Clyde Tunnel | | July 2, 2013


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