Articles
The Clyde Tunnel:
Celebrating 60 Years
A739
The Clyde Tunnel is a crossing of the River Clyde in Glasgow. Scotland’s only road tunnel, it links the areas of Whiteinch and Govan in the west of the city. Part of the A739 route, the tunnel is an important part of Glasgow’s road network, connecting with strategic routes such as the M8 motorway and Clydeside Expressway. It has become a much-loved Glasgow landmark.
Discussions on the need for a new crossing downstream of the city centre began in the 1940s, though it was a decade later before the project moved forward. Opened to traffic in two stages in July 1963 and March 1964, the tunnel remains one of the most ambitious civil engineering projects undertaken in Scotland. Its completion led to significantly improved journey times and connections between the north and south of the city.
The project cost £10.5 million, the equivalent of almost £180 million in 2023. Today, the tunnel is managed by Glasgow City Council and carries more than 65,000 vehicles every day. The Council is investing more than £3 million in the years ahead to ensure it remains operational for decades to come.
Key Data
Location
A739,
west of Glasgow
Designer
Sir William Halcrow and
Partners
Contractor
Charles Brand
and Son
Ltd.
Construction
June 1957
to
March 1964
Cost
£10.5 million
(£180 million
in 2023)
Planning and Design
Plans for a road tunnel beneath the River Clyde between Whiteinch and Govan were outlined by Glasgow Corporation in their ‘First Planning Report’, published in the spring of 1945. The report’s author, City Engineer Robert Bruce, recommended a new, modern roads system that should be taken forward as a priority. His proposals included an inner ring road for the city centre as well as outer bypasses for traffic travelling around the growing suburbs.
A fixed crossing was proposed along the line of the cross-river ferry at Whiteinch. One of many ferries along the Clyde, this could carry multiple vehicles but was increasingly unable to cope with the volume of traffic. As the river was navigable at this location, and many of the city’s docks lay upstream, construction of a bridge with the necessary clearance was considered impractical;
a tunnel was the only appropriate type of crossing.
Located three miles downstream of the city centre, the tunnel aimed to improve connections in the west of Glasgow and alleviate congestion. Linking new housing in the north with industrial sites in the south was another key consideration in the development of the project.
Vehicles queue for the Govan Ferry on Water Row in the early 1960s. To allow for the tide, these distinctive vessels could lift and lower their vehicle deck to match street level at each terminal. The Govan and Whiteinch ferries were withdrawn after the tunnel opened.
Glasgow Corporation was keen to move forward with its construction but a lack of funding hindered progress. Preliminary planning was started shortly after World War II and the Glasgow Corporation Order Confirmation Act 1948, which provided powers for the tunnel’s construction, was approved by Parliament in 1949.
Much progress was made on the project after the appointment of Halcrow & Partners in 1951. Detailed investigations and design work began and continued throughout the first half of the decade.
The final design specified a twin tunnel arrangement, each of which is 762 metres long with an internal diameter of 9 metres. Each carriageway is 6.7 metres wide with two running lanes, built on a transverse three-span bridge supported on abutments attached to the tunnel lining and, intermediately, on the dividing walls that separate the pedestrian walkway and cycle track from the two fresh air ventilation ducts. Each tunnel drains to a sump at its nadir, the collected water is then pumped back to surface level.
The tunnel was designed for a speed limit of 30mph and has a gradient of almost 6%. Great care was taken to manage the transition between the reduced level of illumination within the tunnel and external daylight. A low reflective finish was applied the exposed face of the retaining walls on the approaches and bright, gloss panels were used inside the tunnel portals.
KEY: 1 False Ceiling 2 Inspection Walkway 3 Control/Emergency Panel 4 Carriageway
5 Cycle Track 6 Pedestrian Walkway 7 Ventilation Duct 8 Exhaust Duct 9 Fire Hydrant
Construction
Ground investigations in 1952 revealed the challenges likely to be faced during tunnelling. It became clear that tunnel shields and compressed air would be required for construction works below the river.
Construction of the Clyde Tunnel finally began in 1957 using shields based on Marc Isambard Brunel’s design for the Thames Tunnel in the 19th century. Sixteen miners operating the shields worked in a compressed air environment to ensure rock and the river above did not collapse into the tunnelling area. The techniques for decompression after working in these conditions had not yet been perfected and some workers refused to go through the hour long process. This led to
numerous cases of decompression sickness.
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Construction of the south ventilation building with Govan Road in the background, taken November 1962. Fans in the portal buildings can blow nearly 6,400m3 of fresh air on to the carriageways every minute if needed.
The tunnels were cut perfectly circular with cast iron linings installed for structural support. Manufactured by Carron Company in Falkirk, each ring of the lining was formed from 16 segments and weighed 11 tons. The reinforced concrete road deck was then cast in 10 metre sections at a height of one third of the tunnel’s diameter. The spans below the deck carry services, ventilation ducts and the pedestrian and cycle ways.
Once the tunnelling phase was complete, several further months were required to install the ventilation, cladding and lighting. The northbound tunnel was completed first, with the southbound following eight months later. On opening, the tunnel was immediately popular—within a year it was used by more than 27,000 vehicles daily.
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Main Approach Roads
The main Clyde Tunnel project included connections to Dumbarton Road and Govan Road. Shortly after the southbound tunnel was completed, plans were finalised for the tunnel’s permanent approach roads. Also developed by Sir William Halcrow & Partners, these were designed to ensure the tunnel would be effectively integrated with other routes in the city’s new road system.
Work began on the South Approach, the Clyde Tunnel Expressway, which links to the M8 at Cardonald, in June 1965. Built by Melville, Dundas & Whitson Ltd at a cost of £1.2 million, it was opened on 30th November 1967.
The North Approach includes the distinctive Whiteinch Interchange and direct connections to Crow Road and the Clydeside Expressway. These were built by Balfour Beatty at a cost of £2.2 million. Work began in April 1967 and was completed on 9th April 1969.
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The Clyde Tunnel South Approach project was completed in 1967, connecting the tunnel to the proposed M8 motorway at Cardonald. The project included the Shieldhall Overpass over the A8.
Mission Control
With its remote controlled CCTV and lighting, traffic control systems, emergency telephones and automatic fire detection, the tunnel featured technology unlike anything that had been seen on Scotland’s roads before.
A road heating system that could be activated in icy conditions was also installed, though this has long since been removed. On opening in 1963, the Clyde Tunnel was said to have the most advanced tunnel control room in the world. It has had several makeovers since it was built but its role remains as important as ever. The image below, taken shortly before the tunnel was completed, gives rarely seen glimpse of the main control console. Located above the north portal, it has commanding views over the approach roads and remains operational today.
Construction Summary
Contract
Opening Date
Northbound Tunnel
3rd July 1963
Southbound Tunnel
23rd March 1964
South Approaches
30th November 1967
North Approaches
9th April 1969
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The Tunnel Today
Carrying more than 25 million vehicles, cyclists and pedestrians every year, the Clyde Tunnel’s construction improved access to communities on both sides of the River Clyde. Sixty years on, the tunnel remains a key link in Glasgow’s road system and has become something of a Glasgow icon, enjoyed by people from across the city and beyond.
A popular game amongst those using the tunnel sees children (and adults!) attempting to hold their breath for the duration of their journey through it. A car travelling at 30mph takes only 57 seconds to travel from one end to other, though this is longer at peak times.
Much work has been undertaken by Glasgow City Council to ensure the tunnel remains operational for many years to come. Recently, new lighting and CCTV systems have been installed. A further investment of £3.45 million is planned before 2025 and will see the installation of a new traffic control system and refurbishment of the tunnel ventilation buildings.
Other planned works include installation of lane control lighting, variable message displays, radio rebroadcasting equipment and public address voice alarms.
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Celebrating 60 Years
3rd July 2023 marked the Clyde Tunnel's 60th anniversary. The anniversary was covered widely on TV and in the press. To mark the occasion the Scottish Roads Archive produced a special podcast and, with Glasgow City Council's help and support, a booklet featuring new and unseen images from the archive.
Printed copies of the booklet are available at our Online Shop.
From the Archive
Documents
This article was first published in July 2023. With special thanks to Glasgow City Council and Automated Document Services Ltd.
Related Content
A special episode of the Scottish Roadscast celebrating the 60th anniversary of the tunnel was released in July 2023. It can be heard below.