It’s been carrying passengers and cyclists under Glasgow for generations, and the Clyde Tunnel will celebrate its 60th anniversary in 2023.

Dug in some truly Victorian conditions and coming in well over budget, the subterranean passage has been a point of debate since conception.

Following the end of World War II, the local and national government was keen to improve infrastructure in Glasgow but faced a problem connecting the two sides of the River Clyde.

Downstream of the city centre, areas like Govan and Finnieston were important shipbuilding centres, with the river also providing an important trade link to the Americas and what remained of the British Empire.

It was therefore deemed impossible to construct new bridges over the Clyde – planners would have to go under.

In 1948 the Glasgow Corporation - as the City Council was known then - was given the power to construct a two-lane tunnel at an estimated cost of £3million – around £86.5m in today’s money.

The Herald: The Clyde Tunnel under constructionThe Clyde Tunnel under construction (Image: Newsquest)

Of that total 75 per cent would be provided by the national government, with the city picking up the remainder. As tends to happen with large infrastructure projects though the costs soon began to spiral, reaching £4m by 1953 and £5m a year later.

Proposals were made to reduce the project to one tunnel with two entrances, bringing the cost back down to just over £3m, but by 1957 the projected cost had soared to £6.4m for that option and £10.3m – almost £200m – for the original plan.

On June 26 of that year a ground breaking ceremony was held, Lord Provost Andrew Hood using a silver-plated spade to dump the first soil into an iron barrow, and work could finally commence. To make way 250 tenements were demolished, along with a church, several bowling greens and some allotments.

To construct the subterranean passage, deep tunnels were driven into the soft earth below the riverbed, with the structure reinforced as workers inched forward.

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Those working on the tunnel were offered a decompression chamber on entering and leaving, with ‘the bends’ a real risk for people working in a compressed air environment. Sitting in the chamber meant avoiding adverse effects but also adding an hour to the beginning and end of a shift. Two died due to rapid decompression, while signs were put up along Govan Road informing residents that should they see a man staggering down the road, they should consider he may be a construction worker suffering the bends and not a local drunk.

Conditions below the river were grim. Sixteen men at a time toiled in a circular cage, hacking away at sections of rock before shoring up the passageway behind them. The Herald’s correspondent described the burgeoning underpass as “an obstacle course of hazard and glaur”.

The Herald: Workers construct the Clyde Tunnel inch-by-inchWorkers construct the Clyde Tunnel inch-by-inch (Image: Newsquest)

Deputy resident engineer Graham U Biggart lamented “the Clyde must be the hardest river in Britain to go under”, with workers digging and chipping through solid rock at one moment only to be confronted with gloopy sand and mud the next. They used shovels and picks to advance as little as 9ft per day, 21ft below the bed of the Clyde.

Progress was not rapid. Three years into the project The Herald spoke of the “dismal tale” of mounting costs, with some querying whether tolls should be introduced when the connection was finally finished.

This was rejected by the Scottish Home Department, who reasoned that the nearest bridge was just three miles from the tunnel and even the smallest charge would discourage its use.

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In 1961, a year behind schedule, work had advanced to the stage it was possible to walk between Linthouse and Whiteinch – albeit by shuffling along ledges, dodging pools of water and “the climbing of many ladders”.

The Whiteinch tunnel was finally opened on July 3 1963 by Queen Elizabeth, and was described as “only a first step” in a road redevelopment scheme which would transform the city. Laid out in the 1965 document ‘A Plan for Glasgow’, an inner ring road was to be constructed that would form a box encircling the city centre. The city was deemed to have “few buildings of historical importance”, while the “graceful arcs and curves” of the new ring road would “become Glasgow’s architectural fashion-setter”. In the event only the north and west sections were ever completed, forming today’s M8 which cuts through the city at Charing Cross.

The Herald: Queen Elizabeth opens the Clyde TunnelQueen Elizabeth opens the Clyde Tunnel (Image: Newsquest)

The following day’s Herald ran an eight-page supplement including a first look from the newspaper’s motoring correspondent, who was suitably impressed by the “fluorescent strip lighting of the greatest brilliance” and “first class” tyre adhesion and grading.

Less than a year later, shortly after the five millionth vehicle had made the crossing, the second tunnel was opened to the public just three months behind schedule.

Despite running massively over budget, the Clyde Tunnel was a success. Estimates before its construction had 9-13,000 cars crossing underneath the river per day but 22,000 made the journey on its first day of operation.

That has led to numerous repair works being carried out to a structure experiencing more wear than expected, while five years of work between 2005 and 2010 were needed to bring the crossing up to European safety standards. The Mont Blanc fire of 1999 which claimed 39 lives saw new laws brought in which meant installing a fireproof layer around the existing structure, with the upgrades costing almost as much as the tunnel itself.

In 2016 the Glasgow Times reported that the operating cost for the Clyde Tunnel is around £1m per year, with an infrastructure report stating it needed around £25m in funding to ensure its long-term viability.

The decline of shipbuilding and freight on the Clyde has meant a number of bridges have been constructed since the tunnel was completed, including the Kingston Bridge as part of the aforementioned ring road scheme, and the Clyde Arc which opened in 2006.

Still though, six decades on, 25 million people per year travel through the passageway those men picked and scraped into existence below the bed of the Clyde.