Started in 1966, the first tube of the 1.5 mile road tunnel between Wallasey and Liverpool took five years to build and was opened by the Queen on June 24, 1971.
It was a two-lane tunnel until the second, more northerly tube opened in 1974, making Kingsway the four-lane crossing we know today.
These photographs taken between 1966 and 1971 show the scale of the project and the challenging conditions faced by workers excavating the second road tunnel under the River Mersey. Kingsway was built to accommodate a big post-war increase in traffic that left the Queensway tunnel between Liverpool and Birkenhead struggling to cope.
Consultants recommended a six-lane bridge which, according to Kingsway architect Tom Harker, would have rivalled San Francisco’s Golden Gate Bridge. But the tunnel – unlike the bridge – could be constructed in phases, helping to manage cost and the wider impacts and it could also link to Wirral’s M53 motorway using an old railway cutting for the Wallasey approach road.
Work started with construction by hand of an 8ft high pilot tunnel through sandstone under the River Mersey. It took about a year to complete. Then the giant laser-guided ‘Mersey Mole’ arrived to excavate the main tube.
Having previously been deployed on the construction of Pakistan’s vast Mangla Dam, the 35-tonne, 45-foot long machine carved a route under the River Mersey, leaving a concrete lined tunnel in its wake. However conditions were very different to Pakistan and water mixed with grit to cause the Mersey Mole to break down mid-river.
Unable to move backwards or forwards, it led to a dramatic and difficult month-long operation to replace its main 10 tonne bearing.
A short section on the Liverpool side had to be excavated through clay using different methods.
Despite the challenges the first tube was completed in 1971 with large crowds watching the Queen’s ceremonial opening of the tunnel. It’s now used by around 45,000 vehicles per day.