More than 200,000 people gathered on a fine summer day by the Mersey in July 1934 to witness a major public event for Liverpool.

It wasn’t the Reds or Everton bringing back the FA Cup a few months late – or a victory parade at the end of a conflict.

The big occasion was the official opening of the Queensway tunnel under the Mersey by King George V.

Crowds gather to see King George V open the Queensway Tunnel, July 1934

Crowds gather to see King George V open the Queensway Tunnel, July 1934

The great engineering feat notched up a historical double for Liverpool. The Queensway was not only the longest road tunnel in the world but also the longest underwater.

Constructed at a cost of £8 million, the tunnel took nine years to build. Around 1,700 men worked on the project which proved hazardous at times. Seventeen men were killed.

More than 1.2 million tons of gravel, clay and rock were excavated – much of which was used for the Otterspool Promenade.

Construction workers in the Queensway Tunnel, December 1929

Construction workers in the Queensway Tunnel, December 1929

The road tunnel was first proposed in the 1920s to relieve the long queues of cars and lorries at the Mersey ferry terminal. The Mersey rail tunnel had been open since 1886.

Building work on the tunnel started in 1925 after the granting of Royal Assent. The architect was Sir Basil Mott, one of the most celebrated civil engineers of the day.

Mott laboured tirelessly with Liverpool City Engineer John Brodie to ensure the Queensway’s two pilot tunnels met at precisely the right point under the Mersey.

Builders celebrate the breakthrough moment when two pilot tunnels met to form the Kingsway Tunnel, March 1970

Builders celebrate the breakthrough moment when two pilot tunnels met to form the Kingsway Tunnel, March 1970

When the breakthrough moment arrived, the two tunnels were found to be just 25 millimeters or one inch apart!

The Queensway is 3.24 km long from Liverpool to Birkenhead and contains a single carriageway of four lanes, two in each direction.

Two branches used to lead off the main tunnel to the docks on either side of the Mersey.

The men who made the final push between the pilot tunnels from Birkenhead and Liverpool to create the Kingsway Tunnel, March 1970

The men who made the final push between the pilot tunnels from Birkenhead and Liverpool to create the Kingsway Tunnel, March 1970

The Birkenhead section, or Rendel Street branch, was closed in 1965 – although the tunnel can still clearly be seen just before the left-hand bend to the Birkenhead exit.

By the mid-1960s, traffic had grown to such an extent that a further tunnel was needed – this time carrying the A59 between Liverpool and Wallasey.

Construction work on the 2.4 km Kingsway Tunnel started in 1966 and was completed in 1971. It was officially opened by Queen Elizabeth II in June 1971.

Traffic queuing outside Lime Street Station to enter the Queensway Tunnel, April 1962

Traffic queuing outside Lime Street Station to enter the Queensway Tunnel, April 1962

The tunnel consists of twin tubes with two lanes in each. More than 45,000 vehicles a day travel through it.

While Gerry and the Pacemakers immortalised the Mersey ferry in song and film in the 1960s, the tunnels have also had their share of showbiz acclaim.

Folk group The Dubliners included a verse about the building of the Queensway Tunnel in their song I Wish I Was Back in Liverpool.

Workmen lining the Queensway Tunnel wall with glass, August 1933

Workmen lining the Queensway Tunnel wall with glass, August 1933

And a scene involving Hagrid’s magical motorcycle in Harry Potter and the Deathly Hallows – Part 1 was filmed in the Queensway in 2009.

The tunnel made it on to movies again in 2012 when a car chase from Fast & Furious 6 was shot there.

Last-minute preparations for the grand opening of the Queensway Tunnel, July 1934

Last-minute preparations for the grand opening of the Queensway Tunnel, July 1934