Although several options were considered, it was decided that a tunnel offered several advantages - particularly cost advantages in that, compared with a bridge, it would be only half the cost to build and annual maintenance should be much less.
Although Wallasey and Bootle had been included in the original committee, Liverpool and Birkenhead eventually decided to undertake the project alone. During the week before Christmas 1925, work began on the pilot tunnel at the Liverpool end and, in March the following year, from Birkenhead.
On 3 April 1928, Salvidge and Miss Margaret Beavan, the Lord Mayor of Liverpool, went underground and broke through the last thin wall of rock. On the other side, was the outstretched hand of Alderman Naylor, the Mayor of Birkenhead. After taking suitable measurements, the engineers proudly announced that two tunnels had met in the middle to within an inch. [25 mm].
The tunnel was opened to the public by King George V on 18th July 1934 and, in honour of Queen Mary, who was also at the opening ceremony, it was named Queensway.
A special boring machine, known as The Magna Mole, with a 35-foot diameter bit was used. It was the biggest machine of its kind in the world and had already bored out five tunnels in Pakistan. Working in the wet conditions under the River Mersey, the engineers met with many problems but the Wallasey Tunnel was finally opened by Queen Elizabeth II on 24th June 1971 and was named Kingsway.