30 feet
No, the Mersey tunnels are major engineering works and have only been possible in modern times.
Birkenhead and Liverpool waterfronts face each other across the river Mersey, direct line of sight distance is about 0.75 kilometres, road access through the Kingsway or Queensway road tunnels under the Mersey river is about 2 kilometres.
The River Mersey - 70 miles long from Stockport and ending at Liverpool Bay, Merseyside.
The Mersey river is located in the Northwest of England. The Mersey river is approximately 70 miles long, and stretches from Stockport to Liverpool Bay.
The river Mersey.
Source - Pennines Mouth - River Mersey The link below gives its route through England.
Mersey river
The Queensway tunnel under the River Mersey.
There are several tunnels. Which one do you need to know about.
none
the sun
Gerry Marsden, of Gerry and the Pacemakers, (who lived by the river), in his song "Ferry Cross the Mersey" pronounced it "MURR-zee".