Vyrnwy pipeline.

Before the canal was built there were plans to bring a fresh water supply from Lake Vyrnwy in mid Wales to Liverpool. It was proposed to carry the water through pipes under the Mersey. When the Ship canal was proposed a great deal of opposition to the scheme was raised by Liverpool, and one of the objections to the scheme was in regard to the increased cost of running the Vyrnwy pipes at the much greater depth required.

All objections were eventually overcome and an elliptical tunnel 14ft wide by  8ft high was built at sufficient depth to pass beneath both the canal and the mersey in 1888. Construction proved to be difficult due the waterlogged peat which forms a large part of the substrata in the area. Water is carried in a series of pipes passing through the tunnel.

The tunnel is situated between Moore lane and Randles sluices.