There was a prevailing mood in the Government against deep shelters being built for the protection of large numbers of civilians. Their effectiveness from high explosive bombs was questioned, based on reports of their performance in the Spanish Civil War, and there were also concerns about costs. The Government’s preference for almost two decades had been for smaller, dispersed shelters, and so the large deep shelters that went ahead all had very specific causes, such as their being in areas with previously excavated mines and tunnels, or eminently suitable geological conditions, or even very determined local authorities who were willing to risk losing government grants to build the shelters they wanted.
However when the Blitz started in the autumn of 1940 policy changed and permission was granted for the two large civilian shelters under the sandstone hills of Bidston and Tranmere in the Wirral, across the Mersey from Liverpool. Grant funding was generous given the need to protect the skilled dock workers
Bidston’s shelter was in the side of the hill allowing access at grade into two main entrances, while at the uphill end a 25m ventilation shaft was sunk, doubling up as an emergency escape via a series of steep metal ladders. The tunnels in between these ends were cut out in a familiar gridiron layout, with four long perpendicular tunnels fed at both ends from the two main entrances, and eleven cross tunnels. Toilets, a canteen, and a first aid post were provided either in the cross tunnels or at tunnel intersection nodes. Within this 1596 bunks and 793 seats were provided for those lucky enough to have the requisite shelter permit.
Construction began in December 1941 and was largely completed within a year, having suffered from escalating costs, geological problems, an unskilled labour force, and also paradoxically trespassers and vandalism. The original intention was that the tunnels would be 2.1m wide and 2.0m high with an arched roof, probably similar to those at Tranmere, but the surviving tunnels are considerably larger than this. Records indicate that the considerable height came about following roof trimming required in the latter stages of the project due to the softness of the rock and problems with instability after exposure to the air.
The shelter, like many of the deep shelters reluctantly approved by the Government, came too late to provide mass protection during the periods of heaviest bombing. After the war it was used for customs and excise storage, fire brigade training, and was even considered for Cold War use but rejected due to extensive dry rot. The Borough Council visited in the 1950’s to see if they could find a use for it, but disapprovingly recorded it to be “damp, dark and featureless” and it has been sealed in recent times. Local groups in the last decade have looked at ways of reopening it as a tourist attraction, and hopefully one day will be successful.