'Only three SRHQ bunkers are of recent construction- Basingstoke, (SRHQ62), Herford (SRHQ42) and Southport (SRHQ10).
Each has the same rough design, a All two-storey concrete basement below government office blocks built in the late 1960s.
Walls are 20-30 inches thick (50-75cm) and each has its own borehole for water.
Some one hundred and fifty thousand gallons of water are also stored in permanent tanks, and a generator room can power all the SRHQ's equipment for a month, with a ten thousand gallon fuel reserve.
Two sets of filters are fitted to the air-conditioning plant, one for peacetime exercise use, and the second for war.
If the level of fallout dust becomes too high, air conditioning can be switched to internal circulation for a period.
The bunkers were designed to have a radiation 'protection factor' of about 400, and to resist blast pressure of 1.5psi. In contrast, the average house is unlikely, after attack, to offer a protective factor better than 5-10.'
Quoted from 'War Plan UK, the secret truth about Britain's Civil Defence. Duncan Campbell. 1980'
