During the late '50s-early '60s, proposals were made to provide a second and third tier of post nuclear strike Central Government control, in order to take command should the Alternative Central Government War HQ (ACGWHQ) at Corsham (then codenamed BURLINGTON) be rendered 'inoperative'.

The second tier of Central Government control was to be a small group of 100 staff, covertly located next to the Regional Seat of Government within the former WW2 underground 'SHADOW' factory at Drakelow, near Kidderminster. This facility was known by a number of codenames - MACADAM, QUADRANGLE and LINSTOCK. Its existence was kept from those involved with the adjoining Regional Seat of Government.
-----------------------------------

TOP SECRET

(2) That the last of the advantages are associated with security risks. The existence of this cave may be known to the enemy, and, however successfully we may conceal i, any special provision for a Central Government contingent in it, its partial use as a Regional HQ might become known quite easily. The Joint Intelligence Committee think that the Russians would give high priority to attacks on centres of central government control. Nevertheless it has been assumed that Regional Headquarters would not be attacked. If this assumption were to prove wrong, the enemy would secure a considerable bonus.

The principal costs of providing for an additional 300 men relate to accommodation and communications.

(a) The Ministry of Works advise that minimum facilities for occupation would probably cost no more than £20,000 - £25,000, mainly composed of an additional standby generator set, canteen equipment, water sorage, filters for an existing fan, and alterations to ducting, wiring, etc. This is based upon not making provision for the recirculation of air, and the risk involved is that during heavy fall-out the air intakes of the three fans which now ventilate the establishment would have to be closed to prevent the filters becoming choked. If so, conditions within the HQ would start to become inefficient after some 11-12 hours. The probability that a longer closure would be needed is not thought to be very high, and present advice from the Home Office is that recirculation, which would add greatly to the cost, is not an essential requirement.

(b) The Post Office have made a detailed, though necessarily provisional and tentative estimate of the scale of communications required for 300 policy-makers, executive staff, etc. This assumes that (i) they must be kept to the minimum; (ii) so far as possible they must be consistent with the concept of a Regional HQ (and its support HQ); (iii) all possible use must be made of the Regional HQ’s facilities; (iv) that where more than one private line leads from BURLINGTON to a distant terminal one should go through the repeater station serving QUADRANGLE so that it could be diverted; (v) BURLINGTON requirements mainly planned for the precautionary and destructive periods would not be required at QUADRANGLE. The results are summarised in Annex B. The annual rental charges (which cover much of the capital cost) would be approximately £60,000. The whole problem of communications would of course require very detailed study were this project to go forward, but we record these figures as a preliminary estimate of the minimum cost.