Interim Radio Scheme

A Stop Gap Measure

This topic has been created from the contents of declassified file HO322/299 held in The National Archives at Kew. This related to the period in the mid-nineteen sixties before the Civil Defence Corp was disbanded in 1968. I am most grateful to Dave McKay G1JWG ( www.radiohistory.uk ) for his help on this previously undocumented topic.

Note by General Goddard (RD(63)16) dated 5th Sept 1963

In 1961, at the time of the Berlin crisis, it was decided to set up the means of providing a skeleton civil defence static wireless network by use of mains-operated training sets. Some mains sets working on the 80 and 96 megacycles/second band which had been held by Regions for relay purposes and some mains sets working on 155 and 168 megacycles bands which has been held by Corps authorities for training were used. . . . .

. . . . The short term Berlin plan was never much good, and could not have been implemented anyway in less than 7 days. Since it is now questionable whether we can have this length of warning, it is arguable that no useful purpose is served by the continued retention of the sets in the Home Office wireless depots, and we therefore might as well meet the local authorities desire for training equipment even though by re-adapting the sets for single frequency working we should render them useless for operations. On the other hand, we have no other civil defence wireless communications available now, and will not have anything better operating over the country for about 2 years.

Regional Wireless Plans

These hand written plans date from 1964 and are thought to be the final arrangement after a number of iterations involving changes of sites and radio frequencies. During the Fifties to mid-Sixties, the regional government organisation changed from Regional War Rooms, to Regional Seats of Government (RSG) then incorporating Sub-Regional Controls (SRC). London was originally a single region with five sub-regional controls, then broken up and distributed amongst adjoining regions, only to be unified back as Region 5 with it Regional Government Headquarters at Kelvedon Hatch. These radio scheme plans appear to show London as operating while split across Regions 4, 6 and 12 but with an unspecified RSG 5 as well.

Please Click to View the Regional Radio Scheme Drawings

Region Seats of Government

2 - York Castle
3 - Nottingham War Room
4 - Cambridge War Room
5 - London
- Mill Hill
- Wanstead
- Kemnal Manor
- Cheam
- Southall
6 - Reading War Room
7 - Bolt Head, ex-Rotor radar
8 - Brecon Barracks, Brecon
9 - Birmingham War Room
10 - Fullwoood Barracks, Preston
12 - Dover Castle

Frequencies Used

Channel Allocations
Channel	Lower Frequency	Upper Frequency
P-Band Channels
Ch1	96.350	80.200
Ch2	96.400	80.250
Ch3	96.450	80.300
Ch4	96.500	80.350
Ch5	96.550	80.400

High Band Channels
Ch1	155.750	168.400
Ch2	155.800	168.500
Ch3	155.850	168.600
Ch4	155.900	168.700
Ch5	155.950	168.900

A group of five pairs of P-Band channels were allocated for use by the interim radio schemes. These channels are all within the part of the radio spectrum being used for Police and Fire communications at that time.

A further group of high band VHF channels were allocated, but the pairing is different from expected, normally 154-156 MHz is paired with 146-148 MHz when used as links between Police / Fire control rooms and their hilltop sites. The UKWMO VHF links use 168 MHz paired with 174 MHz, but this interim Civil Defence scheme didn't follow this arrangement and paired 155 with 168.

Masts Required for Scheme

Mast List — Police Masts for Civil Defence in 1964

This list of power consumption gives an idea of the size of the radio scheme as thirty six masts are listed here.

Interim Civil Defence Radio Scheme