Emergency Services Radio Scheme Provided by the Home Office
A look at the history of the radio schemes provided by the Home Office for Civil Defence and the Emergency Services during the Cold War era.
Background to U.K. Emergency Communications
During the Cold War period the Home Office Directorate of Telecommunications ( D of T) provided radio communications for Civil Defence and Emergency Services. In 1991 it changed its name to DTELS. The Civil Defence communications were dismantled after the UKWMO closed in November 1992 but the emergency service radio systems continued under this body.
DTELS moved from the public to private sector when it was sold to NTL Broadcast on 1st March 1994. Emergency Service communications were then sold to ARQIVA who maintained the analogue network. A phased changeover of Police analogue radio scheme to 'Airwave' a secure digital network took place between 2004 and 2006. This was followed by the Fire Brigade VHF analogue radio which completed their move to Airwave by the end of 2009. By 2011 all three 'Blue Light' services had completely transferred from analogue systems to the secure Airwave network.
The UK Police first introduced VHF radios in 1946. In 1963 a Home Office circular indicates the planned introduction of radio for Civil Defence too. At this time Civil Defence radio schemes included the Auxiliary Fire Service and the Civil Defence Corp as well as the UKWMO. Initially Fire Brigades shared their county's Police radio system, by the end of the seventies, all had switched to their own dedicated system. A few Police and Fire authorities opted out of the Home Office D of T contracts and went their own way.
During the early seventies the use of radio technology increased within the Emergency Services. In addition to county wide VHF radios in vehicles, the police introduced personal UHF radios (P Set), in most towns and cities. UHF personal radios were introduced in the Prison Service too. Fire Brigades augmented their VHF county scheme with UHF personal radios for use on the fire ground. Retained firemen had their home call bell and warning siren replaced by a single tone VHF Radio pager. The Royal Observer Corps (ROC) master posts were given VHF radios as a back up to the landline connection.
The Cold War Connection
If Britain had come under attack from nuclear weapons the Police and Fire radio schemes described in the following topics would have played a part in the recovery after the attack. Their radio schemes used radio links and thereby operated independently of Post Office / British Telecom land lines.
The UKWMO and RGHQ landlines were private circuits (known as Private Wires) which shared the same Post Office / British Telecom network hardware as the public telephone system but operated separately from it. As a standby against the failure of the UKWMO and RGHQ private wire network, the Home Office D of T provided radio links as backup to the more important landlines. These radio links utilised the extensive network of radio masts already provided for the Police and Fire authorities.
The standby radio network is described in great detail in the UKWMO and RGHQ Communications topics, accessed via the website menu.
Radio Frequency Changes during the Eighties
In the UK the VHF FM broadcast band had been restricted to 88-97MHz whereas in Europe it was 88-108MHz and most VHF stereo radios in use covered the complete band. The BBC occupied the majority of this restricted band. In the UK the remainder was allocated to mobile radio. In 1979 the World Administrative Radio Conference (WARC) passed a resolution requiring the United Kingdom to remove its mobile radio allocation from 97-108MHz, to harmonise the broadcast band throughout Europe. The change had to be implemented by December 31st, 1989. Once the existing UK users had been moved the band was opened up for commercial radio stations.
The 97-103MHz part of the broadcast band, was used by the Emergency Services, which meant that ordinary members of the public could eavesdrop on the police and fire communications with their home FM Stereo radio, so this change would afford them some privacy.
In order to facilitate this change in frequency, the Home Office D of T was given access to new frequency bands and others extended. The new bands were 70.5-71.5MHz, 143-144MHz and 152-153MHz. The two UHF bands were extended downwards by a Megahertz to now cover 450-453MHz and 464-467MHz. The 80-85MHz band was reduced to 80.0-81.5MHz and 83.5-84.0MHz range. New bands in the microwave region were also allocated.
The change to Emergency Service radios caused by the 1979 WARC was phased in between 1987 and was completed 5 months early on July 31st, 1989. During this phased changeover the opportunity was taken to restructure UKWMO and Government radio communications too. This was very timely as a review of communications in 1981 had identified a number of areas for improvement.
Organisation and Callsign Plan
Regional Wireless Depots
The D of T was organised along the same regional boundaries as the Home Defence. Within each region was a wireless depot. The old term 'Wireless' has been superseded in the modern language by Radio, but modern maps often show mobile radio hilltop sites as W.T. Station for Wireless Telegraph Station, usually indicating their Military or Emergency Service past history. The Regional Wireless Depots and their outstations were responsible for the installation and maintenance of the emergency service radios in the region.
The radio schemes operated by the Home Office and Scottish Office were allocated four character call signs beginning with M2. Most police force and fire brigade radio operators dropped the M2 prefix under normal operations, using the last two letters as an abbreviation. M2QK would be 'QueKay'. Others used the NATO phonetic alphabet for the last two letters M2YM was 'Yankee Mike'. Leicestershire Police was one exception who used the whole of their callsign and ended every transmission with 'emtunnul out', it took me a while to realise the first word was actually 'em-two-en-el' their call sign being 'M2NL'.
In England the first letter of the abbreviated call sign for each County Police or Fire scheme signifies the Region. Whether by design or accident this regional identifier is often the first or last letter of the place name of the wireless depot. All Welsh counties start with a W, Scotland does not fit this naming scheme. The engineers at the wireless depot had a call sign M2Rx with 'x' being the regional identifier. For example in Region 9, the Wireless Depot is Romsley, Regional letter 'Y', its callsign is M2RY serving the counties using M2YA - M2YZ call signs.