UK Wartime Broadcasting Service - WTBS

The BBC referred to WTBS as 'Deferred Facility" or 'DF' internally and should not be confused with the abbreviation for {radio} Direction Finding. The pre-attack national programme would be sourced from an underground bunker at the BBC Training School, Wood Norton on the A44, 2.5 miles north-west of Evesham, Worcestershire. Regional Government Headquarters (RGHQ) were equipped with a basic studio allowing regions to break out from the national programme source and give information pertinent to their local area.

The plans for the WTBS changed during the cold war period to match changes in the Regional Government plans, technical reasons and the listener base moving from Medium Wave to VHF Stereo stations. The original plan was for a single countrywide channel on Medium Wave, using low power transmitters installed during WWII. This was followed by WTBS Phase 1, Phase 2 and Phase 3, although this last plan was not implemented before the end of the Cold War.

There was little in the way of fallout protection or standby power in the seventies. In the eighties, plans were developed to provide fallout protected accommodation for staff at Moorside Edge, Stagshaw, Burghead, Black Hill, Start Point, Brookmans Park, Washford, Sutton Coldfield and Wenvoe and to refurbish the existing protected accommodation at Droitwich, Wrotham, Westerglen, Lisnagarvey, Holme Moss, Oxford, North Hessary Tor, Daventry and Clevedon. Those vital transmitters at Black Hill, Droitwich and Start Point without standby generators would receive them in order to maintain the WTBS in the very likely event of the normal electricity supply being disrupted. The WTBS studios at Wood Norton would be refurbished with an EMP screen, improved air conditioning and replacement diesel generators and to provide a new standby WTBS studio at an undisclosed location by 1988-1989.

The now declassified 'Secret' BBC War Book (1974 edition) gives an insight into the programming policy and timescale for the introduction of the War Time Broadcasting Service (WTBS). The decision to invoke the WTBS is a purely government function taken during the Transition To War (TTW) period. Many parallel activities would be taking place in the TTW period, such as manning up the UKWMO and ROC.

The BBC War Book describes how the BBC would maintain its independence at first, while keeping the WTBS preparation covert: During a period of tension BBC output would be expected to reflect the international situation, and modifications would obviously be made to the advertised programmes, in order to report and comment on the crisis as it developed. How this could best be done would rest with the BBC to decide in relation to circumstances prevailing at the time. . . . another section of the book includes Until authorised to do so, the BBC must not take any action of a character which might alarm the public.

Timing of the warning to the BBC to switch to WTBS is set out in the Government War Book. The BBC War Book does warn that if events were to move swiftly, the timescale may be less, nevertheless it would take them three hours. The Government War Book stipulates that the BBC requires 48 hours' notice to prepare for the WTBS, and a further 2 to 4 hours' notice when authority is given to start it. Having taken these timings into consideration, and without consulting the BBC, the Government will decide the actual time of its start and the BBC must be prepared to act accordingly. The start of the WTBS is known as the 'N' hour and set by the government.

The start time for the WTBS is called the 'N' hour ('N' for National). Sixty minutes before this, the 'A' hour marks the start of a 30 minute 'A' period ('A' for Announcements). All of the BBC radio channels on medium wave and VHF combine and transmit announcements informing listeners in which Civil Defence Region they belong and the appropriate tuning frequencies on Medium Wave and VHF.

The 'S' hour marks the start 30 minute 'S' period ('S' for silence) leading up to the 'N' hour, when the WTBS begins. In order to avoid the complete cessation on all wavelengths during the 'S' period, Droitwich long wave with its countrywide coverage will transmit the same announcements as on Medium Wave and VHF, and repeated for the whole 60 minute duration of the 'A' and 'S' periods. The 'S' period allows Medium Wave transmitters to be retuned to their WTBS frequencies and both VHF and Medium Wave program feeds to be rearranged.

At 'A' hour the BBC and ITA television networks will be combined for sixty minutes before closing down at 'N' hour. During this period they will transmit a specially recorded programme, originated by the BBC, describing the impending WTBS. Television broadcasts are not within the remit of Regional Government controllers and would only restart when permitted by Central Government.

In WWII multiple low power transmitters, known as Group H, all transmitting the same programme on 1474 kHz were used to prevent the Luftwaffe from being able to use the BBC high power transmitters to guide their bombing raids.

The Group 'H' sites were adapted for the single national WTBS service. I don't currently have any information on how the programmes were distributed over the GPO network from WTBS headquarters at Wood Norton, but the diagram shows the transmitter locations and regional frequencies.

National Archives File HO322-1216, quotes Phase 1, which was completed by 1981, provided a national broadcasting system capable of reaching about 50% of the surviving population using seven medium wave transmitters and two additional VHF transmitters. At the time these were known as the (9) priority transmitters.

The transmitters are linked via British Telecom land lines to WTBS Headquarters studio and to those RGHQs where studio facilities have been installed. The transmitters are provided with independent power supplies and accommodation giving protection against nuclear fallout for essential operational staff. The accommodation has simple broadcast injection facilities. The diagram shows the locations of the nine priority transmitters at Moorside Edge, Stagshaw, Burghead, Black Hill, Start Point, Brookmans Park, Washford, Sutton Coldfield and Wenvoe.

National Archives File HO322-1216, quotes Phase 2 which began in 1983, is intended to provide regional broadcasting and additional transmitter coverage to back-up and extend that provided in Phase 1. The work to be carried out included completion of WTBS HQ and studios in RGHQs, development of the network linking studios to transmitters, hardening of protected accommodation (PA) at transmitter sites and the provision of radiac equipment.

The 1976 diagram below shows the programme distribution network. The lines linking sites represent one or more circuits carried over GPO/BT private wires, BBC's own microwave network and in some cases direct reception off-air from another transmitter. Some circuits, such as those from the RGHQs are exclusively used for WTBS, but those linking transmitter sites may have a peacetime purpose too.

This network was further extended by connecting local BBC radio stations to their nearby RGHQ enabling them to carry either the national broadcast from Wood Norton or a regional broadcast originated from the RGHQ studio.

Circuits carrying programmes, known as 'Music Circuits' have a much wider bandwidth than normal telephone speech circuits. They are accompanied by a speech circuit 'Control Line' to allow liaison between the two ends for technical and programme continuity purposes. Under WTBS conditions, these could be pressed into service to carry the broadcasts if the music circuit failed but with reduced sound quality. Documents in the National Archives, suggest as a very last resort Trunk Subs to the GPO Emergency Manual Switching System EMSS from BBC premises could be pressed into service to feed WTBS announcements or relay the message to be announced by someone in the transmitter site's protected accommodation.

By 1987, the Phase 2 network was considered vulnerable to the effects of Nuclear Electromagnetic Pulse (NEMP) created by exploding a weapon high in the earth atmosphere. The WTBS relied on British Telecom circuits being routed through areas relatively safe from blast damage, known a Safe As Possible (SAP) routes, that assumed there would be 22 targets. However as the number of possible targets increased to 134, nowhere could be considered safe. Also British Telecom were unable to guarantee their network would not be affected by NEMP. Protected accommodation at BBC sites provided fallout protection but were vulnerable to NEMP and would require hardening against its effects.

A number of proposals are discussed in National Archives File HO322-1216. However the file closes with a letter dated August 15th 1990 after six years of debate, with nothing to indicate the implementation of WTBS Phase 3 was undertaken. By then the cold war had effectively ended with the Soviet Union disintegrating and Russia's Mikhail Gorbachev had been awarded the Nobel Prize.

To avoid the vulnerability of the BT circuits to NEMP, it was proposed to create a ringmain around the RGHQ using the radio part of the Emergency Communications Network (ECN), primarily designed for speech and telegraph traffic between RGHQ, Local Authority Emergency Centres and the UKWMO.

National broadcasts created in WTBS HQ at Wood Norton would be connected to three RGHQs by radio links as well as BT Private Circuits to those same three RGHQs. These links and the ringmain would be carried on the RN1 & RN2 radio circuits of the ECN described elsewhere on this website. Each RGHQ would have a main and reserve programme feed from Wood Norton carried on BT Private Circuits.

The Private Circuits from the RGHQ to transmitters were seen as another point of vulnerability. A proposal was to place a 1 kW medium wave transmitter at each RGHQ site. A lattice mast kept in pieces on site ready to be erected was one option or a helium balloon suspended aerial.

Various letters within the File HO322-1216 raised many questions about this strategy, who would erect the mast and when, the storage of the mast or helium for the balloon. Radio interference to other equipment in the RGHQ from the transmitter was considered.

A retired BBC engineer, shared some of his experiences, edited into the paragraph below.

In Phase–1, Holme Moss received its WTBS programme from Moorside Edge, but became an important centre under Phase–2 plans. In the 1980s, BBC Holme Moss transmitted BBC Radio 2, 3, 4 VHF FM services to around 10 million people. BBC Moorside Edge transmitted BBC Radio 1, 2, 3, on medium wave to a similar number.

Both these stations had standby generators. The diesel engines at Holme Moss were tested every Wednesday morning. I recall that the whole station was run on diesels for a couple of hours, just to make sure everything worked.

We also had a direct line in the control room to the civil defence headquarters in Preston. This phone was never in day to day to use, but I do vaguely recall an annual test when we were called and required to answer with a given a code word. This phone was accidentally knocked off the hook many times, but whoever was at the other end never called to complain. On a couple of occasions I pressed the "Call" button but nobody ever answered. So whatever exchange this line was connected to, it must only have been used if the various control rooms had been staffed in the direst emergency. This line was only telephone quality, but it could have been connected up to the transmitters as a last resort. This circuit is not shown on any diagram as it is not a programme circuit, but UKWMO Sector HQ at Goosnargh near Preston was the reserve centre for issuing the Attack Warning, via HANDEL. Preston had a direct line to Flylingdales BMEWS facility. Clearly the engineer did not know where the Preston centre was or its purpose.

Recalling this about Wood Norton. As a BBC engineering trainee I spent almost a year at Wood Norton. Some of the rooms in the Bredon Wing bunker were used as classrooms. I remember having lectures in windowless rooms a couple of floors underground. I never went into the control rooms, but they did exist. The diesel generator air intakes were on the side of the Bredon Wing building. There was a microwave antenna mast on top of a nearby hill with, I think, a standby link for wartime use to the BBC transmitter at Daventry. The chap has a good memory as this link is shown on the Phase–1 diagram, until it was removed in the mid-eighties, there was another microwave link between Wood Norton and Drakelow RGHQ 9.2 and continuing on to at tower on Brown Clee Hill. Maybe this removal coincided with WTBS Phase–2 implementation.