Portishead Radio

Broadcasting to ships had been taking place since the early days of radio; the General Post Office (GPO) long wave stations at Poldhu and Caernarvon had been conducting two way traffic with ships within a few hundred miles of the United Kingdom prior to the First World War. However, no long range system existed until 1919 when the GPO and the Marconi Wireless Telegraph Company agreed to convert a redundant Imperial Wireless Chain receiving station at Devizes in Wiltshire for long range maritime use. Comprising a receiver and a 6 kilowatt valve transmitter, station GKT was opened for service early in 1920, with a guaranteed range of 1,500 miles.

The radio officers at GKT were housed in old army huts, with radiotelegrams being sent to and received from ships up to 5 days from any British port at the rate of 11d (just less than 5p) per word. Radio traffic was keyed to and from the London Central Telegraph office from the operating station for onward delivery.

This two way "long range" service proved to be immensely popular, and by 1924 it became necessary to expand the station at Devizes to cope with the increased demand. The GPO constructed a second long wave transmitter and built a new receiving station at Highbridge (near Burnham-on-Sea) in Somerset, to which most of the radio officers transferred.

"The old building was originally a bungalow, and it housed an engineer, handyman. kitchen, writing room and the office of the OC. In addition it had very large long wave receivers, some nine feet in length (guessing).The receiving positions operated on 143 k/cs, answering and calling frequency, and on working frequencies of 121 and 129 kc/s. As you can see they were extremely long waves. 143 was GKU (the familiar name of the station to R/O's). .I worked long wave from wing C in the first half of the 50's but was done away with then.In the heyday it was only large liners who had long waves.Other ships did a QSPon MF to the liners. This system was also used when short wave was introduced. Eventually short wave tests were conducted. I think it was with the Esperance Bay on a trip to Adelaide.

Operating on 8. 12 and 16 kc/s, with callsigns GKL GKG and GKS, and working frequencies of GKN (I think) GKF and GKJ. The familiar name of the station was then GKL. It was Nick Carter the OC

previous to me who thought up the more recent set of callsigns GKA GKB GKC etc. So it was mainly LF downstairs with HF upstairs. GKL had a four poster rotating device operated from inside the station (upstairs ). As a kid I operated it, As a ship was tuned in so is was rotated for the best signal. At the same time a similar contraption at Portishead was rotated. A simple dipole with reflector"

By 1926, experiments on short wavelengths had established that world-wide communication could take place. The GPO installed the first maritime short wave transmitter at Devizes, keyed by operators with receiving equipment at Highbridge that same year. Initials tests proved outstandingly successful, and it became necessary to construct a brand new transmitting station. This station was to be located at Portishead, near Bristol, and thus in July 1928 Portishead Radio was born. Three long wave transmitters were installed, followed in 1929 by a new short wave transmitter, ultimately resulting in the closure of the Devizes station.

Throughout the 1930s this long range service expanded greatly, with a gradual decline in the use of the long wave (short range) service, However, new markets were being discovered, including the use of Portishead by the morse code operators on the flying boats, passing traffic from as far as South America and India. The great liners were also making heavy use of this new service, and by 1936 Portishead Radio, now with 4 short wave transmitters, was handling over 3 million words of radio traffic with a staff of 60 radio officers.

The war years between 1939 and 1945 saw great changes in the role of Portishead Radio, two way communication with ships changed to a broadcast of traffic without any acknowledgment of receipt. For obvious reasons, transmissions from ships were kept to a minimum so as not to release their positions and destinations. However, distress calls, enemy sighting reports, news of the North Africa landings and clandestine signals from Europe ensured the station was kept busy.

Early in 1943, the workload had increased to such levels that Portishead’s civilian staff were augmented by naval operators from HMS Flowerdown. Many of the civilian staff were seconded to Government services at home and abroad, not only to man radio stations but to train the many new radio officers needed for convoy work. A special aircraft section was constructed to maintain communications with patrol aircraft in the North Atlantic.

Peacetime brought a return to commercial activities, and with it a vastly increased demand for long range communications. An "area scheme" was established in 1946 to enable British and Colonial registered vessels to use naval stations around the world to relay their traffic to Portishead.

1948 saw the opening of two new operating rooms with 32 operating positions, a broadcasting and landline room, and a central control room with a steel plotting map of the world measuring 36 by 16 feet. A bureau file of both ship and aircraft positions was maintained, and many were plotted with magnetic indicators.

During the late 1940s and early 1950s transatlantic liners provided a high volume of traffic, all using radiotelegraphy (morse code) transmissions. The development of the landline telex service enabled customers to deposit and receive traffic directly from Portishead, with high traffic users installing their own private wires. The Suez crisis in 1956 brought high levels of telegraph traffic in both the to-ship and from-ship directions, leading to increased staffing levels towards the end of the decade.

The 1960s saw the station continue to expand, with increased traffic levels and the development of a telex over radio (TOR) system. A press transmission of news was transmitted by morse to enable ships to produce their own news sheets. By 1965, 86 radio officers were handling over 11 million words of traffic per year, and communicating with over 1,000 ships each day. The introduction of the Daily Telegraph transmissions to the QE2 in 1968 by radiotelex was another first for the station.

April 1970 saw the transfer of the radiotelephone service from Baldock to Portishead. This necessitated the use of extra transmitters at Rugby and Portishead, and the temporary use of an additional control centre at Somerton (Somerset). Further transmitters at Ongar, Leafield and Dorchester were transferred from the International point-to-point network were brought into service to cater for the increased traffic levels.

The area scheme previously mentioned was terminated in 1972, and with it the Naval presence at Portishead. However, traffic figures continued to rise, with the developing oil market and the deepwater fishing industry all providing work for the station. The leisure market continued to expand, with the early round-the-world yacht races providing valuable publicity for Portishead Radio and its services. By 1974, traffic levels had increased to over 20 million words per year, now handled by 154 radio officers. To-ship traffic was housed in a 'carousel' in callsign order (British and Foreign), and was interrogated by numerous R/Os performing traffic list, WTC (Wireless Telegraphy Control), Circulation and Bureau functions (see cartoon below):

Further expansion of the existing operating area was impossible, so in 1976 work commenced on a purpose-built building to house the various services then available to ships. A new computer based message handling system was installed, and the manual radiotelex service became more popular, resulting in the development of an automatic system.

The Portishead transmitting site was closed in 1978 followed by the Dorchester site in 1979, leaving the sites at Leafield and Ongar operating alongside the main transmitting site at Rugby. However, the famous name of Portishead Radio was maintained to provide the maritime community with a familiar and well known service. The advent of satellite communications in the early 1980s had little initial impact, and in 1983 the new control centre was opened, providing new radiotelephone and radiotelegraphy consoles, with automatic radiotelex being installed later that year. Remotely controlled receivers and receiving aerials, located at Somerton, were utilized for all services, resulting in the dismantling of the receiving aerials at Highbridge. The old operating rooms were demolished, creating space for administration offices and stores. Automation of the w/t service by necessity caused a reduction in operational staff numbers, although management (overseer) posts were maintained (see cartoon below):

1985 saw the opening of a new aircraft service, providing world-wide "phone patch" and flight information services. This service proved so popular that many land based industries based in remote locations in Africa used the aero frequencies, culminating in the opening of the Gateway service. Relief agencies, military units, embassies, and industries used the service, which acted as a lifeline to those located in countries where normal landline links were poor or non-existent.

By the end of the 1980s, satellite communications were making significant inroads into Portishead’s traffic figures. It became clear that a severe rationalization program was necessary in order for the station to remain viable, which resulted in the closure of the transmitter sites at Leafield and Ongar. The number of operating consoles was reduced in line with the decline in radio traffic, and the number of staff employed fell proportionally.

In 1995, the 75th year of the UK's Long-Range maritime radio service, BT's Satellite Services opened a Customer Support office at the Highbridge site, staffed by 12 ex-GKA Radio Officers, leaving the terrestrial radio station manned by less than 20. As the station began to die, more staff transferred to the Satellite Services side, and in early 2000 the decision was made to close down Portishead Radio for good.

So it was that on 30th April 2000 Portishead Radio went off the air for the final time.

The Satellite Services office however continued to thrive, but in early 2001 BT surprisingly decided to sell the whole Aeronautical and Maritime department to Stratos of Canada, resulting in the closure of the Customer Support Office and the redundancy of the staff.

At the time of writing there are no inhabitants at the station - it remains empty and unloved. An ignominious end to what was once a bustling and efficient station. No trace of radio equipment remains - the final aerial mast has gone, the maritime radio display in the reception area has been removed, and all maritime photographs and pictures have disappeared. Only the microwave link tower and the building sign (which still bears the legend 'Portishead Radio Station') serve to remind anyone that a maritime radio station once occupied the site.

The following article appeared in a May 1975 issue of Lloyd's List, and gives a fascinating insight into long-range maritime radio communications in the mid-1970's:

By J. Wall, head of long range communications, maritime radio services division, Post Office External services.

Post Office long distance maritime communications are controlled from an operational and receiving centre near Burnham-on-Sea, Somerset. Universally known as Portishead Radio, it takes its name from the remotely-controlled transmitting station at Portishead which has long been devoted exclusively to the maritime service.

Now, other transmitting stations with improved aerial systems are coming into maritime use as the need for them in the international fixed service diminishes.

Burnham has an establishment of 220 radio operators, a consequence of the constantly expanding volume of maritime traffic. Morse radiotelegraphy remains by far the major service of the station: 44 radio consoles and 25 inland teleprinter circuits are devoted to it, compared with four positions used for radiotelephony and two for radiotelex.

In 1974/75 more than three-quarters of a million telegrams containing 21 million words were handled, against 64,500 radiotelephone and 4,200 radiotelex call of 417,000 and 25,000 minutes respectively.

Morse traffic has grown steadily at about 5 percent a year (messages) and nine percent (words) since tr ansmitting and receiving facilities were expanded to allow for the cessation in 1971 of the former Commonwealth Long Distance Area Scheme, when Burnham increased its world-wide communications role.

Recent months have witnessed a halt in this growth, but it is too early to say whether a peak has been reached. About half the traffic is with British and half with foreign-flag ships; one third is in the to-ship direction and two-thirds from ships; and about 80 percent is business traffic, the remainder social.

About 56 percent of traffic is with the Northern Atlantic, including the busiest areas off the North Western African coast and in the South West approaches. About 47 percent is from around the entire African coast (this area overlapping with the Atlantic one) and the Middle East, 4 percent from the Indian and Singapore areas, and only a further 4 percent from the vast areas of Australasia and the Pacific.

Radio propagation from some parts of the Pacific is such that communication between shore stations using powerful transmitters and directional aerials is reliable only for a few hours daily. Ships' transmitters and aerials lack these facilities (although the results which can be achieved by radio officers with skill and patience are impressive). In 1972 a Long Distance Sector Watch scheme was introduced which provides two periods daily (at the best times and on the best radio frequencies) during which Burnham uses directional receiving aerials and suitable transmitters to assist ships in sectors from 'Panama' to 'Malacca'

Although Burnham handles about three times as much Morse traffic as all the 11 Post Office medium and short range coastal stations, these roles are reversed in radiotelephony. Here, Burnham deals with only about one-fifth as much. The importance of radiotelephone traffic to coastal vessels is due primarily to the fact that vessels below 1,600 gross are not obliged to carry Radio Officers qualified in Morse.

The reasons larger vessels prefer Morse are more complex, but are probably associated with the availability on ships of skilled telegraphists and shipping business communication habits which have developed with past equipment on ships and at shore stations.

Yet the average message to a ship exceeds 30 words at a cost of over £4.50 and constitutes a one-way communication; a three minute telephone call, during which about 60 words can be transmitted at dictation speed or about 400 words of question and answer exchanged without delay, costs £3.15 at the maximum tariff.

It seems that habits are changing however - annual growth rates in long range maritime radiotelephony have successively been 9, 25, 28 and 45 per cent, almost doubling in the two years 1972-74. There is naturally much more social use of radiotelephony than of Morse. A recent investigation showed that about 36 percent of long range traffic was with passenger vessels and other sources of social traffic, 32 percent with oil tankers, 14 percent with cargo vessels, and 10 percent from trawlers. The relatively high proportion of trawler traffic, when the number of trawlers is compared with that of other vessels, is interesting. Much of it is business rather than social: It seems almost as though trawler owners and crews, perhaps because they are accustomed to the use of radiotelephony on smaller fishing vessels, are more telephone-minded than their cargo vessel counterparts.

The volume of radiotelex traffic is considerably less than even the radiotelephone traffic, a feature being the small number of British ships suitably equipped as present.

This service has, however, shown spectacular growth since its introduction in June 1973, and the Post Office is currently engaged on a market research exercise to explore the increases in installation and traffic which might be expected for some years ahead. There is no doubt that this mode of communication, with its automatic error-detection and correction, and its built-in method of selective calling in both ship-to-shore and shore-to-ship directions, is potentially capable of providing a far superior telegraph service to that given in Morse.

Some advantage of this facility has already been taken at Burnham. The two circuits installed there, when not in use for traffic, are left monitoring two notified channels so that ships may make contact with them direct, alerting the Burnham operators, without first being obliged to establish communication in Morse - sometimes a lengthy process.

SSFC selective calling (not the type associated only with radio telex, but which can alert suitably equipped vessels throughout 24 hours to the fact that Burnham has Morse, telephone, or telex traffic for them) was installed at Burnham in 1974 and an experimental service opened in 1975.

Traffic lists in this mode are broadcast at half-hourly intervals throughout the day, but as yet few ships are fitted to take advantage of this service, and it is too early to predict its success.

Other specialised services conducted by Burnham include machine telegraph transmission of the 'Daily Telegraph' to the Queen Elizabeth 2 and Reuter's Morse Press transmissions to subscribing ships, both of which are made nightly. The station maintains continuous watch and instantaneous communication with the trawler support vessel associated with the Icelandic fishing fleet, and experimental facsimile transmissions, both of newspapers broadcast to ships and of two-way exchanges of traffic between ships, have recently been successful.

Radiotelex is the fastest service available, particularly where the ship is fitted with the SSFC selective calling system and uses the direct access method of communicating with Burnham. Radiotelephony also provides a fast service, again especially when the ship has SSFC. Both radiotelex and radiotelephony also, of course, offer the advantage of a two-way exchange of information - unlike the one-way communication of a Morse telegraphy message. Ranked in order of speed, the full list of services is:

Radiotelex to ships using the SSFC selective calling system and direct access.

Radiotelephony to ships using SSFC, radiotelex to ships using direct access but not SSFC.

Messages sent to ships take longer than messages sent by ships, because for the former, receipt and processing at Burnham and the wait until the next broadcast of a traffic list are only part of the process. Having heard the callsign of his ship in the traffic list, a radio officer must follow the same sequence of calling Burnham as he does when he has a message to send from his ship.

This period during which a ship calls Burnham in Morse accounts for much of the delay in both from-ship and to-ship messages, and much of the frustration for radio officers. It is a part of the internationally-agreed long distance maritime Morse system.

The Morse calling bands are shared by all nations, and the radio operators at the shore station scans them as methodically and thoroughly as he can; nevertheless, it is inevitable that some ships are unluckier than ot hers in that they call at instants when the searching operator is scanning a different part of the band.

Strong but unwanted interfering signals and propagation problems add to the difficulties of both ships' radio officers and Burnham operators. A revised calling procedure, agreed at the World Radio Administration Conference in Geneva, 1974, and to be introduced in June 1977, is intended to improve the situation.

The available calling channels have been divided between groups of nations, so that at least fewer ships will be calling on the bands to which the United Kingdom operators at Burnham must listen, and there will be few channels for Burnham to watch.

The new system will have its own problems, and it makes no change from the fundamental procedure that a message to a ship depends upon the shore station being able to notify the ship in some way that a message is held, and upon the ship contacting the coast station to obtain the message. Ships can make contact by radiotelephony more quickly because in this system an operator at Burnham is allocated to each channel is use (the channels are used for both calling and working).

Radiotelex calls from ships are quicker using direct access because the selective calling facility incorporated in the system enables contact to be established without delay; the ultimate achievement will arrive if it should prove possible for automatic access in either direction using radiotelex.

Meanwhile, the fastest radiotelegraph service is available using the SSFC selective calling system in the to-ship direction and the radiotelex selective calling sysem from ships.

Plans for the immediate future include the provision of additional radiotelephone and radiotelex ciruits and further adaptation of transmitters formerly employed by the fixed international services. Burnham Radio Station itself was erected in 1948 and a new operational centre is planned. This will employ remotely controlled receivers and aerials at the Post Office fixed service receiving station at Somerton, some 25 miles away - a vastly better receiving site than Burnham.

A feasibility study has recently been conducted and is being considered to a computerised message handling scheme which would also provide automatic access into the country's telegraph switching network.

In its operation of the maritime radio services, the Post Office looks towards the industry for comments and discussion. In 1972 a committee comprising the Post Office, the General Council of British Shipping, the marine radio installation and maintenance companies, and representatives of the shipping companies who most use the service, was formed to discuss the introduction of the Sector Watch scheme and long distance operations generally. This has now developed into a Post Office and Users Maritime Co-ordination Committee which meets at least twice yearly and considers the medium and short range, as well as the long range, maritime services of the Post Office.