portishead radio 1925-1939





The growth of Devizes Radio became so rapid, that on January 29th 1925 the Post Office opened a new purpose-built receiving station in Highbridge (near Burnham-on-Sea, in Somerset) to cater for the demand.  Later that year, new transmitters were constructed at Portishead near Bristol, a move which brought about the now internationally-famous name of 'Portishead Radio'.  The site was carefully chosen to ensure non-interference between the transmitting and receiving sites, and it also had the advantage of being located on the Burnham-Bristol cable route. Keying of the transmitters was effected over land-line connections from the receiving site at Highbridge.  Three transmitters and three receivers were installed at the new sites, still operating in the range 110-160 kHz, which permitted several ships to be dealt with simultaneously.

1926 saw the first high-frequency ship-to-shore communication service from the new sites at Portishead and Highbridge, with world-wide tests being carried out with the cruising vessels Carinthia and Olympic.  These proved to be very successful, and these tests showed that the range of radio communication could be practically world-wide, but this range could be affected by radio propagation conditions, the time of day, and the location of the vessel. 

As a result of these tests, the ship-to-shore radio service began to develop along two separate lines; (a) the short-range service, including distress, from the normal coast radio stations, and (b) the long-range world-wide service conducted from Burnham/Portishead.  The latter service commenced in earnest in December 1927 on 119 kHz high power and on 143/149 kHz with 6 low power transmitters.  The transmitting aerials were supported on 4 x 300 ft lattice steel masts of 8 ft square cross-section, and were carefully designed to minimize interaction at such close frequencies.  As a result of these new transmitters becoming operational, the Devizes transmitting station was finally closed in 1929. 

Use of the high-frequency wireless telegraphy service continued to grow, and technical facilities at Highbridge and Portishead were improved.  The original HF transmitter, operating on 18/36 metres (GKT/GKC) was supplemented by 4 20kW transmitters of Post office design in 1936.  In addition, primarily for the cruise liner 'Queen Mary', a rotating beam aerial was constructed; four medium sized telegraph poles mounted on a lattice platform supported the aerial, driven around by a sprocket and chain mechanism.  As you will have by now observed, the tariff structure for telegrams was becoming increasingly complex, and a rationalisation took place in 1936.  The ‘full rate’ per word charge was reduced to 8d per word (except for messages exchanged with certain foreign ships), and the ‘intermediate’ and ‘low’ rates were merged into a single rate of 4d per word applicable to all ships on regular voyages not exceeding 1000 miles from the UK.





Communication procedures with Portishead Radio at that time have not differed much from the methods used during the final days of the service.  Before a message could be passed to a ship, direct contact naturally had to be established.  To obtain this contact, Portishead Radio transmitted, at 2-hourly intervals, a list of ships' callsigns for which messages were waiting.  A ship hearing its callsign on this list could then contact Portishead to receive its traffic.  Ships wishing to send messages, however, could of course contact Portishead at any time.   Messages received at Portishead were forwarded to the London Central Telegraph Office (C.T.O.) for onward delivery to the destination.

A student at the South Wales and West of England Radio Training College, Len Adlard, remembers this era with affection; 

"We used to look on Portishead as our own special station on which we practised our morse receiving.  The callsign was then GKU, but the operator always sent it as 'GTAU', lengthening the first dash of the 'K'.  Our landlady would not let us put up an aerial, so we used to hook up our crystal receivers onto the wire mattresses of our beds with excellent results”. 

The mid-1930s saw the station become increasingly busy on all frequencies, which resulted in the station becoming well-known both in the maritime world and within the Post Office.  In order to provide some well-deserved publicity for the service, the station manager at the time (E.F.Greenland) wrote an excellent article for the April 1935 issue of the ‘Marine Observer’, extracts of which are quoted below;

 “The wireless operators at Burnham, as at other British coast stations, are skilled telegraphists drawn from the staff of the Post Office Telegraph Services. It is this personnel which makes immediate contact with the sea-going operator, the two constituting the link through which the service is provided.  On land, however, as at sea, skill in telegraphy is only the first step towards full operating efficiency and the gap between the two covers a long period of operating experience in all its phases.  One of the most important lessons to be learned is that of appreciating the other fellow’s difficulties.  At sea the ‘Old Man’ may be hard to please and require 101 things to be done while the shore operatpr is becoming caustic at the lack of attention having an important message on hand.  On shore there may be several ships waiting at a busy period, when everyone is hard at it and trying to give the more distant man a chance in case he fades out and can’t clear his message, while the ship operator threatens to offer his traffic through a foreign station.  A good example however of the basic co-operation and good fellowship which exist in the mobile service is the patience and forbearance with which both sides treat the ‘young hand’ at the game.” 

The article then goes on to describe the equipment in use at Burnham; 

The medium-wave service is handled by three large receivers covering the 2,000-2,500 metre wave bands, and a receiver for the 600-800 metre range.  These are provided with facilities for all-round reception or for reception only in a certain sector if required to cut out jamming and interference.  This directional reception in a certain sector cuts out also, of course, signals in other sectors.  Another receiver is available for the small craft coastal telephone service, which is provided to enable small craft not carrying wireless telegraph operators to exchange telegrams with the shore.  Out of a total of 14 receivers on the station, the remaining 9 are installed for the short wave service which has grown so rapidly in the last few years that it now carries more than half the load of the station.  These are associated with a dozen or more short wave receiving aerials directive and otherwise.  The directive types present a somewhat novel feature in mobile working as previously their use was confined to long distance services between fixed points.  Judicious arrangements of the directions in which they face, and the angles or sectors covered has permitted their successful employment to serve the main shipping routes of the world.  By their use, at both transmitting and receiving stations, it has been possible to compensate to some extent for the power and equipment limitations which are automatically imposed on ships’ sets.  Their effectiveness is found in the regular and usually daily communication which short wave ships in the most distant parts of the world.”





Operating staff at Portishead Radio were recruited from experienced and qualified marine radio operators, and this continued until the outbreak of war in 1939. Over 3.5 million words of traffic was handled during the year, a figure which had increased rapidly since the start of the decade. However, with a conflict imminent, safeguards to protect the service had to be installed.  To ensure continuity of service, power to the transmitters at Portishead supplied by the North Somerset Electric Company was augmented by a standby diesel generator installed underground beneath the tennis court. It should be stressed that the radio officers of that era had little time to practise their tennis techniques.... 

 On January 30th, 1937, the local Burnham-on-Sea newspaper carried a detailed article about the radio station, running to just over 2 pages.  A lot of the article has little bearing on the activities of the station, but some relevant extracts are quoted below which are of useful historical interest; 

 “Referring to the ship-shore service in which the Burnham station participated, Mr. Read (Deputy Inspector of Wireless Telegraphy) said that it was not really appreciated what a large wireless activity there was in the Post Office.  If the word ‘wireless’ was mentioned, everyone said ‘Marconi’ but actually the Post Office had a very wide telegraph point-to-point service.  They had one of the biggest stations in the world at Rugby, and many telegrams went by the Post Office wireless service to the Continent, and not by Marconi.  With the Rugby transmitters they had a very heavy load and it was continually transmitting from about 10 o'clock in the morning to about 3 or 4 o’clock the following morning, all the year round.  They were handling long official Press messages which went all over the Empire and the Colonies, and they also took a Press service for ships which covered the seven seas, besides a considerable press service for other parts.  With all its services they had probably got an organisation which was as big as any other organisation in existence for wireless purposes.  Coming back to the ship-shore services between the number of stations around the coast, he knew, and headquarters knew that it was second to none in the world.  They had a very fine staff, and the operators were men who got on with the job.  In Burnham and Portishead, they had what he thought was the finest long-distance station in the world.  It handled the biggest traffic load of any ship-shore station in the world, and quite twice as much as any in Europe”. One of the original overseers, Mr W. Williamson, was quoted as saying; 

 “It was exactly 12 years ago when GKU came into being, and they had seen a healthy child grown to recognition.  There had been changes since then; one receiver had grown to 18, and there were nearly 40 operators instead of nine.  The development of the station had only been possible by the kindness and co-operation of everyone at the station.  The co-operation of the operators with him while had been overseer had been splendid, and it had been one perfect team spirit working all the time.  He could have done nothing as overseer unless he could have relied upon everyone to do his best.  The result was shown in the high regard which ships have for GKU.  They had had some difficulties and stiles, but stiles were only made to get over.  GKU was the premier of its kind as regards efficiency and service”.