On January 29^th1925, the Post Office opened their new long-distance maritime radio receiving station at Highbridge, Somerset. The site was chosen with great care, ensuring that no heavy industry was in the vicinity, and that the location was close to the west coast of England. This provided optimum receiving conditions to hear Morse code signals from the many transatlantic liners and similar vessels which were equipped with radio equipment at that time.

The origins of the service can be traced back to 1920 when the Post Office opened a long-distance maritime radio station just outside of Devizes in Wiltshire, where a former World War 1 army base was converted into operating huts. This station became known as ‘Devizes Radio’, and operated on long-wave frequencies with high power.

After a few years, however, it became clear that the amount of radio traffic being handled was too excessive for the small station to deal with, and there were also interference problems with the high-powered transmitters being located at the same location as the receivers.

To solve this issue, it was decided to locate a receiving station away from the existing transmitter site, which is when the Highbridge station was constructed, with the transmitters being remotely keyed via a landline connection from the new site. The Devizes station continued with this arrangement, until it was found that short-wave frequencies could carry radio signals much further and with less power at certain times of day or night than the existing long-wave frequencies.

In December 1927, a new transmitting site at Portishead, near Bristol, took over from the Devizes site with new short-wave equipment, and the famous name ‘Portishead Radio’ came into being.

The existing long-wave service continued to cater for ships fitted with suitable equipment. It soon transpired that the Portishead transmitters could not cope with the amount of traffic being handled, so an existing transmitter site at Rugby was added to handle broadcasts of messages to ships and to complement the Portishead transmitters.

New directional receiving aerials were erected at the Highbridge site, including a rotating beam aerial, which could be manually adjusted to ensure the best possible signal from the ship being contacted. A duplicate aerial was installed at the Portishead transmitting site, which rotated simultaneously when the Highbridge aerial was adjusted. This would assist the ship receiving the transmissions in receiving the optimum signal.

The original single-storey building at Highbridge quickly became too small for the amount of traffic being handled, and an extra floor was added in the early 1930s to install extra operating consoles and landline areas.

The station’s traffic figures rose dramatically during the 1930s. In 1936 alone, over 4 million words of traffic was handled by the station. During this time, the station also handled traffic from Atlantic Patrol aircraft and some of the large Flying Boats which plied their trade in the Western Atlantic and Mediterranean Sea areas.

The outbreak of war in 1939 brought about immense changes to how the station operated; ships could no longer send messages for fear of their signals being intercepted by enemy listening posts, and a single click on their Morse key could give away their position.

Therefore, all messages to ships were broadcast twice at regular times, and it had to be assumed that complete and accurate reception had taken place. Ships had to ensure a 24-hour listening watch took place to ensure their messages would not be missed, which meant at least 2 Radio Officers per ship were required.

The station was used to train Radio Officers before they were despatched to British and allied ships and coast stations worldwide, and for the duration of the war it was under the control of the Admiralty, with a large Royal Naval presence.

To protect the station, an army unit was based locally, and although the station (and the transmitting site at Portishead) was identified by enemy aircraft, no bombing raids ever took place. Many staff members were involved in the local ‘Home Guard’ platoon.

To ensure that worldwide traffic could be expeditiously handled, an ‘Area Scheme’ came into operation, whereby ships could send and receive traffic through Admiralty radio stations such as Bombay, Halifax, Cape Town etc. and their messages would be transferred to and from the UK via Admiralty circuits.

The world was divided into specific ‘areas’ with at least one Admiralty station handling traffic for their particular area. This proved so successful that a slightly amended scheme would continue after the war until 1971, together with Royal Navy staff augmenting the civilian Radio Officers at the station.

In addition to routine traffic, the station also handled messages from SOE (Special Operations Executive) stations throughout Europe, especially from stations in Yugoslavia and Norway, which were then passed to the relevant Admiralty or Military department.