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The Role of the Merchant Navy Radio Officer

The MN Radio Officer existed in his primary role was for that of “Safety of life at Sea”.

Every Ocean going ship and even some coastal vessels of a certain tonnage had by maritime law to carry at least one fully qualified Radio Officer who would either be working for one of the Marine radio companies such as Marconi Marine, Redifon, IMR, Kelvin Hughes, Etc or some were directly employed by individual shipping companies depending upon the guys personal choice for his employment.

The Radio Officer would be assigned to a ship by the companies personnel department, the type of ship when working for a Radio company could have advantages such that on one voyage you may be assigned to a cargo vessel, an oil tanker, a bulk carrier, a passenger liner.

Such a variety was enjoyed by a lot of people and you could literally be visiting any port in the world depending on the type of ship and its trading routes.

Some were on regular runs between certain ports all the time, others would possibly be tramping all over the world. You may be away for 2 or 3 months or up to 2 years on some ships. Direct employed companies would probably be on fixed scheduled runs and maybe the duration would be fixed, say 3 month round trip or sometimes running across the Atlantic for 3 weeks at a time on a passenger liner. A choice of ship and destinations were sometimes available other times you had to take pot luck and could be sent anywhere on any ship with no choice—take it or go somewhere else!

A ship was not allowed to sail without a Radio Officer so sometimes you would have to leave at short notice to a ship that was sailing soon or maybe fly out to certain parts of the world to take over a ship if someone was ill or was going on leave.

When the ship sailed the Radio Officer would go on watch in the radio room and he or she would listen on the international distress frequency of 500 khz in case a distress SOS or urgency signal XXX or maybe a safety signal TTT was being sent. During this time other duties used to take place like sending TR’s (Traffic reports and routings) to local coast stations that were passed by and to the H/F stations informing them also of the ships routing and which areas/stations you were going to be listening to during the voyage.

radio officers in uniform

You may be wondering who these two handsome gentlemen are!
On the right hand side you have our very own Stan, and to his right is his brother, Alan. This photo was taken during the late 1950's.

At 15 to 18 minutes past each hour and at 45 to 48 minutes passed each hour these were known as “Silence Periods” where every ship station and coast station had to listen intently on the distress frequency 500khz for any signs of a ship in a distress situation. Only when this 3 minute period was over and no distress were heard was it ok to resume any normal traffic working. Even when doing other work on different frequencies we still had to listen on 500khz on the emergency receiver for any kind of distress signals.

On ships with only one Radio Officer who used to do an 8 hour watch period per day that still left 16 hours a day for NON cover of the distress frequency. This is the reason the automatic alarm system was introduced whereby we could set the equipment to on and it would monitor the distress frequency of 500 khz.

radio officer telegram painting

Marconi and his spark transmitter

The auto alarm would respond to certain signals (ie) if an auto alarm signal was sent out by another ship that consisted of 12x 4 second dashes which were separated by a 1 second interval and the receiver picked up just 4 of these correctly spaced signals then the auto alarm would trigger, that would ring a bell in the radio room, the Radio Officers cabin and also one on the ships bridge thus alerting any off watch R/O to the radio room immediately and to listen on 500khz for a distress message, thus those unmanned 16 hours were now covered.

Other duties included sending routine traffic reports, messages, telegrams to the ships offices and agents also greetings telegrams. On passenger liners and cruise ships “PRESS” was also received and sent to the onboard printers shop for the daily newspaper distribution. Sometimes weather observation messages were also sent on certain ships.

Occasionally navigational warnings were sent by ships alerting other vessels of dangers at certain positions on the sea routes. We also had to listen to certain stations to “traffic lists” (ie) for messages that a coast station may have for us, if so we then had to contact that coast station to collect the traffic and pass any messages we may have on hand for them. All weather reports and navigational warnings, urgency signals and of course distress messages would be received and passed to the captain or officer of the watch on the bridge.

It was not only CW (morse code) that was used for communications but also radiotelephony where one could speak direct to another person who maybe in the shipping offices or a personal call to home or sometimes to another ship. All this could be done on a variety of frequencies depending on the time of day or night and the whereabouts of the ship compared with where we wished to communicate with.

Sometimes this was not always easy as we depended upon the ionosphere mainly for long distance communications so obviously were sometimes limited by these ever changing factors. Other difficulties included signal fading, interference, static noises other stations on the same frequencies as you and sometimes with a lot more power than you! VHF radio telephone where communication was line of site mostly, these were used mainly for contacting port controls and harbours and for intership working. Channel 16 vhf was the international distress frequency for this band of frequencies. Again navigational warnings were also transmitted on VHF as well.

Sometimes a medium frequency radiotelephone service was operated usually within a few hundred miles of a coastal radio station for making telephone calls on ships business etc and private calls to homes. This band of frequencies was in the 2 mhz band and the calling and international R/T distress frequency was that of 2182 khz.

This band was used quite a lot by coastal vessels and fishing boats. This 2182 frequency also had a ”silence period” this was from 0000 to 0003 minutes past each hour and from 0030 to 0033 minutes past each hour where ship and coast stations would listen out for any distress calls on radiotelephony this was MAYDAY MAYDAY MAYDAY then for urgency signals, PAN PAN PAN or for safety signals of SECURITE SECURITE SECURITE. Other duties of the Radio Officers on ships also included routine maintenance, breakdown repairs of all the ships radio and navigational aids equipment, from transmitters and receivers to radars, echo sounders. Auto-pilots, ships speed logs , direction finders, talk back systems etc.

As the years went on and ships became more complex and automated systems like data-loggers were thrown into the Radio Officers responsibility, then telex machines and weather fax machines were added. Soon followed by all ships alarm systems and even the cine projector. More and more electronic equipment was given to them to look after. Then bridge controlled engines and unmanned engine room electronics were thrown in for good luck!

By the mid 70’s a quite large workload was had by many ships Radio Officers, some were also trained then as ships Electronics Officers receiving specialised training on some of these very sophisticated and complex systems and assigned appropriately to these usually new ships.

More duties included the updating of ships documents for admiralty list of radio signals books, spares ordering, ships accounts, log keeping and most importantly the upkeep of the ships 24 volt Emergency batteries which may have to be used in a distress situation with a power failure of the ships mains supplies. These batteries powered the emergency transmitter and receiver, the automatic keying device and emergency radio room lighting.

As the late 80’s and early 90’s approached, the Radio Officers were slowly being made redundant and not required any more, the type of radio equipment previously used being gradually phased out and new rules and regulations came into force for a new system of communications using satellite communications and the new GMDSS (Global Maritime Distress and Safety System) was being employed and the need for the Radio Officer has ceased, most of the coastal radio stations were closed down as well. New type radio equipment was installed on ships where either the Captain or deck officers did the communications.

Thus the era of the Radio Officer came and went within less than a 100 year period of time. Ships now carry ETO’s (Electro Technical Officers) who are highly trained electrical and electronics personnel who are now responsible for all of the previously mentioned items above to anything that has electricity in it on a ship, from an iron, a kettle, a lift, a washing machine, lighting all around the ship, electric cargo pumps, winches, computers, it has now all changed, that’s technology for you.

Sadly the era of the Radio Officer is no more!

This is why we have the MN marine radio museum at fort perch rock to remember what the equipment was like for others to see and to help understand what our job was all about.


The Marconi international marine radio company was a very well known company for the supply of equipment and Radio Officers to the Merchant Navy.

They had depots in most major ports around the U.K.

Pictured here is the LONDON depot at EAST HAM, with various views both internally and externally of the building.

Eastham Depot
Eastham Depot
Eastham Depot after the Luftwaffe were finished with it!
Signing on, and the admin desk at Eastham


Liverpool wireless college, Princes road Toxteth:

The radio room that acted as a backup for GLV during the war


Riversdale Technical College, Aigburth, Liverpool:

Riversdale Technical College was renowned worldwide