Click here to return to the Table of Content

Cliquez ici pour retourner à la table des matières


While visiting the retired Oberon submarines in 2006, I took the next 8 photos of the radio room onboard HMCS ONONDAGA. This space was my little domain, also known as the Radio Shack, or the Radio Office, or the Wireless Office, or the W/T Office. Taking photos inside the Radio Room was forbidden when I was in the Navy due to the high level of security. This is why I do not have any photos of the Radio Room from the 1960s or 1970s. The submarines and the technologies they used at the time have now been declassified. Much of the information is available on the internet; at least two submarines are now on display as submarine museums; and some of the equipment used at the time is available from time to time on ebay.

Above is a photo of the access door to the Radio Shack which was a Top Secret Level security area. It was the little domain of the Radiomen, also known as Sparkers or "Radio Ladies". This is the place where I spent most of my time in submarines.


Top Secret security clearance was required to enter. In addition to Radio Sparkers, people who were allowed to enter included the Captain, the Communications Officer and the P.O. Tel (also known as POTS). The P.O. Tel (Petty Officer Telecommunication) was the Radio Sparkers's immediate boss.


Note CGNQ on the door. It was ONONDAGA's international call sign when using morse code. The call sign for voice transmission was " Voyage Pride ".


Shipmates who had business with Sparkers knocked on the door and waited. Messages (and hot coffee) were passed on to the sparkers through the little door.

Above is another view of the access door to the radio room. The radio room was on the starboard side of the submarine. When facing the door, aft is on the right and forward is on the left.


If you turned aft, you would see the hatch and the bulkhead separating the control room from the engineering room about 20 feet away, past the officer's head. If you went aft a few feet, on the left would the HF communication mast and the lever to raise the mast. Aft of the HF communication mast would the the exhaust mast and the famous flap valve to stop salt water from coming in when the exhaust pressure drops down suddenly due to an emergency stop of the diesel engines.


When snorkeling at periscope depth, the snorkel rises above the surface and replenishes the air inside the submarine which is sucked up by the diesel engines. There is a floating ball inside the snorkel which prevents the water from coming in when the snorkel dips below the surface. In rough seas, it is sometimes difficult to maintain periscope depth and the snorkel often dips below the surface. When this happens, the air pressure goes down inside the submarine because the diesel engines are sucking up air and the air is not being replenished due to the blocked snorkel. This is not a serious situation if the snorkel remains below the surface for only a few seconds. The air pressure inside the submarine goes up and down as the snorkel  dips below waves and reappears again above the water. However, the situation can become serious on occasion if the air pressure inside the submarine becomes critically low. I do not remember how long the snorkel can remain underwater before it becomes an emergency. At some point, the officer of the watch will make a decision and will yell into the internal communication system:  STOP SNORKELING, STOP SNORKELING, STOP SNORKELING.


When this happens, the diesel engines are stopped immediately. This action causes another immediate danger at the exhaust mast. This mast never breaks the surface. It is always kept underwater to reduce detection by diluting the exhaust smoke in the water. What keeps the water out of the exhaust mast is the air pressure from the diesel engines. When starting the engines, the pressure is allowed to build up high enough before opening the exhaust to the sea. Whenever the engines are stopped normally, there are phases in the shut down process which allows the exhaust to be shut down at the appropriate time. But when there is an emergency STOP SNORKELING, there is no time to follow the normal process. Diesel engines must be stopped as quickly as possible because the crew onboard is in danger due to low air pressure inside the submarine. This is when the famous flap valve comes into action. As the pressure inside the exhaust is suddenly dropped due to engine shut down, sea water starts to pour into the exhaust. As it reaches the flap valve, it forces it to shut suddenly, thus stopping the water from reaching the engines. When this flap valve shuts down, a big bang is heard throughout the submarine. The flap valve is located near the Radio Room. So when the big bang is heard, you can imagine the noise inside the Radio Room. Sparkers got severe jolts each time it happened.

In the photo above, the access doors have been open and we are now looking inside the Radio Room, or Wireless Office, or W/T Office. These doors were always shut when the submarine was operational.


When facing the Radio Room, like in this photo, the Heads (washrooms) are located behind me.

In the above photo, I have now entered the Radio Shack and have turned around to look at the Heads across the passage way. Being so close to the Heads had some good and bad points for the Radiomen.


It was good because if you had to go urgently and there was nobody to replace you, all you had to do is keep both doors open and do "your business" while keeping an eye on the Radio Shack.


The bad thing happened once a day. Being on a submarine, human waste was kept into a tank and had to be emptied daily. The process included shutting some valves, equalizing the pressure, opening other valves, blowing the waste out, and reversing the process.


The problem was the venting of the tank at the end of the process. The aroma which was released inside the submarine sometimes reached the Radio Room due to its proximity.


There was also another problem which affected the users of the Heads when venting was not done properly. There was a flap valve inside the toilet bowl which was open with your foot after you had done your business so you could flush the waste into the tank using a manual hose. Imagine someone opening the flap valve with his foot when high pressure is still in the tank because whoever emptied the tank forgot to vent at the end of the process. You can imagine the results. Not a pleasant experience. It was a good thing that the access door to the Radio Shack was kept shut at all times.

In the above photo, I am now standing inside the Radio Room with the access door on your right and looking aft. A lot of the radio equipment was removed when the submarine retired but some is still there. This equipment seen here is from the 1990s and completely different from what I was using in the late 1960s and early 1970s.


Morse code and teletype were the two main modes of ship-to-shore radio communications back then. The world of satellite communications had not yet arrived. The ionosphere was our only mean of long distance communications. It meant that frequencies used for ship-to-shore communications were different each time, depending on the time of the day and the conditions of the ionosphere. It was sometimes a challenge but it was easier on ships than on submarines.



Surface ships could track the ionospheric conditions and be up-to-date on HF propagation at all times.  They even used frequency discriminators to go up and down the HF spectrum while continuously copying naval broadcast. Frequencies were used in the 4 MHz, 6 MHz, 8 MHz, 12 MHz, 16 MHz, 22 MHz and 25 MHz. As the ionospheric propagation was changing, the receiver receiving the strongest signal through the discriminator was used while the other receiver was tuned to the frequency most likely to improve in the next few hours. Under normal conditions, the best operating frequencies would climb from early morning until late afternoon and then begin downward again until early morning the next day. I did say under normal conditions because the ionospheric propagation was also affected by solar activity. But in general, because sky waves were being used, they were affected by the daily changes of the layers in the ionosphere; the disappearing of the D layer at night, the F layer becoming the F1 and F2 layers during the day and the E layer becoming weaker at night.



Submarines below periscope depth could not track the ionosphere. They had to rely on experience and on ionospheric predictions published in documents to guess the condition of the ionosphere at the specific time when the submarine came up to periscope depth and the HF radio mast was raised above water.


Sometimes the Captain wanted to go back down as soon as the radio traffic was cleared. Submarine sparkers had to decide which HF band and which frequencies to use before raising the HF radio mast. Receivers were tuned in advance and the transmitter was prepared up to the loading of the antenna. Most of the time they were right but sometimes they were wrong. When a call to CFH Halifax was unanswered, a quick decision had to be made. Try to call CFH Halifax again on a different HF radio band; or try to call CKN on the west coast; or try to pass traffic to Halifax via a Commonwealth or NATO shore radio station. The pressure on the sparkers was high when the Captain wanted to minimize the time at periscope depth. When unsuccessful with CFH and CKN, the next best thing was to try British naval radio stations in Gibraltar or England because the relays to Halifax were easier within the Commonwealth. Finally, if all options failed, we called stations of the US Navy.


If the radio traffic consisted only of the 72-hour check report, the message was sent in morse code,  in plain language without encryption and the text had only three words:  CHECK SEVEN TWO. If the proper frequency band had been selected before coming up to periscope depth, if the receiver was already tuned in advance and if all went well during the transmitting process, everything could be done in two to three minutes. By process I mean: getting the OK to raise the HF radio mast; raising the HF radio mast; tuning the final of the transmitter as soon as the lower insulator clears the surface; calling CFH on the calling frequency; getting an immediate reply from CFH on the CW broadcast frequency; transmitting the check report on the calling frequency instead of the working frequency (because it is a check report); getting an acknowledgement from CFH; and confirming to the control room and/or to the Captain that the check report had been sent. At that point, if the Captain was eager to get back below periscope depth, the submarine would begin its descent immediately while the radio mast and the search perisope were being lowered.

In the above photo, it is the same view as before but looking down at the operating desk. This is where I sat with a tape recorder between my legs to record morse code transmissions at 100 words per minute. It would allow us to quickly copy our submarine schedule and return to the deep where the tape was slowed down so I could copy the morse code at 25 words per minute.


Above my head, to the left, was the control for the Collins ARC-552 UHF transceiver used to communicate with aircrafts and ships. This transceiver was mostly used by the Captain and Officers in the Control Room or on the bridge via remote sets. Above my head to the right was the control for the Collins MF/HF 618-T Transceiver. This transceiver was used mostly for morse code ship-to-shore radio communications and SSB communications with surface ships and other submarines.


The safe containing top secret documents was located in the same spot as the safe in this photo. The equipment rack to the right of the safe was not there in my days. This is the spot where the cryptographic equipment was located to manually encrypt and decrypt morse code messages. The process for morse code messages was basically the same process as used by Germans during World War II with their Enigma machines. The KL-7 crypto machine we used in those days was basically an improved Enigma machine using eight rotors.


There was no need to manually encrypt and decrypt teletype messages since we were using an in-line KWR-37 cipher machine. Plain language teletype messages were fed into the KWR-37 and encrypted teletype messages came out of the KWR-37 and fed to the transmitter. So encryption required no manual input. The process  was reversed at the receiving end. The received signal was fed from the receiver to the KWR-37 and the output of the KWR-37 was fed to the model 28 teletype machine.


The cypher codes were changed daily at 0000 Zulu by replacing a perforated card in the KWR-37. In order for the entire encrypted teletype network to work, all KWR-37 machines in the fleet and at naval radio stations on shore had to be synchronized within less than a second of each other. We commonly used the time signal sent by CHU Ottawa on 7335 kHz or 14670 kHz. When the CHU signal was bad, we used WWV Fort Collins, Colorado on 5, 10 or 15 MHz .


If the submarine was below periscope depth at midnight zulu, CHU or WWV was not available for time synchronization. For this reason, the clock in the Radio Room was regularly synchronized with CHU or WWV whenever the radio mast was raised and the submarine had access to the HF band. This way, the KWR-37 could be started at midnight zulu using the Radio Room clock if the submarine was below periscope depth. Sometimes the synchronization did not work. Pushing the button within one second of the time signal was not that easy. Also, if synchronization was done with the Radio Room clock while below periscope depth, there was no indication that it was working until we came up to periscope depth and a signal was fed to the KWR-37 from the HF receiver. Fortunately, the KWR-37 could be restarted every 5 minutes. Sometimes it would take more than one attempt if the button was not pushed within the allowed time slot.

What you see in the above photos are two Collins HF receivers which were used in the 1990s. They were left onboard when HMCS ONONDAGA was retired in 2000 and they are now part of the display at the ONONDAGA submarine museum in Rimouski, Quebec.


In the above photo , I have now turned around and I am looking forward. The operating desk is on my right and the access door on my left. Going back to the 1960s and 1970s, the Model 28 teletype equipment and the shredder was located to the right as well as an intercom system for the submarine. Being in control of the music onboard was not always pleasant. I was accused at one time of playing The Beatles too often.


The equipment racks to the left contained the Collins URC-32 HF transceiver used mainly for teletype radio communications, but also used for morse code and voice AM transmissions. There was also an equipment rack on the left, closer to the operating desk, which had two Racal RA-17 VLF/LF/MF/HF receivers as well as radioteletype and facsimile equipment, the KWR-37 crypto machine, and direction finding equipment.