Volumes of information have been written about Canada's Corvettes and are available elsewhere so the focus of  this document will be the radio fits of this class.
HMCS Sackville as she appeared in 1998 at her permanent berthing in Halifax. Canada had 122 Corvettes in service during WWII. They were built for both the RCN and the RN in seven programs which spanned most of the war years. Sackville is the only survivor of her class and the main reason for that was her quiet steam engine which was a desired characteristic when she was converted to an oceanographic research ship. That conversion saw her survive until 1982 when she was no longer needed and  was taken out of service to ultimately become Canada's Naval Memorial. (Photo by Jerry Proc)

Length: 205.1 feet Breadth: 33 feet
Draught: 11.5 feet Displacement : 950 tons
Top Speed: 16 knots Crew: 6 officers and 70 men

The corvette, in its original design, was a very simple ship intended for very simple tasks of comparatively short duration. Perhaps nowhere is this more evident than in early plans for crew size and accommodation. The original complement was twenty-nine all ranks, but the earliest evidence of crew size for Canadian corvettes suggested a total of four officers and forty-eight ratings, as follows:

1 Lieutenant Commander, as Captain
1 Lieutenant, RCN(R)
2 Lieutenants, or Sub Lieutenants, RCN(VR)
1 Chief Petty Officer
3 Leading Seamen
12 Able or Ordinary Seamen
1 Leading Telegraphist
1 Telegraphist
1 Telegraphist Signalman
1 Signalman
1 Engineer Officer, or Chief Engine Room Artificer
3 ERAs
3 Stoker POs
6 Leading Stokers
10 Stokers
1 UPO or LVA
2 Cooks
2 Stewards

Among these crewmen were the following weapons and sensor specialists (non-substantive ratings):

1 Telegraphist Coder
1 Leading Coder
2 Quarters Ratings (Gunnery Specialists)
1 Leading Torpedoman (in charge of Depth Charges and Electronics)
2 Seamen Torpedomen
3 High Signals Detection Ratings (Sonar operators)
3 Signals Detection Operators

As the size of the crew and the complexity of the weapons and sensors increased, the number of specialists and support personnel grew as well. By1941 radar, anti-aircraft and more signal ratings had been added, as had an additional officer.

(Click on image to enlarge)
corvette_radoffice_location_s.jpg Location of the Radio Office on a Flower class corvette, 1939-1940 program. (Photo courtesy Corvettes of the Royal Canadian Navy)

Accommodation in corvettes was in three main areas; forward of the deckhouse in the area immediately below the 4-inch gun, within and immediately below the deckhouse, and aft ofthe engine room.

corvette_radio_aerials_s.jpg Location of the flattop antennas on a Flower class corvette, 1939-1940 program. (Photo courtesy Corvettes of the Royal Canadian Navy)


The late Albert Yonge of Halifax provided a sketch of Sackville's  radio office  Corvettes only had one radio office and there were wide variations in the equipment fits. These ships, were typically fitted with six receiving flattop aerials each 34 feet in length. In the WWII era, the RN referred to these compartments as Wireless Offices. In the RCN, the common vernacular was to call them Radio Offices as opposed to the more modern term Radio Room.

Additional details on any of the equipment shown on this page are listed in this document.

Layout #1 - Top view of one of  the many variations in radio room layouts.
Hugh Mccaw of Winnipeg recalls the fittings of the radio office aboard his corvette, HMCS Napanee. Receiver #1 was tuned to the broadcast from CFH or GBXZ. (Station GZZ was the main Whitehall broadcast station). Receiver # 2 was the guard receiver for the 500 kc International distress frequency.
Layout  #2  Top view  of radio room in . HMCS Napanee K118

/corvette_radio _office _layout_b1220.jpg
Layout #3 - Fort Willian J311.   Here, the designer was only certain on the placement of the SMR-3 receiver, so the remainder of the operating table was left unpopulated. (Source unknown

Layout #4. This deck plam for HMCS Cobalt, K124, shows that the battery box was siruated on the outside of the radio room. Click on image to elarge. (Deck plan via 

SaACKVILLE's restored  radio office as it appeared in July 1998. Equipment placement is estimated. There are several inaccuracies in this interpretation  with the most glaring one being the gernade-stem table lamp atop the MDF-5 DF unit. To the credit of the restorer, all the equipment is of the right type .  (Photo by Jerry Proc) 
The following equipment list for Corvettes was complied from FECA charts and M-2 cards on February 26, 1945. In the original document, there were columns labelled "Other Transmitters", "Other L.H." (meaning unknown) and "Other Transmitters/Receivers". These have not been copied into the table below because those headings have no meaning. All the Algerines listed were paid off after the end of WWII.

Descriptions for the equipment can be found in another section of this web document. A few notes about the equipment in the tables:

* DAS-1, and DAS-2 are identical pieces of Loran 'A' receiver equipment. The numerical suffix denotes different production contracts.
* RTA, 457 and 431 types remain unknown at this time.
* CCM is crypto equipment.

The ships listed in the Wireless Equipment table below were all Castle class corvettes built in the UK and operated by the RCN. That's the reason why these vessels were fitted with so much British electronics.

Corvettes built at the Burrard Shipyard in Vancouver cost $605,000 each.


SHIP TBS 4T 89M B28 B29 FR12 FR12TH SCR522A 457 431 RTA CCM B19
Arnprior 1 1 1 4 1 1       1     1
Bowmanville 1 1 1 3       1   1   1 1
Copper Cliff 1 1 1 4 1 1   1         1
Huntsville 1 1 1 3 1 1 1 1   1     1
Hespler 1 1 1 2 1 1   1 1 1     1
Humberstone 1 1 1 3 1 1   1   1     1
Kincardine 1 1 1 4 1 1   1     1    
Leaside 1 1 1 4 1 1   1 1 1     1
Orangeville 1 1 1 3 1 1 1 1   1     1
Petrolia 1 1 1 3   1 1 1   1     1
St. Thomas   1 1 3 1     1 1 1     1
Tillsonburg 1 1 1 3 1 1   1         1

WIRELESS EQUIPMENT (CASTLE CLASS ONLY ) - February 1945 (continued)

SHIP FH-3 FH-4 HT-11B HT-11C TV-5 DAS-1 DAS-2
Arnprior 1       1 1  
Bowmanville   1     1    
Coppercliff 1     1 1 1  
Huntsville 1     1 1 1  
Hespler 1     1 1 1  
Humberstone 1         1  
Kincardine 1   1   1   1
Leaside 1   1     1  
Orangeville 1     1 1 1  
Petrolia 1       1 1  
St. Thomas 1     1 1 1 1
Tillsonburg 1           1
The data in the tables below was extracted from BR 299, a Royal Navy publication dated 1947. Photos and specs for some of this equipment can be found in this document including the specs for all 60 series transmitters .  Any numeric suffixes which appear for American made equipment, denote the procurement contract number. A TBL-4 is identical to a TBL-12  but was made on perhaps a under a different contract number or even a different contractor.

BR 299 lists Sackville as a Loop Layer vessel. During the period May 1946 to Apr 1946 she wore pennant Z62. Sackville eventually became a hydrographic research ship then was restored to her wartime configuration to become Canada's Naval Memorial in Halifax

On January 27, 1945, Woodstock was paid off in Esquimalt for conversion to a loop layer but upon recommissioning on May 17, she was employed as a weather observation ship and shared a patrol with United States ships some 500 miles westward of Vancouver Island. She was finally paid off in 1946.

Main Office.  PV500HM - Canadian Marconi, 500 watt, CW/MCW transmitter. Frequency range 3 to 18 MHz  Photo here
FR12T - Low powered transmitter. CW/MCW and phone 15 watts transmitter. Photo here
TW12EH. Transmitter/receiver. Frequency Range: 375 to 500 KHz; 1200 to 3000 KHz;  Modes: CW/MCW/RT.  Photos here.
MSL5 - Receiver 15 to 1775 KHz
SMR3 - Receiver.  Frequency range: 97 to 30000 KHz in six bands 
MDF5 - MFDF set . 285  to 670 KHz
Aerial Outfits  Nothing recorded
Miscellaneous Nothing recorded. 

WOODSTOCK  (as K238)
Main Office.  PV500H - Transmitter. Canadian Marconi, 500 watt, CW/MCW transmitter. Frequency range 3 to 18 MHz. Photo here
FR12T - Transmitter/receiver. CW/MCW and phone. 15 watts . 
TW12EH - Transmitter/receiver. Frequency Range: 375 to 500 KHz; 1200 to 3000 KHz;  Modes: CW/MCW/RT.  Photos here.
MSL5 - Receiver 15 to 1775 KHz
CSR5 -  Receiver 80 KHz to 30 MHz excluding broadcast band.
MDF5 - MFDF set. 285 to 670 KHz
Aerial Outfits  Nothing recorded
Miscellaneous Nothing recorded. 
In 1944, it was decided by the British Admiralty that British Flower class corvettes and trawlers needed radio equipment upgrades The details can be seen in this document. The opening paragraph needs clarification. The new equipment would have been from the group on the left or the group on the right.  Type X refers to the crypto machine.


Layout #5. This was the locationof the Decoder's Office aboard HMCS Sackville. She was fitted with the CCM coding/decoding machine S/N 124. Click on image to enlarge.

Contributors and Credits:

1) Corvettes of the Royal Canadian Navy 1939-1945 by Ken Macpherson and Marc Milner. Vanwell  Publishing. (1993). St. Catharines Ont.
2) Hugh Mccaw, Winnipeg Manitoba
3) Albert Yonge, RCN. Now deceased.
4) Clive Kidd, Collingwood Heritage Museum <cjckidd(at)>
5) BR299  dated 1947, Royal Navy,

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Dec 14/20