Ron Mark launches this section buy describing the radio room layout in HMCS Assiniboine in which he was part of the commissioning crew in August 1956. Assiniboine was a St. Laurent class warship.

"Assiniboine had four radio offices and a separate Message Center. It was equipped with 12 internal phone systems. The radio equipment was similar to other ships I had served on, with two major exceptions; we had eight UHF/VHF transceivers for voice communication within the fleet, and four other transceivers for use in the LF/MF/HF frequency range.

The main radio office had a large switching console, where we were able to switch these twelve transceivers, to remote control units, positioned in about twenty locations within the ship. For example, we could switch a unit to the upper or lower bridge, forward or after steering position, quarterdeck, any one of the four radio rooms.

There were multiple remote units on the bridge and operation room. This allowed the ship to have separate communication frequencies for ship-to-ship, ship-task force, hunter-killer, and ship-air operations. Radio 3 was adjacent to Radio 1, and contained the UHF/VHF transceivers. This arrangement allowed quick changing of frequencies. On most ships, this office was located on another deck or in different parts of the ship. The St. Laurent class of ship, served as the prototype for 11 ships, of two classes, that were built, over the next couple of decades".

By the mid 1980's, most of the equipment described in the previous sections of this web page had been superseded by newer technology. The concept of individual radio rooms was also disappearing to be replaced by the Communications Control Room (CCR). Systems became increasingly more complex as time went on.

Every effort has been made to ensure accuracy of the equipment descriptions, however what is shown cannot always be taken as gospel. For example, there is equipment listed in the Equipment Holdings lists for which there is no description in the 1985 Equipment Manual. Luckily these are in the minority. Many of the block diagrams in the manual have been intentionally omitted since they convey no useful information unless you were training to operate the equipment.

The equipment described in the succeeding web documents of this section could be found in the following classes of ships: AOR/Annapolis/Improved Restigouche/Iroquois/Mackenzie/Improved St. Laurent. The names of the individual ships in each class are listed in the tables below.

Starting in 1979 the DELEX (Destroyer Life Extension Program) was implemented in order to extend the life of Canada's 16 steam driven destroyers by 8 to 12 years beyond their normally anticipated life of 25 years. It extended the life of the St. Laurent Class and improved the capabilities of the Improved Restigouche, Mackenzie, and Annapolis classes.

Excerpts from the book "Cadillac of Destroyers" will highlight ay improvement in radios or communications for each class.

Assiniboine 234 19/5/1952 12/2/1954 16/8/1956 14/12/1988
Fraser 233 11/12/1951 19/2/1953 28/6/1957 5/10/1994
Margaree 230 12/9/1951 29/3/1956 5/10/1957 2/5/1992
Ottawa 229 8/6/1951 29/4/1953 10/11/1956 31/7/1992
Saguenay 206 4/4/1951 30/7/1953 15/12/1956 26/6/1990
Skeena 207 1/6/1951 19/8/1952 30/3/1957 1/11/93
St. Laurent 205 24/11/1950 20/11/1951 29/10/55 14/6/1974
In November 1948, the Canadian government announced its intention to build seven escort vessels whose specialty was anti-submarine warfare. These ships were completely designed and built in Canada with emphasis on seakeeping, noise/weight reduction and nuclear, biological and chemical ( NBC) protection.

The St. Laurent's were described as an "electrical wonderland" because nearly everything in the ship was dependent on electrical power - armament, navigation, cooking, ventilation and communications. One exception was the air conditioner whose prime mover  was a steam turbine coupled to a 150 ton pump. Chilled liquid (believed to be brine) was circulated throughout the ship, especially into the instrument spaces where the most heat was generated from vacuum tube equipment.

As another first, this class used 440 Volt AC power. Total power output from the five generators was 1,400 kilowatts. St. Laurent was fitted with 12 separate telephone systems for internal communications. There were four radio rooms in total along with a specialized Message Centre  and cryptographic room.

The DELEX program was applied to six ships of the St. Laurent Class which enabled them to remain in service until the early 1990s'.


Displacement: 2,263 tons standard. 2,800 filly loaded; As A DDH: 2,263 tons standard; 3,051 tons fully loaded.
Dimensions: 366' x 42' x 13'2"
Speed: Cruising 14 knots; Maximum 28 knots
Endurance: 4570 nm at 12 knots.
Machinery: Geared turbines; 30,000 SHP
Boilers: 2 Babcock and Wilcox, water tube
Crew: 12 officers , 237 men

HMCS Assiniboine. (Via Haze and Gray Web site)
Chaudiére 235 30/7/1953 13/11/1957 14/11/1959 23/5/1974
Columbia  260  11/6/1953 1/11/1956 7/11/1959 18/2/1974
Gatineau 236 30/4/1953 3/6/1957 17/2/1959 1/7/1998
Kootenay 258 21/8/1952 15/6/1954 7/3/1959 18/12/1996
Restigouche 257 15/7/1953 22/11/1954 7/6/1958 31/8/1994
St. Croix 256 15/10/1954 17/11/1956 4/10/1958 15/11/1974
Terra Nova 259 14/11/1952 21/6/1955 6/6/1959 1/7/1998
This class was a follow-up to the St. Laurent Class with certain improvements, notably a 3"/70 calibre gun and a central,  Mk 69 fire control director. The 3"/70 gun proved to be very nettlesome in service with a propensity for jamming which acquired the sobriquet of a "smash".  A typical gun shoot in those days sounded like "BLAM, BLAM, BLAM, smash!"  The problem was eventually resolved with two fixes. First was to replace many shear pins in the shell handling assembly (known as the "bottling plant") with non-shearing types. Secondly, the rate of fire was reduced from 120 rounds per minute to 90 rounds per minute. The original problem was induced by the flexing motion of the ship's hull because the gun had been intended for use in larger ships where the hull did not flex. The larger ships for  which the 3"70 gun had been designed for were HMS Lion, Blake, and Tiger as secondary (AA) armament.

This class was easily recognizable with the new 3"/70 gun mount, a higher bridge to give a better view over the gun, wing platforms attached to the foremast and lookout wings abaft the bridge.

In the late 1960s, four ships of this class were refitted to what is known as the Improved RESTIGOUCHE (IRE) class. In the conversion,  the aft 3"/50 gun was replaced with an 8 tube ASROC launcher and the old mast with a new, taller lattice mast. The stern was also altered in order to accommodate a new variable depth sonar. That also made the ship slightly longer. The ships that did not receive the IRE refit were paid off into Category "C" Reserve. These included Chaudiére, Columbia and St. Croix.

Tom Fullerton adds this note of interest. "In the SCR (Sonar Control Room) of Restigouche there was a fairly large framed photo of a U.S. submarine surfaced with a mortar bomb sticking out of its casing. Before my time aboard, Restigouche had apparently blown a pattern of inert mortars (Mortar Mk NC-10) at the sub during training exercises. The practice of aiming inert bombs at live targets was subsequently banned, but it was a cause for celebration among my sonarmen predecessors".


Displacement: 2,366 tons standard, 2,800 tons full load; As an IRE: 2,390 standard, 2,900 tons full load.
Dimensions: 366' x 42' x 13'6";  As an IRE: 371' x 42' x 14'1"
Speed: Cruising - 14 knots; Maximum 28 knots
Endurance: 4750 nm at 14 knots
Machinery: Geared turbines; 30,000 SHP
Boilers: 2 Babcock and Wilcox water tube
Crew: 12 officers /237 men;  As IRE: 13 Officers, 201 men

When the IRE's received their DELEX that  included the installation of an ADLIPS tactical data system, the fitting of the Sperry Mk 127E navigation radar, the SPS-502 radar and the SPG-515 fire control radar for the Mk 69 gunnery control system. A TACAN antenna was fitted atop a pole mast.  New communications systems were installed including a new message handling system.

HMCS Kootenay.  (DND photo submitted by Dave Shirlaw). 

Mackenzie 261 15/12/1958 25/5/1961 6/10/1962 3/8/1993
Qu'Appelle 264 14/1/1960 2/5/1962 14/9/1963 28/3/1994
Saskatchewan 262 29/10/1959 1/2/1961 16/2/1963 28/2/1994
Yukon 263 25/10/1959 27/7/1961 25/5/1963 3/12/1993
After the last ship in the Restigouche class was delivered in 1959, the RCN decided to build another 6 ships similar to the Restigouche class which are occasionally referred to as the Repeat Restigouche Class. In reality, the six ships ended up as two classes - the first four forming the Mackenzie class and the last two the Annapolis class.


Displacement: 2,380 tons standard. 2,880 tons full load
Dimensions: 366' x 42' x 13'6"
Endurance: 4,750 nm at 14 knots
Machinery: Geared turbines; 30,000 SHP
Boilers: 2 Babcox and Wilcox water tube
Crew: 18 officers. 210 men
Externally, the Mackenzie class differed little from the Restigouche class destroyers. Internally, these ships had a Communications Control Room (CCR) replacing the Message Centre, Radio 1, and Radio 3 . This CCR occupied the same space and included most of the equipment previously distributed in several compartments in the Restigouche and St. Laurent classes. Tom Fullerton indicates that "one of the improvements made to the MacKenzie class was the replacement of the 150 ton air conditioning pump with two 75 ton pumps at different locations. It is believed that this modification was intended to improve survivability in case of damage. The ship's weapon systems would, of course, quickly break down without the air conditioning since it was all tube type gear in enclosed spaces".
HMCS Yukon. (DND photo courtesy of J. Michael Gibson)
Annapolis  265 2/9/61 27/4/1963 19/12/1964 1/7/1998
Nipigon 266 5/8/1960 10/12/1961 30/5/1964 1/7/1998
Displacement: 2,400 tons standard; 2930 tons full load
Dimensions: 371' x 42 ' 14' 4"
Endurance: 4570 nm at 14 knots
Speed: Cruising 14 knots; Maximum 28 knots
Machinery: Geared turbines; 30,000 SHP
Boilers: 2 Babcox and Wilcox water tube
Crew: 18 officers; 210 crew.

The two ships of the Annapolis class had a more complex DELEXing refit  - so much more detailed that its sometimes referred to as the Delex/265 Conversion program.  The IRE mast was fitted with SPS-503 radar and the vacuum tube SPS-10 radar was replaced by the solid state SPS-10D which was compatible to the existing antenna. Below the waterline, the antiquated SQS-502 , 503 and SQS-10/11 sonars were replaced by the AN/SQS-505(V). The Operations room was restructured and fitted with two ADLIPS systems thereby increasing the ships capability to process information and allowing them to share this information with ships of other NATO navies.

HMCS Nipigon (DND photo)

Algonquin  283 1/9/1969 23/5/1971 3/11/1973 June 11/2015
Athabaskan  282 1/6/1969 27/11/1970 30/9/1972 March 10/2017
Huron 281 6/1969 9/4/1971 16/12/1972 Marcch 31/2005
Iroquois 280 15/1/1962 28/11/1970 29/7/72 May 1/2015
The Iroquois Class programme, announced by the government on December 22, 1964, was an advancement on the DDH programme. Each ship was to have space for two helicopters, a surface-to-air missile system, new sonar and a 5" gun. Another first was the all-gas turbine power plant and a point defence missile system - the Sea Sparrow.

In June 1983, the government announced the Tribal Update Modernization program (TRUMP). This modernization would change the ship's role to that of "area air defence". Initially, the Iroquois class was armed with a 5 inch gun, a Mk X Anti-submarine (A/S) mortar and two Sea Sparrow A/S missile launchers. Under TRUMP, the ships received new and improved combat systems which included SM2 Block 2 missiles fired from a Mk 41 vertical launch system, an OTO Melara 76 mm Rapid Fire gun, and Phalanx CIWS (Close In Weapon System). This weapon is designed as a last ditch defence against incoming anti-ship missiles (SSM) Existing helicopters and homing torpedoes have been retained, but obsolete anti-submarine mortars were removed. When originally constructed, the Iroquois Class ships were very distinctive with their twin, outboard-raked  funnels. This was done for concern that funnel gases might interfere with helicopter operations immediately aft on the flight deck. This concern never came to pass, so during TRUMPing, the dual funnels were transformed into a  conventional, single, straight-up funnel.  All work was completed by 1992 and cost $650 million.

For communications,  TRUMP added the Ship Integrated Communications  (SHINCOM) system and a state of the art command and control system, CCS-280. Further improvements to this class included hull strengthening, infrared suppression in the now single funnel, fire detection/supression systems and upgrading of living spaces.

Displacement: 3,551 tons standard; 4,200 tons full load
                      TRUMPED 3,551 tons standard; 5,150 tons full load
Dimensions: 398' x 50'x 14'
Endurance: 4,500 nm at 18 knots
Speed: Cruising 18 knots; Maximum 29+ knots
Machinery: COGOG gas turbines 2- FT4A2 Pratt and Whitney
                   2- FT12AH3 gas turbines; 2 GM Allison 570 KF gas turbines ; 50,000 SHP
Crew: 14 officers; 230 men
HMCS Iroquois in 1987 as Flag Ship for STANAVFORLANT and prior to her TRUMP refit. 
  (DND photo via Len Carriere )

Credits and References:

1) Cadillac of Destroyers by Ron Barrie and Ken Macpherson. Vanwell Publishing.  St. Catharines, Ont. 1996.
2) Canada's Naval Forces 1910-2002. Ken Macpherson and Ron Barrie. Vanwell Publishing.  St. Catharines, Ont. 1996.
3) Haze and Gray Site: Restigouche Description
4) Haze and Gray Site: Assiniboine
5) Len Carriere <CarriereL(at)DFO-MPO.GC.CA>
6) Tom Fullerton <tfullerton(at)>
7) Ron Mark <rondmark(at)>

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Mar 12/17