With Focus on the Electronics Fit

Victoria-class submarines, also known as the Type 2400 due to their displacement of 2,400 tons, are diesel-electric Fleet submarines originally of the Upholder class designed in the UK in the late 1970s. In 1998, Canada purchased four of the submarines and a suite of trainers from the Royal Navy to replace the paid off Oberon submarines.  Formally, the Canadian Navy has designated the boats as the  VICTORIA Class Long Range Patrol Submarine.

HMCS Windsor, SSK 877. The T shaped object protruding from the fin is the Kelvin-Hughes 1007 radar. (DND photo)
The original intent of the Upholder class was to augment the Royal Navy's nuclear submarine fleet. Initially, the RN planned to order 12 Upholder boats but this plan was trimmed first to 10 and then to nine before being curtailed at just four as part of the "peace dividend" at the end of the Cold War in the early 1990s. As a result, the Upholder Class was withdrawn from service in the Royal Navy in 1994, following a defence review by the UK government.

Upholders entered service with the RN from 1990 to 1993. Even though they were initially unable to fire torpedoes, the first three were still refitted in 1992 and 1993 at a cost of some £9 million. They were operating from HMS Dolphin (Gosport) but with only 4 submarines, the base was deemed uneconomic and they transferred to the Devonport Naval Base. In their short period in service, the class operated mostly in the Atlantic Ocean. After being withdrawn from service, they were mothballed until purchased by Canada.

January 1986  HMS Unseen  December 2000 
February 1989  HMS Unicorn  October 2003 
February 1987  HMS Ursula  March 2003 
November 1983  HMS Upholder October 2004 
In 2002, Canada acquired four Upholders as replacements for their old Oberon class. One was to operate in the Pacific fleet and three in the Atlantic. The first of class, HMCS Victoria, was commissioned in Halifax in December 2000, HMCS Windsor in June 2003, HMCS Corner Brook in March 2003, and HMCS Chicoutimi in September 2004. The submarines are packed with technology generally found only on nuclear-power submarines and are still widely regarded as being among the best diesel-electric submarines in the world.

The boats are named after Canadian port cities. Victoria operates out of CFB Esquimalt, British Columbia and is under command of  Maritime Forces Pacific (MARPAC) while the three remaining boats are based at CFB Halifax, Nova Scotia and operate under  Maritime Forces Atlantic (MARLANT) Fleet within the Atlantic and Arctic oceans.


Displacement: 2,200 tons surfaced, 2,400 tons submerged
Length: 70.26 m
Beam: 7.2 m
Height: 7.6 m
Propulsion: Diesel-electric: 2× Paxman Valenta 4070hp (3,035kW) 1600 RPA SZ diesels, 1 GEC electric motor (5000kW), 1 shaft, 20+ knots (37 km/h) submerged, 12 knots (22km/h) surfaced
Range: 10,000 nautical miles (18,500 km) at 12 knots (22 km/h)
Crew: Seven officers, 40 men
Sonar: Type 2040 active/passive bow, Type 2041 MicroPUFFS, Type 2007 flank, Type 2046/CANTASS MOD towed array, Type 2019 active intercept
Fire Control: Lockheed-Martin Librascope TFCS ( Torpedo Fire Control System) Mk 1 Mod C.
Armament: 6 x 21 inch (533 mm) torpedo tubes (18 Mark 48 torpedoes)
Radar: Kelvin Hughes Type 1007
EW: Condor Systems Sea Search 2 radar warning receiver
Communications: * UHF DAMA  (Demand Assigned Multiple Access) SATCOM.
                           * UHF comms.
                           * VHF Marine radio (expected) for harbour communications.
                           * HF - the subs have HF capability .
                           * LF or VLF  - Not known if this capability is fitted.

On October 5 2004, HMCS Chicoutimi, sailing from Faslane Naval Base, Scotland to Nova Scotia declared an emergency north-west of Ireland following a fire onboard. The fire was caused by seawater entering through open hatches in rough seas. It soaked electrical insulation which had not been sufficiently waterproofed thus starting a fire. The sub's electrical cables conformed to an older specification than the three other three submarines. The Chicoutimi lost power and was rescued by Royal Navy frigates HMS Montrose and Marlborough on October 6. Lt (N) Chris Saunders died subsequently from the effects of smoke inhalation, due to the rough weather it was not possible to airlift him and the other casualties to a hospital until two days later. Chicoutimi was later transported to Halifax for repair. A board of inquiry cleared the captain of any fault but the regulations permitting the submarine to run on the surface with open hatches was revised.

victoria_cross_section_s.jpg Cutaway view of a Victoria class submarine. Click to enlarge. (Graphic courtesy Department of National Defence). 
victoria_cross_section2_s.jpg Another cutaway view of a Victoria class submarine. Click to enlarge. (Graphic courtesy Department of National Defence). 

The boats were designed and built by Vickers Shipbuilding and Engineering Ltd for the Royal Navy, but saw only brief service before being mothballed in favour of an all nuclear force. They are essentially identical to modern nuclear submarines (with the distinctive Albacore-derived teardrop hull and sonar-absorbing tiles) but run on diesel engines instead of nuclear reactors which limits their range, but conversely makes them quieter and more manoeuvrable.

The boats were designed with advanced noise-attenuation features to reduce the radiated noise levels below those of the already very quiet Oberon-class. There was also a reduction in the short time required to recharge the batteries to ensure a minimum exposure time of any part of the masts above the water. The design included an updated version of the fire-control system being installed on the SSNs under construction at the same time, designed to reduce stability problems at torpedo launch, a state-of-the-art French passive sonar system, the then-current towed array, and a passive ranging set.

These were Britain's first conventional submarines to feature the hydrodynamic tear-drop shape seen in nuclear powered submarines. This feature greatly reduced the acoustic signature produced by the boat while cruising.

A large double-armature motor was powered by a 9000-ampere-hour battery or a pair of Paxman Valenta diesel engines. Slow patrolling would require only 30 to 60 minutes of snorkling per day; an eight knot (15 km/h) transit would require snorkling some 30% of the time. Top speed matched any comparable SSK class and could be sustained for some 90 minutes.

It was highly automated to reduce manning, however during construction of the first of class, it was recognized that the weapon-discharge system design did contain flaws. The torpedo tube slide valve controlling operation of the torpedo tube doors, could have, under certain system failure conditions, allowed the opening of the inner door while the outer door was open. There was never any chance of this occurring as all tube operations were disabled until this fault was rectified. Had such an event actually occurred, large flowrate flooding could have resulted. The flaw was quickly fixed in the first three boats and the modifications included in the fourth boat while still under construction.

Miscalculations were made in the design of the main-motor control circuitry. During the sea trials of HMS Upholder, when performing the specified trial for an emergency reversal ("crash back"), a flash-over incident occurred, which resulted in catastrophic complete loss of all power and propulsion. On investigation this was traced to a make-before-break fault in the design of the control circuitry resulting in a discharge-to-earth current of more than 60,000 amperes.

The diesels were originally designed for use in railway locomotives, and were not intended to be rapidly stopped and started. Shutting them down after snorting led to many failures. Similarly, the motor-generators were operated at full power for longer than expected and consumed brushes and filters rapidly. The brush problems were not specific to the Upholders, but a widespread issue on all UK RN vessels at that time.

Acceptance of the class into service was delayed for three years, partly due to the programme being scaled back by the UK MoD, while such problems were corrected. The result of those corrections, however, was an extremely capable design. When operating on battery power, Upholders were almost undetectable on passive sonar, and when snorting, their acoustic signature was comparable to their SSN contemporaries in normal operation. They were physically small, and thus difficult to detect by magnetic anomaly or other non-acoustic means.

A local area network was built into the Upholders, supporting most of the sensors and fire-control systems, including remote viewing through the periscopes using both low-light television and infrared, an unmanned helm, and direct control of the main motor from the conn. The boat could fight with a team of four in the sonar room and a conn team of eight. Fire-suppression in unmanned compartments could be initiated remotely, and watch-keeping logs were automatically recorded. In port, the boats could be electronically linked such that one duty watchstander could monitor several submarines.

The submarine has a single skin hull constructed of NQ1 high tensile steel. The outer side of the hull, casing, and fin, of the submarine is fitted with about 22,000 elastomeric acoustic tiles to reduce the submarine's acoustic signature. The hull is a classical teardrop shape design, 70.3 m in length by 7.6 m in width and with a depth of hull of 5.5 m. The fin or main sail houses a five-man lockout chamber. The submarine's escape and rescue system has been extensively upgraded with additional stowage space for escape stores and an underwater telephone to meet the Canadian Maritime Force requirements. The hull displacement is 2,168 t surfaced and 2,455 t dived.

The submarine accommodates a crew of 48 including seven officers. There is room for an additional five mission crew, observers or training crew.


The submarines are fitted with a diesel-electric propulsion system driving a single shaft, based on two Paxman Valenta 16SZ diesel engines each rated at 2.7MW sustained power with two 2.8MW Alsthom alternators and an Alsthom motor rated at 4MW. The propulsion and power systems are controlled from the Machinery Control Room.

For operation under ice, the Victoria-class submarines could be fitted with an air independent power system. The installation of an air-independent propulsion system might be considered in a future refit or upgrade program.

The surface speed is 12 knots and the dived speed is in excess of 20 knots. In snorting mode, travelling at low speed at periscope depth using an extendable air breathing system, the submarine can continue at up to 12 knots. The range at an 8 knots snorting speed is 8,000 miles and the submarine has a patrol endurance of 56 days.
Hull is rated to a diving depth over 200m


Lockheed Martin Canada, Lockheed Martin Undersea Systems and Northstar Technical Inc upgraded and installed the submarine's Lockheed Martin Librascope Torpedo Fire-control system (SFCS) to meet the operational requirements of the Canadian Navy. Components from the fire control system of the Oberon class submarines were removed and installed. The submarine has six 533 mm (21 in) bow torpedo tubes equipped with two air-turbine pump discharge systems. In Canadian service, the sub-Harpoon missile firing and mine-laying capabilities have been removed. The torpedo room or weapons storage compartment houses racks for storing up to 12 Gould Mk 48 Mod 4 heavyweight torpedoes. The remaining six are stored in the tubes. The torpedoes, operating at 40 knots speed, are deployed against targets over a range of 50km. The torpedo's range is 38km at speeds up to 55 knot and it uses active and passive homing to locate the designated target.


The boat is fitted with two submerged signal ejectors (SSE), small vertical discharge tubes which can launch either acoustic or bubble decoys.

The antenna of the passive Condor Systems Sea Search II  (1 to 18 GHz) electronic support measures (ESM) [1] unit is fitted to the CK35 mast.

22,000 acoustic tiles attached to the exterior of the hull muffle any sound emitted by the submarine. The tiles also absorb echoes from the surface and from active sonars.


The Victoria-class submarines are equipped with the CK 35 search periscope and the Barr &Stroud CH 85 attack optronic periscope supplied by Thales Optronics. The CK35 search periscope incorporates a binocular optical system with an optical target ranging system. The CH85 attack periscope incorporates a monocular optical system and an infrared system. It is primarily used for surveillance and attacks on surface targets. Both periscopes have range-estimating devices that allow the Captain to determine the exact distance to other ships or targets.

The submarine's long range sonars are the Thales Underwater Systems Type 2007 flank array sonar and the Thales Underwater Systems Type 2046 towed array sonar, both operating in passive mode and low frequency for long range detection and location. The Canadian Towed Array Sonar (CANTASS) has been integrated into the towed sonar suite.

The Thales Underwater Systems Type 2040 hull mounted sonar installed in the bow is a passive search and intercept sonar operating at medium frequency for optimum medium range performance.

On 06 March 2018, it was announced that HMCS Windsor has become the first of the Victoria-class boats to complete its fitting of the Lockheed Martin AN/BQQ-10 (V)7 sonar processing suite.  It comes in three parts:

The first element comprised the upgrade of the passive ranging sonar fit, replacing the earlier Sonar 2041 MicroPUFFS hardware. The second part covered the bow sonar system upgrade, while the third element was the introduction of a high-frequency active sonar.


The navigation suite includes a Global Positioning System, and a Kelvin Hughes Type 1007 and a Foruno portable navigation radar both operating within the I-band frequency range. Northrop Grumman Sperry Marine was awarded a contract in February 2005 to provide the Mk 49 inertial navigation system, based on ring laser gyro technology.


Kelvin Hughes 1007 Radar  - The Kelvin Hughes CTD or KH-1007 Radar is a high definition surface warning and navigational radar system, and is available in both I and F band versions. Peak power: 25 kW. Displayed range: 300 km. Automatic tracking of up to 50 targets plus manual tracking of 20 targets. The Canadian Navy uses the I-band version.

Kelvin Hughes 1007 Console.  (Courtesy Kelvin-Hughes) 

Type 2007  SONAR

The Type 2007 is a passive, conformal, flank array.


Type 2019 is  a hull mounted intercept array also known as PARIS, or Passive/Active Range and Intercept Sonar.


The type 2040 sonar was developed  from the French Thomson Eledone system DSUV 22 which was originally
designed between 1971 and 1976 and was approved for service in 1976. It comprises both active and passive elements which  include a 64 stave, cylindrical bow array plus flank arrays. The system  can track up to 12 targets simultaneously and is similar in concept to the contemporary AN/BQQ-5 sonar. Type 2040, was developed from DSUV 22 and in 1982, won the British competition for installation in Batch 1 Upholder class submarines.

victoria_2040_passive_attack_s.jpg Pictured here  is the original Eledone passive attack bow array with what appears to be a row of 32 staves and a row of 64 staves. The 2040 sonar has three rows of 64 staves. Click to enlarge. (Photo courtesy Thomson Sintra)
victoria_2040_active_array_s.jpg Eledone active array, typically located in the submarine's fin/sail. Click to enlarge. (Photo courtesy Thomson Sintra)
Type 2041 MicroPUFFS

MicroPUFFS was the sonar system fitted into the upgraded OBERON class submarines. Prior to that, the Oberons used the AN/BQG-501 system. It is a passive ranging sonar system that makes use of three hydrophone arrays equally spaced along the side of the sub's casing. The 2041 is a newer version of the same system produced for the RN who were slow to accept the passive ranging technique developed by the US in late WW II. It came out of a project called PUFFS (Passive Underwater Fire Control Feasibility Study). The original PUFF systems employed vacuum tube technology. Developed in the 1970's for the Australian Navy for use on their Oberons, MicroPUFFS was the first system to be marketed using solid state components like IC's and smaller hydrophone arrays. It was adapted for the Oberons and now fitted on the Victoria class submarines.


Type 2046 is a clip-on array that forms part of the Type 2051 suite.

There is no single photo which permites all the masts to be identified simultaneously. It is hoped that this can be accomplished through a series of photos.
Mast Photo #1.
1 - Snort Exhaust Mast
2 - Snort Induction Mast
3 - Attack Periscope
4 - Search Periscope (With old RN ESM [1] gear - mast looks different in Canadian service) 
5 - Masthead Steaming Light and Grimes Light - that mast is raised manually and it can only be done on the surface. (Canadian Navy photo)

Mast Photo #2.   Item 6  - HF Comm antenna which retracts into the UHF comm mast, item 6A. HF can in fact be sent or received at periscope depth on this mast. Item 6A - UHF comm antenna. There are also some other services in the UHF mast like a GPS receiver.  Item 7 is the slot for the K-H 1007 radar. (Photo by Sandy McClearn)

Closeup of Masthead Steaming Light and Grimes Light.

Mast Photo # 3. Item 8 - KH 1007 radar. Item 9 - Search periscope (with the British ESM antenna on top)
There is definitely rhyme and reason as to what masts are extended from the fin or lowered into the fin depending on where the submarine is.

Because the Masthead Steaming Light can only be raised and lowered manually from the bridge, it is only raised when surface running at night because its a difficult operation to raise and lower it. The navigation radar is usually   deployed and running when on the surface. When entering a foreign port it is a requirement that the Ensign staff with flag be flying.

Generally the attack periscope is used for visual fixing rather than the search periscope for two reasons:

1) The attack periscope is closer to the plot table in the control  room; and
2) The non-RAM parts of the masts are all grease lubricated, and  the Ensign staff is right next to the search periscope.  Having the search periscope up usually gets grease all over the flag.

ALL of the masts are lowered as the submarine is about to come alongside. This is to prevent them from hitting something or something hitting them. Once secure alongside, the induction and exhaust masts will be raised clear of the fin in case the sub needs to generate power. These masts are water-lubricated and will dry out once the sub is alongside, so they are not moved after that.

The sub can transmit and receive with both the comms mast and the search periscope (which also has a VHF antenna ) in the down position. Because of the close proximity of the exhaust and induction masts, it is possible for a strong wind to push exhaust gas towards the induction mast thus fouling the air in the submarine . To minimize this risk,  the sub is pointed into the wind when snorting. When submerged, all masts retract fully into the fin.

If two or more Victoria-class subs are alongside, wooden name boards with brass lettering are attached to the side of the fin to aid in identification.

victoria_mast_starboard_ver2s.jpg Starboard side, cut-away view of the fin, showing the general arrangement. Click on image to enlarge.


July 2003: HMCS Victoria  heads through the Panama Canal to her  home port of Esquimalt B.C.  under the command of Lieutenant-Commander Scott McVicar. That makes it the first time a Canadian submarine has been stationed on the west coast since 1974. Note the acoustic tiles attached to the sub's casing. The man in the centre of the fin is standing in the opening where the original RN ESM mast was located. (DND photo #HS035621D23_rev)
After Chicoutmi's October 2004 fire. The submarine was repaired and comissioned again on 3rd Sept, 2015.(DND photo) 
HMCS Victoria on the west coast. The subs were built with teardrop hulls and the fin was built from fibreglass to keep the weight down. Note the three light gray areas on the casing for the MicoPUFFS hydrophone arrays on the starboard side. There are three more sets on the port side. (DND photo) 
This photo of HMCS Corner Brook was taken during Operation Nanook in August 2007. This sovereignty exercise was held in and around Iqaluit and the Baffin Island Coastal and the Hudson Strait areas. Exercises such as these allow the Canadian Forces to exercise the knowledge and skills necessary to assist civil authorities and to practice inter-departmental communication in the North. Approximately 600 Canadian Forces members, Canadian Coast Guard personnel and RCMP members participated in Operation Nanook. Navy vessels that participated included HMCS  Fredericton (frigate), Summerside (Kingston-class MCDVl) and Corner Brook. (Photo by Master Corporal Blake Rodgers, Crowsnest Vol. 1, No. 2 Fall 2007)
June 2008: HMCS Cornerbrook sits on the synchrolift at HMC Dockyard Halifax. She was undergoing a short work period to get her bottom cleaned. When she left the water it was green from marine growth. (Photo by Sandy McClearn)

In 2001, Zambia issued this K2000 stamp to commemorate  the former Unicorn, now HMCS Windsor. (Via Ship Stamps)

March 16, 2012 -- HMCS Victoria conducted a series of successful weapon system trials, including multiple firings of the exercise version of the MK 48 heavyweight torpedo at Canadian Forces Maritime Experimental and Test Ranges in Nanoose Bay, B.C.

These torpedo firings are part of the technical and operational tests of Victoria's weapons systems and additional weapons system trials are scheduled for the spring of 2012. In the exercise version of the torpedo, the warhead module is replaced with electronics for gathering test data.

(DND Combat Camera Photo #DNPA2012-0313-4.jpg) 


[1] The term ESM (Electronic Warfare-Support Measures) , is no longer used. Now replaced with ES (Electronic Support). In general, it means electronic warfare undertaken under direct control of an operational commander to locate sources of radiated electromagnetic energy for the purpose of immediate threat recognition

Contributors and Credits:

1) Jim Morrice, VE1JKM <jmorrice(at)>
2) Gorka L Martinez Mezo <glmm(at)>
3) Jim Hathaway <hathaway(at)>
4) Ships of Canada's Naval Forces (1910-2001) by Ken Macpherson and Ron Barrie. Vanwell Publishing 2002.
5) Wikipedia
6) Naval-Technology
7) Victoria Class DND
8) Canadian Navy Page
9) Kelvin Hughes 1007
10) 1007 Console
12) USNI Guide to Modern Naval Weapon Systems 1997-1998
13) Jim Hathaway <hathaway(at)>
14) Sandy McClearn <smcclearn(at)>
15) Anonymous Victoria-class submariner.
16) EWCS <ewcs(at)>
17) Johnathon    <hmcsmodels(at)>
18) Ship Stamps

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