Iroquois-class destroyer

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For other uses, see Tribal-class.
HMCS Algonquin (DDG 283)2.jpg
HMCS Algonquin (DDG 283)
Class overview
Name: Iroquois-class destroyer
Builders: Marine Industries Ltd., Sorel
Davie Shipbuilding, Lauzon
Operators:  Royal Canadian Navy
Preceded by: Annapolis-class destroyer
Succeeded by: Single Class Surface Combatant
In commission: 29 July 1972
Completed: 4
Active: Athabaskan
Retired: Huron, Iroquois, Algonquin
General characteristics
Displacement: 5,100 t (5,000 long tons; 5,600 short tons)[1][2][3]
Length: 129.8 m (425.9 ft)
Beam: 15.2 m (49.9 ft)
Draught: 4.7 m (15.4 ft)
Propulsion: COGOG, 2 shaft
2 × Allison 570-KF cruise gas turbines (5.6 MW)
2 × Pratt & Whitney FT4A-2 boost gas turbines (37 MW)
Speed: 29 kn (54 km/h; 33 mph)
Range: 4,500 nmi (8,300 km; 5,200 mi)
Complement: 280
Sensors and
processing systems:
Signaal AN/SPQ 501 DA-08 radar
Signaal LW-08 AN/SPQ 502 radar
SQS-510 hull sonar
SQS-510 VDS sonar
Armament: 32 × VLS, Standard SM-2MR Block IIIA SAMs
1 × 76 mm/62 OTO Melara
6 × 12.75 in tubes firing Mark-46 Mod 5 torpedoes
1 × Phalanx CIWS (Block 1B)
6 × M2 Browning machine guns
Aircraft carried: 2 × CH-124 Sea King helicopters

Iroquois-class destroyers, also known as Tribal class,[4] are a class of four helicopter-carrying, guided missile destroyers of the Royal Canadian Navy. Launched in the 1970s, they were originally fitted out for anti-submarine warfare, but a major upgrade programme in the 1990s overhauled them for area-wide anti-aircraft warfare. HMCS Huron was paid off and later sunk in a live-fire exercise, leaving three ships in the class. The ships are named to honour the First Nations of Canada.

Original design[edit]

Iroquois under way in the North Atlantic in 1982

Designed in the late 1960s, the Iroquois were originally designed as a unique solution for long-range anti-submarine warfare.[5] Their primary weapon for this role is their complement of two Sikorsky CH-124 Sea King helicopters, which are supported on a large flight deck with a two-helicopter hangar that collectively takes up roughly half of the ship's available area.[5] The helicopters can be launched even in high sea states due to their "bear trap" winch system.[6]

The Iroquois represents an original design compromise compared to its contemporaries. Most ships of the same general size and role, like the Royal Navy's Type 22 or US Navy's Oliver Hazard Perry, had much smaller helicopter support areas, typically only the rear ¼ of the ship. These supported a single, small, short-range helicopter, the Westland Lynx or Kaman Seasprite. Such small helicopters were incapable of operating independently of the ship's sensors, and were effectively a system for extending the range of the weapons by carrying them away from the ship before launch.

In contrast, the Iroquois and sister ships' much larger Sea Kings are able to carry a complete sensor suite and operate at much longer ranges independently of the launch ship. This allows a single Iroquois to control a much larger area of the ocean, using both its own sensors and those of its helicopters, combining together to scan larger areas. The downside to this design is that the area taken up by the helicopters would normally be given over to other weapon systems.

For anti-submarine use, the helicopters are backed up by two triple-mount torpedo launchers firing Mk.44 and Mk.46 Mod 5 torpedoes and a Limbo Mark 10 depth charge mortar. For other duties, the ships also mount an Oto Melara 5-in multi-purpose gun and two four-round RIM-7 Sea Sparrow launchers for point anti-aircraft defence.[5] These launchers are located in a protected box on the deck just in front of the bridge area (behind the gun). For firing, the box opens and the battery extends to the sides, requiring some time for them to unlimber.

The ships are powered primarily by two Pratt & Whitney FT12-AH3 of 7,400 shp each, backed up by two more FT4-A2 gas turbines of 50,000 shp each for boost. They were the first large combat ships to be powered entirely by gas turbine. The power from these turbines is used to run the twin shafts through a series of helical gears. One unique feature was the distinctive Y-shaped "Playboy Bunny" funnels, which were designed to exit the exhaust gases to either side of the helicopter deck.

The ships are 425 × 50 × 14 feet (129.8 × 15.2 × 4.4 metres) and 5,000 tonnes displacement. The normal crew complement is 285.

Gulf War modification[edit]

HMCS Athabaskan was deployed on Operation Friction, the Canadian Forces contribution to the international coalition naval task force serving in Operation Desert Shield and Operation Desert Storm (the Gulf War). Athabaskan was the flagship of the Canadian Naval Task Group.

She was hurriedly modified at CFB Halifax in August 1990 prior to the deployment. These modifications included a new mine-avoidance sonar, a Phalanx 20-mm CIWS (mounted over the Limbo mortar well, which was made inoperative) and shoulder-launched Blowpipe and Javelin missiles.

TRUMP modifications[edit]

Iroquois cruising off the coast of Florida in 2002

As a modernization concept, origins of TRUMP date back to early 1980s. By mid-80s the Canadian Federal Government had decided on the necessity of upgrading of Tribal Class c1970s ships and released a RFP foreseeing complete refurbishment. The phrase "update and modernization" essentially meant stripping down of the vessels to the bare hulls and entire re-equipping with modern technologies, mechanical or otherwise. Litton Systems Canada was selected as Prime Contractor and Project Manager.

The entire class underwent major retrofits in the early 1990s as a part of the Tribal Class Update and Modernization Project (TRUMP).[5][7] These refits had the effect of re-purposing the ships for area air defence; following TRUMP the Iroquois-class were referred to as air defence destroyers. Their former anti-submarine role was largely transferred to the Halifax-class frigates.

The main weapon of the new design is the Mk.41 VLS, firing 29 SM-2 Block III long-range anti-aircraft missiles. To provide room for the VLS, the original 5-in L54 gun was replaced with the smaller, but much faster firing, Oto Melara 76 mm gun, relocated from the deck to the bridgework above it. A Phalanx CIWS was also added for self-defence. The torpedo tubes were retained, but the Limbo and Sea Sparrow systems were removed.[5]

The modernization also replaced the original Pratt & Whitney FFT-12 cruise turbines with newer 12,788 shp 570-KF engines from Allison.[5] The speed remained the same, however, as the weight had increased to 5,100 tons full load.[5] The original split funnel was replaced by a simpler single one, as the exhaust proved not to be a problem.

The TRUMP was intended to be a stop-gap measure, since the radar systems on these ships are outdated. Following TRUMP, the Iroquois-class were intended to be decommissioned by 2010. Defence budget cuts during the mid-1990s resulted in Huron being left without a crew. Huron was paid off in 2005, and sunk in a live-fire exercise in 2007 by her sister ship Algonquin.

There was some preliminary work on a replacement design that was informally termed the Province class. This was confined largely to studies of a much-improved phased array radar system being developed for the Royal Netherlands Navy and German Navy known as APAR. Speculation had been that these new ships would have been similar to an enlarged Halifax-class frigate. Such a design would have had a multi-role capability similar to the Arleigh Burke-class destroyer.

The replacement for the Iroquois class is now known to Canadian naval observers as the Single Class Surface Combatant Project and this project has been included in the National Shipbuilding Procurement Strategy, announced in October 2011. The new vessels will replace both the Iroquois-class and the Halifax-class beginning in the late 2010s. Under the NSPS, the federal government has awarded the combat vessel package to Irving Shipbuilding and includes construction of 15 warships.

Retirement of Iroquois and Algonquin[edit]

In August 2013, Algonquin was involved in a collision with HMCS Protecteur during a naval exercise. Algonquin suffered significant damage along her port side hangar. The vessel was laid up following the collision.[8] In May 2014, while visiting Boston, Massachusetts, severe cracks were discovered in the hull of Iroquois requiring her immediate return to Canada and lay up for inspection. The inspection determined the hull was compromised and would require the ship to be laid up indefinitely.[9] On 19 September 2014, the Royal Canadian Navy announced that these two ships were to be decommissioned along with the Protecteur-class, leaving only Athabaskan active.[10]

Ships in class[edit]

Name Pennant Number Builder Laid down Launched Commissioned Fate
Iroquois DDG 280 Marine Industries, Sorel, QC 15 January 1969 28 November 1970 29 July 1972 Awaiting disposal
Huron DDG 281 Davie Shipbuilding, Lauzon, QC 1 June 1969 9 April 1971 16 December 1972 Sunk in live fire exercise off Vancouver Island, 14 May 2007
Athabaskan DDG 282 27 November 1970 30 November 1972 Active in service
Algonquin DDG 283 1 September 1969 23 April 1971 3 November 1972 Awaiting disposal

External links[edit]


  1. ^
  2. ^
  3. ^
  4. ^ HMCS Algonquin Official Site
  5. ^ a b c d e f g "Canadian Navy". Retrieved 24 October 2010. 
  6. ^ "". Retrieved 24 October 2010. 
  7. ^ "Iroquis at". Retrieved 24 October 2010. 
  8. ^ "2 Canadian warships collide en route to Hawaii". CBC News. 31 August 2013. Retrieved 20 September 2014. 
  9. ^ "HMCS Iroquois sidelined indefinitely after rust found in hull". CBC News. 7 May 2014. Retrieved 20 September 2014. 
  10. ^ "Navy sending four Cold War era ships into retirement". CTV News. 19 September 2014. Retrieved 20 September 2014.