Iroquois class destroyer
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| Image:Naval Jack of Canada.svgIroquois-class destroyer | |
|---|---|
| Image:HMCS Algonquin (DDH 283)3.jpg | |
| Class Overview | |
| Class Type | Guided missile destroyer (DDH) |
| Class Name | Iroquois |
| Launched | 1972–1973 |
| Preceded By | Annapolis-class |
| Succeded By | N/A, latest destroyer class authorized |
| Ships of the Class: | Iroquois (DDH 280) Huron (DDH 281) Athabaskan (DDH 282) Algonquin (DDH 283) |
Iroquois-class destroyers are a class of four helicopter-carrying destroyers of the Canadian Navy. Launched in the 1970s, the Iroquois's were the first all gas turbine powered military ships, using two turbines for cruise power, and another two fast starting "boost" turbines for speeds of up to 29 knots (such an arrangement is known as COGOG). The design was a major inspiration for the US's later Spruance-class ships. They were originally fitted out for anti-submarine warfare, but a major upgrade program in the 1990s overhauled them for area-wide anti-aircraft.
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Original design
When they entered service the ships were primarily intended for long-range anti-submarine warfare. Their primary weapon for this role was their complement of two CH-124 Sea King helicopters, which could be launched in even high sea states due to their "bear trap" winch system. The ship included a hangar that provided an enclosed working space for both helicopters at the same time. The helicopters were backed up by two triple-mount torpedo launchers firing Mk.44 and Mk.46 Mod 5 torpedoes and a Limbo depth charge mortar.
For other duties the ships also mounted a 5" OTO Melara multi-purpose gun and two four-round Sea Sparrow launchers for point anti-aircraft defense. The missile batteries were located on the interior of the ship on either side of the superstructure, requiring some time for them to unlimber for firing.
The ships were powered primarily by two Pratt & Whitney FT4-A2's gas turbines of 50,000 shp each, backed up by two more FT12-AH3 of 7,400 shp each for boost. The power from these turbines was 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 gasses to either side of the helicopter deck.
The ships were 425 x 50 x 14 feet (128.92 x 15.24 x 4.42 meters) and 4,700 tons displacement. The normal crew complement was 285.
TRUMP modifications
The entire class underwent major retrofits as a part of the Tribal Class Update and Modernization Program, or TRUMP, in the 1990s. These refits had the effect of re-purposing the ships for area air defence, and the ships now referred to as air defence destroyers. Their former anti-submarine role has since been taken over, to a large degree at least, by the newer 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. In order to provide room for the VLS, the original 5" gun was replaced with the smaller but much faster firing Otobreda 76 mm gun. A Phalanx CIWS was also added for self-defense. The torpedo tubes were retained, but the Sea Sparrow system was removed.
The modernization also replaced the original cruise turbines with newer 12,788 shp 570-KF engines from Allison. The speed remained the same, however, as the weight had increased to 5,100 tons full load. The original split funnel was replaced by a simpler single one, as the exhaust proved not to be a problem.
The TRUMP ships were intended to be a stop-gap measure only, their radar systems in particular being rather outdated. Currently the Iroquois are intended to serve until 2010, after some forty years of service.
There was some work on a replacement design, known to Navy-watchers as the Province-class destroyers, but this was confined largely to studies of a much-improved phased array radar system being developed for the Dutch and Germans, known as APAR. Current speculation is that the ships themselves would be similar to a "stretched" Halifax-class. Such a design would have similar capability to the Iroquois but with only one helicopter, and still be no match for the US's Arleigh Burke-class destroyer or the British Type 45 destroyer. There appear to be no current plans to actually build such a class, however.
General characteristics
- Length: 129 m
- Beam: 15 m
- Draft: 4.4 m
- Displacement: 5100 tons full load
- Power plant:
- two shaft COGOG system
- two Allison 570-KF cruise gas turbines, 5.6 MW at the shaft total
- two Pratt & Whitney FT4-A2 boost gas turbines, 37 MW at the shaft
- Speed: 29+ knots (54 km/h)
- Aircraft: 2 CH-124 Sea King helicopters
- Complement: 285
- Armament:
- one 29-cell VLS, Standard SM-2MR Block IIIA surface-to-air missiles
- one 76 mm/62 OTO Melara (Super Rapid) dual-purpose gun system
- one Phalanx 20 mm Close-In Weapons Systems
- two triple Mark-46 12.75 in (324 mm) torpedo tubes firing Mark-46 Mod 5 torpedoes
- 0.5 in (12.7 mm) machine guns
- Radar: AN/SPQ 501 (Signaal DA-08), AN/SPQ 502 (Signaal LW-08)
- Sonar: SQS-510 hull, SQS-510 VDS
Ships in class
Template:Ship box HMCS Iroquois (DDH 280) Template:Ship box HMCS Huron (DDH 281) Template:Ship box HMCS Athabaskan (DDH 282) Template:Ship box HMCS Algonquin (DDH 283)