Iroquois-class destroyers (also known as the DDH 280 class, DDG 280 class or ambiguously as the Tribal classMacpherson and Barrie, p. 262) were a class of four helicopter-carrying, guided missile destroyers of the Royal Canadian Navy. The ships were named to honour the First Nations of Canada.
The Iroquois class are notable as the first all-gas turbine powered ships of this type in the west. Launched in the 1970s, they were originally fitted out for anti-submarine warfare, using two CH-124 Sea King helicopters and other weapons, while their Mk III RIM-7 Sea Sparrow anti-air missiles were sufficient only for point defense. A major upgrade programme in the 1990s overhauled them for area-wide anti-aircraft warfare with the installation of a vertical launch system for Standard SM-2MR Block IIIA missiles.
Due to their extended service lives, the Iroquois-class destroyers were used in a variety of operational roles. They served as flagships for NATO's maritime force, deployed as part of United Nations and NATO forces in the Adriatic, Arabian and Caribbean seas and Atlantic and Indian oceans. The destroyers also performed coastal security patrols and search and rescue missions nearer to Canada.
One was sunk in a live-fire exercise in 2007, two more were decommissioned in 2015 and the last in 2017.
Background With the disbandment of Banshee fighter aircraft squadrons and the retirement of the Second World War-vintage destroyers in the early 1960s, the Royal Canadian Navy no longer had air cover nor fire support capabilities. The Royal Canadian Navy sought to fulfill both these capabilities with the General Purpose Frigate (GPF) design.Milner, p. 231 However, due to rising costs and an ambitious Defence Minister, Paul Hellyer, who had his own ideas as to where the Royal Canadian Navy should spend its money, the GPF program was cancelled on 24 October 1963.Milner, pp. 237–38
After the cancellation of the GPF program, the Royal Canadian Navy continued to design a vessel able to fulfill the lost capabilities. Several designs were drawn up, one of which was an improved version of the GPF with a better missile system, anti-submarine warfare (ASW) rocket and large calibre gun. In September 1964, Hellyer ordered an ASW design. The Royal Canadian Navy submitted a design that matched what Hellyer required that used steam turbines instead of gas and had a planned cost of $35 million, similar to the most recent ships constructed based on the .Milner, p. 248
On 22 December 1964, Hellyer announced the planned construction of four new helicopter-carrying destroyer escorts as part of a larger package of procurement for the navy.Milner, p. 247 Though the Royal Canadian Navy had submitted an ASW design, it took a further four years to settle on a final one. This was due in large part to the need for the accommodation of large helicopters, variable depth sonar and the requirement to spread the industrial benefits around the country.Milner, p. 258 In the end the design improved over the GPF in several ways. Instead of the twin semi-automatic gun mount, the new design had a single fully automatic 5-inch gun. The GPF was intended to be armed with the RIM-24 Tartar missile system. The new design ended up with the RIM-7 Sea Sparrow missile system which was capable of taking on both missiles and aircraft.Milner, p. 259 Personnel for the new class were to come from the discarded aircraft carrier which had been taken out of service after the government reduced force levels.Milner, p. 265Gimblett, p. 165 In December 1967, four new helicopter-carrying destroyers were announced as part of the five-year equipment program.German, p. 285
In 1968, contracts were awarded to Davie Shipbuilding at Lauzon, Quebec and Marine Industries at Sorel, Quebec. However, the final drawings were not finished when all four ships were laid down in 1969.Milner, p. 266 The entire program ended up costing $252 million. In 1970, the program was almost cancelled despite the fact that the ships were in production. This was due to the poor management of the program costs by the departments that governed the project. This eventually led to a significant reshuffling of senior positions at National Defence Headquarters. Commissioned in 1972–73, the ships perpetuated the names of Second World War-era destroyers, which led to the new class being referred to as the Tribal class.Gimblett, p. 156
With the arrival of the Iroquois-class destroyers, a special service centre was created ashore with the same computer system, which was far more advanced at the time compared to anything else in the navy.German, p. 304
Description
The Iroquois class were ordered in 1968 as a revised design of the GPF. Designed with enclosed citadel, bridge and machinery spaces,Moore, p. 78 the sources disagree about the general description of the Iroquois class. Gardiner and Chumbley state that as designed the ships had a displacement of fully loaded. The destroyers were long overall and long at the waterline with a beam of and a draught of . They had a complement of 258 and 30 aircrew attached to the ship's company.Gardiner, Chumbley and Budzbon, p. 47
Macpherson and Barrie claim that the class displaced , was long overall with a beam of and a draught of . They state the vessels had a maximum speed of and had a complement of 244.
The Iroquois class used a COGOG system that was powered by two Pratt & Whitney FT4A2 gas turbines creating , and for cruising, two Pratt & Whitney FT12AH3 gas turbines creating which drove two five-bladed controllable pitch propellers through reduction gearing. This gave the destroyers a maximum speed of and a range of at .
The Iroquois class was also designed with the ability to carry two Sikorsky CH-124 Sea King helicopters to be used primarily for ASW. These two helicopters enhanced their ASW capability and the Iroquois class were considered excellent ASW ships due to it.Milner, pp. 279–80 The Iroquois class had a landing platform with a double hauldown and Beartrap hauldown device. The platform was large enough for a Mil Mi-14 helicopter, as it was proved during exercises in 1999 in the Baltic Sea. American and British destroyers and frigates at the time each carried a single small helicopter which was 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-class destroyers' much larger Sea Kings were able to carry a complete sensor suite and operate at much longer ranges independently of the launch ship. This allowed a single Iroquois to control a much larger area of the ocean, using both its own sensors and those of its helicopters, combining to scan larger areas.
Armament The Iroquois class was originally equipped with one OTO Melara /54 calibre gun that was capable of firing 40 rounds per minute.
For anti-air defense the ship was originally armed with one Mk III RIM-7 Sea Sparrow missile system. The Iroquois class had two Sea Sparrow launchers installed, each with four missiles which allowed the ship to launch eight missiles at a time for point defense.Milner, p. 275 The ships carried a total of 32 missiles. The launchers were located at the forward end of the superstructure and retracted into the deckhouse. The missile system was guided by the Hollandse Signaal Mk 22 Weapon Control System. The system was criticised for the time it took to deploy from the housing, which took several minutes in order to warm-up the guidance system, as well as the reload time, which could be up to almost ten minutes. Another reason for criticism was that the fire control system was Dutch, and the mix of the Dutch fire control and the US missile system rarely worked as intended. The missiles were also ineffective against sea-skimming anti-ship missiles, such as the Exocet.
The Iroquois class was also equipped with one Mk 10 Limbo anti-submarine mortar for ASW purposes along with two triple Mk 32 torpedo tubes in trainable mounts. The Mk 32 tubes were used to fire Mark 46 torpedoes.
Systems and sensors The class was equipped with the Hollandse Signaal Mk 22 Weapon Control System for its missiles, and a tactical air navigation system (TACAN). The CCS 280 by Litton, which was a compressed version of the Automatic Data Link Plotting System (ADLIPS) electronic tactical system, was also installed aboard the class. Iroquois-class destroyers were equipped with an LW-03 long range warning radar antenna and SPS-501 long range warning radar. They were also equipped with SPQ-2D low level air search, surface search and navigation and M22 fire control radars. The destroyers had SQS-501 bottom target classification sonar and a hull-mounted SQS-505 sonar inside a dome. They also had the SQS-505 towed variable depth sonar.
TRUMP refit
In the 1980s, with the planned arrival of the Canadian Patrol Frigate Project, the Canadian Forces intended to convert the Iroquois class from primarily ASW ships to anti-air warfare (AAW) vessels as a core element of the modernization of the fleet.Milner, p. 287 Named the Tribal Refit and Update Modernization Program (TRUMP), the design contract was awarded to Litton Systems Canada Ltd. and required a total reconstruction of the superstructure, new gas turbines, weaponry and electronics. In addition to their conversion to AAW vessels, the Canadian Forces sought to improve their command, control and communications capabilities in order to make them task group leaders. With this refit, the ships were also reclassified from helicopter destroyers (DDH) to guided-missile destroyers (DDG).
The shipyard contracts were handed out to Quebec shipyards by the Cabinet as a way to placate the Quebec caucus following the decision to award the Canadian Patrol Frigate Project to a New Brunswick shipyard.Milner, p. 289 The total cost of the program was $1.5 billion.
During the Gulf War, before Athabaskan had been able to undergo her TRUMP refit, she was given a Mk 15 Phalanx close-in weapons system (CIWS) on her quarterdeck as part of the upgrades given to ships deploying to the Persian Gulf.
Alterations to initial design The displacement of the ships increased to at deep load after all the changes. The propulsion was overhauled also, with two GM Allison 570-KF cruising turbines being installed in place of the Pratt & Whitney FT12AH3 models which created . Replacing the main FT4A-2 gas turbines with a pair of LM2500-30 was called for, but not done due to cost. The ship's funnels were also reconstructed to reduce their infrared signature, the original uptakes and outboard angled funnels being replaced with singular square model encased in a forced-air cooling system.
As part of the TRUMP refit, the entire armament was overhauled. The OTO Melara 5-inch gun was removed and replaced by a 29-cell Mk 41 vertical launch system (VLS) for the SM-2 Block 2 surface-to-air missile. The Mk 41 VLS system was placed in the reconstructed forecastle deck. In 'B' position an OTO Melara Super Rapid gun was installed in the space vacated by the removal of the Sea Sparrow launchers. A Mk 15 Phalanx CIWS was placed abaft the remodeled funnel. The ships also received new sensors, seeing their radar, sonar, and electronic warfare suites wholly replaced.
Ships in class