Tuesday, 23 October 2012

Carriers; Fully Loaded - Viraat (Hermes)

Viraat (Hermes) India (United Kingdom)
Viraat at Sea
Class/Brief History of design

Hermes started out life as part a class of light fleet carriers, the Centaur class, the were a continuation of the World War II crash building program; which itself had been based on Admiral Henderson’s Unicorn.
Centaur Class
They were initially planned as a class of eight vessels; an intermediate in size between the war built Colossus and Majestic class light carriers and the planned Audacious class fleet carriers. Unfortunately World War II was no different from any other period of long hostility, when it ended - work was suspended; with the last four of class being cancelled outright, whilst the first four vessels were left to be completed in time. Taking the better part of 2 decades to finnish constrcution. Although to be fair this was not just due to funding issues, the post war period was a period of such change and development in naval aviation, let alone aviation as whole that many new technologies had to be inserted into their design and modifications made. Therefore, it was unsurprising that upon their completion the individual vessels differed greatly from each other; expressing each of the various thoughts on naval aviation which were prevalent at the time in their own way.

HMS Centaur was the first to be completed, hence class was named for her, but she was commissioned in 1954. Centaur featured an axial flight deck (aircraft land and take off on the same axis, Figure 26) and was thus unsuitable for operating the jets which at that time were rapidly supplanting the traditional piston engine aircraft in the Fleet Air Arm. So upon commissioning Centaur was sent to Portsmouth Dockyard for six months, emerging, after a not insubstantial reconstruction with an angled (or co-axial/two direction) flight deck. Centaur’s service life was short though; she was decommissioned in 1964 and scrapped in 1965...principally because it was uneconomical to keep on modifying her in comparision to other available vessels.

Figure 26. HMS Centaur in her original axial design 
The next two of the class to be launch; HMS Albion and HMS Bulwark, were forever to seem to be operated as the two halves of one whole. They were both key assets in the amphibious assault on the Suez Canal (Operation Musketeer), during the Suez Crisis; serving as the first ever Landing Platform Helicopters (LPH). It was the experience of this operation and other exercises which had such great impact on their latter conversion from fleet  carriers to commando carriers. The difference of the role being that instead of carrying fast jets, they carried helicopters and marines, like the Royal Navy’s current HMS Ocean. They were fully employed during the 1960s, with each taking turns deploying 'east of Suez' to the Far East Fleet – until this role was scrapped due to the belief, still held according to reports by some in the British Ministry of Defence, that no presence was required east of the Suez canal. The whole was made incomplete when Albion was decommissioned in 1973; Bulwark stayed in service for three more years as a commando carrier, and was even re-commissioned in 1979 as ASW carrier whilst retaining some of her previous capability; but due accidents she was decommissioned in 1980.

HMS Hermes

The final vessel in the four Centaurs, was originally names HMS Elephant, but in an unusual volte-face the Admiralty changes its mind; and she was called Hermes (the name had originally been selected for the last of the class anyway). Hermes was/is special, not just because she had a longer service life than any of her sisters in British hands; she has in fact had the longest service history of any British Aircraft Carrier; she was completed in 1959 and this piece is written in 2009, thus it 50 years and this author knows at this moment still counting.
Initially HMS Hermes was employed as a light attack carrier by the Royal Navy, but it was converted to the commando carrier role after its sister Albion was retired, in the 1970s. This change was short lived, and Hermes was returned to its original role of operating fixed wing aircraft by the beginning of the following decade. To facilitate this role, Hermes was fitted with a ski-jump; enabling it to operate the then new Sea Harrier aircraft. It was in this configuration that HMS Hermes saw action and active service in the 1982 Falklands War; acting as both the flagship and principle strike of the aircraft carrier task force.

Summation of History
Hermes survived the longest as a conventional carrier and survived the longest in service of the Royal Navy, even operating the Blackburn Buccaneer. However, there was no chance of Hermes being able to operate the Phantom FG.1 due to its modifications.

Overall though, the Centaur’s were unusual as a class of naval vessel, in that they proved most successful in roles that they were not originally designed for; for example Albion and Bulwark's helicopter assault capability which was world leading... and the loss of which in 1980 was just as important a factor in the Argentinian Junta's decision to launch the Falklands war as the retirement of the Ark Royal in 1978 and the announced retirement of the Falklands patrol ship, Endurance. It left a horrendous gap in the ability of British government to project power globally or even to conduct expeditionary operations - it was a gap which was only partially filled when HMS Ocean was commissioned in 1998. It's also true that the loss of the last ‘semi-proper’ carrier, HMS Hermes, has had truly damaging effect long term on the Royal Navy and the role it has played in recent history, something which the new Queen Elizabeth’s with their greater potential in comparision to the Invincibles, might go some way to correcting.

 Outline of Design      

Figure 29. INS VIRAAT as it was commissioned in the Indian Navy
It was in 1985 therefore that the Indian Navy acquired the by then already vintage British Centaur class aircraft carrier HMS Hermes[2]. The purchase only happened after the Indian Government, agreed the costs of purchase and the extent of its refit; an extensive development. Two years later, on the 12 May 1987 the former HMS Hermes was commissioned as the INS Viraat into the Indian Navy.  The vessel was fitted out with a compliment of Sea Harrier VSTOL jump jets and Sea Kings;  an air group composition much the same as HMS Hermes had carried in the Falklands. Upon completion of the refit, there was also slight increase in the full load displacement of INS Viraat over HMS Hermes, to 28,700 tons and but the vessel retained her steam turbines with 76,000 shaft horsepower.
During the period 1999-2001 INS Viraat underwent major repairs, refitting and other necessary improvements with the aim of allowing the ship have 10 years more service. This work was mostly carried out in the dry dock at Kochi. The most important of all the upgrades was the installation of the Barak missile defence system, a new radar suite, communications system, and strengthened elevators. Unfortunately though the extensive work did not allow for smooth sailing, and the Viraat had be tugged back dry dock a little over 18 months after this was finished. Viraat had to be tugged back to dry dock for a rehab barely two years after an extensive life-extension, which was intended to give it a 10-year lease of life. The Viraat was unavailable to the Navy for two years during this period.

Weapon Systems/Sensors

Figure 31. Barak Missile VLS on the INS Viraat
With a name taken from the Hebrew word meaning ‘Lightning’ the Barak missile has a lot to live up to. Its performance does more than live up though with a speed of Mach 1.7. Whilst it is just a point defence missile, it is just a point defence missile in same sense as the Seawolf is just a point defence missile. This is a weapon system which warship commanders can afford to put a lot of faith in, for defence against aircraft, missiles or UAVs. The Barak SAM is designed to either replace or work in tandem with gun-based CIWS platforms (like the Russian Kashtan). It is very successful in these roles, primarily some analysts argue because unlike many of the other missiles types within its class, like the MBDA's Mistral missile or Saab's RBS-70 – which have shorter range (the Barak’s is 10km); the Barak is designed for vertical launch. Thus it has the virtues of both greater range, and improved performance that places it close to or beyond the flat-trajectory American RIM-116 Rolling Airframe Missile. It is directed and controlled with information provided by the EL/M-2221 STGR radar.
Barak Missile on Display
The Barak system is further reinforced in its role of providing the last line of defence for the Viraat by two 40mm Bofors guns; weapons which also provide defence against any small boats which penetrate the escort perimeter. The fire control for the Bofors was installed in the INS Viraat’s 1996, a pair of Plessey Type 904 radars at I/J-band frequency. One of these radars however was replaced, when the Barak system was installed, by its EL/M-2221 STGR radar.

Aircraft Carried

When the Viraat was sold to the Indian government it was sold along with a quantity of sea harriers; aircraft which  have  already been described[3]; the current air group includes 12 or 18 of the aforementioned Sea Harrier V/STOL fighters compliment by seven or a eight Sea King or Kamov 'Hormone' ASW helicopters or AEW. In emergencies, the Viraat can operate up to 30 Harriers as she did in the 1982 Falklands War.

History of Service      

Figure 32. Viraat + Nimitz at sea
The Indian Navy evaluated vessels from several countries; particularly the Garibaldi class of Italian ships, Hermes was decided upon. The vessel, as has been stated, underwent a very extensive refit in the Devonport Dockyard to allow for a minimum of another decades operation. Even with this extensive refit, accidents happen, and in September 1993, the engine room of Viraat flooded; temporarily putting the vessel out of service for 15 months. However, the extend time in drydock was taken advantage off by the Indian Navy to install a new search radar; it was back in service with this radar in 1995.
During the next few years Viraat became a regular sight operating as parts of Indian navy task groups in the Indian ocean, the wear and tear of this service is testified to by the fact that between July 1999 and April 2001, INS Viraat completed another life-extension refit. This refit was required to extend here life expectancy to at least 2010. The largest changes were in propulsion and sensory systems; but it also included a new communications suite, upgraded weapons, a further new long range surveillance radar and fire curtains.
Although it only officially returned to service in July 2001, and was still in refit in April, INS Viraat was a key part (for the Indian navy) in the International Fleet Review in Mumbai in February 2001. This event was marked by Wing commander Ashoka Padmanabhan’s flight pass in a Tigermoth-B970. However, perhaps due to distraction of this pomp, the vessel had to be towed back to dry dock for another refit in mid-2003, with propulsion problems. In usual fashion the Indian Navy took advantage of Viraat’s enforced dock time to fit the Barak SAM, Viraat successfully returned to service only in November 2004.
The Viraat’s return to form was typified by her performance during the joint Indo-US Exercise Malabar 2005; in which she performed according to all observers in a most proficient manor. This was put down to the qualities of her crew, although many also said that the quality of the ship and its equipment outfit had a role to play in this. Malabar was a ‘full war’ exercise, so Viraat was fitted out with her wartime ‘official’ compliment of aircraft, and marines (she is still fitted out with LCVPs for operating in the Commando Carrier role).  These capabilities and her size means that INS Viraat is, unlike the case with most dual missioned naval vessels, very well suited for carrying out her two missions. The primary is supporting amphibious operations, with both strike aircraft and helicopters; the other is the conducting ASW operations and fleet defence. As Flagship though, its primary, overriding role in Indian policy is that of projecting Indian power and presence anywhere it is required in the South Asia region.
After four year service, Viraat moved into Cochin Shipyard's dry dock late in 2008 to undergo the mandatory maintenance refit and repair and it will stayed there until the end of June 2009. After the end of this refit/repair period there have been very official rumours that the Viraat might still be in service in 2015; meaning including the period of service as Hermes with the British Royal Navy, the vessel has served 55 years, well over the 25 years service originally planned. All in all Viraat’s continued service suggest that those who felt she was no longer viable for the Royal Navy in 1985 were very, very wrong.  

Figure 33 Viraat at sea

[2] There are reports that this annoyed the Russians as they had been hoping to sell the Indians a vessel... although considering the time that has been taken with the Vikramaditya class transfer, perhaps it was a sensible decision.
[3] (p24 -25)
I found this on an old pen drive and decided to put it up... I did run a spell check, both in word and on this... anyway am thinking of restarting the series, in which case the next post will be on the Gerald R Ford class carrier.

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