Tuesday, 26 April 2011

Royal Navy Subs

Swiftsure Class

The Royal Navy's Swiftsure class of nuclear fleet submarines (SSN) until December 2010, was the oldest of the three classes of fleet submarine in service with the RN.

Six boats were built and commissioned. HMS Swiftsure was decommissioned in 1992 due to damage suffered to her pressure hull during trials. HMS Splendid followed in 2004 after defence cuts caused a reduction in the size of the RN SSN fleet. HMS Spartan was decommissioned in January 2006, with HMS Sovereign following on 12 September 2006. HMS Superb was decommissioned on 26 September 2008. The remaining boat in the class, HMS Sceptre,was decommissioned in December 2010.They are being replaced by the Astute-class submarines.
A few were upgraded to be able to use Tomahawk missiles in addition to their original armaments of torpedoes, mines and anti-ship missiles.


The Dreadnought, Valiant and Improved-Valiant classes all had a "whale-shaped hull", of "near-perfect streamlining giving maximum underwater efficiency". The hulls were of British design, "based on the pioneering work of the US Navy in Skipjack and Albacore."The hull of the Swiftsure was a different shape and maintained its diameter for a much greater length than previous classes. Compared with the Valiants the Swiftsures were 13 feet "shorter with a fuller form, with the fore-planes set further forward, with one less torpedo tube and with a deeper diving depth."

A second major change was in propulsion. Rather than the seven/nine-bladed propeller used by the previous classes, all but the first of the Swiftsure-class submarines used a shrouded pump-jet propulsor. The prototype propulsor had powered the Churchill. It is not clear why the Swiftsure was the only one of the class not fitted with a propulsor. The propulsor was perhaps as much as 50% more efficient than a propeller, producing the same speed at lower revolutions, thus reducing the noise signature. In addition all pipework connections to equipment on the main machinery raft had expansion/flexible coupling connections, which also reduced noise. The US Navy secured a licence to copy the main shaft flexible coupling arrangement in US-built submarines.

 Builder: Vickers Shipbuilding and Engineering Ltd
 Displacement: 4400 tons standard; 4900 tons submerged
 Length: 83 m
 Beam: 9.8 m
 Draught: 8.5 m
 Complement: 13 officers, 103 ratings
 Armament: 5 tubes capable of firing: Spearfish torpedoes
 Tigerfish torpedoes
 RN Sub Harpoon missiles
 Tomahawk missiles (selected submarines only)

 Sensors: sonar (bow, flank, active intercept, and towed array sonar)
 periscopes (attack and search)
 collision avoidance radar


Trafalgar Class

The Trafalgar class is a refinement of the Swiftsure class and designed six years later than its predecessor. The design included a new reactor core and Type 2020 sonar. Internal layout is almost identical to the Swiftsure, and it is only 2.5 metres longer. The Trafalgar class have strengthened fins and retractable hydroplanes, allowing them to surface through thick ice. The hull is also covered in anechoic tiles which are designed to absorb sound rather than reflect it, making the boats more difficult to detect with active sonar.

The first Trafalgar-class submarine was ordered on 7 April 1977 and completed in 1983. Turbulent was ordered on 28 July 1978; Tireless on 5 July 1979; Torbay on 26 June 1981; Trenchant on 22 March 1983; Talent on 10 September 1984; and finally Triumph on 3 July 1986.

In 1993 Triumph sailed to Australia, covering a distance of 41,000 miles whilst submerged and without any forward support. This marked the longest solo deployment by any British nuclear submarine.

The Trafalgar class was to be replaced by the Future Attack Submarine, however this project was effectively cancelled in 2001 and replaced by the Maritime Underwater Future Capability. The Astute class will eventually replace the Trafalgar class as well as the now-retired Swiftsure. As of 2008 it is planned that the last Trafalgar-class submarines will remain in service until 2022. The name Trafalgar refers to the Battle of Trafalgar fought between the Royal Navy and the combined fleets of France and Spain.

                                                             More Details available here

                          Click Here >> Multimedia Centre Interactive Tour of Trafalgar class


Vanguard Class

Beneath the oceans of the world, somewhere, silently and undetected, lies a British submarine.
It is carrying 16 nuclear tipped ballistic missiles and up to 160 men.
Its role is very straightforward: to maintain a constant readiness to unleash nuclear retaliation if the order ever comes.
The aim: to deter any pre-emptive attack on the United Kingdom.
Trident subs are 30 yards longer than a football pitch
The Royal Navy has four of these Vanguard class boats and one always has to be cruising the depths to provide a "continuous at-sea deterrent", the argument being that a weapon based on land would be too vulnerable to a surprise attack.
The vessels themselves are huge. 30 yards longer than a football pitch, or 18 double-decker busses long.
But if the technology of both submarine and missiles are remarkable and very different from other branches of armed forces, then so is the crew.
They see themselves as the Navy's elite, the Dolphins on their uniform as prized as a paratrooper's wings.
As they rehearse their launch drill, the uniqueness of their role in the British armed forces becomes apparent as the guardians of the nation's nuclear arsenal.

Virtually incommunicado for three months at a time, each sailor receives only two 60-word "family grams" a week to which he cannot reply.
600 meals a day
The officers and crew operate in a non-stop cycle of six hours 'on' and six 'off'.

In the downtime, the sailors grab some sleep, study for educational qualifications or take turns in the predictably tiny gym.
In such an environment, it is hardly surprising, as the commanding officer concedes, that the sub's chef is probably "the second most important person" aboard.
His role is to prepare four meals a day for the officers and ratings. With over 600 covers in a galley substantially smaller than your average domestic kitchen. And the fresh food runs out after a month.
The problems of storing food are not the only aspects of life on board which seem strangely reminiscent of Admiral Lord Nelson's HMS Victory, rather than what you might expect on a 21st century modern Vanguard-class submarine.
The accommodation, wrapped around each of the missile tubes is beyond cramped.
The bunks are stacked four high, with 12 men in each tiny compartment.

No wonder that officers told us that tolerance was the single characteristic that submariners share.
Despite her sophisticated internal guidance system, nuclear-powered propulsion, stealthy design and an armament that a sailor at Trafalgar could never have envisaged, this man o'war, like Nelson's flagship, relies on the skill and resilience of a unique breed of seafarer to keep it patrolling the depths, somewhere in the world's vast oceans.

Courtesy of http://news.bbc.co.uk/1/hi/uk_politics/8408383.stm


Astute Class

HMS Astute,is quieter than any of her predecessors, meaning she has the ability to operate covertly and remain undetected in almost all circumstances despite being fifty per cent bigger than any attack submarine in the Royal Navy's current fleet.
The latest nuclear-powered technology means she will never need to be refuelled and can circumnavigate the world submerged, manufacturing the crew's oxygen from seawater as she goes.

The submarine has the capacity to carry a mix of up to 38 Spearfish heavyweight torpedoes and Tomahawk land-attack cruise missiles, and can target enemy submarines, surface ships and land targets with pinpoint accuracy, while her world-beating sonar system has a range of 3,000 nautical miles (5,500km).

Astute is the largest, most advanced and most formidable vessel of its kind
ever operated by the Royal Navy.  She incorporates the latest stealth technology
combined with a world beating sonar system and equipped with Spearfish torpedoes
and state of the art Tomahawk land attack missiles to make her a supremely
effective naval asset. 

The Astute class will progressively replace the Swiftsure and Trafalgar
classes from 2011. 
Displacing 7,400 tonnes and measuring 97 metres from bow to propulsor, Astute
is significantly larger than the Swiftsure and Trafalgar class submarines that
she will replace but requires fewer crew to operate her due to the advanced
technology and automated systems on board.

When she becomes operational on completion of Sea Trials she will be capable
of circumnavigate the globe without surfacing and with the advance of nuclear
technology she will never need refuelling. 
Astute is designed to fulfil a range of key strategic and tactical roles
including anti-ship and anti-submarine operations, surveillance and intelligence
gathering and support for land forces.

"Astute will be a quantum leap in capability from the Trafalgar class and 
all involved can be justifiably proud”.

DE&S Director Submarines, Rear Admiral Simon Lister.

The Future Role of The Submarine

The role of the submarine in the Royal Navy is changing as Rear Admiral
Stevens, Flag Officer Submarines (FOSM), explained recently.

"The services SSN community has made a decisive break away from its Cold War
emphasis on anti-submarine warfare (ASW)to embrace the Navy's new operational
concept of Maritime Contributions to Joint Operations. The challenge now is to
realise the full potential of the SSN across its wider range of taskings.
Operations in direct support of surface forces are becoming a far more important
part of the submarine service's operations.
"The introduction of new secure communications links will provide the
improved connectivity essential for operating in conjunction with other task
force units. Advances in the technological areas of digitisation,
miniaturisation and processing of information gathered, will enable the
submarine to become an increasingly valuable asset in covert intelligence
gathering operations."

About HMS Astute
She is 97 metres from bow to stern.
She has a beam of 11.2 metres.
She displaces 7,400 tonnes of seawater.
Her cabling and pipework would stretch from Glasgow to Dundee.
She is the first Royal Navy submarine not to have a traditional periscope, instead using electro-optics to capture a 360-degree image of the surface for subsequent analysis by the commanding officer.
 Astute is the first submarine to have an individual bunk for each crew member.
She manufactures her own oxygen from seawater as well as her own drinking water.
 She could theoretically remain submerged for her 25-year life, if it were not for the need to restock the crew's food supplies.
 She is faster under the water than she is on the surface - capable of speeds in excess of 20 knots (37km/h), although her top speed is classified.


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