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Royal Navy: SUBMARINE SERVICE
Here is a link to a VIDEO on the Royal Navy's website http://www.royal-navy.mod.uk/ (best using broadband). Unseen and unheard, the Royal Navy’s submarine force can strike against ships and submarines, as well as supporting land operations against targets up to 1000 miles away with pinpoint accuracy. The Submarine Service also provides the UK's strategic nuclear deterrent.
Great Britain operates basically two types of submarine : attack submarines and strategic submarines.
Glossary
Strategic - designed or trained to strike
an enemy at the sources of his military, economic, or political power. Conventional (SS) submarines, powered by diesel, are still used in various parts of the world, but are limited in how long and how far they can go. The modern nuclear submarine uses a PWR and is a stealthy, capable vessel capable of long-range and long-duration patrols. Life in a Sub
Challenging submarine living conditions build strong fellowship among crewmates, who are highly motivated and adaptable. It is a busy life of watches, work and exercise drills. There are four meal a day, including one at midnight. The food is good and there is plenty of it. Submariners eat ordinary everyday food, though fresh fruit and vegetables and dairy products don't last for long missions. There are many forms of recreational activity, such as TV, watching newly released films, games, quizzes - even the occasional variety show. The submarine has a well-stocked library for casual reading or studying for a degree. And there are exercise machines on board. (The messes in Vanguard are comfortable and well appointed, fulfilling the roles of dining room, lecture hall, lounge, games area and chapel.)
One of the highlights of the week is the 'familygram', when members of the crew receive 40 word messages from family and friends back home. When in port, submarines can receive emails and post. Each vessel is allocated two full crews, known as Port and Starboard. In SSNs, two men who are on different shifts (“watches”) often share the same bunk. The Commanding Officer has his own cabin. In SSBNs, which are much larger, each man has his own bunk. All submarines carry qualified medical ratings that can cope with most medical problems. During most storms, submerged submarines remain steady. Hurricanes and cyclones, however, can cause a submarine to roll by up to 10 degrees. Any waste that cannot be disposed of ashore is properly disposed of at sea. HOW A SUBMARINE WORKSA submarine's "tear drop" shape allows it to slice cleanly through the ocean. However, when part of the submarine is out of the water, its forward motion creates turbulence, which causes it to roll and yaw and slows it down by about 12%. Nuclear submarines are able to produce their own indefinite supply of air, water and power. So the only limit to the boat's underwater staying power is the amount of food, the need for any urgent repair and the psychological limits of the crew. A submarine obtains air in two ways:
The boat consists of a Pressure Hull (shaped like an oxygen bottle, domed at both ends), this shape is not hydrodynamic, hence the Casing (which everybody can see) is ‘blunt at the front’, ‘sharp at the back’ like an aircraft wing. In the space between, among other things, are large air bottles and the Ballast Tanks. The Ballast Tanks are open at the bottom, with grids to cover the opening. On the top of the tanks (you can see these when you walk on the casing) are large valves, called the Main Vents. On the surface, and in harbour, the Ballast Tanks are full of air, to maintain the boat on the surface. When the submarine is about to dive, the Main Vents (on the top of the ballast tanks) are opened, reducing the Positive Buoyancy, the planesman then planes down to the depth required. NOW, before we go further, a word about Bouyancy. The POSITIVE buoyancy is defined as the weight of the water displaced. If this is the same as the weight of the boat, then we are in NEUTRAL buoyancy, and the planes do not have to be on dive or rise to maintain depth, they may be centred, the most efficient way to proceed and silent. As the boat goes deeper, the pressure hull compresses, the boat displaces less water, the weight of the water displaced becomes less, and the boat becomes NEGATIVLY buoyant. Not good!!!. So, as the boat dives, to maintain NEUTRAL buoyancy, the weight must be reduced. This is done by pumping water from the internal (inside the pressure hull) ballast tank to sea, restoring NEUTRAL buoyancy. So, contrary to popular concepts, as a boat dives it pumps water out to get lighter, rather than flood water in. When the boat is diving, going deeper, experience will tell them to pump out so much water, given the depth they are required to go to. When that depth is achieved (by planning down) the planesman will centre the planes, and ‘see’ what the boat does (on the depth gauge). If the depth is reducing, the boat is light, too much positive buoyancy, and they will flood water in, else if the boat is heavy, pump out. Now, surfacing. Air is a very precious commodity, and unless it is a dire emergency, the order “Blow Main Ballast” is never given, this would entail blowing precious air from the air bottles into the main ballast tanks between the casing and pressure hull. Instead, the boat planes up to the surface (controlling the positive buoyancy as the pressure reduces, by flooding water into the internal tanks). When the boat is close to the surface, the Ventilation mast is put up, and the blower started, the water is forced out of the Main Ballast Tanks, and the boat is now surfaced. To make the submarine dive, valves on the top of the very large ballast tanks are opened, allowing the air inside the tanks to escape. Seawater floods into the tanks via holes at the bottom, so that the submarine becomes heavier and sinks in a controlled manner. To make a submarine surface, the valves on the top of the ballast tanks are shut and high-pressure air is pumped into the tanks forcing the water out through the holes at the bottom. The tanks fill with air and the submarine floats to the surface. Submarine Navigators use normal charts together with information from on-board computers and Global Positioning System (GPS) satellites. SONAR (Sound Operated aid to Navigation And Ranging) is the system that provides a submarine with its underwater ears and eyes. It is used to detect ships, submarines and undersea mountains. There are two types of sonar:
British submarines have two escape "towers", one at each end. In a crisis situation, the sailors put on special escape suits and, one at a time, enter a tower. Once the inner door has shut and the outer one has opened, the hood of the escape suit can be inflated, allowing the sailor to breath normally as he floats to the surface. (The Royal Navy has a 9 m long submarine, the LR5, designed for rescuing other submarines in inland waters.) For verbal and written communication, submarines use specialised radios and aerials that can communicate with shore bases and other ships, either directly or via a satellite. Periscopes are usually fitted with electronic devices such as radio aerials and TV cameras. Pressurised Water Reactor (PWR).The driving force behind the Royal Navy's submarines
is its Pressurised Water Reactor (PWR), which is nuclear.
The uranium fuel elements provide 2.5 million times more energy than the
same weight of coal and have an extremely long lifetime, so that nuclear
submarines can travel great distances for many years without refuelling.
The heat from the uranium fuel rods turns water into steam that is used
to drive the main turbine engines. The reactor is heavily shielded and
completely protects the crew from radiation. Radiation levels are so low,
that a submariner gets less radiation than a person gets from natural
background radiation. The first British version of the PWR was referred to as ‘Core A’. Cores B, Z and G were later versions. These were all built by Rolls Royce, as is the one currently under construction – Core H. Core H reactors will be fitted to HMS Vanguard during her first refit and to the next generation of attack submarines, the Astute Class. When nuclear powered submarines come to the end of their life, they have to be disposed of very carefully, because the nuclear waste is very toxic. WEAPONS
Torpedoes are nowadays almost always wire guided with their own built-in sonar for homing in on their targets. Propulsion is either via the traditional propeller or the more advanced pump jet, giving a range of up to 55 km. The 'heavyweight' torpedoes employed by submarines are about 6 - 7 m long and usually have a warhead designed to explode on impact (best against submarine targets) or upwards from underneath the target (to 'break the back' of a surface vessel). The two tonne Spearfish Torpedo is a very advanced homing torpedo. It has an impressive acceleration and a long range.
The Tomahawk Land Attack Cruise Missile (TLAM) is fitted inside a waterproof capsule, which - when launched - floats to the surface. Booster rockets then ‘fire’ and the missile heads for its target - usually a land target up to 1100 km away. The missiles usually have conventional warheads. The Tomahawk was fired in the Kosovo conflict in 1999. Anti-Ship Missiles (ASMs), such as the American Harpoon (used by the Royal Navy) or the French Exocet, are effective against surface ships. They are launched in the same way as cruise missiles and hug the waves at a height of a few metres to avoid radar detection. They travel on a pre-programmed course, until the target is within range of the missile’s own radar, at which point the missile can get up to all sorts of amazing tricks to get through the target ship’s defences. These subsonic weapons usually have a range up to about 180 km. Current ASMs have certain drawbacks:
Ballistic nuclear missiles are only carried by SSBNs. They can be fired at targets that are many thousands of miles from the sea and are capable of flying 2000-3000 nm. These missiles have multiple nuclear warheads, enabling a number of different targets to be engaged. They also use penetration aids and decoys. The ability to strike at any time and with huge force is considered to deter hostile governments from using Weapons of Mass Destruction. They have played a key role in our nuclear deterrent policy for over 40 years. The Trident 2 D5 missile is an example of a ballistic nuclear missile. It has a range of over 4,000 nautical miles and lands within few metres of its target. Each missile delivers up to 12 warheads. It is ejected from the submarine by high-pressure gas and only when it reaches the surface does the rocket system actually fire. The USA government is now preparing to keep Trident 2 in service for many years longer than originally planned. The British government, who bought Trident 2 from the USA in 1982, is looking at whether we can do the same. The tactical weapon system has three functions: to avoid detection; to provide self-protection; and to enable effective communications. The Submarine Command System (SMCS) is the tactical weapon system’s “brain”. It receives information from the submarine’s sensors, analyses it and presents it to the ship’s Commanding Officer in an easily understandable way. The SMCS then helps with launching and guiding the tactical weapons. Sub-Surface Nuclear (SSN) SubmarinesThese are also referred to as Attack submarines, Hunter Killer submarines, or Fleet Submarines. (Note: the SSGN is a version of the SSN that has been designed specifically to attack surface vessels with long-range ASMs/guided missiles. They are used by the Russian Federation and are very effective in small oceans such as the Baltic. The USA government is thinking of converting four of its SSBNs to SSGNs. The 'G' stands for 'Guided missiles'). The SSNs combine qualities of stealth, endurance and flexibility. They provide:
Apart from her nuclear powered steam turbine, which gives it much greater endurance, the SSN is not dissimilar from a regular SS (conventional attack submarine). There are two classes of SSN currently in service:
Classes that are due to come into service are:
S (Swiftsure) and T (Trafalgar) class submarines are very similar, with the Trafalgar class being essentially a modernised Swiftsure class.
These classes are sophisticated and capable of diving very deep. HMS Torbay is the first of four Trafalgar Class submarines to re-enter service under a programmethat will give these boats effectively the same very advanced combat capabilities intended for the much larger Astute class, now in build (see below). HMS Astute is the biggest and most powerful attack submarine to be built for the Royal Navy and will have a much smaller ship’s company. Although the Astute will be about 30 per cent larger than the Trafalgar Class, this larger hull means that she is much easier to build and maintain.
Developed from the preceding Trafalgar class, the Astute class incorporates the new Core H reactor. This reactor is in turn a development of the reactors used for the gigantic Vanguard Class see below). As a result, the hull size of Astute will be considerably bigger than other British SSNs, which are powered by smaller reactors. The reactors will provide enough fuel for the submarine’s full 25-year service. Apart form being more powerful and larger, the Astute Class will be quieter and able to dive to depths of 300 metres. For the first time in an attack boat, all crewmembers will have their own bunks. The Astute Class's role in the Royal Navy is changing as Rear Admiral Stevens, explained: "The services SSN community has made a decisive break away from its Cold War emphasis on anti-submarine warfare ... 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." The Astute class will comprise seven hunter killers, replacing the five remaining Swiftsure Class submarines and eventually, the two oldest Trafalgar Class vessels. The FASM (Future Attack Submarine) will replace the Trafalgar class and is still in the early design stage.
Sub-Surface Ballistic Nuclear / Ship Submersible Ballistic Nuclear (SSBN)These are otherwise known as strategic (missile) submarines or ballistic (missile) submarines. They are the heavyweights of the submarine world and are only found in the arsenals of the large nuclear powers. Britain has one class of SSBN:
This class, first launched in 1993, provides the UK's strategic and sub-strategic nuclear deterrent. Known as 'bombers' in the UK, these submarines serve no role in fighting other vessels (though they are equipped with torpedoes and maybe ASMs for self defence). Our four SSBNs carry long-range nuclear warhead Trident missiles. They roam the oceans of the globe avoiding contact and thus detection. They provide Strategic Deterrence - launching retaliatory nuclear strikes against any nation attacking Great Britain or her allies with nuclear weapons. Our submarine fleet has a good communications link with its Commander-in-Chief, the Defence Secretary and the Prime Minister. When authorised to do so, the SSBN will rise from the depths and launch as many multiple warhead nuclear missiles as they can before the enemy detects and attacks them.
History of SubmarinesHolland I was launched in 1901 and so the Royal Navy's Submarine Service was born; but Britain was the last of the major maritime powers to venture into this field of warfare, due to an atmosphere of scepticism in this country. During World War 1 German submarines, attacking Britain's lifelines of sea trade, sank several million tons of merchant shipping. The Royal Navy’s Submarine Service in turn, equipped with the excellent E-Class, sank 54 enemy warships, including 19 submarines in the Baltic and Dardanelles. At the start of World War 2, convoys had few escorts and there were virtually no anti-submarine aircraft. By this time, diesel electric submarines with torpedoes and a small-bore gun had come into being. The German U-boats operated as submersible destroyers, only diving to escape counter attack. British submarines, on the other hand, had to stay underwater due to the strength of German anti-submarine warfare weapons. The war took a heavy toll on submariners' lives; it is estimated that about half of the 74 RN submarines lost during the war fell prey to mines. This did not, however, stop people from volunteering for the Service. The main operating arenas were Norwegian Waters, the Mediterranean and the Far East, operating in appalling conditions. By the end of the war British submarines had sunk 2 million tons of enemy shipping and 57 major war vessels, including 35 submarines. The Royal Navy Submarine Museum is at Gosport (Portsmouth Harbour). Exhibits include the original Holland I, recovered after 70 years on the seabed, and HMS Alliance, a World War II diesel submarine.
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The
photos used below are a very small selection of the photos that can be
viewed on the Royal Navy website http://www.royal-navy.mod.uk, which will
give more information about the subject matter on this page. See the 'Useful
Websites' page.
It
may, for political rather than technical reasons, use AIP (Air Independent
Propulsion) rather than nuclear power. To the left is the BAE Systems
Concept for the future submarine. Ultra-Quiet directable podded water
jet propulsion units plus a single lower rudder would provide unparalled
high/low speed manoeuvrability and stability. Ultra-Sophisticated all-round
sonar coverage would be achieved using platypus bow sonar and arrays.
Class:
Vanguard