Vertical Launching System
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A Vertical Launching System (VLS) is a type of missile-firing system used aboard the submarines and surface vessels of several navies around the world.
Derived from the launch systems developed for ballistic missiles aboard SSBNs, a VLS forms a scaled-down equivalent for launching cruise missiles such as the Tomahawk, surface-to-air missiles (SAMs), and the Standard missile. The system enables SSNs (nuclear-powered attack submarines) to carry more weapons in addition to their torpedo tubes. More significantly, VLSs allow both submarines and surface combatants to have more weapons ready for firing at a given time than with other launching systems. The drawback to a VLS is that, unlike torpedo tubes, it cannot be reloaded at sea without significant support from ships such as a submarine tender or a trip to a submarine base.
VLSs have found a role in Aegis-equipped surface ships on the
- US Navy's Arleigh Burke
- U.S. Ticonderoga class cruisers
- Korean Kongō and KDX-III class destroyers
- Spanish Alvaro de Bazán and
- Norwegian Fridtjof Nansen class frigates.
They have also been implemented on non-Aegis classes, such as the
- 4 Canadian Tribal class Destroyers (retrofit)
- U.S. Spruance class of destroyers
- UK Royal Navy's Type 23 frigates and Type 45 destroyer
- Royal Australian Navy's ANZAC class frigates (and is currently being retro-fitted to four of its ADELAIDE class frigates)
- Korean KDX II class destroyers
- People's Liberation Army Navy's Lanzhou class destroyer and
- Indian Navy's Talwar (Krivak III) class frigates.
The RAN Air Warfare Destroyer, presently (2006) being designed, will have VLS.
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[edit] Hot launch and cold launch
Western VLSs have the missile cells arranged in a grid with one lid per cell and are "hot launch" systems, i.e. the engine ignites within the cell during the launch, and thus requiring complex exhaust piping for flames and gas, while Russia produces both grid systems and a revolver design with more than one missile per lid, and the People's Republic of China uses a circular "cold launch" system that ejects the missile from the launch tube before igniting the engine.
The advantage the hot-launch system has over the cold-launch system is that it utilises the missile's own engine to propel the missile out of the launching cell, and this reduces the weight, the size, maintenance requirement, and the initial production cost of the system. The cold-launch system, in contrast, needs power sources other than that of the missile's own to propel it out of the cell, so additional space, weight, maintenance and cost are added.
The advantage of the cold-launch system is in its safety: should the missile engine malfunction while the warhead is armed to detonate during firing, the hot-launch system would be doomed, but the cold-launch system can still eject the missile out of the cell and eliminate or reduce the threat. For this reason, Russian VLS is often designed with a slanted angle instead of being perpendicular so that when the malfunctioned missile is ejected, it would fall into the water instead of landing on the deck. Another advantage of the cold-launch system is in its low life cycle cost of the launching tubes: since the engine starts within the tube in a hot-launch system during launches, the tubes of the hot-launch system can only sustain a limited number of launches, after which the tube must be replaced. A cold-launch system, in contrast, can last much longer because the tubes are not subject to the extreme heat blasts like that of the hot-launch system, because in the cold-launch system, the engine does not start until after the missile was ejected out of the tube.
[edit] International VLS System types
[edit] Europe
[edit] SYLVER
The SYLVER vertical launching system manufactured by DCN is being deployed on a wide range of European naval vessels, and like most western designs, it is a hot-launch system. Like the USA Mk 41 VLS, the Sylver VLS incorporates a shared flame and gas exhaust system, i.e. several launching cells share a single flame and gas exhaust system.
The primary application of the launcher has been the MBDA Aster missile. The SYLVER, together with the Aster, is the primary component of the PAAMS naval anti-air warfare system to be fitted to British Type 45 destroyers and French and Italian Horizon class frigates. France's Charles de Gaulle nuclear aircraft carrier is fitted with four 8-cell SYLVER launchers carrying the MBDA Aster 15. This VLS currently has the highest maximum rate of fire: it only takes 150 milliseconds to fire a missile.
The French Navy has initiated studies to convert the SCALP EG missile to be capable of launch from the SYLVER. This missile, the SCALP Naval, would give France a land attack capability in the mould of the U.S. Tomahawk missile. It would also be attractive to the Royal Navy.
[edit] Sea Wolf
The Royal Navy utilises the GWS 26 VLS (Vertical Launch Sea Wolf) version of the Sea Wolf SAM aboard its Type 23 frigates. This is a 32 cell VLS mounted on the foredeck just behind the 114 mm (4.5 in) gun. This system, like all other western designs, is a hot-launch system. Unlike the Mk 41 VLS of USA, Sea Wolf VLS has a different flame and gas exhaust system in that each individual cell has its own flame and gas exhaust system: each cell contains four flame and gas exhause pipes which are arranged between the control surfaces of the Sea Wolf SAM, and as a result, the Sea Wolf VLS is limited to launching Sea Wolf only, and thus less versatile than the Mk 41 VLS of USA or the French Sylver VLS.
[edit] United States of America
The current generation of American-produced VLS system is known as the Mk 41 Vertical Launch System. It is capable of carrying an extremely wide range of missiles, including the Sea Sparrow naval self defense, short range SAM, SM-2 medium range/long range SAM/SSM, VLASROC anti-submarine missile with Mk-46 torpedo warhead, very similar to the ASROC, and the Tomahawk cruise cissile (long range strike, an anti-ship version used to exist). There are also plans to increase the number of missiles it is capable of carrying.
For American surface ships, VLS replaced the Armored Box Launcher system and the Mk 26 twin-arm missile launcher system that were previously used by United States Navy ships to fire missiles. All US Arleigh Burke class guided missile destroyers and the remaining 22 active duty Ticonderoga class guided missile cruisers utilize VLS-type launchers. Because of the practicality of the Mk 41 VLS, other US surface ships that had Armored Box Launchers or other horizontal firing systems have been retrofitted with VLS systems (the first five Ticonderoga class ships were not so refit, and they were prematurely decommissioned from 2004-05). In addition to surface ships, all Virginia-class submarines and USS Providence and later Los Angeles-class submarines have had VLS systems installed. The maximum rate of fire is one missile per second.
Raytheon and BAE are currently developing the next generation of the vertical launch system, designated the Mk 57, for use in the DDG-1000 class destroyers and future ships. The most notable difference between the MK 57 and the Mk 41 will be the MK 57s ability to shoot missiles from peripherally placed VLS cells, theoretically reducing the number of missiles lost in the event of a hit and also reducing the chance of vessel loss from a hit (there is also the possibility that the peripherally-placed missiles will be useful as a form of explosive reactive armor). Mk. 57 is considerably less efficient, however, in terms of tonnage use, as the Zumwalt design carries 80 missiles on a 14,000 ton ship, versus 90-122 on a 10,000 ton ship for Arleigh Burke and Ticonderoga.
[edit] Russia
The Soviet/Russian SA-N-6 Grumble fitted to the Kirov-class and the Slava-class uses a revolver-style VLS. The SA-N-6 Grumble VLS utilises cold launch method by adopting a coal-gas ignition system: the coal-gas within the ignition chamber directly below the cell ignites and thus sets the piston into motion, resulting in the SAM being ejected out of the cell. The system adopts a revolver design in which a cell contains 8 launching tubes, each containing a single missile, so that during the launch, the cell has to be rotated into the position in order to launch the SAM that is to be fired. In case of the failure of the ignition of the rocket motor after the missile has been ejected, the launching tubes are tilted 5 degrees instead of being absolutely perpendicular, so that the missile with the failed motor would not fall back onboard.
The shorter-ranged SA-N-9 Gauntlet is another VLS missile, used on the Kirov-class, Udaloy-class and the Kuznetsov-class aviation cruiser.
The SS-N-19 Shipwreck/P-700 Granit is also a VLS missile, fired from below-deck tubes on the Kirov-class and the Oscar class submarine. These tubes are angled due to the length of the missile, and thus not strictly vertical launch, but the system otherwise meets the definition.
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[edit] People's Republic of China
PLAN Type 052C Lanzhou class destroyers (DDG) were the first Chinese ships to have a VLS. The system is an improvement of the Russian SA-N-6 SAM VLS and uses the same coal-gas ignition method. The Chinese VLS eliminates the revolver design by providing separate lids for the launch tubes, which are each capable of independently firing the missile inside because each has a coal-gas ignition chamber directly below. The Chinese Navy claims this results in simplified maintenance, decreased size, weight, and cost. Furthermore, due to the elimination of the revolver mechanism, the power consumption is reportedly reduced as well.
