Vertical launching system

For the Brazilian Space Agency launcher, see VLS-1.

The VLS cells on board USS San Jacinto.

A Tomahawk missile canister being loaded into a VLS aboard the Arleigh Burke class destroyer USS Curtis Wilbur

A vertical launching system (VLS) is a system for holding and firing missiles on surface ships and submarines used by many navies around the world. Each VLS system consists of a number of cells, which can hold one or more missiles ready for firing. Typically, each cell can hold a number of different types of missiles, allowing the ship flexibility to load the best set for any given mission. Further, when new missiles are developed, they are typically fitted to the existing VLS systems of that nation, allowing existing ships to use new types of missiles without expensive rework. When the command is given, the missile flies straight up long enough to clear the cell and the ship, and then turns on course.

A VLS allows surface combatants to have a greater number of weapons ready for firing at any given time compared to older launching systems such as the Mk-13 single-arm and Mk-26 twin-arm launchers, which were fed from behind by a magazine below the main deck. In addition to greater firepower, VLS is much more damage tolerant and reliable than the previous systems, and has a lower radar cross-section (RCS). The U.S. Navy now relies exclusively on VLS for its guided missile destroyers and cruisers.

The most widespread VLS system in the world is the Mk 41, developed by the US Navy. More than 11,000 MK 41 VLS missile cells have been delivered, or are on order, for use on 186 ships and 19 ship classes, in 11 navies around the world. This system currently serves with the US Navy as well as the Australian, Canadian, Danish, Dutch, German, Japanese, New Zealand, Norwegian, South Korean, Spanish, and Turkish navies, while others like the Greek Navy preferred the similar Mk 48 system .

The advanced Mk 57 VLS system is projected to be used on the new Zumwalt class destroyer. The older Mk-13 and Mk-26 systems remain in service on ships that were sold to other countries such as Taiwan and Poland.

When installed on a SSN (nuclear-powered attack submarine), a VLS allows a greater number and variety of weapons to be deployed in comparison to using only torpedo tubes.

Hot launch and cold launch

Diagram depicting a hot launch from a Mark 41 VLS

A VLS system can be either hot launch, where the missile ignites in the cell, or cold launch, where the missile is expelled by gas produced by a gas generator which is not part of the missile itself, and then the missile ignites. "Cold" means relatively cold compared with rocket engine exhaust. A hot launch system does not require an ejection mechanism, but does require some way of disposing of the missile's exhaust and heat as it leaves the cell. If the missile ignites in a cell without an ejection mechanism, the cell must withstand the tremendous heat generated without igniting the missiles in the adjacent cells.

US Navy Mk 41 Tomahawk launch, hot launch.

An advantage of a hot-launch system is that the missile propels itself out of the launching cell using its own engine, which eliminates the need for a separate system to eject the missile from the launching tube. This potentially makes a hot-launch system relatively light, small, and economical to develop and produce, particularly when designed around smaller missiles. A potential disadvantage is that a malfunctioning missile could destroy the launch tube.

The advantage of the cold-launch system is in its safety: should a missile engine malfunction during launch, the cold-launch system can eject the missile thereby reducing or eliminating the threat. For this reason, Russian VLSs are often designed with a slant so that a malfunctioning missile will land in the water instead of on the ship's deck. As missile size grows, the benefits of ejection launching increase. Above a certain size, a missile booster cannot be safely ignited within the confines of a ship's hull.

American VLSs have the missile cells arranged in a grid with one lid per cell and are "hot launch" systems; the engine ignites within the cell during the launch, and thus it requires exhaust piping for the missile flames and gasses. France, Italy and Britain use a similar hot-launching Sylver system in PAAMS. Russia produces both grid systems and a revolver design with more than one missile per lid. Russia also uses a cold launch system for some of its VLS missile systems, e.g., the Tor missile system. The People's Republic of China uses a circular "cold launch" system that ejects the missile from the launch tube before igniting the engine.

Systems in use by nations

Australia

• Adelaide class frigate - Mk 41 (8 cells)
• Anzac class frigate - Mk 41 (8 cells)

Canada

• Iroquois class destroyer - Mk 41 (29 cells)

People's Republic of China

• Type 052C destroyer - (48 cells)
• Type 051C destroyer - (48 cells)
• Type 054A frigate - (32 cells)

Denmark

• Iver Huitfeldt class frigate - MK 41 (4 x 8 cells) and Mk 56 (2 x 12 cells)
• Absalon class support ship- MK 56 (3 x 12 cells)

France

• Charles de Gaulle (R91) aircraft carrier - SYLVER (32 cells)
• Horizon class frigate - SYLVER (48 cells)

Greece

• Hydra class frigate - Mk 48 (16 cells)

India

• INS Viraat - Barak 1 (2 x 8 cells)
• Kolkata class destroyer - Barak 8 (2 x 32 cells)
• Shivalik class frigate - Barak 1 (8 cells)
• Talwar class frigate - 3M-54 Klub or BrahMos (8 cells)

Indonesia

• Van Speijk class frigate - SS-26 Yakhont VLS (4 cells)

SYLVER cells of Italian destroyer Caio Duilio

Israel

• Sa'ar 5-class corvette - Barak 1 (2 x 32 cells)

Italy

• Cavour (550) aircraft carrier - SYLVER (32 cells)
• Horizon class frigate - SYLVER (48 cells)

Japan

• Atago class destroyer - Mk 41 (96 cells)
• Kongō class destroyer - Mk 41 (90 cells)
• Hyūga class helicopter destroyer - Mk 41 (16 cells)
• Takanami class destroyer - Mk 41 (32 cells)
• Murasame class destroyer - Mk 48 (16 cells)

Republic of Korea

• Gwanggaeto the Great class destroyer (KDX-I) - Mk 48 (16 cells)
• Chungmugong Yi Sun-shin class destroyer (KDX-II) - Mk 41 (32 cells) + K-VLS (32 cells)
• King Sejong the Great class destroyer (KDX-III) - Mk 41 (80 cells) + K-VLS (48 cells)

Netherlands

• De Zeven Provinciën class frigate - Mk 41 (40 cells)

Norway

• Fridtjof Nansen class frigate - Mk 41 (32 cells)

Soviet missile cruiser Frunze firing a missile from the Tor VLS

Top view of the Ticonderoga-class USS Lake Champlain (CG-57) with VLS visible fore and aft as the gray boxes near the bow and stern of the ship.

Russia

• Slava class cruiser - Fort (64 cells)
• Kirov class battlecruiser - Fort/Fort-M (96 cells) + Tor (192 cells)
• Udaloy class destroyer Tor (64 cells)
• Admiral Grigorovich class frigate - 3M-54 Klub or BrahMos (8 cells)
• Admiral Gorshkov class frigate - 3M-54 Klub or P-800 Oniks (8 cells)
• Neustrashimyy class frigate - SA-N-9 (4 x 8 cells)
• Steregushchy class corvette - 3M-54 Klub (1 x 6 cells) or P-800 Oniks (2 x 4 cells) or Kh-35 (1 x 8 cells)
• Gremyashchy class corvette - 3M-54 Klub or P-800 Oniks (1 x 8 cells)

Singapore

• Formidable class frigate - SYLVER (32 cells)
• Victory class corvette - Barak 1 (8 cells)

Spain

• Álvaro de Bazán class frigate - Mk 41 (48 cells)

Turkey

• G class frigate- 8 cell VLS
• Barbaros class frigate- VLS Mk 41 Mod.8

United Kingdom

• Type 45 destroyer - SYLVER (48 cells)
• Type 23 frigate - GWS.26 (32 cells)
• Vanguard class - Ballistic Missile Tubes (B.M.T) (16 Cell)

United States

Surface

• Arleigh Burke class destroyer - Mk 41 (96 cells)
• Ticonderoga class cruiser - Mk 41 (122 cells)

Submarine

• Virginia class submarine - Mk 45 (12 tubes) for Tomahawk cruise missiles
• Ohio class submarine, SSGN conversion - Mk 45 (154 tubes) for Tomahawk cruise missiles. 22 ballistic missile tubes were converted to allow for seven conventional VLS tubes in for each SLBM.

See also

• List of United States Navy Guided Missile Launching System

External links

• Mk 41 VLS - Federation of American Scientists
• MK 41 Vertical Launching System (VLS) - GlobalSecurity.org