Trident Submarine-Launched Ballistic Missile (SLBM)

Efran Syah       missiles and rockets    Comment   

A Trident II (D-5) missile clears the launch pad during a US Navy developmental test flight. The missile is designed for submerged firing from nuclear-powered ballistic missile submarine. (via getarchive.net)

The Trident missile is a submarine-launched ballistic missile (SLBM) equipped with multiple independently targetable reentry vehicles (MIRV). The missile is named after the mythological trident of Neptune.

A UGM-96A Trident I submarine launched ballistic missile lifts off on the 14th test launch of the system. (via getarchive.net)

The Trident missile originally developed by Lockheed Missiles and Space Corporation, the missile is armed with thermonuclear warheads and is launched from nuclear-powered ballistic missile submarines (SSBNs).

Trident II D5 Fleet Ballistic Missile (FBM). (via dmitryshulgin.com)

Trident missiles are carried by fourteen United States Navy Ohio-class submarines, with American warheads, as well as four Royal Navy Vanguard-class submarines, with British warheads.

(Petty officer 1st class Ronald Gutridge)

Under development from the late 1960s, the Trident developed into two models.

The first version, the Trident I (C4) UGM-96A, was 34 ft (10.4 m) long and 6 ft (1.8 m) in diameter. It could deliver eight independently targetable 100 kt nuclear warheads to a range of 4,000 nm (7,400 km).

The Trident II (D5) UGM-133A, is about 46 ft (14 m) long and carries multiple independently targeted warheads. It has a maximum range of about 6,500 nm (12,000 km). Their destructive power is estimated as the equivalent of eight Hiroshimas.

U.S. Trident II (D-5) missile underwater launch

The Trident II's increased payload allows nuclear deterrence to be accomplished with fewer submarines, and its high accuracy – approaching that of land-based missiles – enables it to be used as a first strike weapon.

Pictured is the Weapons Engineer Officers Tactical Trigger used to launch a Trident Missile. (Simmo Simpson)

Trident II missiles are carried by 14 US Ohio and four British Vanguard-class submarines, with 24 missiles on each Ohio class and 16 missiles on each Vanguard class (the number of missiles on Ohio-class submarines will be reduced to 20 each in coming years, in compliance with the New Strategic Arms Limitation Treaty).

Missile Technician and Chief Missile Technician at the Trident Training Facility (TTF) go over the launch control simulator. 3 June 2003. (US Navy/Mate Chris Desmond)

There have been 176 successful test flights of the Trident II missile since design completion in 1989. There have been fewer than 10 test flights that were failures. Trident II is the sixth in a series of missile generations deployed since the sea-based deterrent program began 60 years ago. The Trident D5LE (life-extension) version will remain in service until 2042.

Trident C4

The Trident warheads are launched by three solid-fueled booster stages and are dispersed toward their targets by a liquid-fueled "bus" in the missile’s front end.

With inertial guidance refined by stellar or satellite navigation, Tridents are more accurate than most land-based ballistic missiles.

At the time of their deployment during the Cold War, their accuracy gave them the ability, unprecedented among SLBMs, to threaten hardened missile silos and command bunkers in the Soviet Union, and their extended range allowed their submarines to patrol almost anywhere in the Atlantic and Pacific oceans, making detection extremely difficult.

A view of the canister container used to load Trident I C-4 missiles in place aboard the nuclear-powered strategic missile submarine USS OHIO (SSBN-726)

At launch, the pressure of expanding gas in the tube forces the missile out and to the ocean surface where, once it is far enough from the submarine, the solid fuel in the first of three stage motors ignites.

At the same time, an aerospike designed to reduce drag by around 50% extends from the tip of the missile.

Once the missile reaches space, its stellar sighting guidance system takes a reading from the stars to work out the missile's position and make any adjustments necessary to the pre-programmed route to its target area.

A second - or boost stage - rocket then fires, followed by the third stage. Within approximately two minutes from launch the missile is travelling at over 20,000 ft (6,100 m) a second.

Trident Missile System external and cross sectional views including basic dimensions. This is specifically modelled on a Trident II D5 system

Once in position over its targets, the missile's third motor separates from the forward section containing the warheads.

The guidance system takes another star reading to confirm its position.

Small thruster rockets then manoeuvre the forward section so each warhead can be individually released in the right place to freefall to its target, where they detonate according to one of a number of pre-set fuse options.

A UGM-96 Trident missile clears the water during the 20th demonstration and shakedown launch from the nuclear-powered strategic missile submarine USS Mariano G. Vallejo (SSBN 658). This is the 45th flight of the Trident missile. Date Shot: 9 Oct 1984. (JOSN Oscar Sosa)

In 2002, the US Navy announced plans to extend the life of the submarines and the D5 missiles to the year 2042. This requires a D5 Life Extension Program (D5LEP), which is currently underway.

The main aim is to replace obsolete components at minimal cost by using commercial off the shelf (COTS) hardware; all the while maintaining the demonstrated performance of the existing Trident II missiles.

The first flight test of a D-5 LE subsystem, the MK 6 Mod 1 guidance system, in Demonstration and Shakedown Operation (DASO)-23, took place on USS Tennessee on 22 February 2012.

An unarmed Trident II D5 missile launches from the Ohio-class fleet ballistic-missile submarine USS Nevada (SSBN 733) off the coast of Southern California. 1 March 2011. (U.S. Navy/Seaman Benjamin Crossley/Released)

Specifications (Trident II (D5)

Mass: 130,000 lb (59,000 kg)

Length: 44 ft 6.6 in (13.579 m)

Diameter: 6 ft 11 in (2.11 m) (1st stage)

Warhead:

• 1-8 Mk-5 RV/W88 (455 kt) or
• 1-14 Mk-4 RV/W76-0 (100 kt) or1-14 Mk-4A RV/W-76-1 (90 kt)
• Single or multiple W76-2 (5-7 kt)

Engine: Three solid-fuel rocket motors

Propellant: Nitrate ester, plasticized polyethylene glycol

Operational range: More than 7,500 mi (12,000 km)

Maximum speed: Approximately 18,030 mph (29,020 km/h) (Mach 24)

Guidance system: MK 6 astro-inertial guidance which is able to receive GPS (Global Positioning System)

Steering system: Single movable nozzle actuated by a gas generator

Accuracy:

• 90 m with Mk-5 RV using GPS guidance
• 120-183 m with Mk-5 RV using astro-inertial guidance
• 381 m with Mk-4 RV

Launch platform: Ballistic missile submarine