Ballistic missiles launched from submarines are known as submarine launched ballistic missiles (SLBMs). Almost all SLBMs have nuclear weapons and are part of the Naval Strategic Nuclear Forces (NSNF), one of the three components of the nuclear triad. Modern ballistic missiles have an intercontinental range, are equipped with multiple warheads with individual targeting, and can simultaneously attack several targets hundreds of kilometres apart. South Koreans have conventional submarines which can launch conventional SLBM with a conventional warhead. North Koreans, too, have this capability, but it is not known if they have a conventional or nuclear warhead.

Most submarines can launch a single and a salvo, both from the surface and from the underwater position.

After a volley, only a torpedo (and sea mines) remains at the crew’s disposal for anti-ship and submarine application. The submarine is redirected to warships, a sea convoy or an aircraft carrier strike group for protection. If the sub has time to fire all the missiles, the enemy’s missile defense systems will immediately determine its location, and it will most likely be destroyed. Not much is known about how much time it is required to launch an SLBM, but there are references that the Soviet Union had launched three missiles in 12 minutes, not counting the submarine’s ascend, descent and positioning. The SLBM was launched from a Hotel Class / Project 658 nuclear powered submarine carrying marine ballistic missile R-13. R-13 is a single stage liquid fuelled missile. Refuelling of the R-13 was carried out from submarine tanks immediately before the launch. The deeper the launch depth, the better it is for submarine safety from detection. Some navies have equipped their submarines with MANPADS for air defense. A diver can keep the low-flying aircraft at bay while the submarine submerges at a safer depth.

Although the missile can be launched from a depth of up to 60m, the launch from an underwater platform is normally carried out from a depth of 20-30m. For example, on September 10, 1960, the Soviet Union launched an SLBM sailing at a depth of 30 meters at a speed of 3.2 knots. Trident II was launched in December 1989 from a depth of 37.5 m. The submarine was moving at a speed of 3-4 knots relative to the water. The absolute speed was zero.

When a submarine shoots from under the water, it usually is in motion. The speed is low – only three to five knots,

A submarine can launch SLBMs in two methods. The ‘wet launch’ distinguished all Russian liquid SLBMs. However, this method has disadvantages. Filling shafts with water takes time and creates acoustic noise. If a submarine is pursued by an anti-submarine ship, it can locate and destroy it quickly. Solid rockets are good because they can perform a dry launch’. They are fired from the launch tube with a powder charge, and the engine is turned on above the water’s surface. This method is quieter and faster, thanks to which the chances of a successful launch increase dramatically.

SLBM launch is challenging in the Arctic, where a submarine trip in itself is associated with significant risk. Nuclear missile carriers do not shoot from under the ice. Shooting missiles from holes is also not possible as large pieces of ice are no better than the packed layer.

The effectiveness of firing largely depends on the navigators: the more accurately they determine the boat’s position before launch, the more accurately the missiles will hit. Even a tiny error in the coordinates seriously affects the results. Modern missiles are equipped with an Astro-correction system which is triggered when the warhead goes into space to compensate for these errors.

The submerged depth of the submarine is also a part of the survivability of a submarine. Submarines operate in the following depts – periscope depth, test depth, working depth, estimated depth and limited depth.

SLBM launches are usually carried out in the periscope depth if launched from underwater. This is usually about 18m, but since newer submarines have started discarding periscopes for cameras, this may change in the future.

Test depth is where the submarine can be without restrictions in normal peaceful conditions. It is determined during sea trials of the submarine. According to the requirements of the U.S. Navy, this depth should be two-thirds of the design depth, according to the requirements of the British Navy – 4/7 of the design depth, according to the requirements of the German Navy, about half of the design depth.

Working depth or the Operating depth or Maximum operating depth is the maximum depth of a long stay, which does not disrupt the operation of the systems and devices of the submarine. As a rule, it is 80-85% of the maximum immersion depth. Usually, this is about 300 meters.

Estimated depth or the design depth is the nominal depth indicated in a submarine’s tactical and technical requirements.

Depth limit or the Limiting depth or crush depth is – the maximum depth, immersion to which is not accompanied by residual deformations of the strong hull of the submarine.

Some U.S. and Russian nuclear submarines can operate beyond 800 m without experiencing a crush on their hulls. Submarines have no operational roles at this depth and are mostly done for research purposes.

Disclaimer : Articles published under ” MY TAKE ” are articles written by Guest Writers and Opinions expressed within this article are the personal opinions of the author. IDRW.ORG is not responsible for the accuracy, completeness, suitability, or validity of any information on this article. All information is provided on an as-is basis. The information, facts or opinions appearing in the article do not reflect the views of IDRW.ORG and IDRW.ORG does not assume any responsibility or liability for the same. article is for information purposes only and not intended to constitute professional advice .

Article by GIRISH LINGANNA ,  cannot be republished Partially or Full without consent from Writer or