Submarine-launched ballistic missile

A converted Project 611 (Zulu-IV class) submarine launched the world's first SLBM, an R-11FM (SS-N-1 Scud-A, naval variant of the SS-1 Scud) on 16 September 1955.

[3] Rear Admiral W. F. "Red" Raborn headed a Special Project Office to develop Jupiter for the Navy, beginning in late 1955.

[10] The Soviet Union was able to beat the U.S. in launching and testing the first SLBM with a live nuclear warhead, an R-13 that detonated in the Novaya Zemlya Test Range in the Arctic Ocean, doing so on 20 October 1961,[11] just ten days before the gigantic 50 Mt Tsar Bomba's detonation in the same general area.

The SSBN facilities at the Advanced Refit Sites were austere, with only a submarine tender and floating dry dock.

Thirty-one of the 41 original US SSBNs were built with larger diameter launch tubes with future missiles in mind.

In the late 1970s the Trident I (C-4) missile with a range of 7,400 kilometres (4,000 nmi) and eight MIRV warheads was backfitted to 12 of the Poseidon-equipped submarines.

[citation needed] Both the United States and the Soviet Union commissioned larger SSBNs designed for new missiles in 1981.

When the USS Ohio (SSBN-726) commenced sea trials in 1980, two of the first ten US SSBNs had their missiles removed to comply with SALT treaty requirements; the remaining eight were converted to attack submarines (SSN) by the end of 1982.

Eighteen Ohio-class boats were commissioned by 1997,[28] four of which were converted as cruise missile submarines (SSGN) in the 2000s to comply with START I treaty requirements.

[29] New SSBN construction terminated for over 10 years in Russia and slowed in the US with the collapse of the Soviet Union and the end of the Cold War in 1991.

The US rapidly decommissioned its remaining 31 older SSBNs, with a few converted to other roles, and the base at Holy Loch was disestablished.

This class is intended to replace the aging Deltas, and carries 16 solid-fuel RSM-56 Bulava missiles, with a reported range of 10,000 kilometres (5,400 nmi) and six MIRV warheads.

This relieves each side of the necessity to adopt a launch on warning posture, with its attendant risk of accidental nuclear war.

Additionally, the deployment of highly accurate missiles on ultra-quiet submarines allows an attacker to sneak up close to the enemy coast and launch a missile on a depressed trajectory (a non-optimal ballistic trajectory which trades off reduced throw-weight for a faster and lower path, effectively reducing the time between launch and impact), thus opening the possibility of a decapitation strike.