U.S. SLBMs

Cold War Submarines: The Design and Construction of U.S. and Soviet Submarines
By Norman Polmar, Kenneth J. Moore
Page 123 [Referring to Polaris]

“The time to prepare missiles for launching after receipt of a launch order was about 15 minutes; the missiles could then be launched at intervals of about one minute. The submerged Polaris submarine had to be stationary or moving at a maximum of about one knot to launch. The launch depth (from the keel of the submarine) was about 125 feet.”

US Submarines Since 1945
By Norman Friedman
Page 244

“SSBN 598 and 608 classes could launch missiles at the rate of one per minute; SSBN 616 could launch four per minute. These figures apply to Polaris, not necessarily to later missiles.”

Global Zero Alert for Nuclear Forces
By Bruce G. Blair
Page 62 [Trident D-5]

“101. In addition to longer flight limes, the D-5 launches would be staggered, with time intervals of twenty seconds between each. The last of the Trident's twenty-four missiles would thus fire eight minutes after the first was launched, giving the Russian force additional time to respond.”

Soviet/Russian SLBMs

Federation of American Scientists (FAS) (LINK)
Page on 667A YANKEE I

“The SSBN 667A is equipped with the D-5 launch system and 16 R-27 missiles with a range of about 2400 km. They are arranged in two rows in the fourth and fifth compartments. The missiles can be launched from a depth of 40-50 meters below the surface, while the submarine is moving at a speed of up to 3-4 knots. The missiles are fired in four salvos each comprising four missiles. The time needed for pre-launch preparation is 8 minutes, and within a salvo the missiles are fired at intervals of 8 seconds. After each salvo the submarine needs three minutes return to the launching depth and between the second and third salvo it takes 20-35 minutes to pump water from the tanks into the launching tubes.”

Cold War Submarines: The Design and Construction of U.S. and Soviet Submarines
By Norman Polmar, Kenneth J. Moore
Page 169

“The 667A/Yankee could launch from depths to 165 feet (50 m), compared to less than half that depth for Polaris launches, and the submarine could be moving at three to six knots, while U.S. missile submarines were required to move considerably slower or—preferably—to hover while launching missiles. The time for prelaunch preparations was approximately ten minutes; the launch lime for a salvo of four missiles was 24 seconds. However, there were pauses between salvoes so that at least 27 minutes were required from the launching of the first and last missiles. (The later Project 667BDRM/Delta IV SSBN could launch all 16 missiles within one minute while steaming up to five knots.)”

Soviet Naval Tactics
By Milan N. Vego
Page 165

“A Soviet SSBN can reportedly start launching its missiles 15 minutes after receiving the order from the command authority ashore. Ballistic missiles can be launched at intervals of one minute or less. For example, the Typhoon class can fire a salvo of two missiles within 15 seconds of each other; by contrast, the older Yankee Is require intervals of almost two minutes.

A Soviet SSBN can fire its missiles either submerged or from the surface. In the first case it must slow and hover in neutral buoyancy. The maximum depth from which missiles can be launched is classified, but it probably does not exceed 165 feet. The submerged launching of missiles requires constant re-ballasting (because the empty tubes are filled with a volume of water that weighs less than the missiles). Soviet SSBNs have reportedly practiced launching missiles from ice-covered waters only 130 feet deep.

An SSBN operating under ice can make a hole by firing its torpedoes at a lead or opening in the ice cover (an area less than 3 feet in thickness). The frequency of these openings in the ice is critical for launching missiles or for surfacing.”

The Logic of Accidental Nuclear War
By Bruce G. Blair
Page 161

“For a modern Soviet SSBN on combat patrol the time between the receipt of final launch orders and first missile breaking water was about seventeen minutes according to exercise data collected by the United States. An SSBN crew member who served on Delta II and Delta III SSBNs observed launch sequences that ranged from nine minutes to fifteen minutes. Twelve minutes was typical: six for prelaunch procedures, including message validation, and six more for final launch preparations, which were largely automated. Missiles were then automatically fired from each tube, one at a time, zigzagging from one end of the boat to the other. There was a four- to twelve-second interval between each missile launch.

For older SSBNs with severe shortcomings in initial navigation, such as the Yankee-class boats, the firing process probably depended on such external aids as moored undersea navigation buoys that could have been checked for information with acoustic communications from a distance of about half a mile. (A prior alert order would presumably have signaled the SSBN to get within range of such aids.) Several missiles might have been fired during each pass of the navigation buoy, requiring continuing communications with the necessary buoy to ensure the proper orientation of the firing platform at the moment of release. Older Yankee SSBNs wet-launched their missiles (tubes flooded, hatches opened manually, missiles fueled and released for buoyant ascent to surface where motors then fired) from a depth of some 150 feet, traveling at a speed of three knots with a three-degree bow elevation angle.

Contrary to often heard claims, the Yankee-class subs could not have been fired from deskside. By contrast. Delta-class SSBNs and probably the Typhoon submarines could have fired their missiles while submerged or surfaced. This capability to fire from dockside was frequently tested.”