How about the US Navy?
Fleet Ballistic Missile Submarines - SSBN Description
Nuclear-powered submarines armed with long-range strategic missiles.Features
The first eight Ohio class submarines (Tridents) were originally equipped with 24 Trident I C-4 ballistic missiles. Beginning with the ninth Trident submarine, USS Tennessee (SSBN 734), all new ships are equipped with the Trident II D-5 missile system as they are built, and the earlier ships are being retrofitted to Trident II. Trident II can deliver significantly more payload than Trident I C-4 and more accurately.
The Ohio-class submarines are specifically designed for extended deterrent patrols. To decrease the time in port for crew turnover and replenishment, three large logistics hatches are fitted to provide large diameter resupply and repair openings. These hatches allow sailors to rapidly transfer supply pallets, equipment replacement modules and machinery components, significantly reducing the time required for replenishment and maintenance. The class design and modern main concepts allow the submarines to operate for 15+ years between overhauls.
The first four Ohio-class submarines are scheduled for conversion over the next five years to guided missile submarines (SSGN) with an additional capability to transport and support Navy special operations forces.Background
Strategic deterrence has been the sole mission of the fleet ballistic missile submarine (SSBN) since its inception in 1960. The SSBN provides the nation's most survivable and enduring nuclear strike capability. The Ohio-class submarine replaced aging fleet ballistic missile submarines built in the 1960s and is far more capable.
Ohio-class/Trident ballistic missile submarines provide the sea-based "leg" of the triad of U.S. strategic deterrent forces. The 18 Trident SSBNs (each carrying 24 missiles), carry 50 percent of the total U.S. strategic warheads. Although the missiles have no pre-set targets when the submarine goes on patrol, the SSBNs are capable of rapidly targeting their missiles should the need arise, using secure and constant at-sea communications links.Point Of Contact
Public Affairs Office
Naval Sea Systems Command
Washington, DC 20362General Characteristics, Ohio Class
Builder: General Dynamics Electric Boat Division. Date Deployed: November 11, 1981 (USS Ohio) Propulsion: One nuclear reactor, one shaft. Length: 560 feet (170.69 meters). Beam: 42 feet (12.8 meters). Displacement: 16,764 tons (17,033.03 metric tons) surfaced; 18,750 tons (19,000.1 metric tons) submerged. Speed: 20+ knots (23+ miles per hour, 36.8+ kph). Crew: 15 Officers, 140 Enlisted. Armament: 24 tubes for Trident I and II, MK-48 torpedoes, four torpedo tubes. Ships: USS Henry M. Jackson (SSBN 730), Bangor, WA USS Alabama (SSBN 731), Bangor, WA USS Alaska (SSBN 732), Kings Bay, GA USS Nevada (SSBN 733), Bangor, WA USS Tennessee (SSBN 734), Kings Bay, GA USS Pennsylvania (SSBN 735), Bangor, WA USS West Virginia (SSBN 736), Kings Bay, GA USS Kentucky (SSBN 737), Bangor, WA USS Maryland (SSBN 738), Kings Bay, GA USS Nebraska (SSBN 739), Bangor, WA USS Rhode Island (SSBN 740), Kings Bay, GA USS Maine (SSBN 741), Bangor, WA USS Wyoming (SSBN 742), Kings Bay, GA USS Louisiana (SSBN 743), Bangor, WA Last Update: 6 April 2006
From a separate page on the status of the Navy
Attack submarines underway
(away from homeport): 24 submarines (44%)
On deployment: 12 submarines (22%)
That doesn't say how many of those 12 are SSBN, but they have the separate listing for the attack subs, so I assume that most of the 12 are SSBNs on "deterrence patrol" and not SSGNs with conventional warhead equipped cruise missiles. I also question the bit in the Wikipedia article that limits the cruise missiles on the SSGNs to conventional warheads. I don't see why that would be the case.