Hunley A Confederate Navy vessel that made history by being the first submarine to sink a surface ship in battle (USS Housatonic). Unfortunately, the Hunley herself also sank in the attack.
HY-80 High-Yield steel, with a yield strength of 80,000 pounds per square inch.
HY-100 High-Yield steel, with a yield strength of 100,000 pounds per square inch.
Kilo SS Latest Russian diesel-electric submarine. The Kilo is a medium-range coastal defense submarine that is being offered on the export market. Using state-of-the-art Russian sensors and torpedoes, the Kilo class compares favorably against older Western designs. Russia has twenty Kilos in their naval order of battle, and approximately fourteen have been sold to various countries.
Lafayette (SSBN-616) Third generation of U.S. Navy SSBNs. Larger and quieter than the Ethan Allen class, the Lafayette class carries the Poseidon C-3 missile. However, twelve units of the Lafayette class were backfitted with the Trident I C-4 system during the 1980s. A total of thirty-one units were built.
LF Low Frequency.
LOFAR LOw-Frequency Analyzing and Recording. Term used to describe the process by which narrowband "tonals" are displayed on a modern sonar system.
Los Angeles (SSN-688) Admiral Rickover's high-speed submarine design. Most numerous submarine class in the world with a total of sixty-two units to be built. There are three flights with various improvements:* Flight 1: SSNs 688–718. Basic Los Angeles class.* Flight 2: SSNs 719–750. VLS, more powerful reactor core.* Flight 3: SSNs 751–773. AN/BSY-1, bow planes, improved quieting, under-ice capability.
Maneuvering The reactor and propulsion control area located in the engine room. The EOOW stands his watch here.
MEO Marine Engineering Officer. Royal Navy equivalent of the chief engineer; however, an MEO is not eligible for command.
MF Medium Frequency.
MGU Midcourse Guidance Unit. The inertial navigation system used to guide Harpoon and Tomahawk antiship missiles to their targets.
MIDAS MIne Detection and Avoidance Sonar. New mine-hunting sonar on Improved Los Angeles-class SSNs.
Mk 8 (Mark 8) WW II-era straight-running (nonhoming) torpedo used by the Royal Navy up until about the mid-1980s. Two Mk 8s were responsible for the sinking of the Argentinean light cruiser General Belgrano.
Mk 48 (Mods 1–4) Designation of the active homing torpedo used by U.S. SSNs. The various modifications have improvements in wire-guidance capability and allow for deeper depths.
Mk 57 U.S. Navy moored influence mine.
Mk 6 °Captor EnCAPsulated TORpedo mine. A deep-water moored acoustic influence mine containing a Mark 46 lightweight torpedo as the payload.
Mk 67 SLMM Submarine-Launched Mobile Mine. An obsolete Mk 37 electric torpedo that has been converted into a mobile bottom influence mine.
Narwhal (SSN-671) Basic Sturgeon-class hull with a natural circulation reactor. One-of-a-kind experimental submarine. Fully combat capable.
NATO North Atlantic Treaty Organization
Nautilus (SSN-571) First nuclear-powered submarine in the world. Commissioned September 30, 1954.
Navsea Naval Sea Systems Command.
NIFTI Navy InFrared Thermal Imager.
November SSN First-generation Soviet SSN. Fast, noisy, and extremely unsafe because of radiation. These SSNs have all been retired because of their poor safety record. A total of fourteen were built. One was lost off Cape Finisterre in April 1970.
OBA Oxygen Breathing Apparatus. A portable system that chemically generates oxygen for about 30 minutes. Used by damage control teams to fight fires.
Ohio (SSBN-726) Fourth generation of U.S. Navy SSBNs. Largest submarines in the fleet; each carries twenty-four Trident I C-4 or Trident II D-5 missiles. Extremely quiet submarines. Essentially 688s with twenty-four missile tubes. A total of twenty were to be built, but because of START and the collapse of the USSR only eighteen units will be completed.
OOD Officer Of the Deck. U.S. Navy officer in charge of directing the submarine's movement and ensuring that essential actions are conducted. Primary responsibility is to keep the submarine out of dangerous situations and to keep the captain informed.
OPNAV Office of the Chief of NAVal OPerations.
ORSE Operational Reactor Safeguards Examination.
Oscar I & II SSGN Third-generation Soviet SSGN, the Oscar is the largest attack submarine ever built. Fast, quiet, and extremely well armed, the Oscar I & II classes are a threat to any surface ship. To date nine units have been built, and production appears to be continuing.
Otto Fuel The monopropellant (oxidizer and fuel combined) used in Mk 48 and Spearfish torpedoes.
Perisher Royal Navy Submarine Command Course.
Permit (SSN-594) First U.S. Navy production SSN with a primary ASW function. Class was renamed following the loss of USS Thresher in April 1963. Fourteen units of this class were eventually built.
Plank owners The original crew of a boat at the time of its commissioning.
Polaris (A1-A3) First generation of U.S. Navy submarine-launched ballistic missiles. The different variants each have improvements in range. The Royal Navy uses Polaris A-3 missiles in their Resolution-class SSBNs.
"Polishing the cannonball" An attempt to generate a near-perfect fire control solution that may be totally unnecessary. Polishing the cannonball takes too much time, and the submarine may lose its initiative to the intended target.
Poseidon (C-3) Second-generation U.S. Navy submarine-launched ballistic missile.
PSA Post Shakedown Availability. Maintenance period after a new submarine's initial sea trials are completed.
PWR-1 Pressurized Water Reactor-1. The type of reactor found on all current Royal Navy nuclear-powered submarines except the Vanguard-class SSBNs. PWR-1 is essentially the U.S. S5W reactor design, which was sold to the Royal Navy in 1958.
PWR-2 Pressurized Water Reactor-2. An indigenous reactor design for future Royal Navy nuclear-powered submarines. Presently being installed in the new Vanguard-class SSBNs.
Radar RAdio Detection And Ranging.
Raft A large metal frame that supports various rotating parts of machinery such as main engines or turbine generators. Through inertial damping it reduces machinery vibrations that could reach the hull.
In other words, it's heavy, and the vibrations are absorbed as they try to move the raft.
RAM Radar-Absorbing Material. A coating designed to absorb radar energy and reduce a target's ability to be detected.
RBL–L Range Bearing Launch-Large. A launch mode of Harpoon and Tomahawk antiship missiles that uses both bearing and range information. The "Large" refers to the size of the area where the missile is to conduct its search.
RBL-S Range Bearing Launch-Small. A launch mode of Harpoon and Tomahawk antiship missiles that uses both bearing and range information. The "Small" refers to the size of the area where the missile is to conduct its search.