Alarms on submarines

Six standardized alarms are used on submarines of the United States Navy to alert the crew to situations that require immediate actions to be taken without waiting for specific orders. A higher priority alarm will silence an already-sounding lower one; in order of priority, they are:

#Collision alarm
#Diving alarm
#Missile jettison alarm
#Missile emergency alarm
#General alarm
#Propulsion plant casualty

The two missile alarms are used only on submarines that carry missiles.

A mnemonic aid for the order is the question "can dead missile men get paid?"

Collision/flooding alarm

The collision alarm is used to warn of imminent collision or actual flooding and is accompanied by a succinct statement of the emergency such as "flooding in engine room lower level" (if possible; flooding is deafeningly loud).

The alarm is a , rather like a stereotype American police car siren, which sounds continuously as long as the switch is held on.

The collision/flooding alarm handle is a red cog shape.

Diving alarm

The diving alarm is sounded twice to signal a dive and three times for surfacing, and is accompanied by either the announcement "dive, dive" or "surface, surface, surface."

The alarm is On early submarines, it was an actual klaxon; later classes used noisemakers that did not sound much like a klaxon but were variously described as "blats," "honks," or "."

The diving alarm handle is a green square. One turn of the handle sounds one complete "ah-OOG-ah" sequence.

Missile jettison alarm

The missile jettison alarm is used to warn of the imminent jettisoning (not launching) of a ballistic missile.

The alarm is a , often compared to the "Red Alert" alarm from the original Star Trek series.

The missile jettison alarm handle is a blue crown.

Missile emergency alarm

The missile emergency alarm is used to warn of any emergency involving a ballistic missile.

The alarm is a , two high-pitched notes repeated several times a second. People asked to imitate the alarm often say "deedle-leedle-leedle" in a falsetto voice as rapidly as they can.

The missile emergency alarm is an orange crown shape.

General alarm

The general alarm is used to alert the crew to any emergency not covered by another alarm including all varieties of battle stations. It is accompanied by a succinct statement of the situation, such as "fire in Machinery Two" or "man battle stations missile."

The alarm is a .

The general alarm handle is a yellow oval. One turn of the handle causes the alarm to sound for a predetermined amount of time; fourteen gongs is a typical length.

Propulsion plant casualty

The propulsion plant casualty alarm is used to warn of any emergency involving the engine room steam plant.

The alarm is a , two high-pitched notes repeated about twice a second, rather like a stereotype European police car siren. People asked to imitate the alarm often say "wee-ooo-wee-ooo" in a falsetto voice.

The propulsion plant casualty alarm handle is a pink T shape.

Testing

All alarms are tested regularly. The crew is first warned that testing is beginning, then each alarm is sounded from every alarm location. Because the general quarters alarm lasts for several seconds, the collision alarm is sounded very briefly to override and cut it off. The many locations whence the collision alarm can be sounded are traditionally tested from stern to bow, beginning with the engine room lower level aft location sounding the alarm as briefly as possible, then each subsequent location sounding the alarm for a slightly longer period of time. By the time the torpedo room sounds the alarm, it is held on for several complete cycles of the siren.

References

* [http://www.mbelect.com/filecabinet/Switches/15743-17.pdf MIL-DTL-15743/17A, 26 November 2002]
* I.C. Electrician 3 & 2, NAVEDTRA 10558-B, 1974
* Dynalec product brochure "Submarine Intercommunication System AN/WIC (Form AN/WIC, 0187-1500C) January, 1987