The general emergency signal is a signal used on board ships in times of emergency.
The signal is composed of seven or more short blasts followed by one long blast on the ship's whistle and internal alarm system. Within 24 hours of embarkation of all passengers, the crew will conduct a mandatory muster drill in which the General Emergency Signal is sounded. The purpose of the drill is to educate passengers of emergency procedures should an actual emergency occur. The signal alerts passengers of an emergency so that they will begin proper procedures in which all persons collect their life jackets and proceed to their assigned muster stations.
There is also an abandon ship alarm which is used should it become necessary to abandon ship, after all other efforts have been exhausted. This signal is given audibly by the ship's Master (aka Captain) over the PA system. It is never given by automatic means or with recorded media.
Requirements on General Alarm Systems according to the Safety Of Life At Sea (SOLAS) Convention:
1. General Alarm Systems on the Open Deck of New Cargo and Passenger Ships according to the SOLAS Chapter III, Reg. 6.4.3
and the Life Saving Appliances (LSACode), App. 7, Reg. 7.2 the signals issued via the general alarm system shall be audible
in all accommodation and normal working spaces of the crew as well as on the open deck.
The sound pressure level shall be in compliance with LSA-Code 7.2.1.2 - “Recognisability of Audible Alarms”- such that the alarm level is 10 dB(A) over the ambient level.
It shall be possible to trigger the alarms both via an automatic signal generator or by hand. The alarms may be interrupted temporarily by announcements made over the loudspeaker installation.
On the open decks of cargo ships, the signals are triggered by the automatic signal generator and generated by the general alarm system can either be produced by the whistle or by sirens. The sirens shall be located at uniform distances spread over the open deck. It shall be possible to interrupt the driving of the whistle by the automatic signal generator by means of a non-locking pushbutton or a switch or a locking pushbutton.
According to SOLAS Ch. 6.4.2 the general alarm system shall be capable of operation from the navigating bridge and also from other “strategic points”.
Triggering of the automatic signal generator shall only be provided on the navigating bridge. A “strategic point” has been accurately defined in LSA Code, App. 7.2.
General Alarm on the Open Deck and Broadcast Systems (Loudspeaker Installations) on Existing Passenger Ships.
The alarm shall be audible in all accommodation spaces, all normal working spaces of the crew and on all open decks, and its sound pressure level shall be at least 75 dB(A) or 10 dB(A) above the ambient noise level (see LSA-Code App.7.2 and IMO Alarm Code, No. 4.11). The accommodation spaces also include the cabins and living areas as well as the public spaces of the passengers.