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7 Major Ship Alarms to be aware – safety at sea

7 major ship alarms to know while onboard

On this article I will guide you on the 7 major ship alarms you should be aware while boarding the vessel.

Importance of emergency ship alarms and  signals

Emergency ship alarms and signals are installed all over the vessel’s various compartments, machinery space and systems to notify the crew and visitors about a dangerous situation that can arise from different types of emergencies onboard the vessel.

The emergency ship alarms are of the signal (lighting) and audible type. The audible (sounds system) is to ensure that a person can see and listen to the audible alarm when working in an area where seeing a visual alarm is not possible.

Also read about: safety measures onboard vessels

As per ship building standard practice, and in conjunction with international maritime industry, it’s mandatory to have an emergency alarm on the ship for a particular warning that is similar for all ocean and seagoing vessels. These alarms level depends on vessel side, and purpose. Though it doesn’t matter in which seas or ocean they are sailing, so far it accommodation life.

Therefore, before boarding any ship, it’s important to learn within 24 hours what kinds of alarm system are installed, and what actions to take.

Types of ship Alarms and signals

1. Fire System Alarm

The fire signal or alarm must be a continuous blast of the ship whistle or electrical bell and red lightening. This alarm comes up whenever a fire detector sense flame or smoke around the compartment it was installed.

Learn more about: major sources of fire out break onboard ship

Fire systems and alarms

This same system can be activated manually if one sights fire and the detector sensor still not activated. The manual activation are always located near each entrances or compartment.

2. Ship General Alarm

This is a common but Major alarm to be aware of onboard any vessel. As per ships, “the general emergency alarm on the ship is recognised by 7 short ringings of the bell followed by a long ring or using the ship horn signal of 7 short blasts followed by 1 long blast”.

Normally, the vessel general alarm system activation point is located in the navigation bridge. Once the general alarm signal onboard is activated, every ship crew and visitors must follow the instruction and duty’s listed in the muster list and proceed to the designated muster station.

All instructions regarding this alarm are posted on the muster stations of each vessel.

3. Abandon Ship Alarm

The sounds or signal are more than six short blasts and one prolonged blast on the ship’s whistle. Same signal on the general alarm bell is used as an abandon ship sound signal onboard the ship.

Once this signal or sounds comes up, everybody has to quickly advance to emergency muster station where the master or his substitute (Chief mate) will address the situation of the apartment.

Learn more about: onboard ship life saving appliances as per SOLAS

Also note, when the emergency on board ship goes out of hand, and the ship is no longer safe for the crew and visitors on board ship, the signal for abandon ship is given verbally by the master to the station in charge of the crew on the ship’s Personal Addressing (PA) system.

4. Man Overboard Alarm

The alarm signal comprises of the vessel’s internal alarm bell for 3 long rings to notify the crew and visitors on-board, along with 3 long blasts on the ship whistle to inform the other ships in the nearby vicinity to keep away.

If MOB (man over board) , a signal light and smoke can also be mounted in the bridge, attached by the side of the lifebuoy. When thrown in the water, it will emit smoke and light to draw attention of other ships around the vicinity, as well as ship’s crew.

5. Machinery Space and Cargo hold CO2 Alarm

The machinery space and cargo hold are fitted with a CO2 fixed fire extinguishing system. They comprises of audible and visual alarm for the CO2 fixed firefighting system. It’s entirely different from the machinery space alarm, cargo hold water ingress alarm or other alarms.

This alarm normally activate upon opening the release cabinet door, which is used to open and release the CO2 bottle banks either to the machinery space or Cargo hold.

The signal light is red and could be written CO2 alarm indication, The audible and visual alarm for the CO2 fixed firefighting system is entirely different from other ship alarms for your better understanding; the audible alarm usually distinguished from other ships’ alarms by the adjustment of sound pressure and sound patterns.

See, method of handling CO2 system onboard ship

It’s highly recommended once crews and visitors hear or saw such alarm, with immediate effect and through nearest available exit to the muster station for head count.

Secondly, the crew and officer incharge to ensure the cargo hold is sealed (in terms of cargo hold fire) and no crew is inside. Likewise all the ventilation systems to be shut both for the machinery space (in case of engine room fire) and cargo hold vents or fans to shut.

6. Ship Security Alarm

Ship Security Alarm system (SSAS) is silent alert or signal in a pirate attack emergency situation.

When the SSAS is activated, no alarm is sounded on board the ship nor alerts other vessels in the vicinity.

This signal notifies different coastal authorities or competent authorities whose proximity to the ship is presently operating via a global satellite system to inform about the piracy attack location, time, date, etc.

This alarm device is installed onboard vessels as per regulation XI-2/5 of SOLAS Chapter XI, which says that “all ships shall be provided with a ship security alert system”.

7. Navigational bridge and Machinery Space Alarms

Both in the navigation bridge and Machinery Space, most of the equipments are fitted with failure alarms.

If any of these equipment malfunction, a ship alarm signal on the bridge or engine control room (ECR) will be sounded whose details like; location of fault, equipment affected, type of problem etc. will be displayed on the notification screen provided on the control panel.


When boarding ship, always make sure to get proper familiar with all alarm and signal system provided to the vessel. Also, note down nearest exit, to the main deck or muster station, as well as know your responsibility during emergency situation.

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Ship muster station poster signal

In most cases, you will find fire and emergency posters on both muster stations, fire station, and ship diagram showing exits, stations, etc.

Work and sail safely. Did we miss any point on this article? Kindly drop your opinion on the comment box below.

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