Ship alarms and emergency signals are paramount for sailors to tackle a crisis and avoid emergencies resourcefully and in the right manner. 

Royal Van der Leun China specializes in building switchboards and cabinets of every description for maritime and industrial uses. Various types of alarms on ships are installed to alert seafarers about threatening situations that can result from numerous types of tragedies onboard the ship. Ships alarms come in both audible and visible varieties so that workers in locations where viewing a visual alert is not feasible can still hear the audio alarm.

Types of Alarms on Ships

These are various types of alarms on ships that Royal Van der Leun China may design and install on board ships to provide audio-visual alerts:

1. General Alarm

A general alarm is a type of alarm that sounds when there is an unexpected event on the ship—the general warning sound when the ship’s navigation systems detect ice, icebergs, or other objects. These alarms are triggered by water sensors which are located throughout the ship. 

The alarms are monitored on land by Coast Guard personnel. Although the alarms are loud enough to cause hearing damage, the frequency of occurrence and short duration means that these noises' effects are minor.

2. Abandon Ship Alarm

The indicator to desert the ship is vocally sent by the ship's chief to the station in command of the crew through the Personal Addressing (PA) system of the vessel. This typically happens when the danger on board intensifies and the vessel is not safe for the seafarer.

An abandon ship alarm or the sound sign is utilized on board the vessel, consisting of more than six brief flashes and one extended blast on the vessel's horn. Nevertheless, the abandon ship alarm sound is similar to the general alarm; therefore, the crew always assembles at the emergency assembly station, where the chief officer verbally commands to abandon the vessel. 

3. Man overboard alarm 

There have been several incidents where a member of the ship's seafarer fell into the ocean during rough waves. In such a scenario, a man overboard warning is triggered to alert other crew members. The crew overboard alarm signal contains three interminable rings on the ship's inner alarm bell to notify the crew and three elongated flares on the ship trumpet to notify other ships within a given area. 

4. Navigational Alarm navigational instruments and lights

Most navigational instruments and lights on the navigation channel have installed failure alerts. If any of these go wrong, alarms on ships signals will sound on the bridge, and information about the malfunction, such as the location or the nature of the issue, will be shown on the warning shade given on the passage navigation board.

5. Fire alarm on the ship

On most cruise ships, a fire alarm is set off when smoke or flames are detected in a fire-prone area. Most emergency drills aim to keep everyone safe and out of harm during an emergency. However, the best thing to do when you hear an alarm sounding is to stay calm and follow the guide's instructions. Crewmembers will direct you to emergency exits, muster stations, or muster points.

In addition to an audible alarm, you may see warning lights flashing and announcements over the PA system telling crew and guests to report to their muster stations. A ship's electrical bell or horn will continuously ring to signify a fire alarm.

6. Machinery Space CO2 Alarm 

The Machinery Space CO2 Alarm may have one or more sets of sensors mounted on top of the alarm. Each set consists of a dry gas probe, which continuously measures the level of carbon dioxide in the atmosphere, and an electrochemical detector. The alarm operates on a 24-hour basis, alternating sensors each hour. If the measured level rises above an established threshold level, an audible alarm sounds, and the output of the electrochemical detector is sent to the ship's central control console.

The Machinery Space CO2 Alarm is typically located at the entrance of a ship. It is designed to provide a warning before concentrations reach where they are likely to cause incapacitation or death to personnel working in the vessel.

7. Ship Security Alarm System

The ship Security Alarm System (SSAS) is installed to warn the person to leave their ship because of a serious incident occurrence. SSAS actively monitors the system and sounds an alarm when it detects an abnormality.

The SSAS uses a global satellite network to broadcast signals to warn various coastal authorities close to the ship about the pirate.

8. Machinery Space Alarm 

These alarms sound shrill and send a series of vibrating signals to the machinery space to warn the crew of impending damage. The alarm warns that critical equipment must be shut down immediately by giving off an audible alarm during regular running or stopping conditions and sending continuous vibration signals in this space.

If a ship's systems were not cleared of the alarm, the ship's life support system could be damaged over some time with an eventual loss of life.

In case of damage to a nuclear reactor, the alarm is activated by radioactivity in the vicinity of the reactor and sends vibration signals to notify a ship that it has been contaminated. This type of alarm warns against radioactive contamination in any sea area surrounding the vessel.

9. Cargo Space CO2 Alarm

When the CO2 level in the cargo space becomes too high, t alarms on vessels sound an audible alarm and send out a series of vibration signals. The ship's equipment must be cleared of the alarm and the CO2 level restored to normal before sailing again.

The CO2-fixed firefighting system's auditory and visual alerts are completely distinct from those of other ships. The audio alarm should be distinguishable from other ships by varying the sound patterns or sound pressure.

It is extremely important that sailors to comprehend the various types of alarms in a vessel and the meanings of these alarms. They are the simplest way to get a quick understanding of the state of a ship.

Royal Van der Leun China has plenty of experience in integrating and installing different alarms on different types of ships, e.g., general alarm system, engine room alarm system. If you would like to know more deeper, please, send us your inquiry.

Sources: 

https://www.vanderleun.cn/Production1.html 

https://www.marineinsight.com/marine-safety/different-types-of-alarms-on-ship/ 

https://www.vanderleun.cn/news/Marine-Navigational-Lighting-86.html 

https://www.marineinsight.com/marine-piracy-marine/what-is-ship-security-alert-system-ssas/ 

https://www.vanderleun.cn/news/Ship-Navigation-Technologies-That-Are-Changing-The-Marine-Industry-98.html