The purpose of the fire alarm system for ships, like any other, is to detect fire, to report it and, if possible, to indicate the location of the fire. The fire alarm system may also activate the intended fire protection system if it is assigned to operate in an automatic operation mode. In passenger ships, the fire alarm system shall be divided into two parts: for the crew and passengers of the ship. This is done in order not to cause panic among passengers when notifying the crew of a fire hazard. Passengers shall be informed of the fire only, when necessary, through the ship public address  system or when an automatic alarm has been activated.
Due to the different objectives of fire alarm systems, they can be divided into the following types:

  • a fire detection system for the detection and transmission of a signal to a central fire station indicating its take-off location;
  • a fire declaration system to inform the ship's crew and passengers of the fire;
  • a fire warning system to inform those in the protected room about turning on the indoor fire system.

The fire alarm remote control shall be mounted on the Navigating Bridge or in another place where a constant watch is maintained. Signals of fire hazards shall be duplicated in repeaters installed in the Machinery Space or in other rooms where crew responsible for fire safety are located. Fire alarm panels come in various structures and can be combined with the alarm of the security panel. Fire protection systems are conventional and addressable.
Conventional fire alarm system is a radial system in which conventional fire sensors are connected to the rays. As an example, the installation diagram of such a system, consisting of two loops with sensors is provided in Fig.1..

Conventional fire alarm system installation scheme

 

Addressing to fire fighting systems is used in the facilities where the location of a fire needs to be accurately determined when the total area stored is greater than 1200 m2.

Address fire protection system scheme

In the event of a fire, a signal from the fire sensor or manual fire sensor shall be sent to the fire alarm remote control. A tell-tale indicating the area of the ship where the fire is likely to take place lights up in the console. At the same time, the audible signal is activated. In this way, the head of the ship's watch the on-call hubby - is informed about the likely fire and its location. If this signal is not confirmed within two minutes (by pressing the approval button), the fire alarm will be transmitted further to the fire alarm remote control repeaters located in the crew's accommodation, engine room and other service spaces.
The fire alarm shall be transmitted from indicators and sensors to the central fire alarm panel by means of communication line cables forming rays which connect simultaneously several fire indicators and hand fire sensors in one or adjacent premises. The design of the contact fire alarm panel allows you to determine not only the line of the signal that has come with a fire hazard, but also shows the number of the sensor that has been activated. For this purpose, resistance or capacitor is connected in parallel in sensors and sensors. When the fire sensor or manual sensor is activated, its resistance shall be disconnected in such a way as to form an outline, the resistance of which makes it possible to recognize the number of the active sensor.
A fire alarm system can be used to connect loops, which allows the system to work even if the wire between the sensors is removed. It may have programmable outputs and may be connected to a fire protection system. Then, in case of fire in room X, it is possible to automatically activate the extinguishing system in Room X by automating these systems using additional controls, electrical valves.

Connection of equipment, forming a loop of the fire system.

Last modified: Friday, 27 January 2023, 4:22 PM