Shipboard fire often happens. There are many reasons for it, such as circuit faults or aging wires in the engine room, cargo area, or crew living areas, causing electric fires. Or the crew members operating under the open flame, and littering cigarette butts, causing fires due to their negligence. Or, the ships didn't properly load the flammable and explosive dangerous cargo, leading to explosion fires. The above moves can seriously endanger the safety of the ship, cargo, and people. Therefore, installing a set of reliable fire alarm systems on the ship is rather important.
Top 10 Crashing big ships and fires after storm:
Reasons for Shipboard Fire
The burning causes, burning time and burning objects of different ships are different. Here, we will take cargo ship as an example to analyze the reasons of the shipboard fire:
As the using time of the ships increases, the possibilities of occurring a fire increase. On the one hand, the wires of the ship are aging, causing the insulation resistance to be reduced quickly, and may possibly lead to overload or short circuits. On the other hand, the equipment (electrically or mechanically) fault can also cause a fire easily.
Among merchant ships, cargo ships catch the most fires. This is because, first, there are a lot of cargo ships among merchant ships, and the number is large. Second, the fire protection requirements of cargo ships are not that strict compared to passenger ships and oil tankers.
As the tonnage weight of merchant ships increases, the risk of happening fire increases. We should pay close attention to fire-fighting measures for large-tonnage ships.
From the number of ships on fire, we can see that most fires happened in the living areas, followed by the engine rooms and the cargo rooms. If the fire occurred in these rooms can’t be controlled, it will spread to the whole ship. The reasons for occurring fires in these places are as follows:
(1)In places like residences, workplaces and communities, people smoking and littering unextinguished cigarette butts are the main cause of fires in accommodation and service spaces. Electrical short circuits or improper use of electrical equipment is also an important cause of the fire. Improper use of oil stoves in the kitchen can also cause fires.
(2)Smoking while loading and unloading cargo is the main cause for happening a fire. For the cargo that might burn itself, the burning can happen when the ventilation is poor, or the environment is hot and damp. Cargo that reacts chemically with water will also catch fire when it is damaged and meets water. For roll-on-roll-off ships, poor ventilation in the cargo area can make the oil and gas accumulate, and if there is an electrical fault or other sparks, explosions might happen. Besides, when repairing the reefer ships in ports, the high-temperature operation (like electric welding and gas cutting) may light the insulation and cause fires.
(3)Because there are flammable liquids such as fuel oil and lubricating oil in the engine room, and with equipment like boilers, engines, motors, exhaust pipes and super-heated steam burning the ship surfaces, as well as high-temperature operation such as repairing, the possibility of occurring fires is rather high.
(4)When loading oil at the port, due to the closing failure of the self-closing control cock of the measuring pipe of the oil tank in the double bottom of the lower part of the engine room, people might refuel with the nozzle opened, and the oil spilled to the surfaces that are not insulated or have damaged of the exhaust pipe and the super-heated steam pipe, causing a fire.
(5)For oil-burning boiler, we should pay close attention to oil leakage. Because the oil might leak from the burner, after the boiler is off, the oil will slowly leak into the furnace, and the high temperature in it will vaporize the oil. When turning on the boiler, if the front scavenging isn’t enough, it will cause an explosion, and even a fire. When the main engine and auxiliary engine are running, if the fuel pipes or the lubricating oil pipes are broken or the joints are leaking, and the oil splashes onto hot surfaces of the exhaust pipes, it can also cause fires.
(6)The overloading of electrical equipment and the aging cable insulation can also lead to fires.
What will cause shipboard electrical fires and explosions?
The reasons for shipboard electrical fires and explosions are complicated. They could be faults, improper uses or inappropriate management of the ship's electrical equipment. These hidden dangers are mainly the heat source of fire.
First, the heat sources of electrical equipment include normal heat sources and abnormal heat sources, such as sparks generated by normal disconnection of different contacts, and abnormal sparks generated by insulation short-circuit points and line breakpoints. Some high-temperature components, like electric lights, also could have abnormally high temperatures if the electrical equipment (especially sockets) meets water, resulting in short circuit or grounding, overheating at the short-circuit point or grounding point.
Second, if the electrical equipment or cables are overloaded for a long time or due to short-circuit fault, it might result in abnormal voltage, excessive current, and high temperature.
Third, there might be overheating of the line due to the wrong connection of wires, or the irregular connection of the electric heaters to the socket, exceeding the allowable current of the line. Fourth, there might be short circuit and ground fault for the insulation of the line is reduced or is damaged, leading to local overheating.
Normal sparks, abnormal sparks, normal high temperatures, and abnormal high temperatures all could cause fire or explosion.There are also some special areas of the ship that have a better chance to have a fire or explosion. Such as the batteries used as the emergency power supplies, and battery rooms. When the battery is charged, it will generate hydrogen gas, which is lighter than air. If there is no ventilation device, or the ventilation device is not working well in the battery room, the hydrogen gas will likely to accumulate at the highest point, and will explode once it meets fire.
Features of shipboard fire
The structure of the ship is complicated, the space is narrow, and the temperature is high
The fire spreads quickly and is hard to put out
The ship has a lot of combustibles
Traffic is limited, making the fire-fighting job hard
ASENWARE One-stop Shipboard Fire Equipment
The shipboard fire equipment includes fire detection and fire alarm control system, CO₂ fire suppression system, deck fixed foam suppression system, water suppression system, fixed-pressure water mist suppression system, emergency water suppression system, portable dry powder fire suppression system, etc.
1.Shipboard fire detection and fire alarm control system
The function of the shipboard fire detection and fire alarm control system is to find out the fire as soon as possible, and inform people to put it out in time by alarming, minimizing the loss caused by fire. The systems have many types, mainly fixed type fire detection and fire alarm control system, aspirating smoke detection system, etc.
(1)Fire detection and fire alarm control system
The fire detection and fire alarm control system mainly include detectors and strobe sounders. Its working principle is, the detector is the automatic fire detection device installed in the protecting area, converting the heat, smoke or spectral signals generated in a fire into electrical signals, and transmitting them through the connecting wires between the detector and the alarm. The strobe sounder will receive the signals and give fire alarms.
Fire alarming devices: Like strobe sounders, sirens, and fire alarm bells, are normally installed next to the console, and are installed in every ship.
Manual call point: the manual call points are usually installed in the living areas of the crews and the travelers, and the areas with machines. They are normally installed in places where people can easily reach them.
(2)Cargo-area Aspirating Smoke Detection System
Since the cargo area of the ship is an independent airtight cabin and seldom people will be there, it is usually installed the aspirating smoke detection system (most of its smoke pipes are shared with CO₂ suppression pipes).
2.CO₂ fire suppression system
CO₂ fire suppression system mainly includes 2 types: total flooding fire suppression system and local-application fire suppression system.
Total flooding fire suppression system means spraying a certain concentration of fire extinguishing agent into the protecting area within a certain period of time, and making it evenly filled the entire space. For the protecting area where the fire can’t be predicted in advance, it should use the total flooding fire suppression system.
Local-application fire suppression system means spraying the fire extinguishing agent directly at the protected object with the designed injection intensity, it will last for a certain period of time. For the protecting area where the fire can be predicted in advance, it should use the local-application fire suppression system.
3.Deck fixed foam suppression system
Deck fixed foam suppression system includes fixed foam liquid fire pump, foam liquid storage tank, proportional mixer, foam-mixed liquid delivery pipeline and foam generating device, connecting together with the water system.
When there is a fire, first open the fire pump and the relevant valves, then we can deal with the fire. The deck fixed foam suppression system can adopt upper-liquid surface injection and lower-liquid surface injection.
4.Fixed-pressure water mist suppression system
Fixed-pressure water mist suppression system can replace the conventional gas suppression system and water sprinkler. It is usually at normal pressure when in the standby state, solving the leakage problem in the storage of the gas system. about maintenance, the fixed-pressure water mist suppression system costs less than the water sprinkler and gas suppression system.
5.Portable dry powder fire suppression system
The dry powder fire extinguisher uses high-pressure CO₂ gas as the power to spray the fire, suitable for suppressing the first-start fire of oil, combustible gas and electrical equipment.
Portable dry powder fire extinguishers should be put in places dry and ventilated, preventing the cylinder from being damp and corroded, avoiding exposure from the sun and strong radiant heat. The connection parts of the fire extinguishers must not be loose, and the nozzle plug cover shouldn’t fall off, therefore ensuring tightness.
Emergency Plan for Shipboard Fire
When the crew finds out a fire, they should immediately give out the fire alarm (activating the manual call point), put out the fire using the nearest fire extinguishing equipment, and inform the officer on duty.
When the console receives the fire alarm, it should alert the whole ship with the siren or alarm bell immediately. The captain should go to the console to command after hearing the alarm, directing the fire-fighting acts of the whole ship. The ship should be slowed down or stopped, and driven to places where the fire is in the downwind area.
After hearing the alarm signal, all crew members (except those on duty) should rush to the scene within 2 minutes according to the command, carrying the fire-fighting equipment. They should gather in 4 teams (fire-fighting team, isolating team, rescuing team and engine room team).
Commander should lead the fire-fighting team and the isolation team to quickly find out the fire location, fire nature, fire situation, etc., reporting the information to the captain to determine the emergency plan.
Fire-fighting Principles of Shipboard Fire
When there is a fire on a sailing ship, people should put it out themselves and ask for help. The rescue steps should be: give out a fire alarm, search for the fire source, isolate the fire scene, and start putting out the fire. The general fire-fighting principles are as follows:
Slow the ship down and change its course. First consider the wind direction and the fireplace, and adjust the ship to the appropriate direction quickly according to the channel situation. Slowing down can reduce the air pressure in the cabin, and changing the course can make the fire part leeward or blow the flame outboard, helping the fire-fighting acts.
Control the fire first, then put it out
Saving people is more important than putting out fires.
Report the ship position. Do it precisely and in time.
Command correctly, use appropriate methods to put out the fire.
Consider the stability and buoyancy of the ship fully. Judge the situation before shooting out the water to put out the fire. Keep the ship stable and buoyant.
Record the internal and external communications and every part as detailed as possible.
Put out the fire completely.
Check the crew and passengers to prevent separation.
When there is no hope to put out the fire, we should do the beach landing or abandon the ship.
The fire extinguishing agent storage cylinder of the manifold type FM200 gas suppression system is usually placed in the special cylinder room and connected through the pipe network. When a fire occurs, the fire extinguishing agent will be conveyed from the cylinder to the protection area, and will be sprayed through the nozzle to extinguish the fire.
The inspection, test and maintenance of the gas fire suppression system is the guarantee to ensure the normal operation of the system when the fire occurs. Specific examples of 8 routine testing tasks.