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Fire Trucks

Many fire departments have several different types of fire trucks. The main types are (1) engines,(2) ladder trucks, and (3) rescue trucks.

Engines have a large pump that takes water from a fire hydrant or other sources. Engines carry several sizes of hoses and nozzles. Engines used for fighting grass or brush carry a tank of water and such tools as shovels and rakes.

Ladder trucks. There are two kinds of ladder trucks - aerial ladder trucks and elevating platform trucks. An aerial ladder truck has a metal extension ladder mounted on a turntable. The ladder can be raised as high as 30 meters, or about eight stories. An elevating-platform truck has a cagelike platform that can hold several people. The platform is attached to a lifting device that is mounted on a turntable. Ladder trucks are equipped with portable ladders of various types and sizes. They also carry entry tools which firefighters use to enter into a building and to ventilate it to let out smoke. Common forcible entry tools include axes, power saws, and sledge hammers.

Rescue trucks carry additional equipment for unusual rescues. They have such tools as oxyacetylene torches, for cutting through metal, and hydraulic jacks, for lifting heavy objects. Rescue trucks may also carry other hydraulic tools to free people trapped in automobiles after an accident, to rescue people from water or high places. They also carry medical supplies and equipment.

Special fire vehicles include airport crash trucks and hazardous materials trucks. Airports crash trucks are engines that spray foam or dry chemicals on burning aircraft. Water is inefficient against many aircraft fires, such as those that involve jet fuel, gasoline, or certain metals. Hazardous-materials units carry tools to stop gas leaks, and supplies to absorb or clean up spills of dangerous liquids or solids. These trucks also have equipment to prevent the spread of liquid spills that can contaminate the environment. Hazardous materials include pesticides, fertilizers, and other chemicals as well as gasoline, natural gas, and other fuels. Many hazardous-materials emergencies involve truck or train wrecks in which a dangerous substance is accidentally spilled.

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A SHIPBOARD FIRE DETECTION SYSTEM

A fire detector is a device that gives a warning when fire occurs in the area protected by the device. The fire detection system, including one or more detectors, relays the alarm to those endangered by the fire and or.those responsible for firefighting operations. Ashore, a fire detector sounds an alarm so that occupants can leave a burning building promptly, and the fire department can be summoned. The detection system can also activate fire extinguishing equipment. At sea, however, there are no fire escapes, and no professional fire department to call. A shipboard fire detection system alerts the ship's crew, who must cope with the emergency using the resources they have on board.

Early discovery of fire is essential. The fire must be confined, controlled and extinguished in an early stages, before it gets out of control and endangers the ship and the lives of those on board. A well designed fire detection system, properly installed and maintained, and understood by those who must interpret its signals, will give the early warning of a fire, in the area it protects and its location.

Fire detection systems on board a ship are so arranged that in case of a fire, both a visible and audible alarm are received in the pilothouse or fire control station (normally the bridge) and for vessels of over 150 feet in length there should be an audible alarm in the engine room. The receiving equipment indicates both the occurence of a fire and its location aboard the ship. Consoles are located on the bridge and in the CO₂ room. The CO₂ room is the space that contains the fire extinguishing mechanisms. Only a bell is required in the engine room to alert the engineer to an emergency outside the machinery space.

Upon hearing a fire alarm, the watch officer on the bridge sounds the general alarm to call the crew to their fire and emergency stations as listed on the station bill. However, in all cases the master must be alerted immediately and the cause of the alarm must be investigated. If the alarm was for an actual fire action should be taken to confine, control and extinguish it. The crew must respond as per the station bill, under the direction of the master. If it was a false alarm, its cause should be investigated and corrected, if possible. In either event the fire detection system should be checked and the system put back in service after the proper action is taken. Losses have occurred when a system was not reactivated after an alarm, and hence did not send a signal when a subsequent real fire or reflash occurred.

The types of fire protective systems approved for use aboard ship include the following:

1. Automatic fire detection systems.

2. Manual fire alarm systems.

3. Smoke detection systems.

4. Watchmen's supervisory systems.

5. Combinations of the above.

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