FIRE SERVICE LADDERS
Although firefighters use many tools and devices, fire service ladders are essential in the performance of both major functions: saving lives and extinguishing fires. Fire service ladders are similar to any other ladder in shape, design, and purpose, but they have to be constructed under rigid specifications. All of the various types of fire service ladders have a purpose. The specific task at hand will determine which type of ladders is to be used. A STRAIGHT LADDER is nonadjustable in length and consists of only one section. The straight ladder, sometimes called a wall ladder, is used for quick access to windows and roofs of one and two-storeyed buildings. These ladders must be constructed to have a maximum strength and minimum weight. Straight ladders are generally used in lengths of 12, 14, 16, 18, and 24 feet. AN EXTENSION LADDER is adjustable in length. It consists of two or more sections which travel in guides or brackets to permit length adjustment. It provides access to windows and roofs within the limits of its extendable length. Extension ladders are heavier than straight ladders and more manpower is needed to safely handle them. They generally range from 24 to 55 feet in length. AN AERIAL LADDER is a mechanical unit generally operated by hydraulic power that is mounted upon a specially built chassis. Aerial ladders are constructed of metal and are trussed to provide adequate strength. Aerial ladders generally range in length from 65 to 100 feet, but longer aerial ladders do exist. A ROOF LADDER is designed for only one specific function. It is equipped with folding hooks at the top end which provide a means of anchoring the ladder over the roof ridge or other roof part. Roof ladders are generally required to lie flat on the roof surface so that firefighters may stand on the ladder for roof work. Their lengths range from 12 to 20 feet. Ladders can be made of wood, metal, plastic. Metal ladders are usually built of heat-treated aluminum alloy. They are light in weight, have adequate strength, permit a reliable visual inspection of all ladder parts. But aluminum is a good conductor of electricity and can become very cold in winter and noticeably hot in summer because of its good conductive qualities. Some ladders are manufactured as composites of wood and aluminum to take advantage of lightness, strength and resistance to electricity. These ladders have wooden rails and aluminum rungs. Regular and proper cleaning of fire service ladders is absolutely necessary. Ladders should be cleaned after every use. Dirt should be removed with a brush and running water. Solvent cleaners must be used to remove any oily and greasy residues. After rinsing or anytime the ladder is wet, it must be wiped dry. The movable parts should be lubricated at least every six months with waterproof grease. During each cleaning period, firefighters should watch for defects in the ladder. Damaged or weakened portions of a ladder can best be found by regular and systematic inspections.
|
