Ladders

Ladders and Their Various Types

A ladder is an inclined set of rungs leaned against vertical surfaces; it is a special type of stairs and are divided into two main types: rigid ladders and rope ladders where rigid ladders are erected against walls and rope ladders are hung from the tope. Rigid ladders are usually portable but some rigid ladders are permanently fixed to buildings. Escalators and elevators can not be categorized as the types of ladders rather they are special genres of stairs.

In rigid or fixed ladders several rungs are attached with two side members and they do not have any moving parts; in older times most of the rigid ladders were made up of wood but now in modern age aluminum and fiberglass are also used to manufacture ladders; aluminum being lighter in weight and fiber, being an electric insulator. Rigid ladders are available in market in multiple versions like extension ladder, step ladder, telescopic ladder, orchard ladder etc. to prevent workers from sliding light weighted cat ladders another type of rigid ladder is utilized, orchard ladder is specially designed to pick up fruit from trees; it has an extra third leg which is used to insert between the trees for easily plucking frits. Extension ladder uses a pulley to extend its length; it has the ability of sliding apart, any person standing on the ground can operate it maximize or minimize its length added with this, it can also be locked at any required length, turntable ladders are used by firemen fitted with a rotating platform on the top of a fire truck. To grasp the ridge of a pitched roof ladders are the first priority of the customers while bride ladders are used to lay down horizontally and act as a passage.

Rope ladders are used at places where storage space is extremely limited, it may use rigid and flexible rungs, primarily operated at places where the way to climb up is rather camber and arched. It requires more skill of the user, while climbing up, to tackle with a rope ladder for it moves to and fro like a pendulum. Electrostatic Discharge is a natural phenomenon, in which electricity passes through conductive bodies, causing damage to electrical equipment; dissipative ladders are a good resistant against ESD activities as they have the capacity of lowering down the flow of electricity from one body to another. Made up of plastic steps and metal bars on the sides supporting the plastic steps, pool ladders are used on the side of a boat or in a swimming pool.

All fixed ladders, more or less, have following four components; rungs, cages, side members and stand off brackets. In the Us these ladders are covered by OSHA and ANSI standards, fixed ladders are mostly used in industrial applications. OSHA’ standardizes rungs of a fixed ladder to be no more than 12" on centre and 16" at width, OSHA Standard dictates the length of the stand off brackets, the device used at the top of ladder to hold it away from the wall, should be 7" more than the cesspool projecting from the building. Side members help slip off the foot of the ladder. Steel, aluminum, stainless steel, wood and polymer are the materials used to make fixed ladders.

Rigid ladders should be inclined at an angle of 15° to the vertical, for precipitous angles can tumble backward whereas emaciated angles let the grip of ladders to loose easily. So be careful while climbing through a rigid ladder because an adjustment made at a wrong angle can cause the climber to fall down on the ground fracturing his body’s organs.