TYPES OF CRANES USED IN CONSTRUCTION
There are many different types of cranes used in construction. Crane is a machine which is capable of lifting, lowering and moving of heavy materials with the use of pulleys and cables.Cranes are valuable assets for the construction industry because they made things easy for any type of construction. Nowadays there is no worry to build any construction at any place even in the middle of river to sky rise buildings cranes are very helpful.
Different Types of Cranes
There are so many types of cranes for several works. So, we can choose the type of crane based on method of work. Here, different types of cranes along with their duties are discussed.
Vehicle Mounted Crane
Cranes are required only in the construction time as temporary structures. So, cranes are mounted to vehicles for the purpose of easy moving. Generally most of the cranes are mounted to trucks except some heavy cranes. The vehicle wheels are made with rubber. So, these wheeled vehicles are moving faster than trucked but not accessible to uneven areas. Outriggers are provided to the base of vehicle to provide stability to the crane while working.
Tower cranes are one of the widely used cranes now a day. For constructing tall buildings, these type of cranes are used. They are so tall and will work up to 265 feet as well as lower to 230 feet. They are having lifting capacity approximately equal to 20 tons. They are fixed to the ground in the construction period. For the fixing arrangement, strong concrete base is created and anchored the crane by using large bolts. So, after construction this can be removed easily.
Rough Terrain Crane
Rough terrain crane is special type of vehicle mounted crane. A normal vehicle mounted crane is not suitable for off-road work or rough terrain places. Then rough terrain crane is useful. In this crane also vehicle is having rubber tires but these tires are specially designed. Outriggers are provided at the base of the vehicle to provide stability to the crane while working.
A crawler crane is a movable crane but the movement of vehicle is done by tracks. Because of these tracks they do not require outriggers for stability. Their lifting capacity is very high (40 tons to 3500 tons). Because of tracked system it can move to any site even in soft soils. It is capable of traveling with load also so, it is used for heavy load transport in the construction site.
All Terrain Crane
It is also mobile crane but is movable at same speed in the paved road as well as in rough terrains. It is having more number of wheels than normal vehicle and they balance the vehicle without overturning in rough terrains. So we can use this crane instead of both truck mounted crane and rough terrain crane for dual purpose.
Railroad cranes are generally used for construction of railway line, repairing and maintaining of railroad. These are having flanged wheels at its bottom which can be moved in rail track only.
Telescopic Handler Crane
Telescopic cranes are used to handle pallet of bricks, to install steel trusses at the top etc. they are having forklift type part at the end of boom. They also have outriggers at its base. The crane part can be rotatable to 360o.
Harbor cranes are provided in port areas for loading and unloading of ships.
Floating cranes are required for bridge construction, port construction. They are also used to load and unload the ships. They are having a large capacity up to 9000 tons. So these are also useful to lift sunk ships from water.
These are also called as sky cranes. It looks like helicopter and are used when the target is difficult to reach by land. So cables are helped to hang the material.
Telescopic crane has a large boom in which number of tubes are fitted one inside the other. These tubes are extends outwards by hydraulic mechanism. These are generally used to build signal towers, rescue operations, lifting boats from water etc.
Level Luffing Cranes
Level luffing crane has a hinged jib which will move up and down, and this up and down movement enhances the crane arm to move inwards and outwards. It is used in shipyards to place containers or to unload ships.