When you come across a construction site, the first thing that you’ll notice will be a huge crane, painted bright yellow. Construction sites use many kinds of cranes; each crane type has its own specific purpose. Here’s a look-see at these cranes and what they’re used for.
Fixed And Moving Cranes
Cranes fall into two major groups – Fixed Cranes and Mobile Cranes.
Fixed Cranes are usually tethered to a specific location on a pedestal. Since they are fixed, they have better center of gravity control and can therefore load more weights. Fixed cranes are mostly used to load cargo on to ships or other transport vehicles and sometimes also at construction sites.
Mobile Cranes, on the other hand, can be driven to wherever the crane is required. Construction sites use mobile cranes more than fixed cranes, given that all construction sites are temporary.
Common Construction Site Cranes
The Telescopic Crane
Telescopic cranes come with an extendable boom, whose length can be adjusted as required. That’s why it’s called a ‘Telescopic crane’. The boom comprises of a number of inter-fitted tubes, which are extended or retracted using a hydraulic mechanism. This type of crane is usually fitted to a platform and used to lift loads on to trucks and to rope lifts.
The Telescopic Mobile Crane
This type of crane has a telescopic boom that is mounted on a cat truck or a rail, to keep it mobile. This crane can be moved around to the area where it is required. The boom can be lowered or raised using hydraulic cylinders or cables. The boom is hinged at the bottom for easy manipulation.
Tower cranes are ideal for constructing very tall buildings such as skyscrapers. Similar in design to the balance crane of older days, the tower crane is fixed to the ground on a pedestal. This gives it the requisite balance to lift heavy loads to great heights. The boom is extended to the required height using hydraulic cylinders and cables.
In this type of crane, a trailer is fitted with a hydraulically-powered, articulated arm. This arm comprises of several sections that can be folded and squeezed into a small space when the crane is not required for operation. The crane is powered entirely with hydraulics. While the trailer is mobile, the arm of the crane is fixed. This crane is ideal for lifting heavy objects at a construction site, shipyard or factory.
Truck Mounted Crane
These cranes are mounted on rubber tire trucks which afford great mobility; this makes them especially valuable at a construction site where loads have to be moved around to where they are required. These cranes are equipped with vertically or horizontally extending outriggers, which stabilize and level the crane while hoisting loads.
Rough Terrain Crane
This crane is ideal for performing rough, off-the-road operations. It is mounted on an undercarriage which is placed on four rubber tires. The crane is stabilized by long outriggers that vertically and horizontally from the crane while hoisting loads. These cranes are operated by a single engine mounted in the undercarriage, which powers both the undercarriage and the crane.
An overhead crane is sometimes also called a suspended crane. These cranes are usually used in factory settings and at construction sites where heavy loads need to be manipulated. The crane’s hoist is set on a mobile trolley which moves along one or two beams on level or elevated tracks. Usually the beams are mounted alongside an assembly area.
All terrain crane
All terrain cranes are basically mobile cranes which can travel at good speeds on public roads. These cranes are ideal for movement from one construction site to another. They can travel on rough terrain through their all-wheel and crab steering abilities. All Terrain cranes offer the unique combination of the road-worthiness of Truck-mounted Cranes and Rough Terrain Cranes’easy maneuverability. They can lift heavy loads of 1200 tons.
Pick And Carry Crane
A Pick and Carry Crane is used to lift and carry loads to destinations with a small radius. The advantage they offer is that of a road-worthy mobile crane that can travel on public roads. They are ideal for transporting loads in a large construction sites. Each of these cranes can lift upto 10 to 20 tons per lift.