Search results
Results from the WOW.Com Content Network
A jib or jib arm is the horizontal or near-horizontal beam used in many types of crane to support the load clear of the main support. [1] [2] An archaic spelling is gib. [3] Usually jib arms are attached to a vertical mast or tower or sometimes to an inclined boom.
In 2007, Tishman Construction Corporation of New York completed a row of steel columns at the perimeter of the construction site. Two tower crane bases were erected, each base containing a functioning luffing-jib tower crane. By the end of 2007, the tower's footings and foundations were nearly complete. [10]
A jib crane is a type of crane - not to be confused with a crane rigged with a jib to extend its main boom - where a horizontal member (jib or boom), supporting a moveable hoist, is fixed to a wall or to a floor-mounted pillar. Jib cranes are used in industrial premises and on military vehicles.
A level-luffing crane is a crane mechanism where the hook remains at the same level while luffing: moving the jib up and down, so as to move the hook inwards and outwards relative to the base. [ 1 ] Usually the description is only applied to those with a luffing jib that have some additional mechanism applied to keep the hook level when luffing.
It was a luffing-jib tower crane manufactured by Favco that was 200 feet (61 m) tall at the time of the collapse. The accident occurred when workers were attaching a new steel collar to anchor it to the building at the 18th floor, as part of an operation to extend the crane upwards. [6]
Each crane has a span of 140 metres (459 ft) and can lift loads of up to 840 tonnes to a height of 70 metres (230 ft). Their combined lifting capacity of almost 1,700 tonnes is one of the largest in the world. Prior to commissioning, the cranes were tested up to 1,000 tonnes, which bent the gantry downwards by over 30 centimetres (12 in).
Mammoet crane (red) set up in Nigg Energy Park, Scotland to load jacket foundations (yellow) for the Seagreen Offshore Wind Farm. A ring crane is a form of large construction crane with a luffing jib. It is distinguished by its slew pivot [i] being in the form of a ring-shaped track, rather than a narrow central spindle. The broad base this ...
Ships had increased in size by this time and the jib could no longer reach far enough to remove engines or boilers for repair work. It was even considered raising the crane up on a stone tower, as for the smaller crane at Canons Marsh opposite, to increase the lift height. In 1892, hydraulic machinery, including cranes, appeared in the docks ...