Search results
Results From The WOW.Com Content Network
A tower crane is usually assembled by a telescopic jib (mobile) crane of greater reach (also see "self-erecting crane" below) and in the case of tower cranes that have risen while constructing very tall skyscrapers, a smaller crane (or derrick) will often be lifted to the roof of the completed tower to dismantle the tower crane afterwards ...
Dynamic loads considered in lifting design are accounted for in two stages; suction to the casting bed on the initial lift and then the dynamic loads induced from crane vibration. These crane impact loads must be accounted for during transportation in the yard and on-site, and the coefficient increases from an overhead gantry crane through to a ...
Developments in tower crane design and the increasing complexity of construction sites in the 1970’s and 1980’s led to an increase in the quantity and proximity of tower cranes on construction sites. This increased the risk of collisions between cranes, particularly when their operating areas overlapped.
Crane The tower crane (see picture) is a modern form of balance crane that is fixed to the ground. A horizontal boom is balanced asymmetrically across the top of the tower. The long arm carries the lifting gear. The short arm is called the machinery arm; this holds the motors and electronics to operate the crane, as well as the concrete ...
A crane's rated load is its Safe Working Load (SWL) and the design load (DL) is, (p 90) [1] = The dynamic lift factor for offshore cranes in the range 10 kN < SWL ≤ 2500 kN is not less than =.(p 84) [1] Thus for a crane with a SWL of 2000 kN (~200 tonne) its design load is not less than, = = The minimum breaking load (MBL) for the combined capacity of reeves of a steel wire hoisting rope ...
Climbing formwork (crane-climbing): in this type of climbing formwork, the formwork around the structure is displaced upwards with the help of one or more cranes [4] once the hardening of the concrete has proceeded far enough. This may entail lifting the whole section, or be achieved segmentally.
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.
An overhead crane, commonly called a bridge crane, is a type of crane found in industrial environments. An overhead crane consists of two parallel rails seated on longitudinal I-beams attached to opposite steel columns by means of brackets. The traveling bridge spans the gap. A hoist, the lifting component of a crane, travels along the bridge.