Search results
Results From The WOW.Com Content Network
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]
The design and construction of the World Trade Center, most centrally its twin towers, involved many other innovative techniques, such as the slurry wall for digging the foundation, and wind tunnel experiments. Construction of the World Trade Center's North Tower began in August 1968, and the South Tower in 1969.
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 ...
The operator's cabin hosts a display showing the tower crane's position, movement and operating area. Where the tower crane’s operating area overlaps with other cranes or prohibited zones these are also displayed. The system alerts the operator when the crane is approaching a prohibited area or another crane. [9]
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 ]
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
Headframe of the #1 Shaft at Oyuu Tolgoi. A steel headframe is less expensive than a concrete headframe; the tallest steel headframe measures 87 m. [4] Steel headframes are more adaptable to modifications (making any construction errors easier to remedy), and are considerably lighter, requiring less substantial foundations.