دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: 1. a derrick or crane shaped like the letter A and used to handle heavy loads. 2. an A-shaped openwork structure that is the stationary and supporting component of the mast of a jackknife rig and to which the mast is anchored when it is in an upright or drilling position. 3. the uppermost section of a standard derrick, shaped like the letter A and used as a support in lifting objects such as the crown block to the water table.

n: A kind of "A" frame gin pole, used to elevate heavy object.

n: in crane operations, when a sling with two legs is attached to each end of a load, the slant or the angle the two legs make as measured from horizontal. A reduction in the strength of a sling must be allowed for angles other than 90 degrees.

n: 1. a movable arm of tubular or bar steel used on some types of cranes or derricks to support the hoisting lines that carry the load.2. floating device used to contain oil. 3. a period of high activity in the oil industry.

n: a ratchet device on a crane that prevents the boom of the crane from being lowered but still permits it to be raised. Also called a boom ratchet.

n: the large-diameter wire rope or the strands that support the boom of a crane.

n: the steel projections on a crane struck by the boom if it is raised too high or lowered too far.

n: in crane operations, a sling made from a braided wire rope.

n: in crane operations, the amount of load that causes a wire rope or a sling to fail. Also called actual strength. Compare minimum acceptance strength. nominal strength.

n: in crane operations, a sling composed of several legs, the tops of which are gathered in a fitting that goes over the cranes lifting hook. See leg.