QuesTioNs aNd well deFieNed aNswers already
Graded a+
Which area do truck cranes without a 5th outrigger generally have no lifting
capacity unless the manufacturer states otherwise? - ANSWER-The front
What is the definition of "operating radius?" - ANSWER-The distance from the
center of rotation of the crane to the center of gravity of the load
What applies to the capacities below the bold line shown on a load chart? -
ANSWER-They are based on the stability of the crane
In which quadrant are rough terrain crane capacities generally greater? -
ANSWER-Over the front
What percentage do most manufacturers requires a crane's load chart capacity to
be reduced by for duty cycle operations - such as highvolume concrete
placement? - ANSWER-20%
From which two points should the boom be measured? - ANSWER-From the boom
hinge pins, to the center of the boom tip sheave
, What is the preferred method of installing wire rope from a reel onto a hoist
drum? - ANSWER-Running the rope from the top of the reel, to the top of the drum.
What is the primary purpose of placing blocking under the ends of the tracks on a
crawler crane? - ANSWER-To ensure that the tipping axis is the sprocket or idler,
rather than a track roller.
Suppose you are traveling a crawler crane with the drive trains to the rear, and
you need to turn right on hard, and level ground. What should you do? - ANSWER-
Travel the left track forward to minimize wear.
When using outrigger jacks to level a crane, what is the best procedure to follow?
- ANSWER-Make firm contact with all four jacks. Then operate two jacks at a time
on either side of the lowest corner to get to level. Last, make sure the crane is
high enough to have the tires off the ground.
How does the use of outriggers increase the tipping capacity of a crane? -
ANSWER-By moving the tipping axis further from the center of gravity of the crane
Many load charts for cranes state that the area of least stability is over the side.
What statement explains this the best? - ANSWER-The distance between the
crane's center of gravity and the tipping axis is smallest in that quadrant.
List two examples of outrigger use in which the crane's leverage on the load is
reduced. - ANSWER-Outriggers not fully extended, tires not off ground
According to OSHA 29 CFR 1910.180, how accurate must a load weight be if it is
in the structural portion of the load chart? - ANSWER-Plus of minus 10%