Crane Refresher Practice Test Flashcards
List for criteria that make a critical lift
75% of rated capacity, personnel hoisting, special rigging procedures, two or more cranes (or hooks)used to make a lift
What prevents the boom from falling when a hydraulic line fails 
Positive pressure holding valve/ check valves on the cylinder
What are the where criteria for taking a hook out of service?
More than 5% wear in critical areas, 10% in other areas, no more than 1/4” inch at throat opening
What is fleet angle?
The maximum angle made by a rope with a line perpendicular with the drum on a crane. It would be centerline of points to the drum flange farthest from the perpendicular centerline. 1.5 degree smooth 2 degree grooved max
Describe how to make a turn back eye with wire rope clips
Measure the dead end length, fasten first clip furthest from eye, 1 saddle width in from the end of tail, be sure to install all clips with saddle on the live end, install second clip closest to eye, with thimble placed in eye, install remaining clips evenly spaced between the 1st and 2nd, torque to manufacturers specification, then re-torque a second time. Never saddle a dead horse
What is PLP?
Permissible Line Pull. The rated pull capacity of a winch ( allowable in pounds)
Explain D/d ratio
The diameter of the wire rope compared to the diameter of the object it goes around
“D” divided by “d” = D:d ratio
What is the D/d ratio for different types of sheaves?
Block sheave 16:1
Boom point sheave 18:1
Boom hoist sheave15:1
How are parts of line determined?
Suspended load divided by Safe Working Load SWL or PLP Permissible line pull 
What class is 6x25 wire rope?
6x19 (6 strand 15-26 wires, 6x7 6x37 8x19)
What is cabling?
When a multipart hoist spins/twists enough that different parts of line make contact
What will reduce cabling?
Switch to even parts of line, reduce length of the fall, use rotation resistant rope, reeve fall symmetrically, change sheave size
How far out of level may a crane be before the load chart is not valid?
1%
Short sections of boom go towards______
The boom base section
Broken wire out of service criteria, rotation resistant rope.
2 wires in 6 diameters or 4 in 30 diameters. Personnel lifts add 1 valley break
wire rope sling broken wire criteria
5 wires in one strand in one lay , or 10 or more random wires in one lay
Broken wire for running ropes
3 broken wires in one strand in one lay or 6 random broken wires in one lay
Crane hook closest to the center of gravity picks _____ weight.
More
If a two crane pick is not made evenly, more load shifts to the upper or lower hook?
The lower hook
Why would you want one crane to get more of the load in a two crane pick?
Offset C/G, odd sized or shaped load, different load capacities
Wear criteria for taking wire rope out of service.
Reduction in diameter of 1/3 of the outside wires original diameter
Safety factor for running rope
Working 3.5:1
Erecting 3.0:1
Safety factor for standing wire rope
3.0:1 working
2.5:1 erecting
Tower crane 5:1
Safety factor for rotation resistant wire rope
5:1
10:1 for personnel lifting
Reasons for taking wire rope out of service, other than wear and broken wires
Heat damage, corrosion, birdcaging, core protrusions, distortion, high stranding, dog legs, crushing, kinks
What information is obtained from a load chart?
Gross capacity, boom length/angle/radius, deductions, warnings, operational notes, configurations
List 7 reasons for backward tipping
Improper set up, severe unloading, two blocking, rigging failure, erratic swinging, traveling uphill with too high a boom angle, operator error, wind
List the three types of shackles
Pin
Screw
Bolt
Symmetrical reeving of fall block is best, avoids torsion loading of boom tip
What is recommended for blocking (cribbing) off outrigger pads 
3 times the size of outrigger pad surface area, tight together and parallel
What is the minimum allowable amount of wraps on a hoist/boom drum?
2 wraps minimum
What is duty cycle?
Repetitive motion operation, for example digging, concrete, bucket, steel erection
What is the chart reduction for duty cycle
20%
What are the weights for these items per cubic foot in pounds?
Water
Steel
Concrete
Water 62 pounds per cubic foot
Steel, 490 pounds per cubic foot
Concrete150 pounds per cubic foot
What is the efficiency of a Flemish eye
90%
What is the efficiency of a wedge socket? (Becket)
80%
What is the efficiency of wire rope clips
80% under 1 inch diameter
90% 1 inch and above
What is the efficiency of a spelter socket?
100%
What is the efficiency of a swaged fitting?
100%
What should a tail length be on a wedge socket with regular rope? 
Six diameters of the wire rope, but never less than 6 inches
What should the tail length to be on a wedge socket with rotation resistant wire rope?
20 diameters of the wire rope, and no less than 6 inches
What makes wire rope more flexible
More wires equals more flex or softer core construction
Maximum allowable throat opening for a hook
5% of the original dimensions, but no more than a quarter of an inch
Other types of wire rope core besides IWRC
Fiber and synthetic
Triple leg slings have 50% more capacity than double leg slings. Only if the center of gravity is in center of the connection point and legs are adjusted to equally share the load. Quad leg slings offer improved stability but do not provide increased lifting capacity.
Only use drop forged wire, rope clips
What is the criteria when measuring wire rope?
Measure crown to crown, 3 times for 6 strand wire and 4 times for 8 strand wire
How is safe working load (SWL) determined
Ultimate breaking strength divided by the safety factor
Two categories of weight chart
Stability, and structural
How far back from a hole 10 feet deep is recommended
1 to 1 plus 2’ for the berm = 12’
10” plus 2” for the berm= 12”
Sorting hooks should be used at an angle less than___degrees
45°
A 7 1/2 ton sorting hook tip loaded it will only be good for about two tones 
Out of service speeds for wind
20MPH when lifting personnel
30MPH
Load angle factors
90°
60°
50°
45°
30° 
90° 1.0
60°, 1.155
50°, 1.305
45°, 1.414
30° 2.0 
