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What is the rule of thumb for steel weight?
1'x1'x1" = 40 pounds
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What are the rope specs for a tugger drum?
- - flanges of drum must protrude 2 rope diameters above last layer of rope
- - three layers max of rope
- - when hook at lowest, at least 5 full turns of rope left on drum
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What are the fleet angles for grooved drums and smooth drums?
grooved = 1/4' to 1 1/4 (degrees)
smooth = 1' to 2'
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When two or more sling eyes are to be placed in a lifting hook it is preferable to use:
a shackle
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the hoisting hook must always be:
above and in line with the load's centre of gravity
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What is the max allowable wear on chain?
10%
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When should the stretch in a chain be cause for concern?
- 3% check very carefully
- 5% remove from service
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When rigging up load with 2 or 4 leg bridle hitches what must you assume?
that load will be supported by only 2 slings
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What is the load value of a single vertical hitch?
1 times WLL
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What is the load value of a basket hitch?
2 times WLL (if legs are vert., load is circular, diameter is 25 or more times diameter of wire rope sling)
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What is the load value of a choker hitch?
3/4 that of single vertical hitch
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How much is the load value on a load that is the same diameter as the wire rope?
50% because of shearing.
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What is the load on each sling at 60'?
57.7% of total load (eg. 577lbs on 1000lbs load)
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What is the load on each sling at 45'?
70.5% of total load (eg. 707lbs on 1000lbs load)
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What is the load on each sling at 30'?
100% of total load (eg. 1000lbs on 1000lbs load)
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What is the load on each sling at completely vertical to seperate hooks?
50% of total load (eg. 500lbs on 1000lbs load)
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What is the recommended angle for multiple slings to a single hook?
60', creates equalateral triangle
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Sling Stress Formula
T = (W/N) x (L/V)
T= tension/sling in lbs
W= weight in lbs
N = number of legs
L = choker length in feet
V = vertical height from hookup to load
- Rule of Thumb:
- WWL Slings = D2x6
- WWL Wire Slings = D2x8
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When should wire ropes be replaced?
- - 6 or more broken wires in one rope lay
- - 3 or more broken wires in one strand of one rope lay
- - outer diameter wire wear is at 1/3 of total
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What is the standard amount of stretch in new wire rope?
- 6 stranded rope = 6" per 100' of rope
- 8 stranded rope = 9-10" per 100' of rope
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What is the proper placement of a shackle on the hook?
pin on the hook, load on the body of shackle
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What is the load limit of a u-bolt or crosby clip?
80% of wire strength
NEVER SADDLE A DEAD HORSE
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What is a sheave and what is the ROT for them?
the pulley part of the block that carries the rope.
ROT = shoiuld be at least 20 times rope diameter
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Shoulder type eyebolts should only be used with angular pull greater than?
45'
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When slings with hooks are used in a bridle sling arrangement, they should always be:
turned out and have safety latches
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The only chain suitable for construction hoisting is made from?
alloy steel
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Chain that needs to be repaired must be repaired by?
the manufacturer
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A shackle is sized by?
diameter of the bow section
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equlaizer beams are typically used in conjunction with:
dual hoist hooks
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When reeving or lacing rope through sheaves in a block and tackle system, fasten the dead end of the rope to the:
becket
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A wedge socket is used to attach:
a headache ball, a swivel, a hook
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To maintain the highest capacity of a sling, what is the minimum length of contact of wire rope with a softener?
1 rope lay length
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in a bridle sling arrangement, the stress load on each sling leg is equal to the weight of hte load, when the sling angle is:
30' from horizontal
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The recommended sling angle when using a two part bridal sling is:
60' angle from the horizontal
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The ROT for the minimum sheave diamter is the rope diameter times:
20
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Shoulder-type eyebolts should only be used with angular pull (from the horizontal) gerater than:
45'
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When slings with hooks are used in a bridle sling arrangement, they should always be:
turned out and have safety latches
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Which type of block is designed to change the angle of pull for wire rope?
snatch block
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The two methods of reeving are:
square reeving and lacing
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How large should the surface area of blocking be on a crane float?
3 times the size of the float
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What do range diagrams do?
place the crane for a particular job
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Crane load/capacity charts give capacity in:
gross weight
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Do crane load charts have seperate areas for strength and stability?
yes
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What is the least amount of rollers required when moving a load with heavy wall pipe?
3
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What is best used to move a very heavy load precisely to its final position?
tirfor
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What are the two most common forms of scaffold?
- tubular framed
- tube & clamp
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What load must scaffold be able to handle?
4 times possible load imposed
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Free standing or rolling scaffolds must not be more than three:
times higher than the smallest base dimension
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What type of scaffold frame would be used to allow pedestrian traffic at ground/street level?
masonry
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What type of scaffold is used for strange shapes?
tube and clamp
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What is the name of a scaffold support member that is attached on one end to a permanent structural member and suspended by rope or chain to the outside end?
needle beam
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At what height is additional certification needed to erect a scaffold?
80 feet
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At what height are toe boards required on scaffold?
3.5m (11.48/12ft)
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How high must the top of a toe board be?
140mm (5.5"
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What must be installed between the sections when frame scaffolds are stacked on top of each other?
retainer pins and coupling pins
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Define runners on scaffold.
horizontal members on tube/clamp scaffold that tie vertical posts together
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What is the max distance allowed between rungs on a ladder scaffold it used w/o attached ladder?
300mmn or 12"
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Scaffold ladder stats:
- 6" clearance behind rungs
- no more than 21ft long
- extend 3 ft above working platform to be accessed
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