Industrial Rigging Flashcards
The horizontal force on slings increases as the angle becomes ________ than 90*.
Smaller (30, 45)
Which hitch is looped around the load, which must then be balanced to keep from tipping.
The basket hitch.
The ________ hook has a point designed to fit into holes.
The sorting hook.
What are some reasons for removing a hook from service?
Hook throat has increased by 10%
Wear exceeds 10%, or there is a bend or twist prom the plane of the unbent hook.
Hooks shiws obvious signs of wear (crack, gouges)
Throat and hook not parallel.
The main purpose of a sling is to??
Suspend a load from a hoist.
Before lifting a load, you should ensure its center of gravity should be?
Directly below the hoist hook.
To avoid damaging a load from the horizontal forces being to great you should use a _________ beam.
A spreader beam.
Wire rope classification specifies the number of strands the rope contains and the number of wires in each strand.
True
What happens to wire rope that has been bent over curved surfaces?
It is subject to bending stresses, which reduces the efficiency of the rope and also the strength.
The efficiency if the rope depnds on what ratio?
The D/d ratio. Diamenter of the curved surface and the diameter of the wire rope.
When properly installe,spelted and swaged sockets provide how much efficiency?
100%
What are some conditions for removing a wire rope from service?
Rope distortion (kinking, crushing,unstranding)
Heat damage
Corrosion
Broken wires
What grade of chain is the only one recomended for overhead lifting?
Grade 80 alloy steel chain.
High strength, premium quality chain, also identified by an 8,80,800.
What are some terms used to reference chains, their strength, and their capabilities?
Working load limit, proof test, and minimum breaking force.
Alloy steel chains that have been exposed to temperatures above ______*f should be removed from service immediatly.
1000* f
End end fittings are attatched to the metal mesh fabric to make two basic types of slings. Both types can be used in vertical and basket hitches.
True
What are some conditions that should be inspected more before being put to use?
A broken weld or braze on the joints
Broken wire
Heat damage
Distortion
What type of synthetic fiber rope or sling is the most commonly used today?
Nylon is the most used.its the strongest of the fiber materials with its breaking strength being 2.5 times that of manilla rope.
What is a thimble and why is it used in lifting
It is a specially shaped metal sling accesory that maintes a space for hooking up where it would otherwise be pulled into a tight kink.also brotects against abrasion.
The newest style of sling is made up of what? (What we use in the plant)
Mutiple polyesyter fibers yarns encased in a woven polyester tube. The tube cover is color coded to indicate the sling capacity.
What are some reasons for taking a synthetic web sling out of service?
Heat damge ( melting, charring, or scrching)
Excessive wear
Distortion
Frayed or abrasion
Manual overhead operated chain hoist utilize what to do the lifting?
It uses a pocket wheel which actuated the the hoist mechanism.s
What does an upper limit switch safety device for cranes?
It ensures the hook and load isnt lifted too high, its as a cutout for lifting.
What is the difference between underhung and top running cranes?
The digference is in how the end trucks of the bridge beams are supported.
When should hoist brakes be checked?
Before each lift. Lift the load a few inches and ensure the load block and load do not drift downward.
Should a crane operator take a “stop” command from anyone involved in the job or just the signal man?
Respond to a stop command from anyone involved.
Do not use metal mesh slings in which the spirals are locked or do not move freely.
True
When using a crane, ensure the load will not contact any obstructions on its route.
True
What is one hook turning?
A load turning method by which one edge of the load serves as the pivot for the turn.
What is a turnbuckle?
A tool used for tightening the wire to the proper tension.
