Climbing, lifting, rigging, and hoisting: Part C

What is chain

Long links of looped steel designed to lift rough and heavy loads, usually marked on their links with an identification letter such as A or T.

Why is wire rope better for general rigging?

Because chain gives little warning that its about to break

Is wire rope or chain better at withstanding shock loading?

wire rope

What are 4 ways chain is better than wire rope?

More durable, doesn't kink easily, heat resistant, abrasion and more corrosion resistant

What are some limitations of chain?

Inability to stretch and affected by corrosive situations

What is wire rope?

wires that have been twisted together to form a flexible rope, often times consisting of individual wires laid out into strands that are wrapped around a central core.

What are six important factors of wire rope?

Strength, flexibility, resistance to abrasion, resistance to crushing, resistance to rotation, resistance to corrosion.

What are the three types of wire rope core?

Independant wire rope core (IWRC), Fibre core, Wire strand core (WSC)

What is Independent wire rope core?

A small diameter rope forming the center core of the main rope. Resistant to crushing and stretching.

What is fiber core rope?

A rope made with a synthetic core which makes the rope more flexible and elastic but less resistant to temperatures

Whats is wire strand core rope?

A rope core made of a single strand and not to be used for lifting, mostly stabilizing and support lines.

What are the 4 basic kinds of round strands?

Ordinary, Warrington, Seale, Filler

What is an ordinary strand?

All wire are the same size

What is a warrington strand?

Outer wires are alternately larger and smaller

What is a Seale strand?

Wires of the outer layer are larger than the inner layer

What is the Filler strand?

Small wires fill the spaces between the larger wires

Where must you measure wire rope?

Across the crowns

What are the three common grades of wire rope?

Plow, Improved plow, Extra improved plow

What is the lay of a wire rope?

The way in which the wires and strands are twisted relative to each other

What is regular lay?

Wires and strands are twisted in opposite directions which makes the rope resistant to crushing, kinking, and distortion

What is lang lay?

Wires and strands are twisted in the same direction which makes the rope more flexible and resistant to abrasion

What are wire rope slings?

A wire rope manufactured with lifting eyes

What is flemish eye splicing?

when a rope in spliced onto itself in reverse direction and fitted with a metal sleeve to secure the splice

What is a thimble?

A steel sleeve that conforms to the rope size to protect the wire rope sling eye from wear.

What are the two types of rope clips?

the j-clip and U-bolt

Why are j-clips better?

wide bearing surface for maximum strength and it can not be installed correctly.

What is the wire rope saying?

"Never saddle a dead horse"

What is a steel wire mesh sling?

small steel rings or links which form a mesh that have attachment points on each end.

What is a synthetic fiber sling?

a sling made from synthetic fibers with attachment points on each end, commonly made from either nylon or polyester.

What are some common types of web slings?

Triangle and choker, double eye, reverse eye, endless or grommet, return eye

What are some advantages to web slings?

Flexibility, withstand shock load, don't damage materials, light weight, do not corrode, do not spin/twist

What are synthetic fiber round slings?

a sling made from a continuous single synthetic yarn into a circle and encased in a flexible, loose fitting tube cover.

What are the benefits of synthetic fiber round slings?

Low stretch, uv-resistant, abrasion resistant, seamless, high strength to weight ratio

What are 5 types of protective devices for slings?

Buffer strips, Reinforcing strips, sling coatings, edge guards, sleeves

What is the primary reason wire slings may be unsuitable for lifting loads?

They cause damage to the material being lifted?

What is the primary reason synthetic web slings may be unsuitable for lifting loads?

They cant resist heat or abrasion

What are red core yarns?

Red yarn woven inside synthetic web slings that appear to signal when the sling sustains damage and must be removed from use

Who is responsible for inspecting and verifying condition of rigging equipment prior to its use?

The employer

True or False: Workers must nor use any rigging equipment found to be unsafe.

True

What is the weakest part of a wire or synthetic sling?

The part that's damaged

What are common signs of damage to wire rope slings?

Wear, broken wires, stressed strands, flat spots, kinks, corrosion

What are common signs of damage to synthetic web slings?

Wear, dry cracks, uv damage, cuts and tears, damaged stitching

By how much wear should a wire rope sling be replaced?

wear of 1/3 the original diameter.

What is the amount of wear on a chain where it would need to be removed from service?

10%

What is the amount of stretch on a chain where it would need to be removed from service?

5%

What are common signs of damage to chains?

Wear, cuts, twists, knicks, bends, pitting, stretch, lifted fins

When is fiber rope used?

To guide equipment, secure equipment, hoist or lower tools, tag lines

What is the only type of natural rope?

Manila

What are the two types of synthetic ropes?

Nylon and polypropylene

What are the 4 qualities of nylon rope?

Greatest strength, elasticity, durability, and flexibility

Why is polypropylene the most common rope?

Its light weight, floats on water, doesn't absorb moisture, and is the cheapest kind of rope

How must a natural rope be terminated?

The ends must be whipped or bound with twine

How must a synthetic rope be terminated?

By melting the strands together

What is the common rope safety factor?

1:5

What is a knot?

Its formed when the end of a rope intertwines with a section of the rope.

What is a bend?

Its formed intertwining two rope ends, either the same rope to make one endless rope or of two different ropes to make one continuous rope.

What is a hitch?

Its formed by fastening a rope to an object, such as ring, hook, or post.

Whats is a splice

Its made by joining the ends of two ropes. An eye spice is made from a single rope by doubling it back upon itself and interweaking the stands.

What is the strength of a new rope?

100%

What is the strength of a knotted rope?

50%

What is the strength of a bent rope?

50%

What is the strength of a hitched rope?

75%

What is the strength of a spliced rope?

85%

What is the only acceptable type of knot in rigging?

A bowline

What is a bowline on the bight used for?

To make a set of double sling legs

What is a running bowline used for?

To form a free moving slip-knot

What is a self-centering bowline used for?

When equal leg stress is required for hoisting a load

What is the figure eight knot used for?

Tying two ropes of equal diameter

What is the clove hitch used for?

Fastening rope to a post, pipe, or other similar material at the end or in the middle of a rope

What is the round turn and two half-hitches used for?

Attaching the end of a rope to a post, pipe, or other similar material which is almost slip proof

What is the timber hitch used for?

rigging palanks, pipes, tubes, bars, and other similar materials on end which will not loosen or slip until the load is relieved

When is the sheet bend used?

To join two different size diameter ropes

When is the carrick bend used?

To join two large equal diameter ropes

When is the catspaw used?

To attach rope to a hook for the purpose of transportation only, not for hoisting.

What is the sling stress formula?

(Weight/Number of sling legs) multiplied by (sling length/vertical height of hook over the load)

What is chains safety factor?

4:1