Jan 7th Flashcards
What are the two most common types of shackles ?
- Screw pin anchor shackle
2. Screw pin chain shackle
How much does the percentage of capacity decrease when rigging is at a 45 degree angle ?
30 %
How much does the percentage of capacity on a shackle decrease when rigging is at a 90 degree angle ?
50%
Shackles should be tightened by hand so the full threads are engaged.
True or false
True
How often do shackles 80t and above need to be mag particle tested?
Every year
What is another term for a lifting lug?
Pad-eye
What are the two forces placed on a spreader bar under load?
- Compression
2. Bending
How are shackles sized ?
By the diameter of the bow
How is WLL determined on a turn buckle ?
By the outside diameter of threaded portion
When is the only time you may use a jam not on a turnbuckle ?
When the turnbuckle comes equipped with one from OEM
Name the five styles of turnbuckles
- Eye and eye
- Jaw and eye
- Jaw and jaw
- Hook and eye
- Hook and hook
Define a come along
A hand operated winch with a ratchet used to pull objects
When would you use a snatch block in an overhead lift ?
Never. They are used to change the pulling direction of wire rope.
Name two differences between crane blocks and wire rope blocks.
- Crane blocks have cheek weights while wire rope blocks utilize cheek straps
- Crane blocks are designed for heavy objects and frequent lifting while the lighter wire rope blocks are designed for high speed applications
What is the most important factor of a overhead ball?
Being heavy enough to keep the line tight
What is the one style of hook exempt from the rule that they must all be equipped with a swivel and safety latch ?
Sorting/pelican hook
Name the three styles of eye bolts.
- Regular nut type
- Shoulder nut type
- Machinery type
Which style of eye bolt may be loaded at an angle (permitting it is placed in plane of the eye and capacity is reduced accordingly) ?
Shoulder nut type
How much of the exposed area on a shackle pin should be covered by the lug during a lift ?
80%
What is the difference between a spreader bar and an equalizer bar ?
Spreader bars have two lugs on each end and each side whereas an equalizer bar has one on one side and two on the other. (Can be flipped)
What is the safety factor for running lines (iwrc)
3.5 to 1
What is the safety factor for running lines (rotation resistant)
5:1
What is the safety factor for rigging and slings
5:1
What is the safety factor when hoisting personnel
10:1
What is the safety factor for chain slings
4:1
For supporting the boom, working attachments and rated loads (including boom suspensions) the design factor for boom pendants or standing ropes shall not be less than what
3:1
For supporting the boom under recommended boom erection conditions the design factor for boom pendants or standing ropes shall. It be less than what
2.5
How do you determine breaking strength for IWRC
D^2 x 45
What is the formula to determine breaking strength for fibre core wire rope
D^2 x 42
If the core of a wire rope was unknown how would you determine its breaking strength as a rule of thumb
D^2 x 8
What is the rule of thumb to determine the breaking strength of chain
D^2 x6
What is the formula for determining safe working load on an iwrc
D^2 x 45 / 5
Answer will be in tons
What is the formula for determining the safe working load on a fibre core wire rope
D^2 x 42 / 5
What is the formula for determining the safe working load of galvanized wire rope
D^2 x 40 / 10
What is the formula to determine the capacity of a basket hitch (true)
Svc x2
What is the formula to determine the capacity of a choker hitch
Svc x .75
How would you determine how many wire rope clips are needed
D x 3 + 1 (to the next whole number)
How would you determine clip spacing
D x 6 ( centre to centre)
What is replacement criteria on running ropes ?
6 or more broken wires in one lay length or
3 or more broken wires within a strand in one lay length
What is the replacement criteria for standing ropes
More than one broken wire going into an end fitting or
3 or more broken wires in one lay length or
2 broken wires in 6 rope diameters or 4 broken wires in 30 diameters
Do hooks have any tolerance for twists or spreading outside of the normal original opening
No. Rigging shall be used within the 45 degree hash lines and no more than two slings at a time shall be used
At what percentage of wear on the pin or bow shall a shackle be removed from service
10% or over
How efficient are chain falls (%)
85 % effective
15 % loss to friction
What is reduced capacity of a hook if the load is 1/4 off centre
Approx 86 %
What is the reduced capacity of a hook if a load is 1/2 of centre
Approx 80%
What is the reduced capacity of a hook if the load is 3/4 off centre
Approx 70%
If you point load a hook how much is its capacity reduced by
60%
With the exception of pelican/sorting hooks. What must all load hooks be equipped with
A swivel and a safety latch
The latch shall bridge the throat opening of the hook for the purpose of retaining slings or other devices under slack conditions
What is the most flexible wire rope
6x37
What is the most common type of wire rope
Right regular lay
What material has the greatest resistance to shock loading
Nylon
No matter how many legs of a chain sling are used the rating of only ______ shall be used
2
What is the stitching called that goes end to end on a sling
Warp
What is the stitching called that goes across a sling
Weft
What are the characteristics/components of wire rope
Wire rope is comprised of steel wires which are laid and twisted together to form strands, the strands are the laid around a core.
Steel wires
Strands
Core
What is a wire core made of and what are its advantages
It is just another strand
It adds about 7.5 % strength over fibre core
Helps resist rope crushing
Required in extremely hot work environment as fibre core could burn or char
What are the five basic design principles of wire rope
Grade of wire - ips, eips/xips , eeips/xxips etc
Number and pattern of wires used in a strand and the number of strands ex 6x19 means 6 strands with 19 wires per strand
Lay type - regular or Lang lay
Pre forming - resists crushing and helps hold shape when cut also resists unwinding and each strand carries and equal load
Type of core - wire of fibre
Describe the characteristics as benefits of fibre core wire rope
It is lighter and adds flexibility which allows greater resistance to shock loading. During manufacturing the fibre core is impregnated with lubricant, which is released during rope use and helps keep the wires lubricated. It also helps cushion strands during use
What is an example of a synthetic rope starting to see use
Kz-100 rope by Samson
What is plasma rope
Synthetic rope manufactured using polyethylene
Wire rope is manufactured in what five grades
Grade 90/100 mild plow
-has high fatigue resistance but lower tensile strength (applications are limited
Grade 100/110
-has lower tensile strength but can be used when strength is secondary to wear resistance
Grade 110/120 IPS
- most common has good wear resistance high fatigue factor and high tensile strength
Grade 115/125 EIPS
- used when the need for higher breaking strength is required the bending quality is not as good as IPS but it’s about 15% stronger
Grade 120/130 EEIPS
- is used when special installations require max rope strength such as mine shaft hoisting about 10% stronger than EIPS
What are three less common types of specialized wire rope
Corrosion resistant - for military applications
Galvanized finish - for more durability
Phosphor/ bronze/ copper - for corrosion resistance as well as non sparking used in hazardous industrial plants and marine applications
Wire ropes are also characterized by their strand shape. List four and identify the most common
Round strand - most common
Flattened strand
Locked coil ropes
Concentric strand ropes
What is the rule of thumb pertaining to bending fatigue
The greater the number of wires in a strand the greater the resistance to rope bending fatigue
Within round strand classifications the wires may be arranged In certain geometric patterns called constructions. List the four most common and their characteristics
Ordinary - all wires are the same
Seale - larger diameter wires are used on the outside of the strand to resist abrasion and smaller wires are inside to provide flexibility
Warrington - alternating wires are large and small to combine great flexibility with resistance to abrasion
Filler - very small wires fill in the valleys between the outer and inner rows of wires to provide good abrasion and fatigue resistance
How would you spool new wire rope onto the drum
In the same direction it is on the cable spool
Ex top to top
Bottom to bottom
Do fittings and connections reduce cables efficiency
Yes
When using a wedge socket what is the efficiency reduced to
70% AIT
80-85 % real world
Rope should be supported by a sheave over an arc of what
120 to 150 degrees
Since 2001 it has been mandatory for all slings to to have an ID tag with what five things on it
Name/trademark of the manufacturer Diameter or size Type of material used Rated load for a given hitch Lift angle upon which the load rating is based
What is the most common method of making an eye or attaching a piece of wire rope to equipment.
With cable clips
What are the two main types of cable clips
U bolt
Fist grip
What are the three parts or a U bolt
A U shaped bolt
A forged saddle
Two nuts
Cable clips are capable of producing up to _____ % or wire rope strength when properly applied and can drop to _____ % if incorrectly installed
80
40
What are the advantages of a fist grip clip
Offers a wider bearing surface for maximum strength and greater holding power
When should you tighten your clips.
Before tension is applied, making sure to come back and check for tension after a load has been applied
Can you connect two straight wire rope lengths with cable clips
No. If necessary create two eyes and connect the eyes
What do you need to always use to form an eye on wire rope
A thimble
Can you reuse cable clips
No. You will never achieve proper efficiency after use
What is the most popular natural fibre rope/the only one used in the construction industry and what are its characteristics
Number one grade Manilla rope
- strong
- durable
- light yellow colour
- as grade and strength decrease the colour darkens
The breaking strength of 1” dia manilla rope is 9000 pounds
What are four other types of natural fibre ropes and there characteristics
Hemp - strongest of natural fibres
- deteriorates quickly when wet
Sisal - approx 75% strength of untarred hemp
- stands exposure to seawater
Coir - made from coconut husk fibres
- very elastic
- 1/4 the strength of hemp
- floats
Cotton - 60% as strong as hemp
Besides having individual threads and fibres that run continuously through the rope what other characteristics do synthetic fibre ropes share
Resistance to rot and mildew
More strength than natural fibre rope
What are the four common types of synthetic wire ropes and their characteristics and which is the most popular/common
Nylon -other than kevlar it’s the strongest
Polyester -not as strong as nylon twice as strong as Manila
Polypropylene - lightest, most economical and most popular
Polyethylene - 50% as strong as nylon and resists acids and alkalis
