week 10 rigging Flashcards
Between the trolley hook and the load is____.
rigging
1926.251 General
Rigging inspected prior to shift(s) As necessary during use Removed if defective Remove rigging equipment when not in use
Alloy Steel Chain rules
1.Size, 2.Grade 3.Rate d capacity 5. Sling manufacturer. All attachments capacity at least equal to chain.
hoist chains
Check for wear, gouges, stretch, shearing. Inspection is LINK by LINK, Twisted link extremely unsafe. Use with grab hooks. Tags: should be on every chain: Size, Grade, Capacity.
Four grades of hoist chains
Grade 28 General Utility Chain ◦
Grade 43 High Test Chain ◦
Grade 70 Binding Chain ◦
Grade 80 Alloy Steel Chain: The only one used for overhead lifting!
Job or shop hooks and links, or makeshift fasteners, formed from bolts, rods, etc., or other such attachments_______.
shall not be used
CP inspections made & based on:
◦ (A) Frequency of sling use; ◦ (B) Severity of service conditions; ◦ (C) Nature of lifts being made; and ◦ (D) Experience gained on the service life of slings used in similar circumstances.
CP inspections should be done at least once a year _______.
Documented and available
Follow manufacturers safe working load recommendations, or Tables H - 3 through H - 14. No knots in ____ except where permitted
wire rope
Rope core could be made of_____.
Fiber, IWRC, strand
6X25 FW PRF RLL XIP IWRC. This translates to:
A 6 strand (6X25) of filler wire construction (FW). The grade of wire used is Extra Improved Plow Steel (XIP).
The strands are preformed _____ in helical pattern before being laid ______ around an ________.
- (PFR)
- Rigt Land (RLL)
- Independent wire rope core (IWRC)
A mechanical splice cannot have a _____, it must be done in a shop.
pigtail
Wire rope shall not be used if, _________.
in any length of eight diameters, the total number of visible broken wires exceeds 10 percent of the total number of wires, or if the rope shows other signs of excessive wear, corrosion, or defect.
U-bolt applied so that the “U” section is in contact with the _____.
dead end of the rope
Use Table H - 20 to determine number and ____ of clips
spacing
______shorten slings with knots or bolts
Never
Protect slings from ______.
sharp edges
Never apply a shock load when ____.
lifting
Never place finger between sling & load when ____.
tightening
Tables H - 15 through H - 18 apply Knots not used instead of splices Remove from service if:
◦ Abnormal wear. ◦ Powdered fiber between strands. ◦ Broken or cut fibers. ◦ Discoloration or rotting.
(1)Each synthetic web sling marked or coded to show:
◦ (i) Name or trademark of manufacturer. ◦ (ii) Rated capacities for the type of hitch. ◦ (iii) Type of material.
Synthetic webbing
(nylon, polyester, and polypropylene)
Don’t use ___ around synthetic webbing.
acids or phenolics because, Acid or caustic burns ◦ Melting or charring of any part of the sling surface; ◦ Snags, punctures, tears or cuts; ◦ Broken or worn stitches; or ◦ Distortion of fittings.
When dealing with shackles and hooks use table h-19 and Use manufacturers recommendations. Tested to ____ the intended safe working load before they are initially put into use. Maintain a record of the ____ and results of such tests.
twice, dates
- Know the weight of the load 2. Know the center of gravity of the load. 3. Make load attachment above the center of gravity of the load. 4. Select hitch that will hold and control. 5. Know the rated capacity of slings and hardware 6. Select sling best suited for load. 7. Inspect all rigging before the lift. 8. Protect sling from sharp surfaces. 9. Proper calculation of increased tension caused by sling angles (on all rigging components!). 10. Calculate reductions when using choker hitch.11. Keep personnel clear from lift area. 12. Lift load a few inches then check rigging. 13. Know limitations of all lifting devices used. 14. Lift slowly and stop slowly.
rules for rigging ssafety
to which load or force is applied to the base (bowl saddle)
Sling Hooks
contain a throat or slot of uniform width for securing on the link of a chain, usually to form a chain loop for securing the load
Grab hooks
Do not ____ the working load limits.
exceed
Only use alloy heat treated hooks for ____ lifting
over-head
Do not tip load or use the hook in any manner for which it was not intended. Do not ___ load or dynamic load.
shock
Never apply load to hook ___, ___ are only to retain slack chains and sling
latches
What should you look for when inspecting hooks?
Wear Deformation Cracks Sharp Nicks
hook/load angles
A. Balanced 100% B. 1/4 off center 86% C. 1/2 off center 80% D. 3/4 off center 70% E. Point loading 40%
balanced
100%
1/4 off center
86%
1/2 off center
80%
3/4 off center
70%
point loading
40%
Whenever wear at any point of any chain link exceeds that shown in ___, the assembly shall be removed from service.
table H-2
Link by link inspection is facilitated by ____ the chain
collapsing
Wear occurs in areas of high rubbing:
- The bearing points of interlink contact.
2. Outside of straight side barrels.
Wire rope wear is based on:
- Loading 2. Bending (# of times) 3. # of use cycles Change in rope diameter is criteria for retirement. The area in a wire rope to check wear is where it travels over the block in the section from picking a load to lifting it. Wires need lubrication to prevent corrosion. Apply by spray, brush or dip. Wire tends to wear flat on outer strands, especially where it travels over drums & sheaves.
How to check for wear in clevis
•In the bowl of the saddle •Check the pin for: •Straightness •Wear Check for distortion in the: •Open end of the ‘U’
Spreader beams can be used with a double vertical hitch to handle long loads ____.
Reduces tipping
what is the load equation?
see note for example problems.
(Load / Number of legs) X (L / H) = Load each sling leg
A load is stable when:
The hook is directly above the center of gravity of the load.
Estimate the center of gravity
Lift the load just enough to clear the ground. If the hook is not over the center of gravity the hook will travel to the center of gravity
If the load tips more than ___, the rigging should be adjusted
3 degrees
