[RIGGER’S CORNER]
1. The working load limit (WLL) of the master link at the top of the rigging triangle must exceed. A. 1 Ton B. 5 Tons C. 6 Tons D. 8.4 Tons
2. The sling tension for the top two slings in the rigging triangle is approximately (See figure 2). A. 3 Tons each B. 4.2 Tons each C. 6 Tons each
3. Using the wire rope sling capacity chart provided (See figure 1). What size (EIP) wire rope slings minimum would you select for the top two slings in the rigging triangle? (Same slings as question 2) A. 1/2" B. 3/4" C. 7/8"
4. Using the shackle chart provided (See figure 3), what minimum size carbon shackles would you choose for the top two shackles? (The shackles attached to the slings in question 2). D/d > 1 preferred in soft eye sling A. 5/8" B. 3/4" C. 7/8"
5. Using the shackle chart provided (See figure 3), what minimum size carbon shackles would you choose for the bottom two shackles? (The lowest two shackles in the picture at the load). D/d > 1 preferred in soft eye sling A. 5/8" B. 3/4" C. 7/8"
Perhaps the quiz was a breeze for many of you, or perhaps it posed a few challenges to some. Either way it is a small sample of the type of knowledge that can be obtained when you choose to attend a Crosby rigging seminar. See Crosby web site for more information
www.thecrosbygroup.com /training y
Danny Bishop Corporate Director of Training Te Crosby Group LLC
FIGURE 2 HORIZONTAL SLING LOAD ANGLE ANGLE (A)
90 60 50 45 30
DEGREE FACTOR = L/H 1.000 1.155 1.305 1.414 2.000
LOAD ON EACH LEG OF SLING = VERTICAL SHARE OF LOAD X LOAD ANGLE FACTOR
FIGURE 3 CROSBY SHACKLES
NOMINAL SIZE (IN) DIAMETER OF BOW
3/16 1/4
5/16
CARBON MAXIMUM WORKING LOAD TONS (1)
1/3 1/2 3/4
1-1/2 2
ALLOY MAXIMUM WORKING LOAD TONS (1)
--- --- ---
1-1/8 1-1/4 1-3/8 1-1/2
3-1/4 4-3/4 6-1/2 8-1/2 9-1/2 12
2.6 3.3 5 7
INSIDE WIDTH AT PINS (INCHES)
.38 .47 .53
3/8 12 .66 7/16 1/2 5/8 3/4 7/8 1
.75 .81
9.5
13-1/2 17
12.5 15 18 21 30
1.06 1.25 1.44 1.69 1.81 2.03 2.25 2.38
DIAMETER OF PIN (INCHES)
.25 .31 .38 .44 .50 .63 .75 .88
1.00 1.13 1.25 1.38 1.50 1.63
Answers: 1= C, 2= B, 3=B, 4=C, 5= B
Tip: When selecting rigging hardware to be connected to wire rope slings. We encourage that the hardware have a diameter greater than the rope diameter so as to achieve D/d ratio in the eye of the sling greater than 1 to 1. And we need to make sure that the WLL of the rigging hardware is greater than the sling tension.
80 JULY-AUGUST 2015 WIRE ROPE EXCHANGE
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