(1) Shackles used to hang blocks, jacks, or rigging on spars, must have the pins secured with a nut and cotter key or a nut and molle.
(2) Flush pin, straight-sided shackles must be used for mainline, slackline and skyline extensions.
(3) Shackles with screw pins, knockout or slip pins may be used to anchor skylines, slackline, guyline, and/or guyline extensions.
(4) All other shackles must be screw pin type or have the pin secured with a nut and cotter key or a nut and molle, except as specified elsewhere for specific purposes.
(5) The opening between the jaws of shackles used to hang blocks, jacks, and rigging and to join or attach lines, must not be more than one inch greater than the size of the rope, swivel, or shackle to which it is attached.
(6) All shackles must be one size larger than the lines they connect and made of forged steel or material of equivalent strength.
For example: | 1-inch Extra Improved Plow Steel (EIPS) line requires a 1 1/8-inch shackle, 1-inch swaged line require 1 1/4-inch shackle. |
(7) Shackles used to join lines must be hung with the pin and "U" part of the shackle through the eyes of the lines.
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Medium Bell With Safety Pin | Flush Pin Straight Side | Wide Bell-shaped Hanging Type With Safety Pin | Guyline Sleeve With Knock-out Pin |
Figure 2-2: Shackles | |||