296-155-33920  <<  296-155-33925 >>   296-155-340

WAC 296-155-33925

Rigging blocks.

(1) The rigging block components must be fully engaged, with all fasteners and retaining devices in place and in good working order before use.
(2) The rope must be in the sheave groove when the rigging block begins to take load.
(3) The load line multiplied by the block load factor must not exceed the rated load of the rigging block. (See Figure 28, Block Load Factor Multipliers.)
(4) Load line fittings must not contact the rigging block sheave(s).
Example: Load = 1,000 lb
Line Pull: 1,000 lb ÷ 2 = 500 lb
Load Block "C" = 500 lb x 2 = 1,000 lb
(line pull x factor for 0 deg. angle)
Load Block "D" = 500 lb x 1.87 + 500 lb = 1,435 lb
(line pull x factor for 40 deg. angle + dead-end load)
Load Block "E" = 500 lb x 0.84 = 420 lb
(line pull x factor for 130 deg. angle)
Load Block "F" = 500 lb x 1.41 = 705 lb
(line pull x factor for 90 deg. angle)
Figure 28
Block Load Factor Multipliers
[Statutory Authority: RCW 49.17.010, 49.17.040, 49.17.050, 49.17.060 and chapter 49.17 RCW, and 29 C.F.R. 1926, Subpart CC. WSR 13-02-068, § 296-155-33925, filed 12/31/12, effective 2/1/13.]
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