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Subchapter 7. General Industry Safety Orders
Group 13. Cranes and Other Hoisting Equipment
Article 95. Derricks
(1) The minimum number of guys shall be 6, with equal spacing, except where a certified agent or derrick manufacturer approves variations from these requirements and revises the rated capacity to compensate for such variations.
(2) Guy derricks shall not be used unless the employer has the following guy information from the manufacturer or a certified agent, when not available from the manufacturer:
(A) The number of guys.
(B) The spacing around the mast.
(C) The size, grade, and construction of rope to be used for each guy.
(3) For guy derricks manufactured after December 18, 1970, in addition to the information required in subsection (a)(2), the employer shall have the following guy information from the manufacturer or a certified agent, when not available from the manufacturer:
(A) The amount of initial sag or tension.
(B) The amount of tension in guy line rope at anchor.
(4) The mast base shall permit the mast to rotate freely with allowance for slight tilting of the mast caused by guy slack.
(5) The mast cap shall:
(A) Permit the mast to rotate freely.
(B) Withstand tilting and cramping caused by the guy loads.
(C) Be secured to the mast to prevent disengagement during erection.
(D) Be provided with means for attaching guy ropes.
(b) Stiffleg derricks.
(1) The mast shall be supported in the vertical position by at least two stifflegs; one end of each shall be connected to the top of the mast and the other end securely anchored.
(2) The stifflegs shall be capable of withstanding the loads imposed at any point of operation within the load chart range.
(3) The mast base shall:
(A) Permit the mast to rotate freely (when necessary).
(B) Permit deflection of the mast without binding.
(4) The mast shall be prevented from lifting out of its socket when the mast is in tension.
(5) The stiffleg connecting member at the top of the mast shall:
(A) Permit the mast to rotate freely (when necessary).
(B) Withstand the loads imposed by the action of the stifflegs.
(C) Be secured so as to oppose separating forces.
(c) Gin pole derricks.
(1) Guy lines shall be sized and spaced so as to make the gin pole stable in both boomed and vertical positions.
Exception: Where the size and/or spacing of guy lines do not result in the gin pole being stable in both boomed and vertical positions, the employer shall ensure that the derrick is not used in an unstable position.
(2) The base of the gin pole shall permit movement of the pole (when necessary).
(3) The gin pole shall be anchored at the base against horizontal forces (when such forces are present).
(d) Chicago boom derricks. The fittings for stepping the boom and for attaching the topping lift shall be arranged to:
(1) Permit the derrick to swing at all permitted operating radii and mounting heights between fittings.
(2) Accommodate attachment to the upright member of the host structure.
(3) Withstand the forces applied when configured and operated in accordance with the manufacturer's/builder's procedures and within its rated capacity.
(4) Prevent the boom or topping lift from lifting out under tensile forces.
(e) Anchoring and guying.
(1) General requirements.
(A) Derricks shall be guyed and anchored so as to prevent tipping or collapsing.
(B) Reinforcing steel shall not be used for guy line anchors.
(C) Load anchoring data developed by the manufacturer or a certified agent shall be used.
(2) Guy derricks.
(A) The mast base shall be anchored.
(B) The guys shall be secured to the ground or other firm anchorage.
(C) The anchorage and guying shall be designed to withstand maximum horizontal and vertical forces encountered when operating within rated capacity with the particular guy slope and spacing specified for the application.
(3) Stiffleg derricks.
(A) The mast base and stifflegs shall be anchored.
(B) The mast base and stifflegs shall be designed to withstand maximum horizontal and vertical forces encountered when operating within rated capacity with the particular stiffleg spacing and slope specified for the application.
(f) Swingers and hoists.
(1) The boom, swinger mechanisms and hoists shall be suitable for the derrick work intended and shall be anchored to prevent displacement from the imposed loads.
(2) Hoists.
(A) Base mounted drum hoists shall meet the requirements of ASME B30.7-2011 which is incorporated by reference.
(B) Load tests for new, repaired and modified hoists. See Article 99 for testing requirements.
(C) Load test procedure. Load tests required by subsection (f)(2)(B) of this section shall include the following:
1. The test load shall be hoisted a vertical distance to assure that the load is supported by the hoist and held by the hoist brake(s).
2. The test load shall be lowered, stopped and held with the brake(s).
3. New subsections (a)-(e)(1), redesignation of former subsections (a)-(b) to new subsections (e)(1)(A)-(B) and new subsections (e)(1)(C)-(f)(2)(C)2. filed 7-26-2022; operative 7-26-2022 pursuant to Government Code section 11343.4(b)(3) (Register 2022, No. 30). Filing deadline specified in Government Code section 11349.3(a) extended 60 calendar days pursuant to Executive Order N-40-20 and an additional 60 calendar days pursuant to Executive Order N-71-20.
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