R 408.42943
R 408.42943 Gin poles used for personnel lifting.
Cite as Mich. Admin. Code R 408.42943
Rule 2943. The employer shall ensure that gin poles shall meet the following
requirements when used for personnel lifting:
(a) A gin pole used for personnel lifting shall meet the applicable requirements
for design, construction, installation, testing, inspection, maintenance, modification,
repair, and operations as referenced in the ANSI/TIA-1019 2004 Structural
Standards for Steel Gin Poles Used for Installation of Antenna Towers and Antenna
Supporting Structures or as prescribed by a professional engineer.
(b) The following safe working load limits shall be applied for gin pole lifts:
(i) Wire rope, sheaves, rotating rooster heads, blocks, etc., used in the gin pole
lifting process shall meet the manufacturer's safe working load limits. In addition, and
for clarification, each component shall have a nominal breaking strength of no less
than 5 times the static load applied. Adequate consideration for inefficiencies such as
end fitting losses, D/d ratios, frictional losses, etc., shall be considered. "D" is the
diameter of the sheave and "d" is the diameter of the wire rope passing through the
sheave.
(ii) Wire rope slings, chains, shackles, turnbuckles, links, hooks, etc. used to attach
the gin pole to the tower and/or to attach loads to lifting or tagging lines shall not exceed
the manufacturer's safe working load limits. In addition, each individual component, as
well as an attachment assembly, shall have a nominal breaking strength of not less than
5 times the static load applied. End fitting losses and actual positioning of connecting
parts shall be taken into consideration.
(iii) Lugs or other devices for lifting or attaching the gin pole in position shall
be, at a minimum, designed for the combination of all loads to be applied to the gin pole.
(iv) The load factors and factors of safety referenced in this standard are for lifting
of loads only. If personnel are to be lifted by a gin pole and its associated equipment,
then the complete unit capacity shall be reduced by 1/2.
(c) All rigging equipment (cables, slings, shackles, hooks, sockets, and similar
equipment) shall be inspected before each use. Defective equipment shall be removed
from service.
(d) Wire rope used for rigging shall be as follows:
(i) Have a steel wire rope core.
(ii) The sheave grooves in the rooster head and hoisting blocks shall be compatible
with the size of wire rope being used.
(iii) The sheave and block diameter shall be of the proper size as referenced by
the wire rope manufacturer with a minimum D/d ratio of 18:1. A less than 18:1 D/d ratio
may be used if the proper reduction in capacity caused by the reduced diameter is
taken into account and a 10:1 safety factor is maintained following the reduction.
(e) End connections shall be terminated per industry and manufacturer
specification according to the following:
(i) Wedge sockets have a minimum tail length of 1 rope lay with a properly torqued
clip attached to prevent accidental disengagement.
(ii) Only manufactured Flemish eyes will be acceptable.
(iii) Basket slings shall have heavy-duty thimbles in the eyes. An appropriate
percentage of strength reduction for wire ropes shall be taken into consideration based
upon the end connection type.
(f) Only alloy chains marked with an 8, T, or A, rated for lifting shall be used.
(g) Only quenched and tempered hooks, shackles, and similar equipment shall be
used. The manufacturer's load rating shall be stamped on the product.
(h) A gin pole chart shall be provided for each pole and shall contain the following
information at a minimum:
(i) Identification number or other reference.
(ii) Gin pole description.
(iii) Overall gin pole length (L).
(iv) Lifting capacities based on gross load.
(v) Cantilever projection (La) of 20%, 30%, and 40% of the gin pole length.
(vi) Supported by a structure at the bridle and at the basket.
(vii) Load line through the pole not held from horizontal movement (consider
as unrestrained).
(viii) Chart minimum load line angle " " in Figure 7.1, which is the same as cmin
noted in Figure 7.3.
(ix) Type of tag being used.
(x) Straight tag or trolley line angle at grade, alpha ( ), at 60 degrees from the
horizontal.
(xi) Trolley tag line angle, gamma ( ), attached at pole, usually taken at 2 degrees
greater than load line angle.
(xii) A 30 mph effective wind speed at the elevation of the gin pole.
(xiii) Reaction forces at gin pole attachment points.
(xiv) A table to convert degrees to a field measurement (Figure 7.2).
(xv) A warning that the load chart is for lifting loads and instructions to reduce the
calculated allowable lifting capacity by 1/2 (50%) when lifting personnel.
Figures 7.1, 7.2, and 7.3 are from the ANSI/TIA-1019 2004 structural standards
for steel gin poles used for installation of antenna towers and antenna supporting
structures as adopted by reference in R 408.42904.