Current through Vol. 24-16, September 15, 2024
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.
