California Code of Regulations › Title 8 - Industrial Relations › Division 1 - Department of Industrial Relations › Chapter 4 - Division of Industrial Safety › Subchapter 7 - General Industry Safety Orders › Group 13 - Cranes and Other Hoisting Equipment › Article 93 - Boom-Type Mobile Cranes › Section 4923 - Load Rating Chart

Current through Register 2024 Notice Reg. No. 28, July 12, 2024
(a) A
						durable load chart with clearly legible letters and figures provided by the
						certified agent shall be securely fixed to the crane in a location clearly
						visible to the operator or within reach of the operator while at the control
						station. The chart shall contain a full and complete range of crane load
						ratings, consistent with the manufacturers' recommendations, at all stated
						operating radii or boom angles and for all permissible boom lengths, jib
						lengths and angles, also alternate ratings for use and non-use of optional
						equipment on the mobile crane, such as outriggers and counterweights which
						affect ratings. The chart shall also contain essential precautionary or warning
						notes relative to limitations on equipment and operating procedures, including
						indication of the least stable position. In addition, no crane shall be rerated
						unless such rating changes are approved by the certified agent. Load ratings
						shall be expressed in terms related to method of measuring boom angle and
						length or lifting radius.
(b) Where
						boom or jib ratings are limited by structural competence, such ratings shall be
						clearly shown and emphasized on the rating charts.
(c) Load ratings where stability governs
						lifting performance.
(1) The margin of
						stability for determination of load ratings, with booms of stipulated lengths
						at stipulated working radii for the various types of crane mountings is
						established by taking a percentage of the loads which will produce a condition
						of tipping or balance with the boom in the least stable direction, relative to
						the mounting. The load ratings shall not exceed the following percentages for
						cranes, with the indicated types of mounting under conditions stipulated in (2)
						and (3).
Type of Crane
								  Mounting
Maximum Load Ratings (% of Tipping
								  Loads)
Locomotive, without outrigger
								  (stabilizer) support1
Booms 60 feet or
								  less...................................................................................................................................................................................
85
Booms over 60
								  feet.......................................................................................................................................................................................
852
Locomotive, using outriggers
								  (stabilizers) fully extended and
								  set..............................................................................................................
80
Crawler, without outrigger
								  support.................................................................................................................................................................
75
Crawler, using outrigger fully
								  extended and
								  set............................................................................................................................................
85
Wheel mounted using outriggers fully
								  extended and set, with wheels off supporting
								  surface.................................................................
85
Commercial truck vehicle mounted
								  crane with stabilizer extended and
								  set..............................................................................................
85
Wheel mounted without outrigger
								  support.................................................................
75
NOTE: 1. As a precaution while testing for free
						  ratings, outriggers should be loosely applied; rail clamps should not be
						  used.
NOTE: 2. The difference between the backward stability
						  moment and the forward moment resulting from the load should not be less than
						  30,000 lb-ft with the backward stability moment being the
						  greater.
(2) The following
						stipulations shall govern the application of the values in (1) for locomotive
						cranes:
(A) Tipping with or without the use
						of outriggers occurs when half of the wheels farthest from the load leave the
						rail.
(B) The crane shall be
						standing on track which is level within one-percent grade.
(C) Radius of the load is the horizontal
						distance from a projection of the axis of rotation to the rail support surface,
						before loading, to the center of vertical hoist line or tackle with load
						applied.
(D) Tipping loads from
						which ratings are determined shall be applied under static conditions only,
						i.e. without dynamic effect of hoisting, lowering, or swing.
(E) The weight of all auxiliary handling
						devices such as hoist blocks, hooks, and slings shall be considered a part of
						the load rating.
(3)
						Stipulations governing the application of the values in (1) for crawler, truck
						and wheel-mounted cranes shall be in accordance with the Crane Load-Stability
						Test Code, SAEJ765, 1969 or 1980 as applicable.
NOTE: The effectiveness of these preceding stability
						  factors will be influenced by such additional factors as freely suspended
						  loads, track, wind, or ground conditions, condition and inflation of rubber
						  tires, boom lengths, proper operating speeds for existing conditions, and in
						  general, careful and competent operation. All of these shall be taken into
						  account by the user.