(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. (B) The crane shall be standing on track which is level within one-percent grade.

(A) Tipping with or without the use of outriggers occurs when half of the wheels farthest from the load leave the rail. (2) The following stipulations shall govern the application of the values in (1) for locomotive cranes: Than 30,000 lb-ft with the backward stability moment being the greater. The difference between the backward stability momentĪnd the forward moment resulting from the load should not be less Outriggers should be loosely applied rail clamps should not be used.

As a precaution while testing for free ratings, 85Ĭommercial truck vehicle mounted crane with stabilizerĮxtended and set. Wheel mounted using outriggers fully extended and set, with wheels 75Ĭrawler, using outrigger fully extended and set. Locomotive, using outriggers (stabilizers) fully extended and set.

Locomotive, without outrigger (stabilizer) support 1īooms 60 feet or less. Maximum Load Ratings (% of Tipping Loads) The load ratings shall not exceed the following percentages for cranes, with the indicated types of mounting under conditions stipulated in (2) and (3). (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. (c) Load ratings where stability governs lifting performance. (b) Where boom or jib ratings are limited by structural competence, such ratings shall be clearly shown and emphasized on the rating charts. Load ratings shall be expressed in terms related to method of measuring boom angle and length or lifting radius. In addition, no crane shall be rerated unless such rating changes are approved by the certified agent. 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. 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. (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.

Load radius crane