ISO 4304 INTERNATIONAL STANDARD First edition 1987-06-01 INTERNATIONAL ORGANIZATION FOR STANDARDIZATION ORGANISATION INTERNATIONALE DE NORMALISATION MEXKAYHAPOAHAA OPTAHM3ALWA O CTAHAAPTM3ALMM Mst termc Do Sert Cranes other than mobile and floating cranes General requirements for stability Appareils de levage autres que grues mobiles et grues flottantes - Exigences generales relativesalastabilite Reference number ISO 4304 : 1987 (E) Not for Resale Foreword ISo (the International Organization for Standardization) is a worldwide federation of national standards bodies (IsO member bodies). The work of preparing International Standards is normally carried out through Iso technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, govern- mental and non-governmental, in liaison with iso, also take part in the work. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the ISO Council. They are approved in accordance with ISO procedures requiring at least 75 % approval by the member bodies voting. International Standard ISO 4304 was prepared by Technical Committee ISO/TC 96, Cranes, lifting appliances and related equipment. Users should note that all International Standards undergo revision from time to time and that any reference made herein to any other International Standard implies its latest edition, unless otherwise stated. ? International Organization for Standardization,1987 Printed in Switzerland Copyright International Organization for Standardization Not for Resa ISO 4304 : 1987 (E) INTERNATIONAL STANDARD Cranes other than mobile and floating cranes General requirements for stability Scope and field of application 3.1.5 For cranes that are to be permanently installed, earth- quake effects appropriate to the particular site or zone shall be This International Standard specifies the conditions to be met considered as an additional loading under cases , II and Ill of when verifying, by calculation, the stability of all crane types the table. defined in ISO 4306-1 that are subject to tipping (except mobile cranes and floating cranes); it assumes that they are standing 3.1.6 In the calculations shown in the table, consideration on a firm, level supporting surface or track. shall be given to the loads induced by the weight of the crane and its components, including any lifting attachments which The sliding of cranes on their tracks is not covered by this Inter- are a permanent part of the crane in its working condition. national Standard. 3.2 Backwards stability in service conditions 2 References When a crane is in an unladen state and with all operationally movable components retracted to positions closest to the back- iso 4302, Cranes -- Wind load assessment. ward tipping edge, backwards stability in service conditions IsO 4306-1, Lifting appliances -- Vocabulary -- Part 1: General. shali be verified as indicated in either 3.2.1 or 3.2.2 (see also the table, case IV). Stability 3.2.1 Moment method 3 The tipping moment caused by in-service wind W; and inertia 3.1 Calculations forces D shall not be greater than 90 % of the stabilizing moment. 3.1.1 A crane is said to be stable when the algebraic sum of the stabilizing moments is greater than the sum of the tipping 3.2.2 Gravity method moments. The projection of the centre of gravity of the static crane in 3.1.2 Calculations shall be made to verify the stability of the calm air onto a horizontal plane shall be at a position not ex- crane by computing the sum of the tipping moments using the ceeding 80 % of the distance from the forward supporting values given in the table. point to the backward tipping edge. Typical examples are shown in the figure. In all calculations, the position of the crane and its com- , and the effect o