1418.1-2002(+A1)

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(Incorporating Amendment No. 1)

Australian Standard

™

Cranes, hoists and winches

Part 1: General requirements

A

S

1418

.1—

2002

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This Australian Standard was prepared by Committee ME-005, Cranes, General. It was approved on behalf of the Council of Standards Australia on 15 February 2002. This Standard was published on 20 June 2002.

The following are represented on Committee ME-005: Association of Consulting Engineers Australia Australian Elevator Association

Australian Industry Group

Australian Institute for Non-destructive Testing Bureau of Steel Manufacturers of Australia Crane Industry Council of Australia

Department of Administrative and Information Services (SA) Department of Industrial Relations (Qld)

Department of Infrastructure, Energy and Resources (Tas) Department of Labour New Zealand

Institution of Engineers Australia State Chamber of Commerce University of New South Wales Victorian WorkCover Authority WorkCover New South Wales WorkSafe Western Australia

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This Standard was issued in draft form for comment as DR 00321.

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(Incorporating Amendment No. 1)

Australian Standard

™

Cranes, hoists and winches

Part 1: General requirements

Originated as part of AS CB2—1938. Previous edition 1994.

Fourth edition 2002.

Reissued incorporating Amendment No.1 (November 2004)

COPYRIGHT

All rights are reserved. No part of this work may be reproduced or copied in any form or by any means, electronic or mechanical, including photocopying, without the written permission of the publisher.

Published by Standards Australia International Ltd GPO Box 5420, Sydney, NSW 2001,

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PREFACE

This Standard was prepared by the Standards Australia Committee ME-005, Cranes, to supersede AS 1418.1—1994, SAA Crane Code, Part 1: General requirements.

This Standard incorporates Amendment No. 1 (November 2004). The changes required by the Amendment are indicated in the text by a marginal bar and amendment number against the clause, note, table, figure or part thereof affected.

The objective of this Standard is to provide uniform requirements within Australia for the design and construction of cranes and similar lifting appliances.

Requirements that apply to more than one type of crane are included in Part 1: General requirements. Any requirements that apply to only one type of crane should only appear in the specific part for that crane and not in Part 1. Some requirements have been deleted from this Standard and are being moved to their applicable Part.

The term ‘shall’ is used to indicate those requirements that have to be met for compliance with the objectives and intent of this Standard.

The Commonwealth, State and Territory governments may choose to incorporate this Australian Standard into their laws and regulations. The exact manner of incorporation will determine whether the whole document is incorporated or whether specific sections or provisions of the Australian Standard are incorporated. The manner of incorporation will determine which of the Standard’s requirements (‘shall’ statements) have been made a legal requirement in a jurisdiction. As a general principle, where an Australian Standard is incorporated by a regulation, the legal status of the Standard’s requirements and recommendations is made clear by the incorporation of provisions of the regulation.

Thus, the requirements (‘shall’ statements) in an Australian Standard are not mandatory for legal purposes unless incorporated specifically by an Act or regulation. Readers will need to refer to their jurisdiction’s law to determine which parts of the Australian Standard (if any) have been incorporated and the manner of incorporation.

This Standard deviates from ISO 11660.1 in regard to access requirements for safety reasons.

This revision includes the following changes:

(a) The maximum temperature of touchable surfaces is now 55°C.

(b) The term ‘safe working load’ has been changed to ‘rated capacity’ and other uses of the word ‘safe’ have been avoided due to the legal significance placed on the word. (c) Reference to approval by the relevant authority has been removed to reflect the

current regulatory environment.

(d) Tear-out/tear-off forces for cranes equipped with magnets or grabs have to be taken into consideration.

(e) There is a new method of calculating the hoisting factor (φ₂), which is taken from DIN 15018.

(f) Out-of-service wind loads are now considered additional loads instead of special loads.

(g) Transport loads have to be taken into consideration where the crane is transported during its life.

(h) The design of monorail beams has been moved to a new Part 18: Runways and monorails.

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(i) The factor of safety against drifting during operation has changed to 1.5.

(j) The design life of mechanisms may be less than 10 years provided this is documented.

(k) In determining the group classification of mechanisms, an adjustment to an equivalent number of running hours is allowed after the load spectrum factor has been set. (l) Requirements for gearing have been expanded.

(m) Requirements for hoisting, travel, and traverse motion brakes have been expanded. (n) A minimum worn wheel flange thickness has been defined.

(o) Hookbolts used for rail fastening are required to be ductile.

(p) Detachable parts are required to be designed for safe assembly and disassembly. (q) The attachment of hooks directly attached to structural members is required to be

designed such that no bending moment is experienced by the hook shank. (r) Some requirements for counterweights have been added.

(s) Requirements for controllers have been revised. (t) Requirements for limit switches have been revised. (u) Motor protection requirements have been revised.

(v) Mention is made of electromagnetic compatibility (EMC) and phase sequence protection.

(w) Extra requirements for cranes with lifting magnets have been added. (x) Emergency egress requirements have been revised.

(y) Requirements for installation of cranes in hazardous areas have been revised to interface with recently revised applicable Standards.

(z) Requirements for operators and maintenance manuals have been added.

Questions concerning the meaning, the application, or effect of any part of this Standard, may be referred to the Standards Australia Committee on Cranes. The authority of the Committee is limited to matters of interpretations and it will not adjudicate in disputes. Statements expressed in mandatory terms in notes to tables and figures are deemed to be requirements of this Standard.

The terms ‘normative’ and ‘informative’ have been used in this Standard to define the application of the appendix to which they apply. A ‘normative’ appendix is an integral part of a Standard, whereas an ‘informative’ appendix is only for information and guidance.

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FOREWORD

This Standard is an authoritative source of fundamental principles for application by responsible and competent persons and organizations. It has no legal authority in its own right but it may acquire legal standing in one or more of the following ways:

(a) Adoption by a regulatory authority.

(b) Reference to compliance with the Standard as a contractual requirement.

(c) Claim, by a manufacturer or manufacturer’s agent (or both), of compliance with the Standard.

This Standard has been prepared bearing in mind that it will be used by a number of different categories of users, with entirely different objectives.

Essentially, the users of this Standard are—

(i) crane and hoist manufacturers, importers and agents; (ii) crane and hoist owners;

(iii) crane and hoist users and operators; and (iv) regulatory and legal authorities.

Crane and hoist manufacturers, importers and agents require acceptable data that can be used in the design, manufacture, testing and acceptance inspection of cranes and hoists for both general and particular applications.

Crane and hoist owners require data for specification and selection of cranes and hoists. In this situation, applications can be more specific.

Crane and hoist users and operators require statements of their responsibilities in the safe use of equipment.

Regulatory and legal authorities look to Standards as a framework on which regulations, directives and other legislation can be based. Further legal aspects of crane Standards must be recognized because they may also be utilized as measures of legal responsibility.

This Standard references the alternative limit states design method in addition to the working stress design method.

A general requirement for safety is that, upon the occurrence of a high risk condition, a safety device or system (or both) should halt the condition or revert the crane to a non-dangerous condition. Depending on the risk assessment of the application, it may be necessary to exceed the minimum safety requirements described herein.

Where personnel are being conveyed, this principle is modified in one of the following ways:

(A) a fail-safe design, allowing for the simultaneous malfunction of two items, may be required.

(B) The operator in control is at personal risk. (C) An increased factor of safety is applied.

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STANDARDS AUSTRALIA

Australian Standard

Cranes, hoists and winches

Part 1: General requirements

S E C T I O N 1 S C O P E A N D G E N E R A L

1.1 SCOPE

This Standard specifies the general requirements for cranes, hoists, winches, and their components, and appliances intended to carry out similar functions, as defined in AS 2549. It does not include powered industrial trucks as defined in AS 2359.

The term ‘crane’ used herein applies to a crane, hoist or winch as appropriate.

NOTES:

1 Specific requirements for particular types of cranes and associated equipment are specified in other parts of AS 1418; these requirements take precedence over corresponding requirements in this Standard where any difference exists. Appendix A outlines the structure of the AS 1418 series of Standards.

2 Requirements for the selection, operation and maintenance of cranes are given in the appropriate part of AS 2550.

1.2 NEW DESIGNS, INNOVATIONS AND DESIGN METHODS

This Standard does not preclude the use of materials, designs, methods of assembly, procedures, and the like, that do not comply with a specific requirement of this Standard, or are not mentioned in it, but which can be shown to give equivalent or superior results to those specified.

Where the limit states design method is used, cranes shall be designed to give a degree of safety not less than that given in this Standard by the working stress design method for strength, buckling, deflection, torsion, fatigue and the like.

NOTE: This Standard does not provide specific guidance on the limit state design methods, as the necessary dynamic factors have not been formulated for the complex forces cranes are subjected to. This is a worldwide situation and ISO has established a working group specifically to resolve the issue. Design of structural members by limit state methods, including determination of the partial load factors for individual loads, should comply with the appropriate Australian Standard, e.g., AS 1664.1 for aluminium members and AS 4100 for steel members.

1.3 REFERENCED DOCUMENTS

A list of the documents referred to in this Standard is given in Appendix B. 1.4 DEFINITIONS

For the purpose of this Standard, the definitions given in AS 2549 and below apply. 1.4.1 Classification

The system used to provide a means of establishing a rational basis for the design of structures and machinery. It also serves as a framework of reference between the purchasers and the manufacturers, by the use of which a particular crane may be matched to the service

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NOTE: Classification considers only the conditions of operation for the intended life of the crane. These are independent of the type of crane and the way it is operated.

1.4.2 Competent person

A person who has acquired through training, qualification, experience or a combination of these, the knowledge and skill enabling that person to correctly perform the required task. 1.4.3 Controlled stop

The stopping of a machine motion in a controlled manner, which limits the deceleration to significantly less than the deceleration experienced in a sudden uncontrolled stop.

NOTE: An example of one method is to reduce the electrical command signal to zero once the stop signal has been recognized by the control and retain electrical power to the hoisting machine actuators during the stopping process.

1.4.4 Fail-safe

A state or condition whereby if the fail-safe component fails, a system exists to prevent any increase of the assessed risk associated with the device.

NOTE: Information regarding fail-safe systems is given in Appendix C.

1.4.5 May

Indicates the existence of an allowable option.

NOTE: Neither inclusion nor exclusion of the option results in non-compliance with the Standard.

1.4.6 Shall

Indicates that compliance with a statement is mandatory for compliance with the objectives and intent of his Standard (see Preface).

1.4.7 Should

Indicates a recommendation. Neither following nor ignoring the recommendation results in non-compliance with the Standard.

1.4.8 Rated capacity

The maximum gross load which may be applied to the crane or hoist or lifting attachment while in a particular working configuration and under a particular condition of use.

1.4.9 Uncontrolled stop

The stopping of a motion by removing power to the machine actuators, all brakes and/or other mechanical stopping devices being actuated.

1.5 NOTATION

Symbols used in equations in this Standard are defined in relation to the particular equation in which they occur.

1.6 CONTACT SURFACE TEMPERATURE

Surfaces with temperatures exceeding 55°C, which may cause pain by contact with human skin, shall be protected over all areas that can be touched during normal operation, daily maintenance and assembly/erection, such that the touchable surfaces are below 55°C.

Except where surface temperatures can be increased by solar radiation, surfaces on which the temperature exceeds 55°C shall be located more than 300 mm from hand-related access points.

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S E C T I O N 2 C L A S S I F I C A T I O N O F C R A N E S

2.1 SCOPE OF SECTION

This Section specifies the classification of a crane (see Clause 1.1) based on the maximum number of in-service cycles to be carried out during the intended life of the crane and a load spectrum. Other parts of AS 1418 define which parts of the classification range are applicable to the various types of cranes.

NOTES:

1 See Clause 1.4.1 for a definition of classification.

2 The C classification relates to the duty (i.e. load spectrum and number of operating cycles) of the crane as a whole and is intended for contractual and technical reference purposes (see Clause 2.3).

3 The purpose of the ‘S’ and ‘M’ classification is to provide a basis for the load determination and fatigue analysis of the individual structural and mechanical components (see Sections 5 and 7, respectively). The designer takes the estimated load spectrum and the number of load applications to determine the group class of the crane.

4 Cranes for specific applications may require minimum classifications as specified elsewhere in this Standard, or other parts of AS 1418.

2.2 GENERAL

The classification of the crane and its constituent parts shall be as follows:

(a) Group classification Overall classification of the crane based on the number and magnitude of operating cycles the crane will be expected to see during its design life (see Clause 2.3.2).

(b) Structural classification Classification of each part of the crane structure based on the number and magnitude of the load cycles which that part of the structure will see during the design life of the crane (see Clause 5.2.2).

(c) Mechanical classification Classification of each of the mechanical components of the crane based on the expected magnitude of the applied load and the number of operating hours, at the load, for the design life of the crane (see Clause 7.3.4).

Unless otherwise specified in the applicable part of AS 1418, the required design life of any crane and its constituent parts shall be as follows:

(i) Structures ... 25 years. (ii) Mechanical components... 10 years. For cranes designed for special applications, the design life may be less than that specified in Items (i) and (ii) above, provided that—

(A) the structural and mechanical components of the crane have been designed for a specific task of short duration with no intention of redeployment;

(B) the design life and design classification of the components are marked on the components and crane;

(C) the intended service conditions are well defined in writing by the designer; and

(D) the crane is used in accordance with the designer’s instructions and actual service conditions are monitored and recorded in accordance with AS 2550.1.

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2.3 GROUP CLASSIFICATION 2.3.1 Bases of classification

The group classification of the crane shall be determined from the class of utilization (see Clause 2.3.2) and the load spectrum (see Clause 2.3.3) where relevant data is available or selected from typical crane applications in Appendix D.

2.3.2 Class of utilization

The maximum number of in-service cycles expected from the crane during its intended life shall be the first basic parameter of classification. The range of classes of utilization are divided into 10 categories, as shown in Table 2.3.2.

TABLE 2.3.2

CLASSES OF UTILIZATION OF CRANES Maximum number of

operating cycles

Classes of

utilization Description of use 1.6 × 104 U₀ Infrequent use 3.2 × 104 U₁

6.3 × 104 U₂ 1.25 × 105 U₃

2.5 × 105 U₄ Fairly frequent use

5 × 105 U₅ Frequent use

1 × 106 U₆ Very frequent use 2 × 106 U₇ Continuous or near-continuous use

4 × 106 U₈

Greater than

4 × 106 U₉

2.3.3 Load spectrum

The second basic parameter of classification is the load spectrum, which is concerned with the number of times a load of a particular magnitude, in relation to the capacity of the crane, is hoisted. The four nominal values of load spectrum factor (K_p) shall be as shown in Table 2.3.3 and illustrated in Figure 2.3.3, each numerically representative of a corresponding nominal state of loading.

The load spectrum factor for the crane (Kp) is given by the following equation:

            ∑ max i 3 T i p= P P C C K . . . 2.3.3 where

Ci = number of load cycles that occur at the individual load levels = C₁, C₂, C₃, ..., C_n

CT = total of all the individual load cycles at all load levels

= ΣC_i

= C1 + C2 + C3 + ... + Cn

P_i = individual load magnitudes (load levels) characteristic of the duty of the crane

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= P1, P2, P3, ... Pn P_max = rated capacity

NOTE: A load cycle accounts for all motions of the crane when operated between an unloaded state through to loaded state and returns to its unloaded state.

The nominal load spectrum factor for the crane shall be established by matching the calculated load spectrum factor to the closest (higher) nominal value of Kp in Table 2.3.3.

NOTE: t₁, t₂, t₃ and t_∆ are time increments expressed as a percentage of design life. FIGURE 2.3.3 TYPICAL LOAD SPECTRA

TABLE 2.3.3

NOMINAL LOAD SPECTRUM FACTOR AND STATE OF LOADING FOR CRANES Nominal load

spectrum factor (K_p)

State of loading Description of use

0.125 Q1—Light Cranes that hoist the rated capacity very rarely and, normally, very light loads

0.25 Q2—Moderate Cranes that hoist the rated capacity fairly frequently and, normally, light loads

0.50 Q3—Heavy Cranes that hoist the rated capacity frequently and, normally, medium loads

1.00 Q4—Very heavy Cranes that are frequently loaded close to the rated capacity

2.3.4 Group classification

The group classification for the various combinations of classes of utilization and state of loading shall be as given in Table 2.3.4.

NOTE: The application of group classification to specific types of cranes is covered in the appropriate parts of AS 1418.

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TABLE 2.3.4

GROUP CLASSIFICATION OF CRANES Group classification of crane

Classes of utilization State of loading Nominal load spectrum factor (Kp) U0 U1 U2 U3 U4 U5 U6 U7 U8 U9 Q1—Light 0.125 C1 C1 C1 C2 C3 C4 C5 C6 C7 C8 Q2—Moderate 0.25 C1 C1 C2 C3 C4 C5 C6 C7 C8 C8 Q3—Heavy 0.50 C1 C2 C3 C4 C5 C6 C7 C8 C8 C9 Q4—Very heavy 1.00 C2 C3 C4 C5 C6 C7 C8 C8 C9 C9

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S E C T I O N 3 M A T E R I A L S F O R C R A N E S

This Section specifies requirements for materials used in the manufacture of cranes (see Clause 1.1).

3.2 MATERIAL SPECIFICATIONS

Where applicable, materials shall comply with the relevant Australian Standard specifications.

Where the properties of any material are in doubt, the material shall be subjected to sufficient testing in order to determine the properties concerned.

NOTE: Refer to specific parts of AS 1418 for material Standards applicable to a particular crane type.

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S E C T I O N 4 C R A N E L O A D S

This Section specifies the requirements for the determination of loads and load combinations to be used in the design of crane structures (see Clause 1.1).

4.2 REFERENCE TO OTHER PARTS OF THIS STANDARD

The determination of loads in this Section shall be supplemented by the requirements of the other relevant parts of this Standard.

4.3 DETERMINATION OF CRANE LOADS

Determination of crane loads shall include all loads resulting from the intended crane operation, and loads caused by the environment, erection, testing and fault conditions. Steady-state loads, such as gravity-induced loads, shall be determined from the masses of all component parts permanently attached to the crane.

Live loads induced on in-service cabin floor walkways and platforms shall be determined in accordance with the provisions of this Standard and the referenced Standards including AS 1170.1.

Dynamic loads due to acceleration or deceleration of masses shall be determined by either—

(a) dynamic analysis capable of modelling the characteristics of the crane operations; or (b) methods of determination of loads specified in this Section.

4.4 CATEGORIZATION OF CRANE LOADS

For convenience of referencing, the crane loads are divided into three load groups as follows:

(a) Principal loads (see Clause 4.5). (b) Additional loads (see Clause 4.6). (c) Special loads (see Clause 4.7).

Each load group is divided into load types as shown in Table 4.4.

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TABLE 4.4

CATEGORIZATION OF CRANE LOADS

Load group Load Reference

Clause Principal loads (see Clause 4.5) Dead loads Hoisted loads Inertia loads Displacement-induced loads 4.5.2 4.5.3 4.5.4 4.5.5 Additional loads (see Clause 4.6)

In-service and out-of-service wind loads Snow and ice loads

Temperature-induced forces Oblique travelling forces Bulk material loads

4.6.2 4.6.3 4.6.4 4.6.5 4.6.6 Special loads (See Clause 4.7)

Off-vertical hoisting loads Test loads

Buffer impact forces Tilting forces

Live loads on walkways and in chutes, etc Loads due to emergency condition Seismic loads

Loads during erection Loads during transport

4.7.2 4.7.3 4.7.4 4.7.5 4.7.6 4.7.7 4.7.8 4.7.9 4.7.10 4.5 PRINCIPAL LOADS 4.5.1 General

Principal loads comprise the mass of the crane and highly repetitive loads arising from the intended service of the crane.

4.5.2 Dead loads

4.5.2.1 Dead load dynamic factor

The loads due to the mass of the crane in operation shall be given by the following equation:

1

w Wφ

P = . . . 4.5.2.1

where

Pw = factored deadweight load

W = gravitational force induced by the mass of the crane.

φ1 = dynamic factor for the mass of the crane subject to inertial forces and vibrations

The upper bound value of φ1 shall be as given in Table 4.5.2.1 unless a more accurate determination is made by using an appropriate dynamic analysis.

The lower bound value of φ1 shall be taken as 1.0, except where the vibration of the stabilizing part of the crane structure reduces the resistance to overturning. In such case, the lower bound value of φ1 shall be taken as 0.9.

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TABLE 4.5.2.1

APPLICATION OF DYNAMIC Factor (φ1)

1 2 3 4 5 6 7 Dynamic factor (φ₁) Travel velocity, m/s Type of runway Condition of runway Wheel type Suspension type ≤1.0 >1.0 _≤1.5 >1.5 Unsprung 1.1 1.1 1.2 Smooth welded continuously Steel Sprung 1.1 1.1 1.1 Unsprung 1.1 1.2 1.2 Steel rails or beams Joints

≤4 mm wide Steel Sprung 1.1 1.1 1.1 Smooth

no joints Rubber Sprung 1.1 1.1 1.1 Concrete

Jointed Rubber Sprung 1.2 1.2 1.25 Rubber Sprung 1.1 1.1 1.15 Roadway or flexible pavement — _Crawler tracks Sprung 1.1 1.2 1.25 NOTES:

1 Do not interpolate, use nearest higher value for φ₁.

2 It is assumed that the rail joints are in good condition. The detrimental effect on hoisting appliances of rail tracks in poor condition is so great, both for the structure and the machinery, that it is necessary to stipulate that the rail joints must be maintained in good condition: no shock loading coefficient can allow for the damage caused by faulty joints. In so far as high speed appliances are concerned, the best solution is to butt-weld the rails, in order to eliminate entirely the shock loadings that occur when an appliance runs over joints.

4.5.3 Hoisted load 4.5.3.1 Description

The hoisted load shall include the rated capacity together with the weight of the hook and hook block, full length of hoist cable, and any devices attached to the hook block for the purpose of grappling the hoisted load.

Where hoists are equipped with magnets or grabs, allowances shall be made in selecting the hoist’s capacity to account for tear-off or tear-out forces respectively. A tear-out force is equal to the weight of the load plus additional forces applied as a result of removing the load from the heap.

4.5.3.2 Hoisting operations to be considered

The basic hoisting operations covered in this Section are the following:

(a) Hoisting a load from rest The effects of the hoisted load shall be determined by the following equation: 2 h hd Pφ P = . . . 4.5.3.2(1) where

Phd = factored hoisted load

P_h = hoisted load as specified in Clause 4.5.3.1

φ2 = hoisted load dynamic factor for hoisting as given in Clause 4.5.3.3.

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(b) Rapid releasing of a part of the hoisted load Where the intended operation requires rapid releasing of the hoisted load, the effect of rapid release shall be determined by the following equation:

(

h r

)

3 rd P P φ

P = − . . . 4.5.3.2(2)

where

Prd = the peak intensity of the loads acting on the hoist as a result of the rapid releasing

Ph = hoisted load as specified in Clause 4.5.3.1

P_r = the upper estimate of the part of the load being released

φ3 = rapid load release dynamic factor for rapid load release as given in Clause 4.5.3.4.

4.5.3.3 Hoisted load dynamic factor (φ₂)

The value of the dynamic factor for hoisting (φ₂) depends on the hoisting velocity (ν_h), and the hoisting application group as determined by Table 4.5.3.3(A). The dynamic factor (φ2) shall be taken from Table 4.5.3.3(B), except where a more appropriate or more accurate determination has been carried out using a dynamic analysis or by certified tests.

Where the hoist drive control system automatically selects the steady creep speed at the start of hoisting, such speed shall be used for the determination of the dynamic factor (φ2). Where the hoist drive is equipped with a stepless variable speed control, the value of the dynamic factor (φ2) shall be determined for a hoisting velocity of not less than 0.5 times the nominal speed for the unloaded hoist drive.

TABLE 4.5.3.3(A)

HOISTING APPLICATION GROUP FOR CRANES

1 2 3 4 5 Hoisting application group

Hoisting acceleration m/s2 Fundamental natural frequency of structure (vertical plane) Hz ≤0.2 >0.2 to ≤0.4 >0.4 to ≤0.6 >0.6 ≤3.2 H1 H1 H2 H3 >3.2 ≤5.0 H1 H2 H2 H3 to H4 >5.0 H2 H2 H3 H4 NOTE: For hoisting accelerations/decelerations greater than 0.6 m/s2analysis of inertial effects in accordance

with Clause 4.5.4 should be considered.

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TABLE 4.5.3.3(B) HOISTING FACTORS φ2 Hoisting application group νh≤1.5 νh>1.5 H1 H2 H3 H4 1.1 + 0.13ν_h 1.2 + 0.27ν_h 1.3 + 0.40ν_h 1.4 + 0.53ν_h 1.3 1.6 1.9 2.2 LEGEND:

νh = the nominal speed related to the lifting attachment, derived

from the steady rotational speed of the unloaded drive, in metres per second

Where two or more hoists are installed, the dynamic factor (φ₂) shall be applied as follows: (a) Where the two hoists are designed not to operate simultaneously, the appropriate

factor shall be applied to one drive at a time taking into account that drive’s hoisting speed. The other hoist drive shall be considered to be stationary.

(b) Where the hoists are designed to operate simultaneously, the appropriate factor shall be applied to each hoist in accordance with its hoisting speed.

4.5.3.4 Rapid load release dynamic factor (φ3) (see Figure 4.5.3.4.) The value of φ3 is given by the following equation:

W W ∆ × − 51 . 1 = 3

φ for hoisting appliances in the form of grabs; or

W W ∆ × − 02. 1 = 3

φ for hoisting appliances using magnetic holding devices where

∆W = released mass

W = mass of the hoisted load including the load to be released

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FIGURE 4.5.3.4 DYNAMIC FACTOR (φ3)

4.5.4 Inertia loads 4.5.4.1 General

The designer shall determine the inertia forces induced by acceleration, braking and the travel, slewing and luffing drives.

4.5.4.2 Methods of determination of inertia loads

The loads due to acceleration of drives shall be determined by one of the following methods:

(a) Simple method of determination based on upper bounds of parameters for drives relying on frictional transfer of the reactive forces. The procedure shall be as given in Clause 4.5.4.3.

(b) An appropriate method of dynamic analysis for any type of load transfer. 4.5.4.3 Simplified method of determination of traction forces

Where the maximum traction forces are limited by friction, the traction forces shall be determined from the friction between the driven wheels and the runway. To eliminate wheel slip, drives shall be selected so that the maximum traction force does not exceed the minimum frictional force between the driven wheel and the rail.

For travel and traverse motions, the maximum traction forces may be determined by the following equations:

(a) For independent drives: wij 4 S

R N P

T = φ µ . . . 4.5.4.3(1)

NOTE: This equation assumes matched power and rating of motors on each driven wheel.

(b) For synchronized drive:

       

∑

ij N i N j P T t w 1 = 1 = 4 R s =φ µ . . . 4.5.4.3(2)

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where

T_R = resultant of the traction forces

Ns = number of drives—for independent drives

= number of driven pairs of wheels—for synchronized drive(s) φ4 = dynamic factor

µ = coefficient of friction

Pwij = minimum driven wheel load (see below)

i = runway number, e.g., 1 = left runway, 2 = right runway (see below) j = number of the wheel pair

) + ( w 1 w2 s P P j j N 1 = j

∑

= minimum sum of the driven wheel loads The value of φ4 shall be determined as follows:

(i) φ₄ = 1 for centrifugal forces;

(ii) 1φ4 ≤1.5 for drives with no backlash or in cases where existing backlash does not affect the dynamic forces and with smooth change of forces; (iii) 1.5φ4 ≤2 for drives with no backlash or in cases where existing backlash does

not affect the dynamic forces and with sudden change of forces; (iv) φ4 = 3 for drives with considerable backlash, if not estimated accurately by

using a spring-mass model.

Where a force that can be transmitted is limited by friction or by the nature of the drives mechanism, the limited force and a factor φ₄ appropriate to that system shall be used.

For steel wheels on steel rails, the nominal coefficient of friction (µ) shall be taken as 0.20, unless a more accurate determination has been made.

The minimum driven wheel loads of the unladen crane shall be used to calculate the maximum traction forces.

4.5.4.4 Application of traction forces

The traction forces shall be applied to the loaded crane and shall be in accordance with the drive type and the driving system of the crane as illustrated in Figures 4.5.4.4(A) and 4.5.4.4(B). The effect of eccentricity of the resultant traction forces to the centre of mass of the driven system shall be considered.

(a) Acceleration due to cross-travel drives The reactive loads (P_HC) from Table 4.5.4.4(A) due to the traction force of the crab (Pc) shall be transmitted to the runway through all travel wheels equally (see Figure 4.5.4.4(A)).

Horizontal forces due to inertial forces for cranes with more than two wheels per runway side shall be equally shared by all wheels.

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FIGURE 4.5.4.4(A) ACCELERATION LOADS DUE TO CROSS-TRAVEL DRIVES

TABLE 4.5.4.4(A)

LATERAL LOADS DUE TO ACCELERATION FROM CROSS-TRAVEL DRIVES Lateral loads

Lateral fixity of crane wheels

PHC11 PHC12 PHC21 PHC22

All wheels laterally

fixed P₄c P₄c P₄c P₄c

Wheels on only

one side laterally fixed P₂c P₂c

0 0

NOTES:

1 This Table is for four-wheel cranes only; however, similar principles apply for other travel systems. 2 A laterally fixed wheel is a flanged wheel with laterally fixed bearings or side-guide rollers.

(b) Acceleration due to long-travel drives For the travel drive system illustrated in Figure 4.5.4.4(B), the drive forces (P_HT) are assumed to be distributed equally to the driven wheels. The resulting lateral force (PHB) due to the eccentricity (ls) of the centre of the drive force with respect to the centre of mass is assumed to be distributed equally to the applicable travel wheels. The moment shall be calculated from the following equation and the forces from Table 4.5.4.4(B):

R s E l T

M = . . . 4.5.4.4

where

M_E = moment due to eccentricity of drive forces

ls = maximum eccentricity of the point of application of the drive force with respect to the centre of mass of the crane including the rated capacity TR = resultant of the traction forces PHT1 and PHT2 in Figure 4.5.4.4(B)

The effect of acceleration of long travel drives shall be taken into account in designing the crane.

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FIGURE 4.5.4.4(B) ACCELERATION LOADS DUE TO LONG-TRAVEL DRIVES

TABLE 4.5.4.4(B)

LATERAL LOADS DUE TO ACCELERATION FROM LONG-TRAVEL DRIVES

Lateral loads Long travel drive

system _P

HB11 PHB21 PHB12 PHB22

All wheels laterally fixed

G E 2SM 2SM_GE G E 2SM − G E 2SM − Wheels on only one side

laterally fixed M_S G E 0 S M G E − 0 NOTES:

1 For a four-wheel crane, S_G equals the distance between the means of lateral guidance.

2 For cranes with more than four wheels, S_G equals the bogie pivot centre distance (see Figure 4.5.4.4(C)).

3 A laterally fixed wheel is a flanged wheel with laterally fixed bearings or side-guide rollers.

FIGURE 4.5.4.4(C) DISTRIBUTION OF HORIZONTAL FORCES

4.5.4.5 Determination of loads due to slewing and luffing motions

The determination of loads due to slewing and luffing motions shall be as follows:

(a) Loads due to the acceleration of slewing drives shall be determined by an appropriate method of dynamic analysis.

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The centrifugal forces acting on slewing cranes shall be from the dead load of the boom components, the counterweight, where used, and the hoisted load without applying the dynamic factor and assuming the hoisted load to be positioned at the tip of the jib or boom.

(b) Loads due to the acceleration of luffing drives shall be calculated by an appropriate dynamic analysis.

4.5.5 Loads induced by displacements

Account shall be taken of loads arising from displacements caused by movement of the supporting structure, for example, from prestressing or differential movement due to settlement or temperature.

4.6 ADDITIONAL LOADS 4.6.1 General

Additional loads and effects include loads induced by wind, snow, ice, temperature and oblique travel.

4.6.2 Wind forces 4.6.2.1 Principles

The determination of wind forces on a crane exposed to wind (e.g., outdoors operation or partially enclosed building) shall be as specified in AS 1170.2.

NOTES:

1 This applies to in-service and out-of-service wind forces.

2 Cranes are considered to be high-risk installations. Allowances given in AS 1170.2 to reduce loads on temporary structures should only be applied after the appropriate risk analysis has been carried out by the designer.

4.6.2.2 Wind forces on the hoisted load

Wind forces (PD) acting on the hoisted load shall be calculated for the largest dimensions and the least favourable configuration of the load using the drag coefficients (C_D) taken from AS 1170.2.

4.6.3 Snow and ice loads

Snow and ice loads, where applicable, shall be taken into consideration including— (a) increased dead load

(b) increased wind exposure surfaces due to encrustation. 4.6.4 Forces due to temperature variation

Forces caused by the restraint of expansion or contraction of a component due to local temperature variation shall be taken into account.

4.6.5 Lateral forces due to oblique travel 4.6.5.1 General

The following Clauses outline a simplified method of analysis of lateral forces due to oblique travel. A detailed analysis is provided in Appendix E.

Where a crane or crab is subjected to oblique travel in the moment of contact between rail and front guiding element (wheel flange or guide roller), a steering force (P_OT) develops and straightens the crane in its tracks.

The magnitude of the steering force (P_OT) depends on the type of crane drives, the crane geometry, and on the coefficient of frictional contact (KO) which is determined by the

α).

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4.6.5.2 Coefficient of frictional contact (KO)

The coefficient of frictional contact (K_O) shall be obtained from Table 4.6.5.2.

NOTE: Interpolation of KO values is permissible under this Standard.

TABLE 4.6.5.2

COEFFICIENT OF FRICTIONAL CONTACT

α 2.0 3.0 4.0 5.0 7.0 9.0 12.5 15 >15 KO 0.118 0.158 0.196 0.214 0.248 0.268 0.287 0.293 0.3

LEGEND:

α = oblique travel gradient, in millimetres per metre α = S C G L where

CL = maximum clearance between wheel flange or guide roller and side of rail, in millimetres

SG = centre distance of track wheels, track wheel groups or guide rollers, in metres

4.6.5.3 Calculation of steering contact force (POTE)

The calculation of the steering contact force (POTE) and Y11 and Y21 reactions for a crane supported by four wheels with two independent drives is determined in accordance with Figure 4.6.5.3.

Equilibrium condition gives: 0

OTE j= = ΣYi P where

Y_ij are the frictional forces between the wheels and the rail Y21 = POTE− Y11

= K_O P_W21 K_F

NOTE: Y₂₁ is the force that is to be used for design of crane structure and runway beams; P_OTE is only important for design of guiding elements and the like. The most adverse condition for analysis is with the crab on the opposite side of the crane girder to the contact force.

FIGURE 4.6.5.3 WHEELS WITH TWO INDEPENDENT DRIVES (EFF)

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4.6.5.4 Calculation of steering contact force (POTW)

The calculation of the steering contact force (P_OTW) and Y₁₁, Y₁₂, Y₂₁ and Y₂₂ reactions for a crane supported by four wheels with two or more mechanically or electrically coupled drive wheels is determined in accordance with Figure 4.6.5.4.

NOTE: This method is simplified and the results are slightly conservative, being not more than 15% greater than the exact calculation in Appendix E. Forces parallel with runway beams are very small and can be disregarded.

NOTES:

1 P_OTW, Y₁₁ and Y₂₁ are calculated in accordance with Clause 4.6.5.3.

2 Y₂₁ and Y₂₂ are forces to be used for design of crane structure and the runway beams; P_OTW is only important for the design of guiding elements and the like.

3 Equilibrium condition gives approximately: 0

OTW ij+ = ΣY P where

Yij are frictional forces between the wheels and the rail.

FIGURE 4.6.5.4 MECHANICALLY OR ELECTRICALLY COUPLED DRIVE WHEELS (WFF)

4.6.5.5 Oblique travel force (POTE) and reduction factor (KF)

Because of flexibility of the crane and runway, reactions Y in Clauses 4.6.5.3 and 4.6.5.4 shall be reduced by multiplying with factor (KF) from Table 4.6.5.5. The natural frequency of the crane beams shall be determined for vibrations in the vertical plane.

TABLE 4.6.5.5 REDUCTION FACTORS Type of crane Natural frequency of crane beams, Hz (vertical plane) Reduction factor (KF) Double girder Cranes only > 5.0 1.0

Single girder and Double girder cranes

> 3.2 ≤ 5.0 0.83

Single girder and Double girder cranes

≤ 3.2 0.66

4.6.6 Bulk material loads

Where applicable, effects due to the dropping of bulk material shall be taken into consideration. Effects include impact and recoil.

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4.7 SPECIAL LOADS 4.7.1 General

Special loads include loads caused by testing, buffer forces and tilting, as well as from emergency cut-out, failure of drive components, and external excitation of the crane foundation.

4.7.2 Loads due to off-vertical hoisting

A lateral load of not less than 4% of the rated capacity shall be applied to account for inadvertent off-vertical lifting.

Where off-vertical hoisting is required by the crane operation, lateral loads induced by this effect shall be determined by a competent person.

4.7.3 Dynamic effects of test loads

The values of test loads and their locations shall be determined as appropriate for the type of crane or hoist tested.

The dynamic test load shall be multiplied by a factor (φ₅) from the following equation:

(

2

)

5 0.5 1 φ

φ = + . . . 4.7.3

where

φ2 is calculated in accordance with Clause 4.5.3.3. 4.7.4 Buffer forces

The impact force (P_B) due to cranes or parts of a crane running against other cranes or stops shall be absorbed by appropriately designed buffers or similar energy-absorbing means. The total buffer capacities required and the maximum buffer force (P_B) shall be determined for longitudinal travel at 85% of full travel velocity and for traverse at 100%. Where automatic retarding means are provided, the maximum buffer force (P_B) shall be determined for cranes and crabs at not less than 70% of full travel velocity.

For two-speed cranes fitted with fail-safe duplicated automatic retard switching to slow speed and sufficient distance from end stop to slow before impacting buffer, the maximum buffer force (P_B) may be determined for 100% of the slow speed.

Where two cranes of masses m1 and m2 and having velocities VF1 and VF2 collide, the kinetic energy released on the collision shall be calculated by the following equation:

) + 2( ) + ( = 2 1 2 2 1 2 1 m m V V m m E F F _{. . . 4.7.4(1)}

The total energy (E) shall be absorbed by all buffers engaged in the collision, with each taking its share of energy in proportion to its rigidity.

Where a crane of mass m and having a velocity V collides with an end stop, the kinetic energy released on collision shall be calculated by the following equation:

mV

E 2

2 1

= . . . 4.7.4(2)

NOTE: In some circumstances, the effects of the kinetic energy of the rotating long travel components, e.g., motors, brake drums, gearboxes, should be considered.

For calculation of the buffer capacities and the strength of the structure, the forces resulting from the masses in motion (dead loads plus any rigidly guided hoisted loads in the worst position) shall be used, but not the factors mentioned in Clause 4.5.3. Loads suspended from hoisting equipment and freely swinging loads need not be taken into consideration.

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For cranes and crabs with or without attached hoisted loads, no negative wheel loads shall result from 1.1 times the buffer force and the abovementioned dead loads and hoisted loads. For tower cranes and portal slewing cranes, an analysis of the buffer capacity and of the effect that the buffer forces have on the structure need not be made, provided that the rated travelling velocity is lower than 0.67 m/s and reliable limit switches are provided in addition to the buffer stops.

The resulting forces as well as the horizontal inertia forces in balance with the buffer forces shall be multiplied by a factor (φ₆) to account for elastic effects that cannot be evaluated using a rigid body analysis. Factor φ6 shall be taken as 1.25 in the case of buffers with linear characteristics (e.g., springs) and as 1.60 in the case of buffers with rectangular characteristics (e.g., hydraulic constant force buffers). For buffers with other characteristics, other values justified by calculation or by test shall be used (see Figure 4.7.4).

Intermediate values of φ₆ shall be calculated as follows: (a) φ6 = 1.25 for 0.0 ≤ ξ ≤ 0.5

(b) φ₆ = 1.25 + 0.7 (ξ − 0.5) for 0.5 < ξ ≤ 1.0 where ξ

is defined in Figure 4.7.4.

FIGURE 4.7.4 DYNAMIC Factor (φ6) FOR BUFFERS

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4.7.5 Tilting forces

If an appliance with a horizontally restrained load (rigidly guided load) can tilt when its load or lifting attachment is in collision with an obstacle, the resulting static forces shall be determined. For the determination of this force, the crab shall be assumed to be in the worst position. The possibility of lifting the crab wheels off one of the crane bridge girders shall be considered.

If a tilted appliance can fall back into its normal position uncontrolled, the resulting impact on the supporting structure shall be evaluated and taken into account.

4.7.6 Miscellaneous loads

The effects of other loads that may be applied to the crane, for example lights, advertising boards, chutes, maintenance activities and the like shall be considered.

Live loads on walkways during maintenance shall be determined in accordance with AS 1657 unless higher loads can be generated, for example, placement of equipment on walkways during maintenance.

4.7.7 Loads caused by emergency conditions 4.7.7.1 Mechanical failure

Where protection is provided by emergency brakes in addition to service brakes, failure and emergency brake activation shall be assumed to occur under the least favourable condition. Where mechanisms are duplicated for safety reasons, failure shall be assumed to occur in any part of either system.

The value of the dynamic factor (φ4) shall be taken between 1.5 and 2.0. 4.7.7.2 Emergency cut-out

Loads caused by emergency cut-out shall be evaluated in accordance with Clause 4.5.4 taking into account the most unfavourable combination of acceleration and loading at the time of cut-out. The coefficient of friction shall be taken at its upper bound value. The value of the dynamic factor (φ₄) shall be taken between 1.5 and 2.0.

4.7.7.3 Application of loads

The resulting loads shall be distributed in accordance with the principles set out in Clause 4.5.4 for traction forces.

In both these cases, resulting loads shall be evaluated in accordance with Clause 4.5.4, taking into account any impacts resulting from the transfer of forces.

4.7.8 Seismic loads

Loads induced by seismic or other vibratory excitations of crane foundations shall be considered.

4.7.9 Loads during erection

The loads acting at each stage of the erection and dismantling process shall be taken into account.

4.7.10 Forces during transport

The effects of loads occurring during transport shall be considered, where appropriate. 4.8 PRINCIPLES FOR DETERMINATION OF CRANE LOAD COMBINATIONS 4.8.1 Basic considerations

Loads shall be combined to determine the maximum stresses an appliance will experience during operation. To achieve this, the appliance shall be taken in its most unfavourable

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attitude and configuration while the loads are assumed to act in magnitude, position and direction causing the maximum stresses at the critical points selected for evaluation on the basis of engineering considerations.

The load combinations appropriate to individual types of appliances shall be in accordance with Table 4.8, as applicable. The designer shall also consider other load combinations not shown in Table 4.8, as appropriate to the type of appliance and its operation.

4.8.2 Application of load combinations 4.8.2.1 Use of Table 4.8

For each type of load and each load combination, the Table gives— (a) a dynamic factor (φ) for the particular load;

(b) numeral 1, which signifies that no dynamic factor is required for that load type unless special conditions of intended operation require that a dynamic factor (different from 1.0) be included; or

(c) a dash (—), which signifies that the load of that type need not be included in the load combination unless special conditions of operation require its inclusion.

4.8.2.2 Working stress design method

Where the working stress design method is used for the verification of the strength and serviceability of the crane structure, the load effects (moments, shear and normal forces) derived from each load combination shall be multiplied by the load combination factor (γc).

NOTE: As an example for load combination 5, the total load (Ptot) in a girder will be derived from:

γc = 0.9

Ptot = 0.9 × [The effect of (φ1 P1 + φ2 P2 + φ4 P3 + 1.0 P4 + 1.0 P5 + 1.0 P6 + 1.0 P7)]

4.8.2.3 Limit states design method

The limit states design method uses partial load factors γ_P, which differ for each type of load and range generally between 1.2 and 1.5 depending on the statistical variability of the load type in that particular type of crane.

Where the limit states design method is used, cranes shall be designed to give a degree of safety not less than that given in this Standard for the working stress design method for strength, buckling, deflection, torsion, fatigue, and the like.

NOTE: At this stage, Standards Australia is unable to give specific guidance on the range of values of the partial load factors.

4.8.2.4 Proof of fatigue strength

The effects of fatigue shall be considered. Where proof of fatigue strength is found to be necessary, it shall be carried out in accordance with the principles set down in Clause 4.8.1. In some applications it may be necessary to also consider occasional loads such as in-service wind, skewing and exceptional loads such as test loads and excitation of the lifting appliance foundation (for example, wave effects).

4.8.2.5 High risk applications

In special cases where the human or economic consequences of failure are exceptionally severe (e.g., ladle cranes or cranes for nuclear applications) increased reliability shall be obtained by the use of a risk coefficient γ_n > 1, the value of which shall be selected according to the requirements of the particular application.

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TABLE 4.8

CRANE LOAD COMBINATIONS

Load combination number* Frequently occurring

load combinations

Infrequently occurring load

combinations

Rarely occurring load combinations Load group Line No. Description 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Principal loads 1 Dead loads φ1 1 0.9 φ1 φ1 0.9 φ1 1 1 1 φ1 φ1 1 φ1 1.2 2 Hoisted loads φ2 1 φ3 φ2 φ1 φ3 φ2 η† — 1 1 1 1 1 1 3 Inertia loads φ4 φ4 1 φ4 φ1 1 1 1 φ4 1 1 1 — — — 4 Displacement-induced loads 1 1 1 1 1 1 — — — — — — — — 1 Additional loads 5 In-service wind forces 1 — 1 1 — — 1 1 1 1 — 1

6 Snow or ice loads 1 1 — — 1 — — — — — — — 7 Temperature-induced forces 1 1 — — 1 — — — — — — — 8 Oblique travelling forces — 1 — — — — — — — — — — Special loads 9 Off-vertical hoisting loads 1 — — — — — — — — 10 Out-of-service wind forces — 1 — — — — — — — 11 Test loads — — φ5 — — — — — — 12 Buffer impact forces — — — φ6 — — — — — 13 Tilting forces — — — — 1 — — — — 14 Live loads on walkways and in chutes — — — — — 1 — — — 15 Loads due to emergency conditions — — — — — — φ4 — — 16 Seismic loads — — — — — — — 1 — 17 Loads during erection — — — — — — — — 1.2 18 Loads during transit* 1 Load combination factor, γc 1.0 0.9 0.8

* Applicable only to cranes that are frequently moved e.g., mobile cranes, elevating work platforms. † η is the mass of that part of the hoist load remaining suspended from the appliance.

NOTE: φ1 to φ6 are dynamic factors as described earlier in this Section.

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S E C T I O N 5 D E S I G N O F C R A N E S T R U C T U R E

5.1 GENERAL

This Section specifies requirements for both the crane structure and its supporting structure (see Clause 1.1). The design life shall be 25 years unless the requirements of Clause 2.2(A) to (D) are followed.

5.2 BASIS OF DESIGN 5.2.1 Design of structure

The crane and its supporting structure shall be designed in accordance with this Section and Clause 2.2, except where other parts of AS 1418 take precedence, and with the following: (a) AS 1163. (b) AS 1594. (c) AS 1664.1 or AS 1664.2. (d) AS 1720.1. (e) AS 1726. (f) AS 3600. (g) AS 3990; or AS 4100.

5.2.2 Classification of crane structures 5.2.2.1 Bases of classification

The classification of the structure of a crane or crane components, e.g., the boom, shall be determined from the class of utilization (see Clause 5.2.2.2) and the state of loading (see Clause 5.2.2.3).

5.2.2.2 Class of utilization

The number of in-service cycles expected from the structure of a crane or crane component during its useful life shall be one basic parameter of classification and shall comply with Table 5.2.2.2.

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TABLE 5.2.2.2

CLASS OF UTILIZATION OF STRUCTURES Maximum number

of operating cycles

Class of

utilization Description of use) 1.6 × 104 U₀ Infrequent use 3.2 × 104 U₁

6.3 × 104 U₂ 1.25 × 105 U₃

2.5 × 105 U₄ Fairly frequent use

5 × 105 U₅ Frequent use

1 × 106 U₆ Very frequent use 2 × 106 U₇ Continuous or near continuous use 4 × 106 U₈ Greater than 4 × 106 _U 9

NOTE: The number of loading cycles is often significantly higher than the number of in-service cycles in Table 2.3.2.

5.2.2.3 State of loading

The second basic parameter of classification is the state of loading, which is concerned with the number of times a load of a particular magnitude, in relation to the capacity of the structure of the crane or crane component, is hoisted. The nominal values of the load spectrum factor (Kp) shall comply with Clause 2.3.3.

5.2.2.4 Structure classification

The structure classification for the various combinations of class utilization and state of loading shall be as given in Table 5.2.2.4.

TABLE 5.2.2.4

CLASSIFICATION OF CRANE STRUCTURES

1 2 3 4 5 6 7 8 9 10 11 12

Classification of crane structure Class of utilization State of loading Nominal load spectrum factor (Kp) U0 U1 U2 U3 U4 U5 U6 U7 U8 U9 Q1—Light 0.125 S1 S1 S1 S2 S3 S4 S5 S6 S7 S8 Q2—Moderate 0.25 S1 S1 S2 S3 S4 S5 S6 S7 S8 S8 Q3—Heavy 0.50 S1 S2 S3 S4 S5 S6 S7 S8 S8 S9 Q4—Very heavy 1.00 S2 S3 S4 S5 S6 S7 S8 S8 S9 S9 Load condition 0* 1† 2† 3† 4†

* Fatigue analysis not required.

† Corresponds to same loading condition in AS 3990.

NOTE: The solid lines in the Table group together the state of loading (Q) and the class of utilization (U), which belong to the same loading condition (see Clause 5.5).

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5.3 DESIGN OBJECTIVE

Design objectives are to achieve adequate strength and serviceability during the design life of the crane. Design calculation shall be carried out to determine that the crane structure will have adequate strength in service when operated in compliance with the manufacturer’s written instructions.

The proof of adequacy shall include proof of safety against yielding, elastic instability or fatigue.

Proof of adequacy shall also include stability against overturning.

The elastic displacements shall be checked to prove that the appliance shall not become unfit to perform its intended duties, affect stability, or interfere with the proper functioning of mechanisms.

5.4 METHOD OF DESIGN 5.4.1 General

The design of the lifting appliance shall be carried out by one of the following methods: (a) The working stress design method.

(b) The limit states method.

5.4.2 Working stress design method

Design by working stress design method shall be determined in accordance with the provisions of AS 3990, except where otherwise specified in this Standard.

5.4.3 Limit states method

Individual specified or characteristic loads (Fj) are determined and amplified where specified in Table 7.9 using the dynamic factors (φ) and multiplied by the appropriate partial load factors (γp). They are then combined according to the load combination under consideration to give the combined load (M). Partial load factors (γ_p) for individual loads shall be determined in accordance with the principles laid down in AS 4100.

If a probabilistic proof of adequacy is used, the relevant assumption, particularly the acceptable probability of failure, shall be stated.

5.5 FATIGUE STRENGTH 5.5.1 General

The crane structure shall be checked for fatigue strength under load combinations involving frequently applied loads (i.e. 1, 2, 3 and 4), and for the service life specified in Clause 5.1. 5.5.2 Working stress design

Load conditions for fatigue design by AS 3990 are given in Table 5.5.2. The stress ranges shall be determined in accordance with the appropriate load combinations of Section 4. Fatigue assessment shall be carried out in accordance with AS 3990.

NOTE: AS 4100 should be referenced for details of connections where such details are not addressed by AS 3990.

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TABLE 5.5.2

LOAD CONDITION AND EQUIVALENT LOAD CYCLES Number of equivalent cycles Classification of crane

structure

Load condition

from AS 3990 From design by allowable stress method (AS 3990)

For design by limit state method

(AS 4100) S1, S2, S3 Fatigue analysis not

required — — S4 1 >20 000 ≤100 000 100 000 S6, S7 2 >100 000 ≤500 000 500 000 S8 3 >500 000 ≤2 000 000 2 000 000 S9 4 >2 000 000 5 000 000

NOTE: The number of equivalent cycles is obtained after conversion of actual loading cycles and load spectrum, as defined in Table 5.2.2.2, to equivalent loading cycles for load spectrum factor K_{p = 1}.

5.5.3 Limit states design

The verification of fatigue strength shall be carried out in accordance with AS 4100. In the absence of a load cycle analysis based on time and motion analysis, an equivalent number of load cycles to be used in the design shall be as given in Table 5.5.2.

5.6 DESIGN FOR SERVICEABILITY DEFLECTION AND VIBRATION 5.6.1 General

Deflections of the crane structure shall be kept within the limits imposed by the mechanical and operational requirements as specified in the relevant part of the AS 1418 series of Standards.

The actual deflection shall not affect the function of the crane. 5.6.2 Deflection limits of crane structural members

The calculated maximum deflection of any crane structural member shall be not greater than the following:

(a) Vertical static deflection due to all dead loads and live loads without dynamic factors applied—

(i) between supports: 1/500 span or 60 mm, whichever is the lesser; or (ii) cantilever: 1/300 span.

NOTE: The effects of adjacent spans on cantilever deflection have to be taken into account in calculating cantilever deflection.

(b) Lateral deflection induced by inertial forces or off-vertical lift—

(i) bridge beam or truss under the inertial forces acting on dead loads and live loads: 1/600 span; and

(ii) bridge beam or truss under the inertial forces acting on dead loads only: 20 mm. Load combination factor (γc) may be applied (see Table 4.8).

5.6.3 Driver exposure to vibration

Vibration amplitudes and frequencies experienced by the operators of cabin-controlled cranes shall be in accordance with the applicable parts of AS 2670.

Consideration shall be given to the frequency and amplitude of vibration in the design of cranes, ensuring that vibrations do not affect the correct function of the crane.

1418.1-2002(+A1)

Australian Standard

™

Cranes, hoists and winches

Part 1: General requirements

Australian Standard

™

Cranes, hoists and winches

Part 1: General requirements

PREFACE

CONTENTS

FOREWORD

STANDARDS AUSTRALIA

Australian Standard

Cranes, hoists and winches

Part 1: General requirements

S E C T I O N 1 S C O P E A N D G E N E R A L

S E C T I O N 2 C L A S S I F I C A T I O N O F C R A N E S

S E C T I O N 3 M A T E R I A L S F O R C R A N E S

S E C T I O N 4 C R A N E L O A D S

(

)

∑

∑

∑

(

)

is defined in Figure 4.7.4.

S E C T I O N 5 D E S I G N O F C R A N E S T R U C T U R E