The design and testing of steel overhead runway beams

Transcription

1 BRITISH STANDARD BS 2853:1957 Incorporating Amendment Nos. 1,2,3, and 4 Specification The design and testing of steel overhead runway beams

2 Co-operating organizations This British Standard, having been approved by the Mechanical Engineering Industry Standards Committee and endorsed by the Chairman of the Engineering Divisional Council, was published under the authority of the General Council on 8th May, 1957 BSI The following BSI references relate to the work on this standard: Committee reference MEE/128 Draft for comment CV(MEE) 7608 ISBN The Mechanical Engineering Industry Standards Committee, under whose supervision this British Standard was prepared, consists of representatives from the following Government departments and scientific and industrial organizations: Admiralty Institute of Marine Engineers Air Ministry Institute of Petroleum Associated Offices Technical Committee * Institution of Civil Engineers * Association of Consulting Engineers (Incorporated) * Institution of Gas Engineers British Chemical Plant Manufacturers Association Institution of Heating and Ventilating Engineers British Compressed Air Society * Institution of Mechanical Engineers * British Electrical and Allied Manufacturers Institution of Mechanical Engineers Association * (Automobile Division) British Engineers Association * Institution of Production Engineers * British Internal Combustion Engine Locomotive and Allied Manufacturers Manufacturers Association Association of Great Britain British Iron and Steel Federation * Machine Tool Trades Association British Railways, British Transport Commission * Ministry of Labour and National Service British Chemical Plant Manufacturers Association (Factory Department) * Central Electricity Authority and Area Boards * Ministry of Power * Crown Agents for Overseas Governments and Ministry of Supply Administrations Ministry of Transport and Civil Aviation D.S.I.R. Mechanical Engineering Research Ministry of Works Laboratory National Physical Laboratory (D.S.I.R.) Engineering Equipment Users Association * Radio Industry Council Gas Council * War Office High Commission of India The Government departments and scientific and industrial organizations marked with an asterisk in the above list, together with the following, were directly represented on the Committee entrusted with the preparation of this British Standard: Aluminium Development Association Aluminium Industry Council Association of British Chemical Manufacturers Association of Mining Electrical and Mechanical Engineers British Cast Concrete Federation British Constructional Steelwork Association British Granite and Whinstone Federation British Rubber and Plastics Belting Manufacturers Association British Slag Federation British Tin Box Manufacturers Federation Chain Testers Association of Great Britain Coke Oven Managers Association Council of British Manufacturers of Petroleum Equipment Dairy Engineers Association Dock and Harbour Authorities Association Amendments issued since publication Amd. No. Date Comments PD 3362 May 1959 PD 4279 August 1961 PD 6225 August 1967 Federation of British Rubber and Allied Manufacturers Associations Federation of Civil Engineering Contractors Federation of Manufacturers of Contractors Plant Food Manufacturers Federation (Incorporated) Incorporated Plant Engineers Institute of British Foundrymen Institute of Materials Handling Institute of Quarrying Institution of Mining Engineers Institution of Mining and Metallurgy Mechanical Handling Engineers Association National Association of Soft Drink Manufacturers National Coal Board Sand and Gravel Association of Great Britain Society of British Gas Industries Society of Dairy Technology AMD 495 April 1970 Indicated by a sideline in the margin

3 Contents Co-operating organizations Foreword Page Inside front cover iii 1 Scope 1 2 Definitions 1 3 Information to be supplied 1 4 Design 1 a. Runway beams 1 b. Bending stress in tension 2 c. Bending stress in compression 2 d. Cantilever beams 2 e. Shear stress 3 f. Curved beams 3 g. Bolts and rivets made of steel to BS 15 3 h. Connections to supporting structure 3 j. Joints in runways 4 k. Deflection 4 I. Permissible pressure under bearings 4 5 Materials 4 6 Fabrication and erection 4 7 End stops 4 8 Testing and inspection 4 a. Duty of certifier 4 b. Accuracy of the weights 4 c. Amount of the proof load 5 d. Inspection before application of loads 5 e. Application of loads 5 f. Deflection measuring equipment 5 g. Inspection and thorough examination 5 9 Marking 5 10 Certificates 6 a. Certificate of test and thorough examination 6 b. Certificate of thorough examination 6 11 Compliance with statutory requirements 6 Appendix A Recommended minimum runway beam sizes 7 Appendix B List of British Standards for materials and equipment 7 Appendix C Certificate of test and thorough examination of runway beams 9 Appendix D Certificate of thorough examination of runway beams 10 Appendix E Statutory requirements 11 Appendix F Crushing strength 11 Appendix G Notes on design of runways using as universal beams and BS beams 11 Figure 2 Cantilever continuous at support, unrestrained against torsion at the support and unrestrained at the end 16 BSI i

4 Page Figure 3 Cantilever continuous at support, partially restrained against torsion at the support and unrestrained at the end 16 Figure 4 Cantilever span, continuous at support, fully restrained against torsion at the support and unrestrained at free end 17 Figure 5 Values of f 1 and f 2 for steel to BS Figure 6 Values of f 1 and f 2 for steel to BS Table 1 Allowable stresses P bc in bending (Tonf/in 2 ) for beams of steel to BS Table 2 Allowable stresses P bc in bending (Tonf/in 2 ) for beams of steel to BS Table 3 Values of C 15 Table 4 Values of K 1 15 Table 5 Values of K 2 15 ii BSI

5 Foreword The Institution desires to call attention to the fact that this British Standard does not purport to include all the necessary provisions of a contract. In order to keep abreast of progress in the industries concerned, British Standards are subject to periodical review. Suggestions for improvements will be recorded and in due course brought to the notice of the committees charged with the revision of the standards to which they refer. A complete list of British Standards, numbering over 9,000, fully indexed and with a note of the contents of each, will be found in the BSI Catalogue which may be purchased from BSI Sales Department. The Catalogue may be consulted in many public libraries and similar institutions. This standard makes reference to the British Standards listed in Appendix B. This British Standard was prepared at the request of the Chain Testers Association of Great Britain, under the authority of the Mechanical Engineering Industry Standards Committee. The purpose of this British Standard is to specify such fundamental principles as appear desirable to ensure reliability and safety of overhead runways, without hampering the freedom of the runway maker in his selection of the most appropriate design for the purpose in view. This standard is intended to apply to runway beams made from rolled steel sections. The suitability of other materials may be considered in relation to the circumstances, bearing in mind the particular properties of the material used. The prime duty of the tester is to test the actual runway; nevertheless he should satisfy himself that the supports and structures are sound and suitable for all loads which they will be called upon to take. In certain cases this may not be practicable; it will then be the responsibility of the purchaser, in consultation with the architect, consulting engineer, or other competent authority, to satisfy the tester that the structure is suitable. Users of this British Standard should satisfy themselves that effective compliance is secured with statutory requirements (e.g. the Factories Acts,1937 and 1948, the Mines and Quarries Acts,1954, regulations made under these Acts (see Appendix E), local byelaws and regulations), and for fire insurance purposes, with the rules of the Fire Offices Committee, as appropriate. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i to iv, pages 1 to 19 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on theinside front cover. BSI iii

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7 1 Scope This British Standard specifies the minimum requirements for the design and testing of fixed overhead runway beams made from rolled sections of steel complying with the requirements of BS 15 1) and BS 968 2). This British Standard applies to the runway beams and their components only: it does not apply to supporting structures, to travelling trolleys and lifting appliances operating on the beams, nor to crane gantries or rails. NOTE Structures supporting runway beams should comply with the requirements of the relevant British Standards (e.g. for structural steel, see BS 449, The use of structural steel in buildings ). 2 Definitions For the purposes of this British Standard the following definitions shall apply: a. Runway. 3) The runway beam and runway components. b. Runway components. Those parts of the runway immediately attached to the runway beam, e.g. splices, end stops, clamps and switches. c. Runway beam. An overhead track for carrying loads which are moved along it. d. Effective span. The distance between the centres of two adjacent supports, due allowance being made for end fixity, continuous beams and cantilevers. e. Calculated deflections. The deflections due to the safe working and proof loads computed by using the formula applicable to the particular circumstances. f. Measured deflections. The deflections measured in such a manner that they relate to precisely the same conditions as those covering the calculated deflection referred to in Clause 2 e. 3 Information to be supplied The purchaser shall supply to the manufacturer full details of the loads to be handled and the service required of the runway; this information shall form the basis of the design and test. These loads shall include any additional items, such as apparatus or services, which may have to be supported by the runway. 4 Design The runway beam on which the trolley moves shall be of proper size and adequate strength, and have an even running surface. It shall be adequately supported or suspended, and capable of being properly maintained. a. Runway beams. When computing stresses in runway beams, account shall be taken of load lifted, weight of beam, weight of lifting appliance, the effort on the hand chain, and any other superimposed loads. Also, to allow for swinging loads, dynamic effects due to slipping slings, and kinetic action of acceleration and retardation, the total maximum static wheel-loads shall be increased by the following percentages: i) Runways for power-operated appliances ii) Runways for hand-operated appliances 25 per cent 10 per cent These allowances are deemed adequate for normal runways, but it is emphasized that all the stress calculations given in Clause4 are based on the assumption that the load is applied in the plane of the web. If this is not the case the use of I-section beams will probably be uneconomical, and the use of beams specially designed to resist torsion should be considered. Appropriate additional allowances shall be made to cover any known special conditions, such as possible accumulation of loads (e.g. more than one trolley on the same span), or non-vertical lifts. When the runway is used for special duty of greater severity, e.g. over molten metal or where there is a possibility of accidental overloads, higher factors of safety are recommended with proportionately lower working stresses. Provided that lifting and lowering speeds of power-operated appliances on runways do not exceed 10ft/min, and travelling speeds of power-operated trolleys do not exceed 50ft/min, for the purpose of the above allowances (i) and (ii), they may be classed as hand operated. NOTE In connection with the detail design of the runway beam it is impracticable to specify a standard minimum section of runway beam 4) for any particular loading, as this will depend on the standards adopted by the manufacturer of the hoist block or other equipment which is to be used on the runway. The details of the block and trolley assembly will affect such important considerations as: 1) BS 15, Structural steel. 2) BS 968, High yield stress (welding quality) structural steel. 3) It should be noted that this definition is more limited in its scope than that contained in Section 24 (8) of the Factories Act, 1937; in the latter case the expression runway includes the actual lifting machine. 4) Nevertheless, some guidance is given in Appendix A. BSI

8 1. Type of runway beam section. This might be of a proprietary design. 2. Minimum section of runway beam to support a given load locally. 3. Profile of section to suit trolley wheel assembly. 4. Details of runway joints and suspensions to allow the necessary clearances. 5. Minimum runway radius. 6. Head room required. 7. Type of runway switches, crossovers and junctions. 8. Detail of power supply arrangements, if any. b. Bending stresses in tension. The bending stresses in the extreme fibres in tension for British Standard universal beams complying with BS 4-1 5) shall not exceed the following: The bending stresses due to longitudinal bending and flange loading shall, when plotted on the graph (Figure 5) for steel complying with BS15 6) or on the graph (Figure 6) for steel complying with BS 968 7), as f 1 and f 2, fall within the hatched areas. NOTE i) Due to longitudinal bending stress f 1 If made from steel complying with BS 15 a 10 5 tonf/in 2 If made from steel complying with BS 968 b 14 5 tonf/in 2 ii) Due to transverse bending stress f 2 arising from flange loading. (For method of calculation see Appendix G.) If made from steel complying with BS 15 a 14 5 tonf/in 2 If made from steel complying with BS 968 b 17 0 tonf/in 2 a BS 15, Mild steel for general structural purposes. b BS 968, High yield stress (welding quality) structural steel. Runway beam flanges should be of sufficient thickness to ensure that the stresses due to transverse bending (caused by the trolley wheels tending to bend the bottom of the flange downwards, or the fixings tending to bend the top flange, particularly at a joint) in conjunction with all other stresses do not exceed those specified. c. Bending stress in compression. The bending stress in the extreme fibres in compression for British Standard universal beams complying with BS4 8), Part 1 shall not exceed the lesser of the values of P bc obtained as follows: i) If made from steel complying with BS 15 9) NOTE P bc = 10 5 tonf/in 2 P bc = the allowable stress given in Figure 1. ii) If made from steel complying with BS 968 7) P bc = 14 5 tonf/in 2 P bc = the allowable stress given in Figure 2. Where: l = the effective span or, where effective lateral restraint is provided, the length, centre to centre, between the restraint members in inches. r y = the radius of gyration, in inches, of the beam section about its axis lying in the plane of bending. D = the overall depth of the beam in inches. T = the mean thickness, in inches, of the flange as given in the appropriate British Standard or other reference book. The effective length of compression flanges should be in accordance with BS 449, Clause 2.6. d. Cantilever beams. The effective length l to be used in the above equation in Clause 4 c ii) for cantilever beams shall be taken as follows (see Figure 2, Figure 3and Figure 4): Where L = the length of the cantilever: i) Cantilever beam continuous at the support, unrestrained against torsion at the support and unrestrained at the end; l =3L. ii) Cantilever beam continuous at the support with partial restraint against torsion at the support and unrestrained at the end, as, for example, a cantilever bolted hard up to a lintel, l =2L. iii) Cantilever beam continuous at the support, restrained against torsion at the support and unrestrained at the end; l = L. Cantilever runway beams shall be side stayed to a lintel or other supporting structure where practicable. 5) BS 4, Structural steel sections, Part 1, Hot rolled sections. 6) BS 15, Mild steel for general structural purposes. 7) BS 968, High yeild stress (welding quality) structural steel 8) BS 4, Structural steel sections, Part 1, Hot rolled sections. 9) BS 15, Structural steel 2 BSI

9 e. Shear stress. The average shear stress on gross section of rolled steel joist webs (gross section being taken as depth of beam in inches by web thickness in inches), of any material complying with BS15 10) shall not exceed 6 5 tonf/in 2 and of any material complying with BS968 11) shall not exceed 8 5 tonf/in 2. f. Curved beams. Curved runway beams shall be supported in such a way that the stresses due to torsional bending moments are negligible, and they shall also be such as to withstand the maximum vertical bending moment and shearing force induced by travelling loads and the dead weight of the beam. g. Bolts made of 28-ton steel to BS ) and rivets made of steel to BS 15 10). NOTE i) Allowable stresses in bolts. Maximum allowable tensile stress calculated on the area at the root of the thread Maximum allowable stress in single shear Maximum allowable stress in bearing = = 4 tons/sq.in. for bolts¾ in. diameter and upwards.3tons/sq.in. for bolts less than ¾ in. diameter. Black bolts:4tons/sq.in. Turned and fitted bolts:6tons/sq.in. Black bolts:8tons/sq.in. = Turned and fitted bolts: 12 tons/sq.in. Where turned and fitted bolts are in double shear, the permissible bearing stress on the central thickness of metal may be increased by 25 per cent. Where high tensile steel bolts are used they shall comply with BS ) orbs1768, 14) with a minimum factor of safety of 8. Where friction grip bolts are used, they shall comply with BS3139 High strength friction grip bolts for structural engineering. Part1: General grade bolts and their application shall be in accordance with BS 3294 The use of high strength friction grip bolts in structural steel-work. Part 1: General grade bolts. In cases where bolts are used exclusively under tensile loading, the permissible working loads shall not exceed 60per cent of the proof loads shown in Table 3 of BS Where high strength friction grip bolts are used, special attention is drawn to Clause 7, Note 2, in BS All bolts in tension, other than high strength friction grip bolts, shall be fitted with effective locking devices and, where the bolts pass through tapered flanges, they shall be fitted with washers complying with BS ) In the case of high strength friction grip bolts, they shall be fitted with washers complying with BS ii) Allowable stresses in rivets. Maximum allowable stress in single shear Maximum allowable stress in bearing Rivets shall not be used in tension. = Shop-driven: 6tons/sq.in. Field-driven: 4tons/sq.in. = 10 tons/sq.in. h. Connections to supporting structure. Connections shall be of adequate strength and stiffness to withstand safely the maximum loads applied. Clamps are an acceptable method of support, provided that the strength of the various parts complies with the foregoing and the various parts do not produce stresses in excess of the permissible stresses. The clamps themselves shall be made of steel complying with the requirements of BS15 16) or other material equally suitable for the purpose. (For bolts and rivets, see Clause4 g.) 10) BS 15, Mild steel for general structural purposes. 11) BS 968, High yield stress (welding quality) structural steel. 12) BS 916, Black bolts, screws and nuts. 13) BS 1083, Precision hexagon bolts, screws, nuts and plain washers. 14) BS 1768, Unified precision hexagon bolts, screws, nuts (UNC and UNF threads) and plain washers normal series. 15) BS2466, Black taper washers. 16) BS 15, Structural steel. BSI

10 j. Joints in runways. Joints shall be of adequate strength to withstand the maximum loads occurring at the joint(s) and to ensure the maintenance of true alignment. When welded joints are used they shall comply with the following requirements: i) Butt welds. Butt welds shall be treated as parent metal with a thickness equal to the throat thickness (or a reduced throat thickness as specified in BS ) for incomplete penetration butt welds), and the basic stress shall be that used for the parent metal. ii) Fillet welds. The basic stress in a fillet weld, for a thickness equal to the throat thickness, shall be 6 5 tons/sq.in. NOTE When a weld is subjected to a combination of direct bending or axial stress and shear stress, the maximum resultant stress shall be calculated as the vector sum. k. Deflection. The maximum measured deflection of runway beams under the safe working load shall not exceed 1/500 of the span. For cantilever beams the maximum measured deflection under the safe working load shall not exceed 1/250 of the span. l. Permissible pressure under bearings. The area of bearings shall be so proportioned that the maximum pressure due to normal load on material forming the bed shall not exceed the following limits: On brickwork F u /12 tons/sq.ft, where F u is the crushing strength of the bricks used in tons per square foot. On stone masonry F u /6 tons/sq.ft, where F u is the crushing strength of the stone used in tons On cement concrete unreinforced On cement concrete reinforced F u /4 per square foot. tons/sq.ft, where F u is the crushing strength in tons per square foot for 6 in. test cubes at 28 days for ordinary Portland cement or the equivalent period of time for other cements. Where adequáte shear and distribution reinforcement is provided distributing the load over at least twice the area of bearing the above value for unreinforced concrete may be doubled. Where the normal load is not transmitted centrally to the bearing plates and the maximum intensity of pressure is not computed, the above values shall be halved. For typical crushing strengths, see Appendix F. 5 Materials Materials shall comply with the relevant British Standards listed in Appendix B. 6 Fabrication and erection The fabrication and erection of overhead runways shall be in accordance with the requirements of Part6 of BS 449, The use of structural steel in building. 7 End stops Effective end stops shall be provided on the runway to prevent the trolley either falling from the beams or fouling the structure of the building in which the runway is installed. The stops shall not operate on the flanges of the trolley wheels. 8 Testing and inspection a. Duty of certifier. The person signing the certificate specified in Clause 10 a and given in Appendix C shall satisfy himself that the maximum allowable stresses and calculated deflections specified in this British Standard are not exceéded, and that all other requirements of this standard are complied with. He shall also satisfy himself that any curved runway beams are supported in such a way that the stresses due to torsional bending moments are negligible. b. Accuracy of the weights. Where practicable the load used shall be made up of certified weights. In other cases the weight shall be measured by a recognized form of certified weighing machine, such that the sum of the inaccuracies of the load and weighing machine do not exceed plus or minus 4per cent. The load referred to includes the test frame, chain slings, tackle, etc., and the weighing machine if used on the actual test. 17) BS 449, The use of structural steel in building. 4 BSI

11 c. Amount of the proof load. The proof load applied for the purpose of the certificate given in Appendix C shall be the weight of the appropriate heaviest lifting appliance supported by the runway plus 25 per cent in excess of the safe working load lifted by this appliance. Where the runway supports more than one lifting appliance due allowance shall be made for the permissible proximity of any other lifting appliance or appliances supported by the runway. d. Inspection before application of loads. All joints, connections and supports shall be carefully inspected, special attention being paid to the security of nuts on bolts. The nuts shall not be tightened to such an extent as to over-stress the bolts. Attention shall be paid to the condition of walls surrounding and adjacent to the end fastening of runways fixed therein. Where the runway beam is carried on timber supports (which in many cases may be roof trusses) it shall be the responsibility of the purchaser, in consultation with his architect, consulting engineer, or other competent authority, to satisfy the tester that the members are suitable for the load to be carried. It is recommended that, where reinforced concrete beams are used for the suspension of runways, the beams should be coated with solution (e.g. whitewash) so that any cracks will show under proof load test. e. Application of loads. The preliminary inspection having been carried out as specified in Clause 8 d, a test load equivalent to the maximum safe working load, together with the weight of the appropriate heaviest lifting appliance supported by the runway, shall be applied and traversed along the whole length of the runway. The load shall be halted during its passage along the runway and kept at rest at suitable positions, in order that stable deflection readings may be taken at these positions and recorded. Sufficient stable readings shall be taken to ensure that the maximum reading is obtained. The procedure outlined shall then be repeated except that, instead of the test load referred to in the previous paragraph, the proof load (see Clause8 c) shall be applied. A stable deflection reading shall be taken and recorded only at that position where the maximum reading was obtained during the application of the test load referred to in the previous paragraph. f. Deflection measuring equipment. Deflection measuring equipment shall be adequate to ensure accurate measurement of the vertical deflection of the beam at any point under any system of vertical loading. g. Inspection and thorough examination. During the application of the test load referred to in Clause 8 e and of the proof load as specified in Clause 8 e the runway shall be kept under such observation as will ensure the ready detection of any obvious defect in the runway. Following the application of the proof load as specified in Clause 8 e the runway shall be thoroughly examined in order to ascertain, for the purposes of Clause 10, that the runway has withstood the proof load without injury or permanent deformation. For the purpose of this clause, thorough examination means a visual examination, supplemented if necessary by other means, carried out as carefully as the conditions permit, in order to arrive at a reliable conclusion as to the safety of the runway, and, if necessary for the purpose, parts of the runway shall be dismantled. 9 Marking The safe working load, identification number and any limiting conditions shall be plainly and permanently marked on the runway so as to be clearly visible to the operator. If high yield stress steel complying with BS ) is used, and if the letters HYS are not marked permanently on the beam, as specified in BS ), then the manufacturer of the runway shall stamp the letters HYS on the beam adjacent to the identification mark. The safe working load here referred to applies to the runway beam and its components only; it does not apply to a travelling trolley or lifting appliance operating on the runway beam. Hence, the actual load lifted, lowered, or transported in any particular instance, will not only be governed by the safe working load of the runway beam, but also the safe working load of the trolley and lifting appliance used, and any other relevant factors, e.g. any limitation governing the operation of an adjacent trolley and lifting appliance. The safe working load marked on the runway beam shall not exceed that of any transporting or lifting appliance used on it, even though the runway beam and its components have been tested satisfactorily with a proof load greater than that specified for this safe working load. 18) BS 968, High yield stress (welding quality) structural steel. BSI

12 10 Certificates a. Certificate of test and thorough examination. Before any runway beam is taken into use the first time after erection, re-erection or having undergone any substantial alteration or repair; a certificate that the runway beam has been tested and subsequently thoroughly examined as required by Clause 8 g shall be supplied. The certificate shall identify the runway beam to which it refers, quoting its distinguishing number or mark and grades of steel, its size and length, and state (i) the date on which the proof load was applied and thorough examination made, (ii) the position and magnitude of the deflections obtained during the traversing of the maximum safe working load and of the proof load as required by Clause 8 e, (iii) the maximum safe working load, and (iv) that the runway beam complies in all respects with this British Standard, i.e. BS The certificate, which shall be signed by the person making the test and examination, shall indicate clearly that it applies to the runway beam only and not to any trolley or lifting appliance travelling thereon (see Appendix C). b. Certificate of thorough examination. When a thorough examination only is made of a runway beam already in use and for which a certificate of test and thorough examination as referred to in Clause 10 a above has been granted, the certificate of such examination shall identify the runway beam to which it refers, quoting its distinguishing number or mark and grades of steel, its size and length, and state (i) the date on which the examination was made, (ii) date of certificate of test and thorough examination referred to in Clause 10 a above, (iii) particulars of any defect found during the examination and affecting the maximum safe working load and of the steps taken to remedy such defect. The certificate, which shall be signed by the person making the examination, shall indicate clearly that it applies to the runway beam only and not to any trolley or lifting appliance travelling thereon (see Appendix D). 11 Compliance with statutory requirements Attention shall be paid to the appropriate statutory requirements. (For requirements under the Factories Acts and the Mines and Quarries Act, 1954, see AppendixE.) 6 BSI

13 Appendix A Recommended minimum runway beam sizes The minimum size of a runway beam is governed by the dimensions of the trolley required to run on it, but considerations of load and span must be taken into account in deciding the actual size to be adopted. There are not at present any generally recognized standard trolleys, and runway spans vary according to site conditions; therefore dimensional standards for runway beams are not practicable. It is preferable to make a choice of trolley before considering other factors relating to beam details. However, as this is not always possible, in order to comply with good practice in runway design, the following recommended sizes of rolled steel beams are given as a guide only; they are the minimum that will accept appropriate trolleys of ordinary design. Sizes of runway beams a Capacity Beams a for hand operated trolleys Small radius bends and junctions (Push travel) Beams a for power operated trolleys tons in. in. in. ¼ ½ ½ ½ ½ ½ a The dimensions comply with BS 4, Dimensions and properties of channels and beams for structural purposes. Appendix B List of British Standards for materials and equipment NOTE More than one grade or class is provided for in certain of the standards. 1. Materials BS Case hardening steel 3 per cent nickel chromium Castings, steel Machined parts, steel bars for Structural steel and rivets Structural steel, high tensile Structural steel, high tensile fusion welding quality Wrought iron 2. Structural details, etc. Bolts, nuts and washers Rivets Sections, steel Welding 3. Miscellaneous Limits and fits Paint Screw threads 970 o En j 32 e 15 d 548 i 968 n 51 f 916, m 1083, p 1768, r 1769, s 1981 v 2466 w , y z 275, h 641 k 4, a 4A, b 6 c 693, l 1856 t , u /32 x 84, g 1580 q Use of structural steel 449* The above sizes allow for normal supporting bolts. Consideration should be given to other possible obstructions such as joint plates and clamps which might interfere with the working of the trolley. If runway beams are smaller than those recommended in this appendix local bending stresses at open ends should be examined, and the bottom flange reinforced if necessary. BSI

14 a BS 4 Dimensions and properties of channels and beams for structural purposes. b BS 4A Dimensions and properties of equal angles, unequal angles and T-bars for structural purposes. c BS 6 Dimensions and properties of bulb angles and bulb plates for structural purposes. d BS 15 Structural steel. e BS 32 Steel bars for the production of machined parts. f BS 51 Wrought iron for general engineering purposes (Grades A, B and C). g BS 84 Parallel screw threads of Whitworth form. h BS 275 Dimensions of rivets (½ in. to 1¾ in. diameter). i BS 548 High-tensile structural steel for bridges, etc., and general building construction. j BS 592 Carbon steel castings for general engineering purposes. k BS 641 Dimensions of small rivets for general purposes. l BS 693 Oxy-acetylene welding in mild steel. m BS 916 Black bolts, screws and nuts. n BS 968 High-tensile (fusion welding quality) structural steel for bridges, etc., and general building construction. o BS 970 Wrought steels in the form of bars, billets and forgings. En series. p BS 1083 Precision hexagon bolts, screws, nuts and plain washers. q BS 1580 Unified screw threads. r BS 1768 Unified precision hexagon bolts, screws, nuts (UNC and UNF threads) and plain washers normal series. s BS 1769 Unified black hexagon bolts, screws and nuts and plain washers heavy series. t BS 1856 General requirements for the metal-arc welding of mild steel. u BS 1916 Limits and fits for engineering. Parts 1 and 2. v BS 1981 Unified machine screws and machine screw nuts. w BS 2466 Black taper washers. x BS 2525/32 Ready mixed oil-based undercoating and finishing paints (exterior quality). y BS 3139 High strength friction grip bolts for structural engineering. Part 1: General grade bolts. z BS 3294 The use of high strength friction grip bolts in structural steelwork. Part 1: General grade bolts. 8 BSI

15 Appendix C Certificate of test and thorough examination of runway beams to BS 2853 Certificate No Distinguishing number or mark and grade of steel Description sufficient to identify the runway beams and lifting appliance used for the test Date of application of proof load and making of thorough examination (Clause 10 a) Proof load applied (Clause 8 c) Maximum deflection during application of safe working load recorded in Column 7 (Clause 8e) Maximum deflection during application of proof load stated in Column 4 at position of maximum deflections recorded in Column 5 (Clause 8 e) Maximum safe working load (Any limiting condition to be stated) tons inches Ratio of deflection to span inches tons (8) Do the runway beams comply in all respects with BS 2853?... (9) Were the runway and supports thoroughly examined after the application of the proof load referred to in Column 4 and found to have withstood the load without permanent deformation and to be free from cracks, flaws or other defects?... (10) Name and address of makers or suppliers... (11) Name and address of public service, association, firm or person making the test and examination... (12) Position in public service, association or firm named above of person who made the test and examination or, if he is working on his own account, qualification... I certify, on behalf of the firm or persons named in (10) a, (11) a above, that the above particulars are correct. Signature... Date... This certificate applies to the runway beams only, and not to any trolley or lifting appliance travelling thereon. a Delete inapplicable figure. BSI

16 Appendix D Certificate of thorough examination of runway beams to BS 2853 Certificate No Distinguishing number or mark Description sufficient to identify the runway beams Date of certificate of test and examination and safe working load shown therein Date of thorough examination Particulars of any defect found and affecting the safe working load (6) Particulars of steps taken to remedy the defects mentioned in Column 5... (7) Name and address of public service association, firm or person making the examination... (8) Position of signatory in public service, association or firm named above, or, if the certificate is given by a person who made the examination on his own account, qualification... I certify on behalf of the firm or persons named in (7) above, that the above runway beams were thoroughly examined and that no defects affecting their safe working load were found other than those indicated in Column 5. Signature... Date... This certificate applies to the runway beams only, and not to any trolley or lifting appliance travelling thereon. 10 BSI

17 Appendix E Statutory requirements 1) Factories Act, Sections 24, 26, 60 and ) The Cranes and Other Lifting Machines (Register of Examinations) Order, 1938, dated 16th June, S.R. & O. 1938, No ) Docks Regulations, S.R. & O. 1934, No.279. Regulations 18, 21-22, 29, 33, 49, 51 and the schedule of manner of test and examination before taking lifting machinery and gear into use. 4) Shipbuilding Regulations, S.R. &O.1931, No Regulations 34, 40 and 53. 5) Building (Safety, Health & Welfare) Regulations,1948, S.I.1948, No Regulations 2-3, 5,29,34-36,38-41, 50, 51, 52, 56, 91 and the third schedule to these Regulations. 6) Electricity Regulations, S.R. & O. 1908, No ) Electricity (Factories Act) Special Regulations,1944. S.R. &O.1944,No ) The Mines and Quarries Act,1954, Sections 81,82 and 85. 9) Coal and other Mines (Electricity) Regulations,1956. (S.I.No.1766, 1956.) 10) Miscellaneous Mines (Electricity) Regulations,1956. (S.I.No.1779, 1956.) 11) Quarries (Electricity) Regulations, (S.I. No. 1781,1956.) Appendix F Crushing strength The following approximate figures of crushing strength are given solely as a guide to users, for use where it is not practicable to make tests of the actual materials in use: i) Bricks Type Common soft 96 Crushing strength tons/sq.ft Flettons Load-bearing Engineering Blue Stafford 643 ii) Unreinforced concrete (6 in. test cubes at 28 days for ordinary Portland cement) Nominal mix 1 : 2 : : 1½ : : 1 : iii) Stone Type of Stone Crushing strength tons/sq.ft Crushing strength tons/sq.ft Min. Max. Limestone Sandstone Granite Appendix G Notes on design of runways using as universal beams and BS beams When considering the design of runways using universal beams complying with BS ), calculations should be made to ensure that the longitudinal stresses combined with the transverse stress induced into the bottom flange of the beam by trolley wheels is not excessive. It should also be ensured that the stresses on the top flange induced by beam fixing are not excessive, in computing the transverse stresses the following equations apply: When the trolley is remote from the end of the beam, When the trolley is at the end of the beam or at joint where edges of flanges are unsupported, 19) BS 4, Structural steel sections, Part 1, Hot rolled sections. BSI

18 Where: Unit f 1 = longitudinal stress M ---- bending moment tonf/in Z modulus of section 2 f 2 = transverse stress tonf/in 2 C K 1 K 2 = a constant dependent on wheel centres or beam fixing centres and flange width (Table 3) = a constant dependent on set-in of wheels for trolleys (or set-in of beam fixings) remote from end of beam or unsupported joint (Table 4) = a constant dependent on set-in of wheels for trolleys (or set-in of beam fixings) at or near end of beam (Table 5) W = effective loads (see Clause 4 a) tonf T = the mean thickness of the flange as given in the appropriate British Standard or other reference book The stress f 2 given by the above equations shall, when plotted with the stress f 1, due to the longitudinal bending, on the graphs Figure 5or Figure 6, as appropriate, fall within the hatched areas. For the purpose of calculating the transverse stress,f 2, in the flanges of joists having 5 taper, it 2 is permissible to substitute T in place of T 2 1 in Formulae (1) and (2): where T (b t) = T (3) 2 b = flange width, in inches. t = web thickness, in inches as given in the appropriate British Standard or other reference book. in 12 BSI

19 l/r y Table 1 Allowable stresses P bc in bending (tonf/in 2 ) for beams of steel to BS 15 D/T Intermediate values may be obtained by linear interpolation. NOTE 1 Figure 1 has been deleted in accordance with Amendment No. 1, PD 3362, May, NOTE 2 The above table supersedes that given in Amendment No. 1, PD 3362, May, BSI

20 Table 2 Allowable stresses P bc in bending (tonf/in 2 ) for beams of steel to BS 968 D/T l/r y Intermediate values may be obtained by linear interpolation. 14 BSI

21 Table 4 Values of K 1 Table 5 Values of K 2 Table 3 Values of C Flange width Two wheeled Four wheeled trolley wheel centres in trolley 5 in 6 in 7 in 8 in 9 in Over 9 in ¼ ¾ ½ ¾ ½ ¼ Set-in of wheels Two wheeled trolley Edge ¾b ½b ¼b Set-in of wheels Edge 0 5 ¾b 0 59 ½b 0 77 ¼b 1 4 Four wheeled trolley Two or Four wheeled trolley BSI

22 16 BSI Figure 2 Cantilever continuous at support, unrestrained against torsion at the support and unrestrained at the end Figure 3 Cantilever continuous at support, partially restrained against torsion at the support and unrestrained at the end BS 2853:1957

23 BSI Figure 4 Cantilever span, continuous at support, fully restrained against torsion at the support and unrestrained at free end BS 2853:1957

24 18 BSI Figure 5 Values of f 1 and f 2 for steel to BS 15 BS 2853:1957

25 BSI Figure 6 Values of f 1 and f 2 for steel to BS 968 BS 2853:1957

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