The effect of wind loading on the jib of a luffing tower crane

Health and Safety Executive The effect of wind loading on the jib of a luffing tower crane Prepared by the Health and Safety Laboratory for the Health and Safety Executive 2012 tailieuxdcd@gmail.com RR917 Research Report Health and Safety Executive The effect of wind loading on the jib of a luffing tower crane Richard Isherwood BEng (Hons) CEng MIMechE Robert Richardson BEng (Hons) CEng MIMechE Health and Safety Laboratory Harpur Hill Buxton Derbyshire SK17 9JN Following a luffing crane collapse in Liverpool in January 2007, the UK Health and Safety Executive (HSE) were concerned that standards concerned with tower crane manufacture may not offer sufficient protection in relation to slack rope conditions on a luffing tower crane HSE wished to determine if foreseeable conditions could be identified that could give rise to dangerous operational conditions below maximum in service wind speeds A luffing tower crane was erected at the Health and Safety Laboratory (HSL), Buxton Measurements of wind speed and luffing system tension were taken to determine combinations of wind speed and jib elevation likely to result in slack luffing rope conditions Calculations of jib wind loading were carried out using four standards, FEM 1.001, FEM 1.004, ISO 4302 and BS EN 13001- 2:2004 Wind loading calculations compared closely with values obtained during the tests The jib was found to be susceptible to uncontrolled movement below the maximum in service wind speed and at jib elevations within the limits specified by the manufacturer Differences of up to 150% between wind speed readings provided by anemometers fitted at the jib outer end and the ‘A’ frame were experienced during the testing This report and the work it describes were funded by the Health and Safety Executive (HSE) Its contents, including any opinions and/or conclusions expressed, are those of the authors alone and not necessarily reflect HSE policy HSE Books tailieuxdcd@gmail.com © Crown copyright 2012 First published 2012 You may reuse this information (not including logos) free of charge in any format or medium, under the terms of the Open Government Licence To view the licence visit www.nationalarchives.gov.uk/doc/open-government-licence/, write to the Information Policy Team, The National Archives, Kew, London TW9 4DU, or email psi@nationalarchives.gsi.gov.uk Some images and illustrations may not be owned by the Crown so cannot be reproduced without permission of the copyright owner Enquiries should be sent to copyright@hse.gsi.gov.uk ii tailieuxdcd@gmail.com CONTENTS INTRODUCTION DESCRIPTION OF A LUFFING TOWER CRANE CRANE USED IN TESTING 3.1 Details of the Jaso J80 PA Luffing Crane Used in Testing 3.1.1 The J80 PA Crane Jib INSTRUMENTATION 4.1 Jib load monitoring 4.2 Wind speed monitoring 4.3 Wind direction monitoring 4.4 Jib angle monitoring 4.5 Other logged channels 10 4.6 Data Logger 11 4.7 Weather Station 12 4.8 Video cameras 12 JIB WIND LOADING CALCULATIONS 13 5.1 Preamble 13 5.2 Wind loading Calculations 14 5.2.1 Anomalies with the Standards 16 TESTING OF THE CRANE 19 6.1 Crane Set up 19 6.2 Test Procedure 19 6.2.1 6.2.2 6.2.3 6.3 Checks Before Testing 19 Data Collection 20 Checks After Testing 20 Results of Testing 20 6.3.1 6.3.2 6.3.3 Load Cell Readings to Determine the Effect of Wind Loading on the Jib 20 Discrepancy between the Anemometers 22 Jib “Blow Back” Incident During Testing 22 ASSESSMENT 27 7.1 Assessment of the testing 27 7.1.1 7.1.2 7.1.3 7.1.4 7.2 Crane in the “as received” condition at HSL 27 Discrepancy between the anemometers 27 Jib “Blow Back Incident During Testing 29 Crane Modifications 29 Assesment of the wind loading calculations 29 CONCLUSIONS 31 REFERENCES 32 tailieuxdcd@gmail.com iii CONTENTS (continued) 11 APPENDICES………………………….………………………………… 62 APPENDIX - Specification for tender to supply the Luffing crane used in testing……………………………………………… ………….62 APPENDIX - Calculation of the moment acting at the jib pivot points arising from the weight of the jib and hook block of the crane…….66 APPENDIX - Calculation of the jib lattice area and moment acting at the jib pivot points arising from the wind loading on the jib of the crane……………………………………………… ….…73 APPENDIX - Calculation of the wind loading and consequent moment acting at the jib pivot points according to FEM 1.001 “Rules for the Design of Hoisting Appliances – Classification and Loading on Structures and Mechanisms”… …97 APPENDIX - Calculation of the wind loading and consequent moment acting at the jib pivot points according to FEM 1.004 “Heavy Lifting Appliances –Section – Recommendations for the Calculation of Wind Loads on Crane Structures”… … 109 APPENDIX - Calculation of the wind loading and consequent moment acting at the jib pivot points according to ISO 4302 “Cranes – Wind Load Assessment”………………………….… 121 APPENDIX - Calculation of the wind loading and consequent moment acting at the jib pivot points according to BS EN 13001 – 2:2004 “Crane Safety – General Design – Part Load Actions”…………133 iv tailieuxdcd@gmail.com ACKNOWLEDGEMENTS The authors would like to express their gratitude to Falcon Crane Hire Ltd of Shipdham, Norfolk and Jaso Equipos de Obras Y Construcciones S.L of Idiazabal, Gipuzkoa, Spain for their invaluable support during the course of this project In particular, thanks must go to Mr Gary Potter of Falcon Crane Hire who provided regular technical support for the crane whilst at HSL with never failing good humour, even after the events of 16 November 2009 (described later in this report) and Mr Philip Gale also of Falcon Crane Hire who was always available for consultation and advice We learned a lot from them Thanks are also due to Mr Bosko Mujika of Jaso Equipos de Obras y Construcciones S.L who provided details, calculations and technical drawings for the crane used in testing Much of the work described in this report would have been made very much more difficult without this generous assistance from the crane manufacturer In addition, thanks are due to Mr Marc Polette, Research and Development Manager and Mr Vincent Thevenet, Technical Research and Development Director, of Ascorel, Pont-Evêque, France, for their technical support and assistance with integrating the output of the Ascorel Alize wind speed monitoring equipment, with the HSL data logging equipment tailieuxdcd@gmail.com v vi tailieuxdcd@gmail.com EXECUTIVE SUMMARY In a luffing crane, the hook block is located at the end of the jib and the angle of the jib is altered by raising and lowering it to place the load on the hook the required distance from the mast On some cranes the jib is raised and lowered (luffing) using wire rope wound around a luffing winch drum and travelling over two sets of pulleys One set of pulleys at the top of the tower head or ‘A’ frame are fixed in position whereas the other set are fitted in a pulley block that is not fixed in any single position and is commonly referred to as the “flying” or “floating” pulley block The flying pulley block is usually attached to the jib at a single pivot towards the hook end of the jib by a series of tie bars pinned together Objectives Following an incident in Liverpool in January 2007, HSE were concerned that current standards concerned with tower crane manufacture may not offer sufficient protection in relation to preventing and guarding against slack rope conditions on a luffing type crane The standards deal in a simple manner by “winding off” (ceasing operation of the crane) should the wind speed reach pre-determined levels, known as the maximum in service wind speed, despite the number of variables involved Mr Ian Simpson, FOD Mechanical Portfolio Holder (Lifting Equipment & Lifting Operations) requested that HSL obtain and test a luffing tower crane to determine if foreseeable conditions could be identified which might arise that could give rise to dangerous operational conditions for the crane The standards also provide guidance on how the wind force acting on the crane structure can be calculated Mr Simpson requested that wind force calculations be carried out in accordance with the standards on the jib of the crane used in testing and that the results of these calculations be compared with results from testing of the crane to determine if the calculations provided a reasonable estimate of the wind force Main Findings A suitable luffing type tower crane was identified and erected at HSL The crane was fitted with instrumentation to measure and log the wind speeds at the outer end of the jib and on top of the ‘A’ frame of the crane, the latter being the location for wind measuring instrumentation most commonly used by the U.K Tower Crane Industry Because the jib of a luffing crane is raised and lowered during operation to manoeuvre the hook/load being carried by the crane there was a difference in height between the two wind measuring instruments of between nominally to 33m The crane was also fitted with instrumentation to measure and record the tension in the luffing system which altered according to the angle of elevation of the jib and speed of the wind acting against the jib Calculations of wind loading were carried out using four standards, FEM 1.001, FEM 1.004, ISO 4302 and BS EN 13001- 2:2004 It was found that the method of calculating the wind force acting on the jib of the crane was reasonably close to values obtained during testing of the crane and so can be used with confidence to predict the wind loads on the jib of the crane used in testing Consequently, it would be expected that they provide similar reasonably accurate results when applied to other structures, e.g other crane jibs and mast sections etc tailieuxdcd@gmail.com vii The jib of the crane used in testing at HSL was proven by calculation and testing to be susceptible to uncontrolled movement arising from wind loading below the maximum in service wind speed and at jib elevations within the normal maximum and minimum radius quoted by the manufacturer Uncontrolled movement took place when the wind speed was approaching, but below, the maximum in service wind speed and when the jib of the crane was close to its maximum elevation or minimum radius On one occasion, during testing of the crane at HSL the jib of the crane suffered an uncontrolled movement and was “blown back” against a spring buffer arrangement mounted on the jib support ‘A’ frame At this time the luffing system lost tension and the luffing rope became slack The guarding on the crane against slack rope conditions was ineffective in preventing the luffing rope from leaving the grooves of one of the ‘A’ frame pulleys Following this event, the crane manufacturer and their U.K representative’s implemented modifications to prevent reoccurrence These consisted of a system to maintain tension in the luffing system as the jib approached minimum radius and improved physical guarding against rope leaving the grooves of the ‘A’ frame pulleys These modifications were fitted to the crane at HSL Subsequent testing of the crane under similar conditions whereby the uncontrolled movement of the jib first took place showed that these modifications were effective in preventing the slack rope conditions from arising Since tension was maintained in the luffing system at all operational angles of the jib the improved physical guarding against the rope leaving the grooves of pulleys could not be assessed Significant differences between the readings of the two wind instruments fitted at the outer end of the jib and on the ‘A’ frame were found on occasion during the testing Consequently, wind speed readings obtained from an anemometer mounted on the ‘A’ frame of a luffing tower crane may not, on occasion, be an accurate representation of the wind speed being experienced by other parts of the crane structure, e.g the outer end of the jib This may give rise to unintentional operation of the crane at wind speeds approaching or perhaps exceeding the maximum in service wind speed viii tailieuxdcd@gmail.com INTRODUCTION On Monday 15 January 2007 a luffing tower crane collapsed at the Elysian Fields Construction Site, Colquitt Street, Liverpool injuring the driver and killing a construction worker on the ground The crane involved in this incident was a J138PA manufactured by Jaso Equipos de Obras y Construcciones S.L of Idiazabal, Gipuzkoa, Spain Subsequent investigation by HSE (assisted by HSL) determined that, at the time of the accident, the crane was being operated within its duty envelope as specified by the manufacturer However, the jib was facing towards the wind and had been raised to near or at its maximum angle of elevation in order to bring the hook as close towards the central mast section as possible The hook was very lightly loaded and the wind speed was close to, but within, the maximum in service wind speed Under these conditions the system of ropes used to raise and lower the crane jib could have become slack, jumped from their pulleys and become jammed or tangled The accident raised the issue of the effect of wind on luffing jib cranes when working close to minimum radius In particular, the susceptibility of uncontrolled movement of the jib, resulting from the action of the wind, was of concern The crane was approximately three years old and its manufacturer had followed the Harmonised European Standard for Tower Cranes, BS EN 14439:2006 “Cranes – Safety – Tower Cranes” The effect of wind on the jib of a tower crane is covered in BS EN 14339 by reference to a set of FEM standards FEM Standards are produced by a European Trade Association representing crane manufacturers and provide information to designers on the loadings for both the in service and out of service wind conditions and associated factors of safety According to relevant FEM and other European standards the maximum in service wind speed is 20 m/s The HSE view was that the current standard may not offer sufficient protection in relation to preventing and guarding against slack rope conditions The standard deals in a simple manner with “winding off” (ceasing operation of the crane) should the wind speed reach pre-determined levels despite the number of variables involved These variables include weight on the hook, jib angle and its orientation i.e facing into or away from the wind and if the wind speed is steady or gusting Consideration of these variables could argue for a more complex solution than the current requirement for the manufacturer to quote a single wind speed limit Consequently, Mr Ian Simpson, FOD Mechanical Portfolio Holder (Lifting Equipment & Lifting Operations) requested that HSL obtain and test a luffing tower crane to determine if foreseeable conditions could be identified which might arise within the variables that could give rise to dangerous operational conditions for the crane The objective of this project was to determine the effect of different wind speeds on the jib of the crane at different angles of elevation and therefore establish likely combinations of wind speed versus jib angle at which the wind would be expected to hold the jib in the elevated position or force it backwards Mr Robert Richardson of HSL Engineering Support Unit wrote Section of this report, which is concerned with the instrumentation fitted to the crane under test Mr Richard Isherwood, also of HSL Engineering Safety Unit, wrote all other sections Photographs shown in this report were taken by members of the Visual Presentation Services Section of HSL, Mr Richardson, Mr Isherwood, or Mr Gary Potter of Falcon Crane Hire Ltd All measurements given in this report are for indication only unless a statement of accuracy accompanies them tailieuxdcd@gmail.com APPENDIX Calculation of the wind loading and consequent moment acting at the jib pivot point according to BS EN 13001 – 2:2004 “Crane Safety – General Design – Part Load Actions” Theoretical properties of the jib sections i.e the masses provided in the crane manual and positions of centre of gravity provided by Jaso ………………134 Masses and positions of centre of gravity measured during erection of the crane at HSL………………….…………………… …………………………140 133 tailieuxdcd@gmail.com Appendix Calculation of the moment acting at the jib pivot points due to wind loading on the jib and jib end platform according to BS EN 13001 – :2004 0.301m Jib End Platform 0.295m 0.242m ‘A’ 0.299m Theoretical properties of the jib sections i.e the masses provided in the crane manual and positions of centre of gravity provided by Jaso 0.164m 4.105m 14.119m 24.101m 31.717m 37.825m 40.812m 41.691m 90º º Jib Angle 0º The moment, MWIND, acting at the jib pivot point ‘A’ arising from the wind loading is given by: MWIND = FN cos(tan-1y/x)x where FN is the wind load normal to the underside of the jib component under consideration (N) x is the dimension along the jib section from ‘A’ to the centre of gravity of the jib section (m) y is the dimension from ‘A’ to the centre of gravity of the jib section perpendicular to the x is the dimension (m) Since the centre of gravity of the jib sections are slightly offset from the pivot point in the vertical (y) direction the term cos(tan-1y/x) in the above equation resolves FN (the wind load normal to the underside of the jib component under consideration) to the lever arm joining the centre of gravity to the pivot point such that the resultant force is completely perpendicular to the lever arm However, the angles between the centres of gravity of the jib sections and the pivot point are very small such that cos(tan-1y/x) tends to unity Hence this is ignored and 134 tailieuxdcd@gmail.com Hook Block the moment, MWIND, acting at the jib pivot point ‘A’ arising from the wind loading is given by: MWIND = FN x where FN is the wind load normal to the underside of the jib component under consideration (N) x is the dimension along the jib section from ‘A’ to the centre of gravity of the jib section (m) Since the wind load, FN, is normal to the underside of the jib component under consideration, x remains constant at the dimensions shown in the sketch above as the angle of the jib to the horizontal alters For any given jib angle to the horizontal, the total moment acting at the jib pivot point ‘A’ arising from the wind load acting on each jib section is given by adding the moment arising from each individual jib section to (MWIND1 – MWIND5) and that arising from the jib end platform (MWINDPLATFORM), i.e: MWINDTOTAL = MWIND1 + MWIND2 + MWIND3 + MWIND4 + MWIND5 + MWINDPLATFORM The wind loading on each jib section and the jib end platform has been calculated in Appendix according to FEM 1.001, FEM 1.004, ISO 4302 and BS EN 13001 – 2:2004 and equations for FN derived Example Calculation – BS EN 13001 – 2:2004 (wind speed = m/s, jib angle = 28º to the horizontal) Assuming a wind speed of m/s, the wind pressure q is given by: q=½x x v2 = ½ x 1.25 x 62 = 22.5 N/m2 Using equations 1c – 6c derived in Appendix Section 8.3.3 for a jib angle of 28º to the horizontal the wind load normal to the underside of the jib component under consideration and acting at the centre of gravity is: For jib section 1, the wind load normal to the underside of the jib section and resulting moment at the jib pivot point is: FN1 = 3.98 q sin = 3.98 x 22.5 x sin 28º = 42.04 N MWIND1 = 42.04 x 4.105 = 171.18 Nm For jib section 2, the wind load normal to the underside of the jib section and resulting moment at the jib pivot point is: FN2 = 4.38 q sin = 4.38 x 22.5 x sin 28º = 46.27 N MWIND2 = 46.27 x 14.119 = 653.24 Nm For jib section 3, the wind load normal to the underside of the jib section and resulting moment at the jib pivot point is: FN3 = 4.30 q sin = 4.30 x 22.5 x sin 28º = 45.42 N MWIND3 = 45.42 x 24.101 = 1094.70 Nm For jib section 4, the wind load normal to the underside of the jib section and resulting moment at the jib pivot point is: 135 tailieuxdcd@gmail.com FN4 = 2.20 q sin = 2.20 x 22.5 x sin 28º = 23.24 N MWIND4 = 23.24 x 31.717 = 737.07 Nm For jib section 5, the wind load normal to the underside of the jib section and resulting moment at the jib pivot point is: FN5 = 3.19 q sin = 3.19 x 22.5 x sin 28º = 33.70 N MWIND5 = 33.70 x 37.825 = 1,274.56 Nm The wind load normal to the jib end platform floor and resulting moment at the jib pivot point is: FNPLATFORM = 0.62 q sin = 0.62 x 22.5 x sin 28º = 6.5 N MWINDPLATFORM = 6.5 x 40.812 = 265.28 Nm The total moment at the jib pivot point due to wind loading at a wind speed of m/s and a jib angle of 28º to the horizontal is: MWINDTOTAL = 171.18 + 653.24 + 1094.70 + 737.07 + 1,274.56 + 265.28 = 4.20 kNm Similar calculations can be performed for different wind speeds and jib angles and the resultant moments at the jib pivot point are given in Table of this appendix 136 tailieuxdcd@gmail.com Table - Moment at the Jib Pivot Point due to Wind Loading (kNm) Theoretical Jib Properties (BS EN 13001 – 2:2004) 137 tailieuxdcd@gmail.com Jib Angle (º) 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 0.06 0.07 0.07 0.08 0.08 0.08 0.09 0.09 0.10 0.10 0.11 0.11 0.11 0.12 0.12 0.12 0.13 0.13 0.14 0.14 0.14 0.15 0.15 0.15 0.16 0.16 0.16 0.17 0.17 0.26 0.27 0.29 0.31 0.32 0.34 0.36 0.37 0.39 0.40 0.42 0.44 0.45 0.47 0.48 0.50 0.51 0.53 0.54 0.56 0.57 0.58 0.60 0.61 0.63 0.64 0.65 0.67 0.68 0.58 0.62 0.65 0.69 0.73 0.76 0.80 0.84 0.87 0.91 0.95 0.98 1.02 1.05 1.08 1.12 1.15 1.19 1.22 1.25 1.28 1.31 1.35 1.38 1.41 1.44 1.47 1.50 1.53 1.03 1.10 1.16 1.23 1.29 1.36 1.42 1.49 1.55 1.62 1.68 1.74 1.80 1.87 1.93 1.99 2.05 2.11 2.17 2.22 2.28 2.34 2.39 2.45 2.50 2.56 2.61 2.66 2.71 1.61 1.71 1.82 1.92 2.02 2.12 2.23 2.33 2.43 2.53 2.63 2.72 2.82 2.92 3.01 3.11 3.20 3.29 3.38 3.47 3.56 3.65 3.74 3.82 3.91 3.99 4.08 4.16 4.24 2.32 2.47 2.62 2.76 2.91 3.06 3.21 3.35 3.50 3.64 3.78 3.92 4.06 4.20 4.34 4.47 4.61 4.74 4.87 5.00 5.13 5.26 5.38 5.51 5.63 5.75 5.87 5.99 6.10 3.15 3.36 3.56 3.76 3.96 4.16 4.36 4.56 4.76 4.95 5.15 5.34 5.53 5.72 5.90 6.09 6.27 6.45 6.63 6.81 6.98 7.16 7.33 7.50 7.66 7.83 7.99 8.15 8.30 4.12 4.38 4.65 4.91 5.18 5.44 5.70 5.96 6.21 6.47 6.72 6.97 7.22 7.47 7.71 7.95 8.19 8.43 8.66 8.89 9.12 9.35 9.57 9.79 10.01 10.22 10.43 10.64 10.85 Wind Speed (m/s) 10 11 5.21 5.55 5.88 6.22 6.55 6.88 7.21 7.54 7.86 8.19 8.51 8.82 9.14 9.45 9.76 10.06 10.37 10.67 10.96 11.25 11.54 11.83 12.11 12.39 12.67 12.94 13.20 13.47 13.73 6.43 6.85 7.26 7.68 8.09 8.50 8.90 9.31 9.71 10.11 10.50 10.89 11.28 11.67 12.05 12.42 12.80 13.17 13.53 13.89 14.25 14.60 14.95 15.30 15.64 15.97 16.30 16.63 16.95 Appendix - Page 7.78 8.29 8.79 9.29 9.79 10.28 10.77 11.26 11.75 12.23 12.71 13.18 13.65 14.11 14.58 15.03 15.48 15.93 16.37 16.81 17.24 17.67 18.09 18.51 18.92 19.33 19.72 20.12 20.50 12 13 14 15 16 17 18 19 20 9.26 9.86 10.46 11.06 11.65 12.24 12.82 13.40 13.98 14.55 15.12 15.68 16.24 16.80 17.35 17.89 18.43 18.96 19.49 20.01 20.52 21.03 21.53 22.03 22.52 23.00 23.47 23.94 24.40 10.87 11.57 12.28 12.98 13.67 14.36 15.05 15.73 16.41 17.08 17.75 18.41 19.06 19.71 20.36 21.00 21.63 22.25 22.87 23.48 24.09 24.68 25.27 25.85 26.43 26.99 27.55 28.10 28.64 12.60 13.42 14.24 15.05 15.86 16.66 17.45 18.24 19.03 19.81 20.58 21.35 22.11 22.86 23.61 24.35 25.08 25.81 26.52 27.23 27.93 28.63 29.31 29.98 30.65 31.30 31.95 32.59 33.21 14.47 15.41 16.35 17.28 18.20 19.12 20.04 20.94 21.84 22.74 23.63 24.51 25.38 26.25 27.10 27.95 28.79 29.63 30.45 31.26 32.07 32.86 33.65 34.42 35.18 35.94 36.68 37.41 38.13 16.46 17.53 18.60 19.66 20.71 21.76 22.80 23.83 24.85 25.87 26.88 27.88 28.88 29.86 30.84 31.80 32.76 33.71 34.64 35.57 36.48 37.39 38.28 39.16 40.03 40.89 41.73 42.56 43.38 18.59 19.79 20.99 22.19 23.38 24.56 25.73 26.90 28.06 29.21 30.35 31.48 32.60 33.71 34.81 35.90 36.98 38.05 39.11 40.15 41.19 42.21 43.22 44.21 45.19 46.16 47.11 48.05 48.97 20.84 22.19 23.54 24.88 26.21 27.53 28.85 30.16 31.46 32.74 34.02 35.29 36.55 37.79 39.03 40.25 41.46 42.66 43.85 45.02 46.18 47.32 48.45 49.56 50.66 51.75 52.82 53.87 54.90 23.22 24.72 26.23 27.72 29.20 30.68 32.15 33.60 35.05 36.48 37.91 39.32 40.72 42.11 43.49 44.85 46.20 47.53 48.85 50.16 51.45 52.72 53.98 55.22 56.45 57.66 58.85 60.02 61.17 25.72 27.40 29.06 30.71 32.36 33.99 35.62 37.23 38.83 40.43 42.00 43.57 45.12 46.66 48.18 49.69 51.19 52.67 54.13 55.58 57.01 58.42 59.81 61.19 62.55 63.89 65.21 66.50 67.78 Table - (continued) Moment at the Jib Pivot Point due to Wind Loading (kNm) Theoretical jib Properties (BS EN 13001 – 2:2004) 138 tailieuxdcd@gmail.com Jib Angle (º) 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 0.17 0.18 0.18 0.18 0.18 0.19 0.19 0.19 0.20 0.20 0.20 0.20 0.21 0.21 0.21 0.21 0.22 0.22 0.22 0.22 0.22 0.23 0.23 0.23 0.23 0.23 0.23 0.23 0.24 0.24 0.24 0.69 0.70 0.71 0.73 0.74 0.75 0.76 0.77 0.78 0.79 0.80 0.81 0.82 0.83 0.84 0.85 0.86 0.87 0.88 0.89 0.89 0.90 0.91 0.91 0.92 0.93 0.93 0.94 0.95 0.95 0.96 1.55 1.58 1.61 1.64 1.66 1.69 1.71 1.74 1.76 1.79 1.81 1.83 1.85 1.88 1.90 1.92 1.94 1.96 1.97 1.99 2.01 2.03 2.04 2.06 2.07 2.09 2.10 2.11 2.13 2.14 2.15 2.76 2.81 2.86 2.91 2.95 3.00 3.05 3.09 3.13 3.18 3.22 3.26 3.30 3.33 3.37 3.41 3.44 3.48 3.51 3.54 3.57 3.60 3.63 3.66 3.69 3.71 3.74 3.76 3.78 3.80 3.82 4.32 4.39 4.47 4.54 4.62 4.69 4.76 4.83 4.89 4.96 5.03 5.09 5.15 5.21 5.27 5.32 5.38 5.43 5.48 5.53 5.58 5.63 5.67 5.72 5.76 5.80 5.84 5.87 5.91 5.94 5.97 6.21 6.33 6.43 6.54 6.65 6.75 6.85 6.95 7.05 7.14 7.24 7.33 7.42 7.50 7.59 7.67 7.75 7.82 7.90 7.97 8.04 8.11 8.17 8.23 8.29 8.35 8.41 8.46 8.51 8.55 8.60 8.46 8.61 8.76 8.90 9.05 9.19 9.33 9.46 9.59 9.72 9.85 9.97 10.09 10.21 10.33 10.44 10.54 10.65 10.75 10.85 10.94 11.03 11.12 11.21 11.29 11.37 11.44 11.51 11.58 11.64 11.70 11.05 11.24 11.44 11.63 11.82 12.00 12.18 12.36 12.53 12.70 12.87 13.03 13.18 13.34 13.49 13.63 13.77 13.91 14.04 14.17 14.29 14.41 14.53 14.64 14.74 14.85 14.94 15.04 15.12 15.21 15.29 Wind Speed (m/s) 10 11 13.98 14.23 14.48 14.72 14.96 15.19 15.42 15.64 15.86 16.07 16.28 16.49 16.69 16.88 17.07 17.25 17.43 17.60 17.77 17.93 18.09 18.24 18.39 18.53 18.66 18.79 18.91 19.03 19.14 19.25 19.35 17.26 17.57 17.87 18.17 18.47 18.75 19.03 19.31 19.58 19.84 20.10 20.35 20.60 20.84 21.07 21.30 21.52 21.73 21.94 22.14 22.33 22.52 22.70 22.87 23.04 23.20 23.35 23.49 23.63 23.76 23.88 Appendix - Page 20.89 21.26 21.63 21.99 22.34 22.69 23.03 23.37 23.69 24.01 24.32 24.63 24.93 25.21 25.50 25.77 26.04 26.30 26.55 26.79 27.02 27.25 27.47 27.68 27.88 28.07 28.25 28.43 28.59 28.75 28.90 12 13 14 15 16 17 18 19 20 24.85 25.30 25.74 26.17 26.59 27.00 27.41 27.81 28.20 28.58 28.95 29.31 29.66 30.01 30.34 30.67 30.99 31.29 31.59 31.88 32.16 32.43 32.69 32.94 33.17 33.40 33.62 33.83 34.03 34.22 34.39 29.17 29.69 30.21 30.71 31.21 31.69 32.17 32.63 33.09 33.54 33.97 34.40 34.81 35.22 35.61 35.99 36.37 36.73 37.08 37.42 37.74 38.06 38.36 38.65 38.93 39.20 39.46 39.70 39.94 40.16 40.37 33.83 34.44 35.03 35.62 36.19 36.75 37.31 37.85 38.38 38.89 39.40 39.89 40.37 40.84 41.30 41.74 42.18 42.59 43.00 43.39 43.77 44.14 44.49 44.83 45.15 45.47 45.76 46.05 46.32 46.57 46.81 38.84 39.53 40.22 40.89 41.55 42.19 42.83 43.45 44.05 44.65 45.23 45.80 46.35 46.89 47.41 47.92 48.42 48.90 49.36 49.81 50.25 50.67 51.07 51.46 51.84 52.19 52.53 52.86 53.17 53.46 53.74 44.19 44.98 45.76 46.52 47.27 48.01 48.73 49.43 50.12 50.80 51.46 52.11 52.73 53.35 53.94 54.52 55.09 55.63 56.16 56.68 57.17 57.65 58.11 58.55 58.98 59.38 59.77 60.14 60.50 60.83 61.14 49.88 50.78 51.65 52.52 53.36 54.19 55.01 55.81 56.59 57.35 58.09 58.82 59.53 60.22 60.90 61.55 62.19 62.81 63.40 63.98 64.54 65.08 65.60 66.10 66.58 67.04 67.48 67.90 68.29 68.67 69.03 55.92 56.93 57.91 58.88 59.83 60.76 61.67 62.56 63.44 64.29 65.13 65.95 66.74 67.52 68.27 69.01 69.72 70.41 71.08 71.73 72.36 72.96 73.55 74.11 74.64 75.16 75.65 76.12 76.56 76.99 77.39 62.31 63.43 64.52 65.60 66.66 67.70 68.71 69.71 70.68 71.64 72.57 73.48 74.36 75.23 76.07 76.89 77.68 78.45 79.20 79.92 80.62 81.29 81.94 82.57 83.17 83.74 84.29 84.81 85.31 85.78 86.22 69.04 70.28 71.49 72.69 73.86 75.01 76.14 77.24 78.32 79.38 80.41 81.41 82.40 83.35 84.29 85.19 86.07 86.93 87.76 88.56 89.33 90.08 90.80 91.49 92.15 92.79 93.40 93.97 94.52 95.05 95.54 Table - (continued) Moment at the Jib Pivot Point due to Wind Loading (kNm) Theoretical Jib properties (BS EN 13001 – 2:2004) 139 tailieuxdcd@gmail.com Jib Angle (º) 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 0.24 0.24 0.24 0.24 0.24 0.24 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.96 0.96 0.97 0.97 0.98 0.98 0.98 0.98 0.99 0.99 0.99 0.99 0.99 0.99 0.99 0.99 2.16 2.17 2.18 2.19 2.20 2.20 2.21 2.21 2.22 2.22 2.23 2.23 2.23 2.23 2.24 2.24 3.84 3.86 3.87 3.89 3.90 3.92 3.93 3.94 3.95 3.95 3.96 3.97 3.97 3.97 3.97 3.98 6.00 6.03 6.05 6.08 6.10 6.12 6.14 6.15 6.17 6.18 6.19 6.20 6.20 6.21 6.21 6.21 8.64 8.68 8.72 8.75 8.78 8.81 8.83 8.86 8.88 8.90 8.91 8.92 8.93 8.94 8.94 8.95 11.76 11.81 11.86 11.91 11.95 11.99 12.03 12.06 12.08 12.11 12.13 12.15 12.16 12.17 12.17 12.18 15.36 15.43 15.49 15.55 15.61 15.66 15.71 15.75 15.78 15.82 15.84 15.86 15.88 15.89 15.90 15.90 Wind Speed (m/s) 10 11 19.44 19.53 19.61 19.69 19.76 19.82 19.88 19.93 19.98 20.02 20.05 20.08 20.10 20.11 20.12 20.13 24.00 24.11 24.21 24.30 24.39 24.47 24.54 24.61 24.66 24.71 24.75 24.79 24.81 24.83 24.84 24.85 Appendix - Page 29.04 29.17 29.29 29.41 29.51 29.61 29.70 29.77 29.84 29.90 29.95 29.99 30.02 30.05 30.06 30.07 12 13 14 15 16 17 18 19 20 34.56 34.72 34.86 35.00 35.12 35.24 35.34 35.43 35.51 35.58 35.64 35.69 35.73 35.76 35.77 35.78 40.56 40.74 40.92 41.07 41.22 41.35 41.47 41.58 41.68 41.76 41.83 41.89 41.93 41.97 41.99 41.99 47.04 47.25 47.45 47.64 47.81 47.96 48.10 48.23 48.34 48.43 48.52 48.58 48.63 48.67 48.69 48.70 54.00 54.25 54.47 54.68 54.88 55.06 55.22 55.36 55.49 55.60 55.69 55.77 55.83 55.87 55.90 55.91 61.44 61.72 61.98 62.22 62.44 62.64 62.83 62.99 63.13 63.26 63.37 63.45 63.52 63.57 63.60 63.61 69.36 69.68 69.97 70.24 70.49 70.72 70.92 71.11 71.27 71.42 71.54 71.63 71.71 71.76 71.80 71.81 77.76 78.11 78.44 78.75 79.03 79.28 79.51 79.72 79.91 80.06 80.20 80.31 80.39 80.46 80.49 80.51 86.64 87.03 87.40 87.74 88.05 88.34 88.59 88.83 89.03 89.21 89.36 89.48 89.58 89.64 89.68 89.70 96.00 96.44 96.84 97.22 97.56 97.88 98.17 98.42 98.65 98.84 99.01 99.15 99.25 99.33 99.37 99.39 Hook Block 4.170m 14.085m 24.035m 31.835m 38.060m 41.795m As before, the moment, MWIND, acting at the jib pivot point ‘A’ arising from the wind loading is given by: MWIND = FN x where FN is the wind load normal to the underside of the jib component under consideration (N) x is the dimension along the jib section from ‘A’ to the centre of gravity of the jib section (m) Since the wind load, FN, is normal to the underside of the jib component under consideration, x remains constant at the dimensions shown in the sketch above as the angle of the jib to the horizontal alters For any given jib angle to the horizontal, the total moment acting at the jib pivot point ‘A’ arising from the wind load acting on each jib section is given by adding the moment arising from each individual jib section to (MWIND1 – MWIND5) In this case, the position of the centre of gravity for Jib section incorporates the jib end platform since the platform was fitted when the position of the centre of gravity was measured during erection of the crane at HSL To determine MWIND5, the wind load on the jib and on the end platform are added and then multiplied by the x dimension MWINDTOTAL = MWIND1 + MWIND2 + MWIND3 + MWIND4 + MWIND5 Example Calculation – BS EN 13001 – 2:2004 (wind speed = 12 m/s, jib angle = 65º to the horizontal) Assuming a wind speed of 12 m/s, the wind pressure q is given by: q=½x 0.358m 0.278m 0.238m ‘A’ 0.188m Masses and positions of centre of gravity measured during erection of the crane at HSL 0.278m x v2 = ½ x 1.25 x 122 = 90 N/m2 Using equations 1c – 6c derived in Appendix for a jib angle of 65º to the horizontal the wind load normal to the underside of the jib component under consideration and acting at the centre of gravity is: 140 tailieuxdcd@gmail.com For jib section 1, the wind load normal to the underside of the jib section and resulting moment at the jib pivot point is: FN1 = 3.98 q sin = 3.98 x 90 x sin 65º = 324.64 N MWIND1 = 324.64 x 4.17 = 1.35 kNm For jib section 2, the wind load normal to the underside of the jib section and resulting moment at the jib pivot point is: FN2 = 4.38 q sin = 4.38 x 90 x sin 65º = 357.27 N MWIND2 = 357.27 x 14.085 = 5.03 kNm For jib section 3, the wind load normal to the underside of the jib section and resulting moment at the jib pivot point is: FN3 = 4.30 q sin = 4.30 x 90 x sin 65º = 350.74 N MWIND3 = 350.74 x 24.035 = 8.43 kNm For jib section 4, the wind load normal to the underside of the jib section and resulting moment at the jib pivot point is: FN4 = 2.20 q sin = 2.20 x 90 x sin 65º = 179.45 N MWIND4 = 178.63 x 31.835 m = 5.69 kNm For jib section 5, the wind load normal to the underside of the jib section is: FN5 = 3.19 q sin = 3.19 x 90 x sin 65º = 260.20 N The wind load normal to the jib end platform floor is: FNPLATFORM = 0.62 q sin = 0.62 x 90 x sin 65º = 50.6 N For jib section and the jib end platform, the resulting moment at the jib pivot point is: MWIND5 = (260.20 + 50.6) x 38.060 = 11.83 kNm The total moment at the jib pivot point due to wind loading at a wind speed of 12 m/s and a jib angle of 65º to the horizontal is: MWINDTOTAL = 1.35 + 5.03 + 8.43 + 5.69 + 11.83 = 32.33 kNm Similar calculations can be performed for different wind speeds and jib angles and the resultant moments at the jib pivot point are given in Table of this appendix 141 tailieuxdcd@gmail.com Table - Moment at the Jib Pivot Point due to Wind Loading (kNm) Measured Jib Properties (BS EN 13001 – 2:2004) 142 tailieuxdcd@gmail.com Jib Angle (º) 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 0.06 0.07 0.07 0.08 0.08 0.08 0.09 0.09 0.10 0.10 0.10 0.11 0.11 0.12 0.12 0.12 0.13 0.13 0.14 0.14 0.14 0.15 0.15 0.15 0.16 0.16 0.16 0.17 0.17 0.26 0.27 0.29 0.31 0.32 0.34 0.36 0.37 0.39 0.40 0.42 0.43 0.45 0.47 0.48 0.50 0.51 0.53 0.54 0.55 0.57 0.58 0.60 0.61 0.62 0.64 0.65 0.66 0.68 0.58 0.62 0.65 0.69 0.73 0.76 0.80 0.84 0.87 0.91 0.94 0.98 1.01 1.05 1.08 1.12 1.15 1.18 1.22 1.25 1.28 1.31 1.34 1.37 1.40 1.43 1.46 1.49 1.52 1.03 1.09 1.16 1.23 1.29 1.36 1.42 1.49 1.55 1.61 1.68 1.74 1.80 1.86 1.92 1.98 2.04 2.10 2.16 2.22 2.28 2.33 2.39 2.44 2.50 2.55 2.60 2.65 2.71 1.60 1.71 1.81 1.92 2.02 2.12 2.22 2.32 2.42 2.52 2.62 2.72 2.81 2.91 3.00 3.10 3.19 3.28 3.38 3.47 3.56 3.64 3.73 3.82 3.90 3.98 4.07 4.15 4.23 2.31 2.46 2.61 2.76 2.91 3.05 3.20 3.34 3.49 3.63 3.77 3.91 4.05 4.19 4.33 4.46 4.60 4.73 4.86 4.99 5.12 5.25 5.37 5.50 5.62 5.74 5.86 5.97 6.09 3.14 3.35 3.55 3.75 3.96 4.16 4.35 4.55 4.75 4.94 5.13 5.33 5.52 5.70 5.89 6.07 6.26 6.44 6.62 6.79 6.97 7.14 7.31 7.48 7.65 7.81 7.97 8.13 8.29 4.11 4.37 4.64 4.90 5.17 5.43 5.69 5.94 6.20 6.45 6.71 6.96 7.20 7.45 7.69 7.93 8.17 8.41 8.64 8.87 9.10 9.33 9.55 9.77 9.99 10.20 10.41 10.62 10.82 Wind Speed (m/s) 10 11 5.20 5.54 5.87 6.21 6.54 6.87 7.20 7.52 7.85 8.17 8.49 8.80 9.12 9.43 9.74 10.04 10.34 10.64 10.94 11.23 11.52 11.80 12.09 12.36 12.64 12.91 13.18 13.44 13.70 6.42 6.83 7.25 7.66 8.07 8.48 8.88 9.29 9.69 10.08 10.48 10.87 11.26 11.64 12.02 12.40 12.77 13.14 13.50 13.86 14.22 14.57 14.92 15.26 15.60 15.94 16.27 16.59 16.91 Appendix - Page 7.76 8.27 8.77 9.27 9.77 10.26 10.75 11.24 11.72 12.20 12.68 13.15 13.62 14.08 14.54 15.00 15.45 15.90 16.34 16.78 17.21 17.63 18.05 18.47 18.88 19.28 19.68 20.07 20.46 12 13 14 15 16 17 18 19 20 9.24 9.84 10.44 11.03 11.62 12.21 12.79 13.37 13.95 14.52 15.09 15.65 16.21 16.76 17.31 17.85 18.39 18.92 19.44 19.96 20.48 20.98 21.49 21.98 22.47 22.95 23.42 23.89 24.35 10.84 11.55 12.25 12.95 13.64 14.33 15.02 15.70 16.37 17.04 17.71 18.37 19.02 19.67 20.31 20.95 21.58 22.20 22.82 23.43 24.03 24.63 25.22 25.80 26.37 26.93 27.49 28.04 28.58 12.58 13.39 14.21 15.02 15.82 16.62 17.41 18.20 18.99 19.76 20.54 21.30 22.06 22.81 23.56 24.30 25.03 25.75 26.47 27.17 27.87 28.56 29.24 29.92 30.58 31.24 31.88 32.52 33.14 14.44 15.38 16.31 17.24 18.16 19.08 19.99 20.90 21.80 22.69 23.58 24.45 25.33 26.19 27.04 27.89 28.73 29.56 30.38 31.19 32.00 32.79 33.57 34.34 35.11 35.86 36.60 37.33 38.04 16.43 17.49 18.56 19.61 20.66 21.71 22.75 23.78 24.80 25.82 26.82 27.82 28.81 29.80 30.77 31.73 32.69 33.63 34.57 35.49 36.40 37.31 38.20 39.08 39.94 40.80 41.64 42.47 43.29 18.54 19.75 20.95 22.14 23.33 24.51 25.68 26.84 28.00 29.14 30.28 31.41 32.53 33.64 34.74 35.83 36.90 37.97 39.02 40.07 41.10 42.12 43.12 44.11 45.09 46.06 47.01 47.94 48.87 20.79 22.14 23.49 24.82 26.15 27.47 28.79 30.09 31.39 32.67 33.95 35.21 36.47 37.71 38.94 40.16 41.37 42.57 43.75 44.92 46.07 47.22 48.34 49.46 50.55 51.63 52.70 53.75 54.78 23.16 24.67 26.17 27.66 29.14 30.61 32.07 33.53 34.97 36.40 37.83 39.24 40.63 42.02 43.39 44.75 46.10 47.43 48.75 50.05 51.34 52.61 53.86 55.10 56.33 57.53 58.72 59.89 61.04 25.67 27.34 28.99 30.65 32.29 33.92 35.54 37.15 38.75 40.34 41.91 43.47 45.02 46.56 48.08 49.59 51.08 52.55 54.01 55.46 56.88 58.29 59.68 61.06 62.41 63.75 65.06 66.36 67.63 Table - Moment at the Jib Pivot Point due to Wind Loading (kNm) Measured Jib Properties (BS EN 13001 – 2:2004) 143 tailieuxdcd@gmail.com Jib Angle (º) 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 0.17 0.18 0.18 0.18 0.18 0.19 0.19 0.19 0.20 0.20 0.20 0.20 0.21 0.21 0.21 0.21 0.21 0.22 0.22 0.22 0.22 0.22 0.23 0.23 0.23 0.23 0.23 0.23 0.24 0.24 0.69 0.70 0.71 0.73 0.74 0.75 0.76 0.77 0.78 0.79 0.80 0.81 0.82 0.83 0.84 0.85 0.86 0.87 0.88 0.88 0.89 0.90 0.91 0.91 0.92 0.93 0.93 0.94 0.94 0.95 1.55 1.58 1.61 1.63 1.66 1.68 1.71 1.73 1.76 1.78 1.81 1.83 1.85 1.87 1.89 1.91 1.93 1.95 1.97 1.99 2.01 2.02 2.04 2.05 2.07 2.08 2.10 2.11 2.12 2.13 2.76 2.80 2.85 2.90 2.95 2.99 3.04 3.08 3.13 3.17 3.21 3.25 3.29 3.33 3.36 3.40 3.44 3.47 3.50 3.53 3.57 3.60 3.62 3.65 3.68 3.70 3.73 3.75 3.77 3.79 4.31 4.38 4.46 4.53 4.61 4.68 4.75 4.82 4.88 4.95 5.01 5.08 5.14 5.20 5.26 5.31 5.37 5.42 5.47 5.52 5.57 5.62 5.66 5.71 5.75 5.79 5.82 5.86 5.89 5.93 6.20 6.31 6.42 6.53 6.63 6.74 6.84 6.94 7.03 7.13 7.22 7.31 7.40 7.49 7.57 7.65 7.73 7.81 7.88 7.95 8.02 8.09 8.15 8.22 8.28 8.33 8.39 8.44 8.49 8.54 8.44 8.59 8.74 8.88 9.03 9.17 9.31 9.44 9.57 9.70 9.83 9.95 10.07 10.19 10.30 10.41 10.52 10.63 10.73 10.82 10.92 11.01 11.10 11.18 11.26 11.34 11.42 11.49 11.55 11.62 11.02 11.22 11.41 11.60 11.79 11.98 12.16 12.33 12.50 12.67 12.84 13.00 13.15 13.31 13.46 13.60 13.74 13.88 14.01 14.14 14.26 14.38 14.50 14.61 14.71 14.81 14.91 15.00 15.09 15.17 Wind Speed (m/s) 10 11 13.95 14.20 14.45 14.69 14.92 15.16 15.38 15.61 15.82 16.04 16.25 16.45 16.65 16.84 17.03 17.21 17.39 17.56 17.73 17.89 18.05 18.20 18.35 18.49 18.62 18.75 18.87 18.99 19.10 19.20 17.22 17.53 17.83 18.13 18.42 18.71 18.99 19.27 19.54 19.80 20.06 20.31 20.55 20.79 21.03 21.25 21.47 21.68 21.89 22.09 22.28 22.47 22.65 22.82 22.99 23.15 23.30 23.44 23.58 23.71 Appendix - Page 10 20.84 21.21 21.58 21.94 22.29 22.64 22.98 23.31 23.64 23.96 24.27 24.57 24.87 25.16 25.44 25.71 25.98 26.24 26.49 26.73 26.96 27.19 27.41 27.61 27.81 28.01 28.19 28.36 28.53 28.69 12 13 14 15 16 17 18 19 20 24.80 25.24 25.68 26.11 26.53 26.94 27.35 27.75 28.13 28.51 28.88 29.25 29.60 29.94 30.28 30.60 30.92 31.23 31.52 31.81 32.09 32.36 32.62 32.86 33.10 33.33 33.55 33.76 33.95 34.14 29.11 29.63 30.14 30.64 31.14 31.62 32.10 32.56 33.02 33.46 33.90 34.32 34.74 35.14 35.53 35.92 36.29 36.65 37.00 37.33 37.66 37.97 38.28 38.57 38.85 39.12 39.37 39.62 39.85 40.07 33.76 34.36 34.96 35.54 36.11 36.67 37.23 37.76 38.29 38.81 39.31 39.81 40.29 40.75 41.21 41.65 42.08 42.50 42.91 43.30 43.68 44.04 44.39 44.73 45.06 45.37 45.66 45.95 46.22 46.47 38.75 39.45 40.13 40.80 41.46 42.10 42.73 43.35 43.96 44.55 45.13 45.70 46.25 46.78 47.31 47.82 48.31 48.79 49.25 49.70 50.14 50.56 50.96 51.35 51.72 52.08 52.42 52.74 53.05 53.35 44.09 44.88 45.66 46.42 47.17 47.90 48.62 49.33 50.01 50.69 51.35 51.99 52.62 53.23 53.83 54.40 54.97 55.51 56.04 56.55 57.05 57.52 57.98 58.42 58.85 59.25 59.64 60.01 60.36 60.70 49.77 50.67 51.54 52.40 53.25 54.08 54.89 55.68 56.46 57.22 57.97 58.69 59.40 60.09 60.76 61.42 62.05 62.67 63.26 63.84 64.40 64.94 65.46 65.96 66.43 66.89 67.33 67.75 68.14 68.52 55.80 56.80 57.78 58.75 59.70 60.62 61.54 62.43 63.30 64.15 64.99 65.80 66.60 67.37 68.12 68.86 69.57 70.26 70.93 71.57 72.20 72.80 73.38 73.94 74.48 74.99 75.48 75.95 76.40 76.82 62.17 63.29 64.38 65.46 66.51 67.55 68.56 69.56 70.53 71.48 72.41 73.32 74.20 75.06 75.90 76.72 77.51 78.28 79.03 79.75 80.44 81.12 81.76 82.39 82.98 83.56 84.10 84.63 85.12 85.59 68.89 70.12 71.34 72.53 73.70 74.85 75.97 77.07 78.15 79.20 80.23 81.24 82.22 83.17 84.10 85.01 85.88 86.74 87.56 88.36 89.13 89.88 90.60 91.29 91.95 92.58 93.19 93.77 94.32 94.84 Table - Moment at the Jib Pivot Point due to Wind Loading (kNm) Measured Jib Properties (BS EN 13001 – 2:2004) 144 tailieuxdcd@gmail.com Jib Angle (º) 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 0.24 0.24 0.24 0.24 0.24 0.24 0.24 0.24 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.95 0.96 0.96 0.97 0.97 0.97 0.98 0.98 0.98 0.98 0.99 0.99 0.99 0.99 0.99 0.99 0.99 2.14 2.16 2.17 2.17 2.18 2.19 2.20 2.20 2.21 2.21 2.22 2.22 2.23 2.23 2.23 2.23 2.23 3.81 3.83 3.85 3.87 3.88 3.89 3.91 3.92 3.93 3.94 3.95 3.95 3.96 3.96 3.96 3.97 3.97 5.96 5.99 6.01 6.04 6.06 6.08 6.10 6.12 6.14 6.15 6.16 6.17 6.18 6.19 6.19 6.20 6.20 8.58 8.62 8.66 8.70 8.73 8.76 8.79 8.82 8.84 8.86 8.88 8.89 8.90 8.91 8.92 8.92 8.93 11.68 11.73 11.79 11.84 11.88 11.93 11.96 12.00 12.03 12.06 12.08 12.10 12.12 12.13 12.14 12.15 12.15 15.25 15.33 15.40 15.46 15.52 15.58 15.63 15.67 15.71 15.75 15.78 15.81 15.83 15.85 15.86 15.86 15.87 Wind Speed (m/s) 10 11 19.30 19.40 19.49 19.57 19.64 19.71 19.78 19.83 19.89 19.93 19.97 20.01 20.03 20.05 20.07 20.08 20.08 23.83 23.95 24.06 24.16 24.25 24.34 24.42 24.49 24.55 24.61 24.66 24.70 24.73 24.76 24.78 24.79 24.79 Appendix - Page 11 28.84 28.98 29.11 29.23 29.34 29.45 29.54 29.63 29.71 29.78 29.83 29.89 29.93 29.96 29.98 29.99 30.00 12 13 14 15 16 17 18 19 20 34.32 34.49 34.64 34.79 34.92 35.05 35.16 35.26 35.35 35.44 35.51 35.57 35.61 35.65 35.68 35.70 35.70 40.28 40.47 40.66 40.83 40.98 41.13 41.26 41.38 41.49 41.59 41.67 41.74 41.80 41.84 41.87 41.89 41.90 46.71 46.94 47.15 47.35 47.53 47.70 47.86 48.00 48.12 48.23 48.33 48.41 48.48 48.53 48.56 48.59 48.59 53.62 53.88 54.13 54.35 54.56 54.76 54.94 55.10 55.24 55.37 55.48 55.57 55.65 55.71 55.75 55.78 55.78 61.01 61.31 61.58 61.84 62.08 62.30 62.51 62.69 62.85 63.00 63.12 63.23 63.31 63.38 63.43 63.46 63.47 68.88 69.21 69.52 69.81 70.09 70.33 70.56 70.77 70.95 71.12 71.26 71.38 71.48 71.55 71.61 71.64 71.65 77.22 77.59 77.94 78.27 78.57 78.85 79.11 79.34 79.55 79.73 79.89 80.02 80.13 80.22 80.28 80.32 80.33 86.03 86.45 86.84 87.21 87.55 87.86 88.14 88.40 88.63 88.83 89.01 89.16 89.28 89.38 89.45 89.49 89.50 95.33 95.79 96.23 96.63 97.00 97.35 97.66 97.95 98.21 98.43 98.63 98.79 98.93 99.04 99.11 99.16 99.17 145 tailieuxdcd@gmail.com Published by the Health and Safety Executive tailieuxdcd@gmail.com 03/12 Health and Safety Executive The effect of wind loading on the jib of a luffing tower crane Following a luffing crane collapse in Liverpool in January 2007, the UK Health and Safety Executive (HSE) were concerned that standards concerned with tower crane manufacture may not offer sufficient protection in relation to slack rope conditions on a luffing tower crane HSE wished to determine if foreseeable conditions could be identified that could give rise to dangerous operational conditions below maximum in service wind speeds A luffing tower crane was erected at the Health and Safety Laboratory (HSL), Buxton Measurements of wind speed and luffing system tension were taken to determine combinations of wind speed and jib elevation likely to result in slack luffing rope conditions Calculations of jib wind loading were carried out using four standards, FEM 1.001, FEM 1.004, ISO 4302 and BS EN 130012:2004 Wind loading calculations compared closely with values obtained during the tests The jib was found to be susceptible to uncontrolled movement below the maximum in service wind speed and at jib elevations within the limits specified by the manufacturer Differences of up to 150% between wind speed readings provided by anemometers fitted at the jib outer end and the ‘A’ frame were experienced during the testing This report and the work it describes were funded by the Health and Safety Executive (HSE) Its contents, including any opinions and/or conclusions expressed, are those of the authors alone and not necessarily reflect HSE policy RR917 www.hse.gov.uk tailieuxdcd@gmail.com