Operating practices


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Operating practices

  3. 3. INTRODUCTIONLearn the basic of lifting equipment and operating practices.Characteristic of the load and how to use the different configuration of liftingequipment.How to choose the right lifting equipment for your needs, how to extend thelifting equipment service. life, the importance inspection, and how toproperly store and handle lifting equipment.
  4. 4. DEFINITIONS• Lifting Equipment (Crane) – Work equipment for lifting or lowering loads and including its attachments used for anchoring, fixing or supporting it. (includes suspension if a lifting operation is involved).• Lifting Accessory (Lifting Gear) – Work equipment used for attaching loads to machinery for lifting. E.g. a shackle.• Proof or Test Load – A load (mass or force) applied by the manufacturer or Competent Person for the purpose of a test. This load appears on test certificates, typically 2 x WLL• Minimum Breaking (or Failure) Load (MBL) – The guaranteed strength (mass or force) below which the item of equipment does not fail Mass Units are usually tonnes (t)/ Force units are usually Newtons (N)• Working Load Limit (WLL) – The maximum load (mass) that an item of lifting equipment is designed to raise, lower or suspend. In some standards and documents the WLL is referred to as the maximum safe working load or SWL’• Factor of Safety – The ratio between MBL and WLL identified on the test certificate as the Coefficient of Utilisation. – E.G. For a Single Chain Sling - MBL = 4t, F.O.S. = 4:1,WLL = 1t• Safe Working Load (SWL) – The maximum load (mass), as assessed by a Competent Person, which an item of lifting equipment may raise, lower or suspend under the particular service conditions. The SWL will normally be the same as the working load limit or the maximum safe working load, where the term is used but it may be less. – The SWL appears in statutory records.
  5. 5. STRENGTH & STABILITYLIFTING ACCESSORIESObjective:- The candidate shall be able to identify the purpose & capacity of accessories ingeneral use for lifting including methods of safe use, handling & storage.Must be of adequate strength and stability for each load having regard in particular to thestress induced at its mounting or fixing point.Every part of a load and anything attached to it must be of adequate strength.Packing must be used to protect the sling from damage.Every load must be securely suspended or supported to prevent it drifting, falling freely orbeing released unintentionally.Hooks should be fitted with a safety catch or be of such a shape to prevent the load slippingoff the hook.Accessories should ride freely on the crane hook.Crane hooks should not be overcrowded.If more than one sling is to be used the upper ends must be attached by using a shackle orlink.Slings should not be overloaded as a result of the angle between the legs.Loads must not be lifted on slings with knots in them.Chain slings must not be joined by nuts and bolts inserted into links.Loads must not be left unattended whilst suspended.
  6. 6. MINIMUM REQUIREMENT FORMARKING OF LIFTING EQUIPMENT  Safe Working Load (SWL/WLL), for use in the VERTICAL  Unique Identity Number/Reference  Date of inspection or Colour code  The marking of the SWL for multi leg slings is given to take into account the extra tension generated at angles (The marking is normally the uniform load method of marking 0 0 – 90 0.)  Accessories marked with SWL including marking for different configurations and to show characteristics necessary for safe use.(or clear instructions)  If for lifting persons should be marked to say so (and number of persons)
  7. 7. FACTOR OF SAFETY MINIMUM BREAKING LOAD (MBL)FACTOR OF SAFETY (FoS)= SAFE WORKING LOAD FoS= MBL ÷ SWL The safety factor consists of a safe working load limit set below a given safety margin. The limit ensures that no immediate danger will occur if the CHAIN 4 maximum safety load is exceede. The safety factor does not give the operator licence to exceed the WLL, rather it provides a safety margin to WIRE 5 compensate fo the weakening of the lifting appliance during normal use due to wear and SLING 7 ageing, jolting during lifting and inaccuracies in load weight estimations SAFE WORKING LOAD NEVER CAN BE OVERRANGE/OVERLOADED
  8. 8. EC, STATEMENT OF CONFORMITY AND TEST CERTIFICATEEC DECLARATION OF CONFORMITY – Declaration by the manufacturer or other responsible person that the equipment described complies with the relevant European Directive(s). – It is a legal document enabling an item to be placed on the market and taken into service. – The CE mark is a mark affixed to the accessory to signify that it complies with all relevant European Directives.STATEMENT OF CONFORMITY – A Certificate issued by the manufacturer confirming that any necessary manufacturing tests have been carried out and confirming the safe working load. – Where equipment is unsuitable for proof load testing due to the nature of the materials used, e.g. textile slings, a statement of conformity is issued.TEST CERTIFICATE – A certificate issued by the Competent Person giving details of tests, conducted on an accessory. – Valid for the life of the accessory. – New test certificate required if the accessory has been repaired and strength has been affected.
  10. 10. REGULATIONS INSPECTIONSLOLER(1998) AND FACTORIES ACT (1961) LIFTING OPERATION REGULATION ALL LIFTINGAPPLICANCES MUST BE TESTED AND EXAMINED BEFORE SERVICEAll lifting equipment deteriorates in use and, therefore, a thorough examination must be carriedout by a competent person and colour code. Thorough examination intervals:  Every 6 months if the equipment is used for lifting persons.  Every 6 months for lifting accessories (slings, shackles, eyebolts, etc).  Every 12 months for all other lifting equipment (chain hoists, lever hoists etc). COLOUR CODE (CHANGE EVERY 6 MONTHS) YEAR 2013 JANUARY- JUNE JULY-DECEMBER YEAR 2013 JANUARY- JUNE JULY-DECEMBERThe inspection should include visual checks and function tests and be carried out by personscompetent to do so.Inspection by competent person who is sufficiently independent and impartial.
  12. 12. ALTERATION OR REPAIR OF LIFTING ACCESSORIESNo lifting accesories which has been alterated or repaired by weldingshall be used in raising or lowering or as a means of suspension until suchalteration or repair has been tested and throughly examined by acompetent person and a certificate has been obtained of such test andexamination on the prescribed form signed by the person carrying out thetest and thorough examintaion
  13. 13. LOAD-WEIGHT ESTIMATION• It is the responsibility of the slinger to check the established weight of the load to be lifted, or if it has not been established, to evaluate it himself.• It is on the basis of this estimate that the appropriate tackle is chosen.• Guidance as follows:- – Look to see if the weight is marked on the load. If it is, check to ensure that it is the weight of all parts of the load. – Check the weight stated on any documentation. – If the load is still on a trailer or truck, weigh it. – Estimate the weight of the load using a table of weights. – When dealing with a hollow body, check whether it contains anything. – Charts are available which give the weights of various materials by metres or cubic metres.
  14. 14. LOAD-WEIGHT ESTIMATIONWEIGHT =Volumen x ----Volumes of common shapesdensity
  15. 15. LOAD-WEIGHT ESTIMATION WEIGHT =Volumen x ----Volumes of common shapes density 3.14 x 1.5²= 7.1Solid cylinder = Лr²xL Thick walled pipe = Л(r1²-r2²)xL
  16. 16. LOAD-WEIGHT ESTIMATIONWEIGHT =Volumen xdensityWeight per unit volume for a range of materials: Weight in Kilograms Weight in pounds Material per cubic metre per cubic foot Aluminium 2700 170 Brass 8500 530 Brick 2100 130 Coal 1450 90 Copper 8800 550 Concrete 2400 150 Earth 1600 100 Iron-Steel 7700 480 Lead 11200 700 Magnesium 1750 110 Oil 800 50 Hardwood 1120 70 Water 1000 62
  17. 17. LOAD CONSIDERATIONS• Will the sling damage the load?• Will the load damage the sling?• If so packing required – a legal requirement.• Is it hazardous?• Does the load have lifting points?• Is the load loose material, hollow, solid, can it absorb water?• Are there chemicals about?• Do you need adjustment?• How will the sling be attached?• What is the size of the load?• Will a tag line be needed?• What is the weight of the load?
  18. 18. UNITS OF WEIGHT AND MEASURES1 Ton = 2240 lbs. (1016 Kgs.) 1kN= 0.102 Tonne1 Tonne = 1000 Kgs. 1 kg = 10 N1 American Ton = 2000 lbs. (907 Kg) 1 Tn= 10 kN1 ft³ of steel = 480 lbs. (218 Kgs.) 1 in = 25.4 mm1 m³ of Steel = 8.07 Tonnes 1 ft=0.3048 m1 ft ³of Water = 62.5 Lbs. (28.4 Kgs) 1 yard= 0.9144 m1 Litre of water = 1 Kg. 1 mile= 1.609 Km1 Gallon of water = 10 Lbs. (4.54 in² = 6.4516 m² Kg.) ft²=0.0929 m²1 N = 1/9.807 kg = 0.102 kg
  19. 19. WEIGHT ESTIMATION (IMPERIAL UNITS) The formula for estimating the weight of solid steel is : Volumen=Length x Breadth x Height 2 Ft. V= 4 x 3 x 2=24 ft³ Density=1 ft³ of steel weighs 480 lbs WEIGHT =Volumen x density 3 Ft. W= 24 ft³ x 480 lbs/ ft³ =11.520 lbs The formula for estimating the weight of solid steel is 4 Ft. (All measurements in millimetres) Length x Breadth x Height = Tonnes 12500• The formula for estimating the weight of solid steel is : Length x Breadth x Height – 1 M3 of steel weighs 7.7t. 2M 4 x 2 x 3 = 24 m3 3M 24 m3 x 7.7 t/ m3 = 184.8t total weight of load 4M
  20. 20. WEIGHT ESTIMATION• Objects which appear solid but are not, such as a Centre Lathe - Milling Machines etc. the same formula will give the overall weight but, because a lot of space is taken up by air, it is necessary to guess this air space and subtract to reach its true weight.• 1/2 to 2/3 deduction of gross load weight for the air space in machines will give a reasonably accurate indication of total machine weight. Example 1 : Centre Lathe 6 ft. long x 4 ft high x 3 ft wide 6x4x3 = 18 Tons minus 2/3 air 4 ft 4 Depth 3ft 18 = 6 tons Weight of the lathe is approximately 6 Tons 3 6 ft Example 2: 1 M3 of steel weighs 7.7t. Dimensions of lathe 2 x 1 x 1.5 M = 3 M3 3 M3 x 7.7 t/ M3 = 23.1t Height 1.5M Minus 2/3 for air space = 15.4t Width 1M Weight of lathe 23.1t minus 15.4t = 7.7t 2M Long
  21. 21. CENTRE OF GRAVITY Centres of Gravity for each part A B C Centre of Gravity for the whole loadThe CG is a point which, if the load could be suspended from it, the loadwould be in perfect balanceThe crane hook needs to be directly over the CG for the load to be stable.The load is not stable. The hooks are under the CG, and the CG is abovethe hooks. The loads is stable/The hook is right over the load’s CGLifting a load with the CG offset will cause the load to shift until a balance isrestored/The load will shift until the CG is under the hook. The hook is NOT over the CGCAUTION - when lifting loads with an offset CG one leg of the slings willhave more of the weight of the load than the other sling leg. Offset C/GSelect the SWL of the slings on the basis that all the weight of the load willbe on one leg of the sling.Be aware the load could also kick in an unexpected manner.Lift carefully. Once a load with an offset CG has been lifted the CG will CGposition itself directly below the crane hook. Unequal distribution of load. This leg has most of the load weight
  22. 22. SLINGS CALCUTATIONSPythagoras’ Theoremx²+y²=h² y=4 hypotenus=53²+4²=9+16=25=h² h= =5 25 hypotenus=6 x=3To find the Sling Hook angle we now use: αSine α= x/hypotenyse cosine α= y/hypotenus tangent α=y/x x=3Sine α = 3/6=0.5, α=30 º hypotenus=6 Y = 5.2 αSAFE WORKING LOAD FOR SLING LO AD 10 TN x=3SWL = (True sling length x Total weight)/(number of sling x Load to hook height)SWL = (6 x 10 )/ (2 X5.2)=5.77 TN MINIMUN SWL PER LING LEG
  23. 23. SLINGS CALCULTIONSCalculations (NO DEGREES AND ANGLES) This formula is:T= Tension per leg in kgW= weight in kgN= number of legs HL= sling length in metresH= vertical height in metresExample: W=5000 kg, N= 2, V= 2metres, L = 3.5 metres T = (5000 x 3.5 ) / (2 x 2) = 4.375 kg per legYou would need a two-legged sling rated at 5000 kg WLL capacity per legINCREASING TENSIONLifting Weight [LW] x the Tension Factor [TF] = Minimum Sling Rating for the type of hitch that will be used. TF = L/HExample:Load = 1,000 lbs.Lifting Weight (LW) per sling = 500 lbs.L = 10 ft.H = 5 ft.TF = 10 (L) 5 (H) = 2.0Minimum Vertical Rated Capacity required for this lift = 500 (LW) x 2.0 (TF) = 1,000 lbs. per sling
  24. 24. SLINGS CALCULTIONSKNOW THE EFFECT OF REEVING ON SLINGS-CHOKING=NIPPINGReeving is the practice of wrapping s sling around an object, andeither doubling it back on the hook, or passing one eye of thesling through the other and then to the hookThis practice is perfectly safe when done properly, BUT youMUST realise that the act of reeving create an “included angle”withing the sling which reduces the permissible load on that slingThis will work for any reeved sling with an included angleLESS that 120º, which must be the absolute maximum angle.Use the following formula. EXAMPLE Load= 2 tonnes L= 675 mm R= 300 m T= (0.5x2000kgx0.675)/0.3= 2.25 tonnes Select sling for 2x2.25 = 4.5 tonnes
  25. 25. UNEQUAL SLING LEGSWhen the CG is closer to one slingattachment point than the otherm in order 4=yto position the hook over the CG, the sling ylegs must be of unequal length which mean 8= x xthat their angles and loads will also be 4unequal. 5 2The sling that attaches ti the point closest to D1 10t D2the CG will see the most stress. STRESS X=Load x D2 x S1 / (Hx (D1+D2) X = 10 x 2 x 8 / (4 x (5+2) )= 5.7 Tn Y = 10 x 5 x 4 /( 4 x (5+2) ) = 7.14 Tn
  27. 27. MEASURES Measures • Scalar-MODULE- is the measurement of a medium strictly in magnitude. Singular measures of a characteristic against arbitrary scale: weigth and length • Vector- MODULE+DIRECTION+SENSE- is a measurement that refers to both the magnitude of the medium as well as the direction of the movement the medium has taken. FORCES-(Vector) The vertical component of force + the horizontal component would have exactly the same effect as the applied force.Vertical component The parallelogram of forces Resultant R Force 1 Applied Force Engine thrust Horizontal component Force 2 Wind force Wind force The resultant R could replace forces 1 & 2 and have the same effect 27
  28. 28. MEASURES-FORCESFORCES Single leg sling• Understanding the forces in slings is all about knowing the 10 Units magnitude & direction of those forces J• Design and use of lifting slings is all about knowing what forces are acting and in what directions• A force has two components – A magnitude (size) exerted by the weight of the load. – A direction generated by the angle of the sling(s). 10 tRESOLUTION OF FORCES 1 1t• The force shown above might represent the force in one leg of a 0.7t two legged sling tension in VERTICAL each leg COMPONENT FORCE 90o ? ß Angle o 45 Included Angle 1 tonne HORIZONTAL COMPONENT
  29. 29. TRIANGLE OF FORCES• The Triangle of Forces• Can be used to consider three forces in equilibrium (balancing each other)• The same results can be achieved without drawing to scale by using trigonometry The Magic Triangle Example Bow’s Notation 2t b b J A B c o b 90 C b LOAD =2 tonnes FORCE DIAGRAM a VECTOR DIAGRAM FORCE FORCE bc = 20 b DIAGRAM 10 N FORCE ac = 17.2 60 o 10 A 90 o B 90 o 30 o ac = bc = 1.4t 120 o a c VECTOR C DIAGRAM
  30. 30. CALCULATING SLING CAPACITYExamples: b 35o 55o ab bc ac = = sin 90o sin 55o sin 35o A 35o ab x sin 55o 10 x 0.82 B bc = = = 8.2t sin 90o 1 10 Tonnes (ab = 10) C ab x sin 35o 10 x 0.57 55o ac = o = = 5.7t sin 90 1 c C of G aThe force on each hoist ring is not just the total weight divided by the number of hoist rings. Theforce will be greater at lower lift angles. Make sure load is evenly distributed.Eq. 1: Calculating Hoist Ring ForceF = W/ N(sin A)Where:F = Force on each hoist ringW = Total weight = 4000 lbs.N = Number of hoist rings = 4A = Lifting angleSafe UnsafeA = 65 : A = 14F= 4000/4(sin 65º)=1103 lbs F =4000/4(sin14)= 4134 lbs
  31. 31. UNIFORM AND TRIGONOMETRIC METHOD UNIFORM METHOD- Slings are rated for a range of angles. Calculations are done for the “Worst Case”TRIGONOMETRIC METHOD-Slings are rated for a Specific Angle. They are then only used at that angle
  32. 32. UNIFORM LOAD METHOD• Sling rated for a range of angles• Calculations are for worst case – Sling rated for use at 0-90o by uniform load method will have the same rating as a sling rated for use at 90o by the Trig. Method – Sling rated for use at 90-120o by uniform load method will have the same rating as a sling rated for use at 120o by the Trig. method• N.B. The master link will not be strong enough to permit re-rating by the Trig. method Do not mix the two methodsMethods of Rating Lifting Slings-Uniform Load Method Single leg sling = 1.0 x WLL of a single leg 2 leg sling (0 - 90o) = 1.4 x WLL of a single leg 2 leg sling (90 - 120o) = 1.0 x WLL of a single leg 3 & 4 leg sling (0 - 90o) = 2.1 x WLL of a single leg* 4 leg sling (90 - 120o) = 1.5 x WLL of a single leg* In current British Standards covering textile slings,this factor is given as 2.0.
  33. 33. TRIGONOMETRIC METHOD Sling rated at a fixed angle to the vertical. • Trigonometrically rated slings can be re-rated at smaller angles by using the cosine of the angle to be employed (included angle) Single leg sling = 1 x WLL of a single leg Two leg sling = 2 x WLL of a single leg x cos. b Three leg sling = 3 x WLL of a single leg x cos. b Four leg sling = 4 x WLL of a single leg x cos. bNormally tables are available with the calculation already done Divide sling height [H] by sling length [L].=REDUCTION FACTOR= H/L Divided sling length [L] by sling height [H]= TENSION FACTOR = L/H SWL EACH SLING = (LOAD/NUMBER OF LEG SLING)/ REDUCTION FACTOR SWL EACH SLING = (LOAD/NUMBER OF LEG SLING)x TENSION FACTOR REDUCED CAPACITY Each sling = 6,000 lbs. L = 6 ft. H = 4 ft. RF = 4 (H) 6 (L) =0.667 SWL EACH SLING=0 .667 (RF) x 6,000 lbs. = 4,000 lbs. of lifting capacity per sling
  34. 34. RIGGERS’ GUIDEUsing Riggers’ GuideAs an example:1.Each leg of a two-leg has a WLL of 100 kg. The included angle between the legs of the sling is not more than 60º Safe working load= (100/0.58)= 172 kg2. Should the included angle between legs be increased to 120º SWL = 100/1 = 100 kg3. The load is 100kg and the included angle is 30º Sling load = 100 kg x 0.52 = 52 kg per leg4. SWL =4500 kg, WLL of each sling = 3200 kg Load in each sling leg will be the actual load x 0.7 (90º) SWL= WLL of ONE sling leg divided by 0.7SLING LOAD = WEIGHT LOAD x FACTOR OF ANGLEWEIGHT LOAD = SLING LOAD /FACTOR OF
  35. 35. RIGGERS’ GUIDETHREE- LEG SLINGSSpecial consideration, because rarely do all three legs take an equal share of the load. It is bestto assume that only TWO legs are sharing the load, with third leg only acting as a “balance” SLING LOAD = WEIGHT LOAD x FACTOR OF ANGLE WEIGHT LOAD = SLING LOAD /FACTOR OF ANGLEExample:Sling legs are 3 m longPitch diameter of the sling attachments is 3m.Included angle is 60º (30º from vertical) = 0.58Using the approximation method, we assume the load is taken on two legs only.Therefore, from our Riggers Chart, SLING LOAD = 100 kg x 0.58 = 58 kgAssuming the load is equally distributed between the three legs, SLING LOAD= 100 kg x 0.58x(2legs/3legs) = 39 kg
  36. 36. RIGGERS’ GUIDESWL- FOUR LEG SLINGSYou will have noticed that the rigger charts treats 2,3 and 4 legs sling as havingthe same SWL for various configurations.Wit a 4-legs sling, unless a load-sharing device exists in the system, the load willALWAYS be taken by TWO slings only. The other two will only serve to balancethe load.If the load is flexible, some sharing of the load will take place as the load twists.The degree os sharing is dependent on the stiffness of the load. If the effect ofthis stiffness is unknow, we MUST assume it to be perfectly stiff, and NO loadsharing takes place.Sling calculations are therefore the same as for two-leg sling.EXAMPLE: Precast slung from four points, is the capacity of the pin anchors.Load10 tons – 4 x 2.5 tonnes pins = 10 tonnes. 10 mm chains (=3.15 tons each)OH, REALLY? Sling angle =90º(0.7) Sling load must be 7.0 tonnes (=10 x 0.7)Therefore, 4 x 10 tonne pins are required, and 16 mm chains (=8tons each).Some difference!
  37. 37. SLINGS ANGLES/SWL 6 M long sling 1200 10.5 M distance between lifting points If the distance between lifting points is 1.75 times the leg length the included angle will be 1200 (600 beta) ANGLES AT HOOK 30 DegreesDistance between lift points Half sling leg length. 60 DegreesDistance between lift points Equal to sling leg length. 90 DegreesDistance between lift points 1.5 X sling leg length.
  41. 41. HITCHING MODE FACTORS Maximum load to be lifted = mode factor x SWL marked on the sling 1 2 3 4 5 6 7 8 9 Single leg Endless Single leg Single leg Single leg Single leg Endless in Endless Material back basket in line choked basket halshed line choked hooked 0-90oChain 1 0.8 1.4 1 NP NP 1 NPWire Rope 1 1 1.4 1 2 NP 1 1.4Webbing 1 0.8 1.4 NA NP 1 0.8 1.4Fibre Rope 1 0.8 1.4 1 1.6 1 0.8 1.4Roundsling NA NA NA NA NA 1 0.8 1.4
  42. 42. SINGLE LEG HITCH-STRAIGHT LIFT1. The total weight of the load is supported by a single leg.  Spreader beams are used to support long and hard-to-handle loads.2. The SWL of the sling MUST EXCEED the  Reduces the tendency for the load to tip or load weight. bend.3. This hitch should not be used for:  Both single leg slings will support the load. Lifting loose materials If load is even, each will carry half the load. Long loads Any load that can tip  These slings provide good load control. THE SPREADER BEAM MUST BE4. A Single leg vertical hitch does not: CERTIFIED. Provide good control over the load. The load can rotate and tip. 2t chain will lift 2t vertical
  43. 43. TWO LEGGED HITCH 1.4 x WLL of 1 leg = total combined WLLLeg Loadings• Weight exerted on any leg of a sling or chain will increase the greater the angle• Angle between 2 chains or webbing slings must NEVER exceed 90 TWO SINGLE LEGS– 1.4 x WLL E.g. two single 2t each sling 1.4 x 2t = 2.8t
  44. 44. MULTIPLE LEGGED HITCHTWO SETS OF TWO SLING- 1.5 x WLLWhen using two sets of two leg sling assemblies to make 1.5 x WLL of 1 set = total combined WLLup a four point lift another angle is generated betweenopposite master link. In order to prevent overloading of Third included anglethe master links a mode factor of 1.5 x WLL of one setshould be used.E.g. Two sets of 30t chains can lift 1.5 x 30t = 45tTHREE OR FOUR SLING• Rate a four leg sling the same as a three leg sling.• Why the same rating for 3 and 4 legs? – Why does a photographer use a tripod? – Why does a milking stool have 3 legs? – Why do beer mats get shoved under table legs ?• Because with a four legged structure, one leg is:- REDUNDANT-It assumes that in a four legged sling one leg is redundant• Hence 3 and 4 legged slings made from the same materials will have the same W.L.L.
  45. 45. MULTIPLE LEGGED HITCHTHREE SINGLE SLING- WLL x 2.1 (0-90º) /WLL x 1.5 (90-120º) 2.1 x WLL of 1 leg = total combined WLLWith three single vertically rated slings being used atangles the mode factor of 2.1 x WLL of a single leg will give 450 ßthe maximum load to be lifted.E.g. if each single sling has a WLL of 1t the total load thatcan be lifted is 1 x 2.1 = 2.1t. 5t 0E.g. If load is 15 t –Load in each leg= 7t at 45 to vertical o 45 15 tFOUR SINGLE SLING-WLL x 2.1 (0-90º) /WLL x 1.5 (90-120º) Load in each leg = 7.07tWith four single vertically rated slings being used at anglesThe mode factor of 2.1 x WLL of a single leg will give theMaximum load to be lifted. 900 90oE.g. if each single sling has a WLL of 2t the total load that 10 tcan be lifted is 2 x 2.1 = 4.2t. 15tE.g. A four legged sling lifting 15 tonnes.Force in each leg 7 tonnes. 2.1 x WLL of 1 leg = total combined WLL
  46. 46. MULTIPLE LEGGED HITCH MULTIPLE LEGS: 2 – LEGS/3 - LEGS/4 - 450 ß (beta) LEGS angleTHE INCLUDED ANGLE SHOULD NOT EXCEED 90 0. 90O 450ß MAXAll hooks face outwards. max 900α maxThe individual legs are not twisted.The legs are not crossed over.All the legs are taking their share of the load.A multi – leg chain sling is a permanent joining of two ormore chain legs.A multi – leg set used in straight lift have a WLL as marked Note hookfor use at angles, never exceed the SWL directionE.g. WLL 4.25t @ 450ß or SWL 4.25t @ 900 included(α angle)THREE LEG AND FOUR LEG slings in straight hitch are ratedwith the same WLL.The reference for the largest included angle on a three legsling is the largest angle between any two legs.The reference point for the largest included angle on a fourleg sling are diagonal opposite legs.
  47. 47. CHOKER AND BASKET HITCHES 1. Load Control The ability of the sling to control the movement of the load. 2 Capacity The load capacity of the sling and type of hitch used. 3 Type of sling Wire rope - chain 4 Centre of gravity The location of the centre of the load’s weight.When in choked lifting mode, the capacity is reduced !Can be 50%, or lower if you beat down the sling eye to an angleless than 120For large loads a 4-leg bridle sling can be made into a doublebasket sling by adding 2 single leg slings. These single leg slingscan be made of larger diameter rope to better withstand loadconditions. And they are less expensive to replace than the entire4-leg sling.Depending on the load a simple basket hitch may not provide thebest load stability. Danger of the load slipping out of the sling
  48. 48. CHOKE HITCHStandard choker hitches provide better load controls This as long as the loads are short. When lifting longerbundled loads there is the danger that some of the A choke hitch has only 70% to 80% the capacity ofbundle content may slide out of the sling. As can beseen, a standard choker hitch compresses the loadfrom three sides only. 900 α (included)A better way to do the same lift. Use a double wrap anglechoker hitch and for long loads use 2 slings. Thedouble wrap compresses the load on all 4 sides andprovides far better load control. Double wrap chokehitch is used to grip loose material loadsObserve the choker hitch reduction factors.MAXIMUM INCLUDED ANGLE IS 900CHOKERS:DOUBLE WRAPDOUBLE LEG
  49. 49. CHOKE HITCHCHOKE HITCH- SINGLE CHAIN----------------------WLL x 0.8 2t chain SWL 1.6tWLL is reduced by 20% for choke hitch.E.g. A 2t chain will lift 2t x 0.8 WLL = 1.6tTWO SINGLE SLING IN DOUBLE WRAP CHOKE--- WLL x 0.8 Note the use of packing on this load.Double wrap choke hitch must have the WLL reduced by 20%.E.g. a 4t set of chains can lift 4t x 0.8 = 3.2t 2 x 2t chains WLL – 4 x 0.8 = 3.2tTWO SLINGLE SLING IN CHOKE HITCH-------WLL x 0.8 x 1.4Then when being used at angles of up to 900 a mode factor of1.4 x SWL of a single leg will give the combined capacity of thetwo slings. 2t chains WLL-2 x0.8 x1.4 = 2.24tE.g. if each sling has WLL of 2t-total load is 2x0.8x 1.4 = 2.24t Total 2.24+2.24 =4.48tTWO SINGLE –(single or double wrap)CHOKE HITCH Slings led in Hooks must face outwards and both slings led in from the same side of load same side of the load. Slings led in correctly from the same side of the load - not opposed. Hooks face outwards
  50. 50. BASKET HITCHWhen using a basket (or double wrap) hitch you must take A basket is 1 or 1.4 the capacity ofThe sling angle into accout. Make sure the load is properlypadded to prevent sling damage. 1.0 X WLL = TOTAL WLLGood load control and the capacity of the sling depends on: This the vertical sling angle the angle formed in the basket 1.4 x WLL = total SWLDOUBLE BASKETThe two hitches must be placed carefully to ensure that theload is correctly balanced.The legs must be kept far enough apart to balance the load butnot too far to cause slippage. 900 max αNEVER USE A VERTICAL ANGLE OF GREATER THAN 60 ! angleTHE INCLUDED ANGLE SHOULD NOT EXCEED 90 0. this shouldbe taken from diagonal opposites.DOUBLE WRAP BASKETA double wrap basket is a basket hitch that is wrapped roundthe load. A single hitch does not control slippage of the load.Requires adjustment of legs as load is applied, to equalise loadin each leg.Good for handling loose materials and smooth loads because BASKET:of a full 360 wrap without battening down the eye. DOUBLEGood load control when two hitches are used at a horizontal WRAPsling angle of 45 or smaller (Dependent on load length)
  51. 51. BASKET HITCHBASKET HITCH (HOOKED BACK)-------- 1 x WLL Note hook on Note both linksA single chain being used in basket hitch with the hook hooked master link. on the hook.back to The master link has a WLL marked on the sling. 2t chain WLL 2t 2t chain WLL 2.8tE.g. a 2t chain will be able to lift 1 x 2t = 2t.BASKET HITCH (REEVABLE COLLAR)------1.4 x WLLA reevable collar sling in basket hitch will have a WLL of 1.4 x WLLwith both links on the hook. Angle must not exceed 90 0 4.25t chain WLL 4.25t 2 x 2t chains WLL 2.8tE.g. a 2t reevable sling will be able to lift 1.4 x 2t= 2.8tA TWO LEG SET IN BASKET HITCH- 1 x WLLthe WLL is as marked on the sling. E.g. a 4.25t set will lift 4.25t.TWO SINGLE LEG USED IN BASKET --1.4 x WLLhitch hooked back have a WLL based on a mode of 1.4 x WLL of asingle leg. E.g. two single 2t chains can lift 1.4 x 2t = 2.8t 2.1 x WLL of 1 leg = total combined WLLTWO SINGLE LEGS IN BASKET HITCH- 2.1 x WLLThe same mode factor is used here when using 2/3 or 4 singleSlings together in basket hitch.E.g. if each wire has a SWL of 3t the total load that can be lifted is 3t x 2.1 = 6.3t
  52. 52. CHOKER AND BASKET HITCHES BAD RIGGING PRACTICES GOOD SLINGING PRACTISE Double Padding on sharp edges RIGHT WRONG SECURE THOSE LEGSThey can get stuck under another piece ofequipment causing severe overload of the crane or hoist, or someone may trip overthem. Do not lift when loose equipment is not secured. 60º
  53. 53. ENDLESS HITCHEndless chains used in choke hitch can be used at the marked WLL with no reduction in WLL.E.g. a 2t endless chain will lift 2t.TURNING THE LOADTurning the load with a double choker (that is a loop & loop sling used inverted) gives good loadcontrol. To rig place both sling eyes on top the load, pointing in the opposite direction of theturn. The body of the sling is then passed under the load and through both eyes.When using a two leg sling with only one leg in use rate the sling at half the marked WLL – ifused with a direct hitch like this.• E.g. WLL 7.5t 2 = 3.75t• If the leg was used in choke hitch the leg would require a further down rating of 20% 2t chain WLL 2t
  54. 54. PREVENT DAMAGE TO THE SLING AND THE LOADUSE SUITABLE PACKING-Proper coner protection. Severe bendingDo not place the splice sleeves, rope thimbles, or slinghooks around corners.A sleeve failure under these condition will result in thefailure of the sling and you will drop the load.Check the sleeves regularly for nicks and cracks.A sharp steel edge will cut through any wire rope sling, atleast it will permanently damage the sling.Sliced steel pipes have proven to an affective cornerprotector.For square and round objects proper wooden padding willbe sufficient.MAKE THE LOAD MONOLITHIC (make loading elementsinterdependent, with a metalic or plastic strapping)Before making the final lift do a trial lift and check, if the padding is strong enough and does not crackunder the load weight
  55. 55. PREVENT DAMAGE TO THE SLING AND THE LOADTHE OBJECTS TO PACKING ARE:-To provide an adequate radius around which a sling may pass without unacceptable loss of load carrying capacity-To assist the sling in gripping the load-To prevent damage to the load itselfSHARP EDGEDS AND EDGE PROTECTIONContact of the lifting sling with sharp edges during the liftingoperations dramatically reduces the sling’s strength.Burn, load imbalance, stop/start jolting during lifting or wornslings further increase the damaging effect of sharp edges.A sharp edge with a corner radius of 1-7 mm reduces the load-bearing capacity of lifting belts and round sling by 50%. Withlifting belts a 13 mm corner radius is required to maintain aload-bearing capacity close to that of straight lifting.Edge protection must be used whenever the corner radius isbelow 7 mm.A wide range of edge protection types and materials areavailable for specific applications. Timber blocks, rubber,sectios of old vehicles tyres, conveyor belts)
  56. 56. SLINGS AND EYE BOLTSOnly collared eyebolts are used for lifting.Make sure that eyebolts are NOsecurely screwed into the ferrule or nut before use.Eye bolts are marked with their thread size. Not with their ratedcapacities.Only Swivel Hoist Rings are marked with their rated capacities.You can NOT assume that a stardard eye bolts has the same Swivel hoist ringsangularity strength loss factor as your sling.NOT RECOMEMMEND use eye bolts down to a 45 (30)º horizontalangle (loss approaches 75% of vertical rated capacity)The VERTICAL SLING CAPACITY MATCHES THE VERTICAL EYEBOLTS CAPACITY.Never rig a sling through eye bolts. You severely increase the stresson the eye bolts and the bolt can breakIt is BEST to use SWIVEL hoist rings for every angled lift. Theyadjust to any sling angle by rotating around the bolt and the hoistingeye pivots 180ºDo not hammer an eyebolt to tighten. Use a podger bar.Use two slings attached to the eyebolts with shacklesDo not attach slings to eyebolts with hooks because the hook isusually too smallAfter slings have been properly attached to the hoist ring apply forceslowly. Make sure the bail is parallel to the direction of the load.Watch the load and be prepared to stop applying force if the loadstarts buckingSling should not be reeved from one bail to another.
  57. 57. HOOKS•Slings should never be superimposed in the hook•All hooks shall be installed with safety latches toprevente the accidental unhooking•Hooks can be installed with swivels to allow the loadto revolve.•Select hooks of the right size•Do not tie or remove the safety latches.•Maintain the hook in a vertical position. If the hook iseccentrically loaded, the SWL will be reduced.•To avoid the breaking of the sewing wire the openingangle of the loop must be 20º maximumDO NOT FORCE THE EYE OF A SLING TO OPEN MORETHAN 20o AS THIS WILL PLACE UNDUE TENSION ON THEFERRULE
  58. 58. SAFE USE OF SLINGS- HOOKDO NOT WRAP A WIRE ROPE ROUND A HOOK. IT WILL KINK THE WIRE AND RUIN THESLINGShackles must always be used on lifting hooks if more than one sling is to be connected to it,and if the hook would be overcrowded by the ends of the same sling. The angles between slinglegs on a hook must never exceed 90º.SLINGS WITH HOOK
  59. 59. SHACKLESShackles must always be used on lifting hooks if more than one sling is to beconnected to it, and if the hook would be overcrowded by the ends of the same sling.The angle between sling legs on a hook must never exceed 90º
  60. 60. UNSAFE CONDITIONS SHACKLES AND HOOKS Unsafe Condition --Welded Pad eye, Shackle Use
  61. 61. DUNNAGE-SLING PRACTICEKNOW HOW TO USE DUNNAGE PROPERLY:Always use dunnage to allow the slings to be removed after lowering the load in to place.Use the “fifth-point” rule as shown.The common materials for dunnage are timber offcuts.NEVER use hollow light-wall tubes or pipes which could collapse under the load weight, andNEVER use material which is to be used on the job- the load could damage them beyond use.
  62. 62. STORAGE SLINGSStore all sling in a clean dry storage cabinet or area and hang them or coil them neatly.
  63. 63. PLAN YOUR SLINGINGFOUR STEPS TO SAFE RIGGING 1. Identify the load and determine the weight (and CG). 2. Determine slinging arrangements and select appropriate lifting gear. 3. Check that the route the load is to travel is clear and contains no hazards.. The lifted item must be kept balanced and under the control of the lifting appliance operator throughout the lifting operation 4. Prepare the load landing area. If necessary, perform a test lift to verify the secure fastening of the loadPLANNING THE LIFT WITH SLINGS 1. Know (determine) the weight of the load. 2. Decide the slinging arrangement.- Choose a lifting accessory that is compatible with the load, the lifting appliance and the operating environment: Load control Load type (Determinate how the weight is to be divided between the sling legs) Means of attachment (Use edge protection as necessary) 3. Sling length Available headroom Leg angleEnsure the lifting accessories are inspected and necessary user guidance is provided.
  64. 64. PLAN YOUR SLINGINGLOAD STABILITY Good slingers develop the habit of assessing unusual loads and estimating their CoG. They will attach slings so that the C of G is below the lifting points, or well within them. If there is the slightest doubt as to the stability of the load it must be lifted VERY slowly, just clear of the ground. If the load tilts it must be lowered and re-slung in a more stable mode. To ensure a balanced lift, the weight, shape, lifting position and CG of the load must be determined.SAFE RIGGING Is the movement of a mass (Load) by mechanical appliances, ie Lifting Gear and Slings. (Lifting Appliance and Lifting Accessories) Also, it is determining where and how lifting appliances and slings shall be fitted. Slings and attachments must be fitted to control the load - NEVER VICE VERSALANDING THE LOAD Before the load is lifted, a place should have been prepared where it is to be landed. The nature of the load will determine the type of preparation for landing, but most loads should be lowered onto timber battens. The slings can then be easily withdrawn (they can be removed both safely and without damage) A LOAD MUST NEVER BE LANDED DIRECTLY ON THE SLINGS.
  66. 66. RIGGING SAFETY Sling centered in bowl of hook. Each leg supports it’s part of the load so that load is under control. Slings are long enough to insure rated load angle is adequate. Multiple slings selected for specific angles, do not allow a load in each leg greater than that permitted. When using individual slings in a multi-leg lift, always remember the loading factors; Ensure the load will not collapse or change shape/form when subject to jerks, bumps, etc Keep clear of sling, load and hook; stand clear of suspended load. Be alert for possible snagging. Do not drag slings on the floor or over other abrasive surfaces. Do not pull sling from under load. Basket hitches, in choker hitches, must be balanced to prevent slippage. The load should not exceed the rated load of the sling and/or components. Load should be within rated load of sling, avoid shock loading. Avoid twisting and kinking. Do not use damaged slings. After use carefully inspect and store slings.
  67. 67. SLINGSEXECUTING THE LIFT WITH SLINGS Protect load and sling from damage at sharp corners. Pad the corners. Block as needed.THE LOAD MUST NOT BE DAMAGED BY THE SLINGS Examine sling before every lift. Use safe operating practices.
  68. 68. BEAUFORT WIND SCALE Wind Description of Velocity Velocity Velocity Wind Effect Locally Force No. Wind mph m/sec kphThe effect of wind on Load on 0 Calm Smoke rises vertically 0-1 - 1.6the hook- strong winds may Direction of wind shown by smokeswing suspended loads out of 1 Light Air drift, but not by wind or weather 1-3 1-2 2-5balance and radius, making the vanescrane unstable. 2 Light Breeze Wind felt on face. Leaves rustle. 4-7 2-3 6-11 Wind or weather vanes moveAnemometer-windspeed indicator Leaves and small twigs in constant 3 Gentle Breeze motion. Wind extends light fag 8-12 3-5 13-19Generally limit for safe crane Moderate Wind raises dust and loose paper. 4 Breeze Small branches move 13-18 5-8 21-29operation refer to specific cranemanual Small trees in leaf beginning to 5 Fresh Breeze sway. Little wavelets from on 19-24 8-11 31-39 inland watersVelocity is measured approx 6 Large branches in motion whistling 6 Strong Breeze heard in power wives 25-31 11-14 40-50metres (20 ft) above groun level. Moderate Whole trees in motion. Becoming 7 Gale difficult to walk against wind 32-38 14-17 52-61 Twigs/branches break of trees. 8 Gale Progress is generally impeded. 39-49 17-21 63-74 Chimney pots, slates and tiles may 9 Strong Gale be blown off. Other slight 47-54 21-24 76-87 structural damage may be caused.
  69. 69. YOUR SAFETYIs this an accident or an Incident?
  70. 70. WALL/COLUMN SHUTTERS Lifting Shutters Unacceptable…..Extract fromRC Code Use of tested lifting cleats as previous slide is a better option than wrapping chains around dividags
  72. 72. PRACTICE SLINGINGLoose bars, tubes, etc- Pipe tubes Site plantPre-fabricated reinforcement Portable buildingsWall/column shutters Forklift lifting suspended loadsTableforms Multiple liftsRigid sheet maaterials, scaffold Chandelier lift boards or similar Tandem liftingRubbish skips Specialised lifts-Glass stillageSteelwork Specialised lifts-Vacuum liftersPrecast concrete
  73. 73. LOOSE BARS, TUBES, ETC Scaffold tubes Loose re-barMethod:• Two leg webbing slings• Double wrap to avoid slippagePrecautions:• Where choked, the SWL is reduced Excessive deformation (20% or more)• Position of slings to be determined to limit sag in centre of bundle or at either end• Consider requirement for Tag lines to land load Use chain clutches to level load… Loose scaffold tube Slings wrapped in opposite directions
  74. 74. PIPE TUBES Is this safe? WHAT ARE THE HAZARDS ? ENTRAPMENT Slings not secured to the loadNO SAFE ESCAPE ROUTE
  75. 75. PRE-FABRICATED REINFORCEMENTGeneral notes: Re-bar lifting beam – (columns) Re-bar – (column)• Fabricated items should be designed and constructed to allow crane lifting and have such lifting points identified• Each cage to have been inspected prior to lifting and approved for lift• Slinging points to be a Re-bar lifting beam – (walls) Wall re-bar - unacceptable minimum of 3 links down from the top• On initial lift, check balance point is correct and that deflection is acceptable• Stop and consult Appointed Person if excess deflection.
  76. 76. WALL/COLUMN SHUTTERSMethod:• Lift by the designed lifting points only Acceptable…..• Use the manufacturers supplied & certified lifting eyes/accessories onlyPrecautions:• Avoid lifting over others wherever possible• Tag lines are to be used for all lifts wherever practicable• Shutters are to be visually inspected before any lift System column shutters• Loose materials are to be removed from all shutters
  77. 77. TABLEFORMSMethod: Tableforms Tableform lifting hook• Tables are to be lifted at the designed lifting points only• Properly designed, tested lifting equipment to be used• Method statement/risk assessment to be rigidly adhered to when lifting these shuttersPrecautions:• Exclusion zones to be established below all areas where these shutters are being removed from the building Table form Lifting• Additional training may be required for slinger/signallersWhen not using lifting forks attach chainsfrom behind guardrail not from top of table.Use boat hook and or slings wrappedaround lifting points before table is pushedout so chains can be attached.
  78. 78. RIGID SHEET MATERIALS / SCAFFOLD BOARDS OR SIMILAR Acceptable…..Method:• Typical load, rigid sheets such as Plywood, scaffold boards• Double wrapped with webbing slings or chains unless bandedPrecautions:• Webbing slings to be less than 6 months from 1st issue Unacceptable…..• Webbing slings must be protected from sharp edges, not be worn, have cuts or any damage• The load must be level for uniform loading• Sleeves or secure packing should be used at corners to avoid damaging materials or slings.
  80. 80. LOOSE TIMBER• Timber to be double wrapped• Slings or chains may be used• Beware of damage to timber if using chains• Bulky loads may require a combination of slings & chains Four point lifting – use sling and chain combination
  81. 81. PALLETISED LOADS Palletised lift• Ensure that slings or chains are passed below or through the pallet• Loads to be double wrapped wherever practicable – check with coordinator if in doubt Unacceptable…..
  82. 82. STILLAGE BINS AcceptableMethod:• Chains or slings double wrapped & choked• or Lifting forks with debris nettingPrecautions:• Ensure stillage is loaded within capacity• Check stillage for impact damage• Beware of rusted bases Unacceptable….
  83. 83. OPEN STILLAGES Acceptable………Method:• Where possible, lift load and stillage separately• Where lifting together, two leg chains or slings double wrapped around both load & stillage Unacceptable…..Precautions:• Ensure bite to avoid risk of tube slippage• Avoid risk of compression to structure of stillage• Essential that load is level
  84. 84. PALLET / BRICK FORKS & NETMethod: Brick forks/nets• Pallet Forks (netted) are frequently used for palletised or banded materials e.g. bricks, blocksPrecautions:• Check the load is within the capacity of the forks• The SWL of the forks is sufficient for the load• Ensure the net is secured and mesh size is smaller than the smallest item to be lifted
  85. 85. CONCRETE OR MUCK SKIPMethod: Concrete skip & drop chain Muck-skip & drop chain• Use only single leg drop chain of correct capacityPrecautions:• Skips approved for lifting & identified in Lifting Plan• Never lift directly with the crane hook• Beware of overloaded skips - If in doubt, don’t lift Tremmie pipe & pin location• Beware of rusted floors or loosely fitting traps• Tremmie pipe with chain attached to skip frame to avoid fall• Tremmie pipe to have discharge end secured to upper edge of skip• Tremmie pipe connecting pin must be locked in place before concrete skip is moved/loaded.
  86. 86. RUBBISH SKIPSMethod: Rubbish skip with lifting cradle• Skips must be marked as tested & certified for lifting• Otherwise use skip cradle for all skips EXCEPT as noted above & with specific agreement with the EHS department• Use appropriately rated & sized 4 leg chain slings attached to tested lifting lugsPrecautions:• Never lift waste skips which are not approved for lifting Designated lifting skip• Skips that can be lifted are identified in Lifting Plan & uniquely coloured• Beware of overloaded skips - If in doubt, don’t lift• Skips should be netted or lids closed during lift• Beware of rusted floors - If in doubt, don’t lift.
  87. 87. STEELWORKLifting Connections Dawson Shackle• Generally all beams and columns will be lifted using positive lifting points, i.e. Dawson shackles, LBG shackles and or bolted on lifting plates etc.• Wrapped chains may be used where there is no possibility of them slipping even if the loads is suddenly relieved, due to a clash with the structure etc. In Steelwork Positive Lifting practice this probably mean that only where chains are wrapped through an Chains wrapped through holes Lifting Shackles / Plates element, ie where chains are wrapped through holes in Metsec beams, will this technique be acceptable.• In certain exceptional circumstances traditional lifting techniques may be required, but these will be planed out where possible, and must be agreed in writing by the EHS department before any lift takes place.
  88. 88. PRECAST CONCRETEMethod:• Lift using ALL manufacturers cast-in lifting points provided• Use correct Lifting Accessories (check if provided by manufacturer)Precautions:• Ensure lifting eyes fully inserted & lifted at correct angle• Ensure multiple legs slings are evenly loaded• Consider required angle of unit to allow safe positioning• Consider supplier constraints such as limitations on orientation or intermediate support requirements etc
  89. 89. SITE PLANTMethod:• Only lift using integral lifting points (or refer to manufacturer instructions)Precautions:• Only lift from manufacturer’s approved & rated lifting points (Some lugs are for transportation restraint only)• Secure any loose equipment, including jockey/dolly wheels• Check correct lifting shackles are used• Visually check condition of item to be lifted. Does it look well maintained? Address any concerns to the Crane Supervisor• Check loads & centre gravity – are fuel/oil/water tanks filled?• Do not lift MEWPS with boom/scissor elevated.
  90. 90. PORTABLE BUILDINGSMethod:• 4 leg chain slings attached to designated lifting points with D Shackles or safety hooks• Chains to be minimum 45 degrees to horizontalPrecautions:• Remove all heavy items or hazards inside, before lifting• Only lift high enough to place on trailer and under no circumstances to lift over anything or anybody• Do not walk the roof to remove chains. Use ladders safely to access chains or shackles• Connect fall prevention lanyard to crane hook via inertia reel if necessary
  91. 91. FORKLIFT LIFTING SUSPENDED LOADSForklifts used in this manner are regarded as CranesMethod:• An approved certificated Lifting Attachment must be used, centred between the forks• Assess accessories for Ensure attachment is properly secured individual requirements• Safe working load is as markedPrecautions:• Forklifts lifting suspended loads must be controlled by a Slinger / Signaller
  92. 92. MULTIPLE LIFTSOther lifts-Multiple / chandelier / special liftsMethod:• Multiple items can be slung & lifted together provided there is no risk of loss of load (or part load), both are level with one another, & there is a safe method of removing the lifting gear once landed• Both must be treated as individual loads Acceptable… & slung accordinglyPrecautions:• Multiple lifts are to be agreed with the Lifting Coordinator• Beware when removing slings / chains etc – load may shift
  93. 93. CHANDELIER LIFTWhere 2 or more loads are liftedsimultaneously, one being slung directly above theother, on a common hookMethod:• Each load is to be treated as an individual load & slung accordinglyPrecautions:• Where loads are of unequal lengths, the longer load must be slung as the LOWEST load, & the lengths reduced progressively upwards• Tag lines are essential• There is a safe method of removing the lifting gear once landed Unacceptable…..why?
  94. 94. TANDEM LIFTING• Tandem lifts are NOT to be carried out by Tower Cranes• Any tandem lift is to be the subject of a separate Method Statement & full Risk Assessment process
  95. 95. SPECIALISED LIFTS – GLASS STILLAGE• Stillages should be used when lifting glass• Glass to be secured to the stillage• Stillage should be thoroughly examined & tested• Plate showing SWL on glass stillage and date of thorough examination• Lifts should be planned by a competent person
  96. 96. SPECIALISED LIFTS - VACUUM LIFTERS• Subject to thorough examination Battery power must be at least 25% SWL is shown, lifter is checked• Trained and competent operators only to daily prior to use for serviceability use• Secondary means of support required• A secondary mechanical device must be used when using vacuum lifters• These may need removal for FINAL locating Each pad has a non-return valve The SWL of this machine is 8 to maintain vacuum, giving a tonnes, with each of the vacuum maximum stated time of 20 pads rated at 2t. minutes to lower the load safely