twin-path® slings in action - Hanes Supply, Inc

asic lift engineeringYOUR SLING AND RIGGING SPECIALISTstRaIGHt oR VeRtIcal, attachment,is simply using a sling to connecta lifting hook to a load. Full rated liftingcapacity of the sling may be utilized,but must not be exceeded. Whenevera single sling is used in this manner, atagline should be used to prevent loadrotation which may cause damage tothe sling.When two or more slings are attachedto the same lifting hook in straight orvertical manner, the total hitch becomes,in effect, a lifting bridle, and theload is distributed among the individualslings.cHokeR hitches reduce lifting capabilityof a sling, since this method of riggingaffects ability of the wire ropecomponents to adjust during the lift. Achoker is used when the load will notbe seriously damaged by the slingbody – or the sling damaged by theload, and when the lift requires thesling to snug up against the load.As the horizontal angle between thelegs of a sling decreases, the loadon each leg increases. The effect isthe same whether a single sling isused as a basket, or two slings areused with each in a straight pull, aswith a 2-legged bridle.Anytime pull is exerted at an angle on aleg – or legs – of a sling, the load perleg can be determined by using thedata in the table at right. Proceed asfollows to calculate this load – anddetermine the rated capacity requiredof the sling, or slings, needed for a lift.500 LBS.1000 LBS500 LBS.518 LBSEVERY LIFT USES 1 OF 3 BASIC HITCHESThe diameter of the bend where the slingcontacts the load should keep the pointof choke against the sling BODY – neveragainst a splice or the base of the eye.When a choke is used, the sling ratedcapacity must be adjusted downward tocompensate for loss of capability.A choker hitch should be pulled tight beforea lift is made – NOT PULLEDDOWN DURING THE LIFT. It is alsodangerous to use only one choker hitchto lift a load which might shift or slide outof the choke.basket hitches distribute a load betweenthe two legs of a sling – withinlimitations described below. Capacity ofa sling used in a basket is affected bythe bend, or curvature, where the slingbody comes in contact with the load –just as any sling is affected and limitedby bending action, as over a sheave.CALCULATING THE LOAD ON EACH LEG OF A SLING1000 LBS1. First, divide the total load to be lifted by the number of legs to be used. Thisprovides the load per leg if the lift were being made with all legs lifting vertically.2. Determine the angle.leG anGle loaD3. Then MULTIPLY the load per leg (as computed inNo. 1 above) by the Load Factor for the leg anglebeing used (from the table below) – to computethe ACTUAL LOAD on each leg for this lift andangle. THE ACTUAL LOAD MUST NOT EXCEEDTHE RATED SLING CAPACITY.Thus, in drawing three (sling angle at 60°):1000 ÷ 2 = 500 (Load Per Leg if vertical lift)500 x 1.154 = 577 lbs. = ACTUAL LOAD oneach leg at the 60° HORIZ angle being used.In drawing four (sling angle of 45°):1000 ÷ 2 = 500 (Load Per Leg if a vertical lift)500 x 1.414 = 70 lbs. = ACTUAL LOADon each leg at the 45° HORIZ angle being used.1000 LBS90° 75° 60°518 LBS577 LBS577 LBS707 LBS1000 LBS 1000 LBS 1000 LBSHEADQUARTERS: 55 James E. Casey Drive • Buffalo, NY 14206 PHONE: 716.826.2636 FAX: 716.826.4412 www.hanessupply.com1000 LBS45°149707 LBSstRaIGHtcHokeRloaDloaDbasketloaD(DeGRees) factoR90° 1.00085° 1.00380° 1.01575° 1.03570° 1.06465° 1.10360° 1.15455° 1.22050° 1.30545° 1.41435° 1.56630° 2.000Rated Capacity AdjustmentFor Choker HitchesANGLE PERCENTOF OF SLINGCHOKE RATEDIN CAPACITYDEGREES APPLICABLE120-18090-11960-8930-590-29100%87%74%62%49%When a choke is drawn down tight against a load,or a side pull is exerted resulting in an angle of lessthan 120°, an adjustment must be made for furtherreduction of the sling rated capacity.