Rope Services Direct are pleased to offer a wide variety of lifting chains. All are supplied complete with certification and are available in single and multi-leg (2 leg, 3 leg and 4 leg) chain versions.
We sell both grade 8 and 10 steel from brands like Gunnebo. Lifting chains are custom-made to each customer’s requirements. Meaning we can vary the length, working load limits and also attachments such as hooks. We also supply a basic range of lifting gear to compliment the chain slings.
Lifting Chains / Chain Slings
Rope Services Direct can supply, inspect, test and repair all types of lifting chains and chain slings. Chain slings are a popular piece of lifting equipment and are commonly used in many types of everyday lifting applications. Lifting chains & slings come in a range of configurations including single leg slings, 2 leg slings, 3 leg slings and 4 leg slings. The choice of lifting chains & slings used is largely dependent on the type of load which is to be lifted and the way in which it needs to be handled. Lifting chains can be used in a variety of hitches, however the hitch type will affect the overall working load limit of the sling.
We can also supply multi leg web slings in industrial webbing in a wide range of sizes, these can be custom made to your specifications due to us having our own industrial sewing machines. Wire Rope Slings are another option for slinging purposes.
2 Leg Chain Slings
2 leg slings can be utilized in many different hitches, straight, choke, basket, drum and 2 leg with just one leg utilized. Here’s the diagrams of how they are normally used in addition to their respective working load limit (WLL)
1, STRAIGHT LIFT; In normal circumstances the WLL is going to be as for a two leg sling.
2, CHOKE HITCH: The WLL must be not more than 80% of the WLL for a 2 leg sling.
3, BASKET HITCH: This should be rated as a 2 leg sling. The angle of any leg shouldn’t exceed 45 degrees from the vertical axis. (this sort assumes the looks of a 4 leg sling. However it needs to be noted that the master link will probably be suitable for 2 leg loads only and so the sling therefore, be rated as a 2 leg.)
4, DRUM SLING: Must be rated as a single sling. (With this configuration the included angle needs to be maintained as close as possible to 60 degrees (30 degrees from vertical). If then drums of various lengths are to be lifted, a shortening clutch needs to be attached. So that the length of chain may be adjusted to keep this angle).
5, TWO LEG SLING; WITH ONLY ONE LEG USED: This should be rated at half the working load marked on the sling, the WLL needs to be not more than 80% if utilized in choke hitch. (two leg slings with just one leg in use must make certain that the unused leg is hooked securely back out of the way.)
2 Single Leg Chain Slings Used Together
2 single leg chain slings really should not be used together to create a pair unless:
They are the identical type, grade, size and length.
They are both marked with the same WLL rating
The included angle between the two legs will not exceed 90 degrees or 45 degrees from vertical
The crane hook is big enough to comfortably receive both upper terminal fittings of the sling.
1, STRAIGHT LIFT: WLL should be rated as a 2 leg sling. The WLL, as a result will be the same as a similar 2 leg sling.
2, CHOKE HITCH: The WLL must be not more than 80% of the WLL for a 2 leg sling.
3, BASKET HITCH: Should be rated as a 2 leg sling. The WLL must be not more than the equivalent 2 leg sling.
3 Leg Chain Slings
STRAIGHT LIFT: under ordinary conditions the WLL would be the same as for 3-leg slings.
CHOKE HITCH: The WLL must be not more than 80% of the WLL for a 3-leg sling. (Rate as stated only in incidences where the load appears to be sensibly and as equally distributed as possible between all 3-legs. If 2 are supporting the majority of the load, rate at 2/3 of the marked WLL.)
4 Leg lifting chains
STRAIGHT LIFT: Under normal conditions the WLL is going to be as for the WLL for 4-leg slings
CHOKE HITCH: The WLL must be not more than 80% of the WLL for a 4-leg sling.
DOUBLE BASKET SLING: This should be rated like a 4-leg. ( This applies to double basket slings that are intended as such and should be fitted with a strong enough master assembly. It doesn’t apply to a 2-leg sling which is back hooked. The maximum angle should be 90 degrees measured diagonally between opposite legs or a max. 45 degrees from the vertical plane.)
Call us at Rope Services Direct to place your order for lifting chains, chain slings or other lifting slings today and also to speak to our experienced team.
Good Chain Slinging Practices
Skilled chain slinging practice can’t be learned from a book or instruction manual, it has to be learned from practical training, and plenty of practice, particularly whilst utilizing lifting chains & chain slings using a crane or electric hoist.
Nevertheless here we have listed for you a number of essential principals in safe slinging using lifting chains including malpractices to avoid, and we have also included a diagram for the restrictions on the angle of use.
EVALUATING THE LOAD
The user should take steps to ascertain the weight of the load, guessing just isn’t satisfactory. Drawings might be available providing the weight or it might be calculable with reasonable accuracy. If the load is probably going to be lifted again the weight ought to be marked on it.
An experienced slinger will always assess uncommon loads and estimate where the centre of gravity is, after which you can fit the sling in such a way that the centre of gravity is straight below the lifting points, or else if this technique is unfeasible, well within them. The load needs to be slowly lifted off the ground, and if the load tilts the chain sling must be adjusted to a more even position, this is known as a test lift.
OFF BALANCE LOADS:
There are some loads which are asymmetrical and will not balance at their centre of gravity, and so tilting takes place. If the form of the load permits the sling needs to be placed equally about the centre of gravity to ensure a safe horizontal lift. An experienced slinger will be able to estimate the centre of gravity and therefore know where to position the slings.
If an off balance load has a sling attached in a way so that the lifting hook is not directly above the centre of gravity the load will almost certainly tip until the centre of gravity is positioned directly below the crane’s lifting hook. In this instance the sling leg which is nearest the heavier end is going to be taking a bigger force than the leg at the lightest end. This situation may well become increasingly more extreme until one leg is supporting the nearly all the load while the 2nd leg is merely steadying the load.
As a result of varying shapes and sizes of loads it’s impossible to provide precise guidance in lifting these loads, however the slinger should be aware that whilst handling an off balance load the leg on the tilted heavier end may be supporting up to 100% of the weight of the load, therefore the sling needs to be chosen that is capable of supporting the weight on one leg.
Crane drivers and slingers need to be conscious of shock loading. High acceleration forces, or shock loads, could be brought on by sudden operation of the crane by not taking up the slack before beginning to lift, or else by abrupt collision of falling objects. Shock loads may break a chain despite the fact that the weight of the load is well under the working load limit for that chain. Lifting and lowering must always be done slowly.
LANDING THE LOAD
Before a load is lifted, an area needs to be arranged where it is to be put down. The majority of loads will be lowered onto wood battens, so that the chain sling may be easily removed. The load must on no account be landed directly onto the chain.
TIP LIFTING OF HOOKS
Hooks are intended to support the load within the bowl of the hook never on its tip. Users must always guarantee that the hook of a sling engages freely in the lifting point so the weight of the load is supported inside the bowl. Forcing or wedging the hook tip into the lifting points leads to the hook being stressed which can result in failure.
KNOTTING, TWISTING AND TRANVERSE BENDING OF CHAIN
Chain that is twisted, or even worse, knotted , can’t develop its full strength and will surely fail. Chain is intended to support the load in a straight line of force running directly through the crowns of each link. Therefore twists must be removed prior to use and knotted chain must on no account be used. Chain that bends under strain around a sharp corner will be stressed in such a way that it isn’t designed for. Timber or other suitable packing material needs to be used to avoid this kind of stressing.
MISUSE OF SHORTENING CLUTCHES
The chain which carries the load must ALWAYS lead from the underside of the clutch. If ever the direction is reversed so that the load carrying chain leads from the top of the clutch, the front portion of the clutch could possibly be pulled off and the load released, causing possible injury.
On occasion it can be alleged that a choke hitch may be made secure by striking the hook, link or adjacent chain in an effort to force the bight into closer contact with the load. This technique is serious malpractice (referred to as battening down) and is dangerous, the bight must be allowed to take on its natural angle which will be approximately 120 degrees.
When elongated loads are to be lifted, particularly in confined places, slingers should fasten a rope or tag line to at least one or both ends of the load in order that any rotational movement may be controlled and corrected quickly.
HOOKING BACK UNUSED LEGS
In the case of multi-leg chain slings when not all legs are in use, the unused leg must always be hooked back by means of engaging the hook within the master link or the master assembly.
CODE OF SIGNALS
Slingers and drivers must always use an agreed code of signals prior to lifting any load. An agreement must be made in order that just one slinger is in command of giving the signals, all other signals will be ignored except for the emergency stop signal which must always be acted upon.
SLINGERS DUTY OF PROTECTION
Slingers ought to wear appropriate garments, and at the instant the strain is taken on the chain sling, the slingers hands and feet must be away from the load, after which position himself to ensure that he doesn’t risk injury if the load was to fail and fall.
Chain slings ought to be removed from crane hooks and stored in an appropriately designed rack, they should in no way be left lying on the floor where they could suffer damage.
Lifting Chains & Chain Slings…….Restrictions on the angel of use:
All multi-leg chain slings apply a horizontal component of force, that raises as the angle from the vertical gets greater.
NO chain sling should be used if ever the angle from the vertical is greater than 60 degrees, since beyond this point the forces in the legs drastically increases.
Angles of lower than 15 degrees must be avoided since these can lead to the load becoming unstable.