4
Horizontal forces
All multi-leg slings exert a horizontal component of force (see figure) which increases as the leg angle to the vertical is increased.
As a result of this the leg angle should never exceed 60°. Care should always be taken to ensure that the load to be moved is able to resist the
horizontal component of force, without being damaged.
How the load of sling leg changes
according to the vertical angle for a 10 ton load.
The red area indicates angles greater than 60° for which
slings are not intended to be used.
Reduction of WLL due to sharp edges
It is important to protect the chain links from damages from sharp edges. If proper padding can’t be used the WLL of the sling needs to be redu-
ced according to below reduction table.
Working load limit (WLL) of the chain sling
Taking into consideration the recommendations and the cumulative effects of de-rating, the method of slinging should be decided, and a suitable
chain sling selected so that the mass to be lifted does not exceed the WLL of the sling.
Load diagram
Multi-leg chain slings with less than the full number of legs in use
Occasions may arise when a lift needs to be made using a smaller number of legs than the number of legs in the chain sling. Legs that are not
in use should be hooked back to reduce the risk of such legs swinging freely or snagging when the load is moved. POWERTEX chain sling tag
addresses these situations as it gives correct information for 1-, 2- , 3- & 4-leg applications.
Combining two POWERTEX chain slings
Two POWERTEX chain slings may be used in combination on the same crane hook to increase capacity and number of legs in use. Make sure
the crane hook design is suitable for handling more than one chain sling. POWERTEX chain sling ID tags give correct WLL infor-mation for 1-, 2- ,
3- & 4-leg applications.
Horizontal
component
of force
Loading of leg
Load 10 ton
20 t
20 t
10 t
10 t
7 t
7 t
80°
75°
60°
ß = 45°
30 t
30 t
Edge load effect on WLL
R = larger than 2 x chain Ø
R = larger than chain Ø
R = chain Ø or smaller
Load factor
1 x WLL
0,7 x WLL
0,5 x WLL
Chain
Single
2-leg*
3−4-leg*
Endless
Ø
mm
Straight
Choke
Basket
0°−45°
45
°
−60
°
0°−45°
45
°
−60
°
Choke
6
1,4
1,12
2,8
2
1,4
3
2,12
2,24
8
2,5
2
5
3,55
2,5
5,3
3,75
4
10
4
3,15
8
5,6
4
8
6
6,3
13
6,7
5,3
13,4
9,5
6,7
14
10
10,6
Factor (K
L
)
1
0,8
2
1,4
1
2,1
1,5
1,6
* When using multi-leg sling in choke lift - reduce the value by 20%.
Summary of Contents for Grade 10
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