Chain hoist and round slings

[mrtc]

Is it ok to hook a chain hoist directly to a suitably rated sling or is it better to use shackles? 
thanks 

[J Pearce]

Generally accepted professional practice is to use only a shackle or masterlink in a chain hook. A chain hook isn’t designed to accept and retain a roundsling.

[Simon Lewis]

A Jon suggests, the manufacturers say not to use a sling directly on a hook, and the training centres all say not to put the round sling directly in a chain hoist hook, but to use a shackle or Masterlink.

[sunray]

It's one of those thing I've seen quite regularly but somehow an open hook straight on both ends of a sling (fabric or steel) never looks right.

[alistermorton]

I did see a picture of a ram's horn double hook being used to lift a sling on a rigging supplies website - is that an acceptable alternative?

[MarkB]

Hooks are generally designed to be loaded directly in line with their seat, it may be appropriate to use a sling directly on the hook so long as the hook is loaded correctly. Slings come in multiple formats; textile, wire rope, & chain being common.

Any loading that applies a force acting to "open" the hook profile should be avoided. If a sling is selected it should not only be suitably rated but also have the correct geometry to sit in the hook seat. For example, a sling profile that is wider than the hook seat may apply an opening force to the hook. 

Shackles and masterlinks are often a better choice because their size relative to the hook seat ensures they sit in the correct location for the hook. Again it is possible to have hardware that is suitably rated but their geometry applies the load to the hook incorrectly. A common example of this is using a shackle that is too small for the hook profile.

All of the above applies to single and rams horn hooks.

Some, but not all, shackles/masterlinks are designed to be loaded from multiple directions. This is useful when slinging around and load or structure members, rather than connecting point to point. 

Any questions feel free to ask, I work in the lifting industry.

 

 

[dje]

On 12/4/2024 at 9:16 AM, Simon Lewis said:

A Jon suggests, the manufacturers say not to use a sling directly on a hook, and the training centres all say not to put the round sling directly in a chain hoist hook, but to use a shackle or Masterlink.

Out of interest which manufacturers say that?

[Simon Lewis]

11 hours ago, dje said:

Out of interest which manufacturers say that?

I think it is in the LEEA Code of Practice, "When attaching more than one sling to the hook of the appliance use a shackle to join the slings and avoid overcrowding the hook".

Manufacturers such as SpanSet mention having sufficient contact area between sling and hook, or make smaller size slings to better fit small hooks without crushing or provide many of their slings with a ring to allow use with smaller hooks. That's not a definitive "don't use without shackles" but the underlying advice is get the radius right - which a shackle helps to do.

[TomHoward]

Chris Higgs book Introduction to Rigging is worth a read, it covers practical advice on slinging trusses etc and why. 
 

I’d use a D shackle downwards to gather the two legs of the sling, and put the pin of the shackle in the hook. 

[dje]

On 12/17/2024 at 9:13 AM, Simon Lewis said:

I think it is in the LEEA Code of Practice, "When attaching more than one sling to the hook of the appliance use a shackle to join the slings and avoid overcrowding the hook".

Manufacturers such as SpanSet mention having sufficient contact area between sling and hook, or make smaller size slings to better fit small hooks without crushing or provide many of their slings with a ring to allow use with smaller hooks. That's not a definitive "don't use without shackles" but the underlying advice is get the radius right - which a shackle helps to do.

OK I was mainly looking for an example of a manufacturer saying that you can't clip a roundsling directly to the hook which is neither of those things. I have never heard of a manufacturer stipulating that, which was why I ask. 

I took the OP as asking to connect one sling not two. Yes if using 2 slings (or one sling back to itself like a basket) it would be good practice to use a shackle or a master link. But I see no good reason to mandatorily use a shackle to connect a motor hook to a single roundsling. 

There are definitely many times when using a shackle is good practice - competent person as required by LOLER should be designing the lifting system anyway and that design process will include how the sling is connected to the machine. But I think to say the manufacturers expressly prohibit it, is misleading.

[sunray]

I recall seeing some hooks in use designed to be fitted to round slings and also to hang a round sling from: Crappy sketch:

[sunray]

Of course Google is useful

In hind sight I'm quite proud of my original sketch from an experience maybe 10-15 years ago

Edited January 5 by sunray

[TomHoward]

On 1/4/2025 at 11:58 PM, dje said:

I took the OP as asking to connect one sling not two. Yes if using 2 slings (or one sling back to itself like a basket) it would be good practice to use a shackle or a master link. But I see no good reason to mandatorily use a shackle to connect a motor hook to a single roundsling. 

Yes sorry I was taking a single roundsling and a chain block as being with the sling thrown over a beam and in a basket, ie two ends of the roundsling in the hook so I'd shackle in that setup

[dje]

On 1/6/2025 at 7:15 PM, TomHoward said:

Yes sorry I was taking a single roundsling and a chain block as being with the sling thrown over a beam and in a basket, ie two ends of the roundsling in the hook so I'd shackle in that setup

Yes in that case you'd use a shackle, or even two if you want to make your life easier at the cost of a little trim height.

[sunray]

1 hour ago, dje said:

Yes in that case you'd use a shackle, or even two if you want to make your life easier at the cost of a little trim height.

How would you use 2 shackles in that situation?