Is this correct?: SWL (Safe Working Load) has been phased out and should no longer be used

Didn’t know about this.

Anyone encountered this anywhere?

SWL is still in effect in quite a few ports. Particularly the cranes loading boxes.

Yes, I’m not sure what the context is. The article says:

The term SWL was changed to Rated Capacity for cranes, hoists and winches and Working Load Limit (WLL) should replace Safe Working Load (SWL) in describing the capacity of items such as hooks, slings and shackles etc.; that is for lifting devices below the crane hook, as referenced in AS4991:2004 Lifting devices.

So a crane would have a “Rated Capacity” and lifting gear would have WLL (Working Load Limit)

The article also says the change occurred 20 years ago but I don’t recall seeing anything but SWL.

About 20 years ago, the USA ceased using this term, because of legal implications and the European and ISO Standards followed suit a few years later.

I’m not sure this guy knows what he is talking about. Maybe he stopped using the term 20 years ago, but I’ve only been in the industry 15 years and “SWL” has been painted on the side of every crane on every ship I’ve sailed on…including those built two years ago.

Even Crosby, one of the oldest and largest rigging manufacturers in the world still says WLL is synonymous with SWL.


Same here, I’ve never heard of WLL or encountered anything except SWL. But I did a search the other day and at least a couple of first hits say the same thing.

Here’s another

Safe Working Load, SWL, (or Normal Working Load, NWL) is an outdated term that was used to indicate the amount of weight that a lifting device could safely carry without fear of breaking. It is a calculation of the Minimum Breaking Strength, or MBS.

The more up-to-date phrase for the term SWL is Working Load Limit, or WLL.

The specific definition for the Working Load Limit (WLL) is: The maximum mass or force which a product is authorized to support in general service when the pull is applied in-line, unless noted otherwise, with respect to the centerline of the product.


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Perhaps same thing but only different “Wordology”. Not worth a debate . Don’t overload your shit.

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I was wondering if anyone else had encountered this or how widespread it was. I edited my OP.

A difference with no distinction. The article referenced above list SWL, NWL, and WLL as synonyms. The only difference is when lawyers are involved.


Is will say I’ve seen WLL on most rigging gear/shackles/etc. It makes sense as a term. But SWL is still prevalent enough that it seems odd to call it outdated and something that was phased out decades ago. I’ve certainly not heard it brought up in that sense until your post link.

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Maybe just Australian lawyers, that’s where the writer if from.

“The term ‘safe working load’ has been changed to ‘rated capacity’ and other uses of the word ‘safe’ have been avoided due to the legal significance placed on the word.”

Seems like that the part about the use in the U.S. is incorrect.

Never heard of it.
Did all my exams ect 30 years ago.
SWL is written all over the place and on test certification I have on board as far as I know.
I will have to go and look.

Which was the whole point in changing the nomenclature. SWL implies unconditional safety at that load, it is a static point and there are several factors which might cause the dynamic load to exceed that by a considerable amount and make a widow’s lawyer rich.


My brother and nephew run rather large cranes doing commercial pile driving. I will ask him about this subject when he/they gets back in town. My son oversees/manages loading of box ships, am curious as well what numbers or swl, wll, or nwl are on the rigs. I do know they have a limit switch on the box cranes, but have no idea what triggers it other than weight.

As if NWL, MLL, or MWL don’t create the same mental model or have the same caveats…

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I can see the SIRE observation now… Your crane has SWL not WLL…stop the ship!

Better Call Saul before lifting.

WLL does seem to have replaced SWL around here. I had to google it when it first turned up, and assumed it had to do with a different rating method or somesuch. Should have known it was just “preferred term” bullshit. A random sling from the workshop:

It takes a special kind of lawyer to think that using the word “safe” to indicate a safe condition is somehow detrimental. I know a couple that physically cringe when I confront them with this kind of BS, and who resort to defenses centering on the fallibility of the human psyche and the evils of US litigatory culture.

It also takes a certain kind of manager to agree that this makes sense, and that the word “safe” should henceforth be reserved for marketing purposes. How these people came to rule the Western world is a very interesting question that I don’t fully understand. Ultimately, it doesn’t just circle back to lawyers and the legal framework that lets them have at it, but also says something about the basic human desire to be kept safe from harm. I suspect that my own aversion to the concept is value based as much as it is rational.


Couldn’t it be argued the other way around? Safe Working Load - You’re working, with a load, but no worries! It’s safe.

BTW, I can see us provincials on this side of the pond using tons, or tuns, but shouldn’t that be KN?

I am talking about the idea that a society should insulate its members from all risk, which has led to draconian product liability laws, which in turn has led to lawyers having their way with how things are worded.

No, because WLL describes the mass of an object that can be safely suspended within given parameters. Also no, because the people handling lifting gear are often the kind of people who think that a kilonewton describes the weight of an apple. Better use terms they understand…