Harness weight limits

[Freeman]

i weigh nearly 19st and i've always used a weaver i know that will hold me but will the branch???

[b101uk]

Harnesses are to arrest falls,

 

A 100kg person falling a couple of meters or so on a static rope with little stretch will rapidly exceed 15KN, given as speed doubles kinetic energy quadruples and the shorter the stop the higher that peak KN loading will be.

 

So assuming a fall is given as a standard drop of x distance, the design factor is known e.g. at 10:1 of WLL with a peak MBL of e.g. 15KN then its easy to arrive at a maximum weight for a person in the harness who then WONT brake the harness from a standard drop of x distance given as this thread proves very few people understand how kinetic energy ramps up vs. speed or KN ratings hence the weight limits now on harnesses.

[Rupe]

Harnesses are to arrest falls,

 

Are they? I know that "fall arrest" harnesses are designed to "arrest falls" but I was always under the impression that "work positioning" harnesses were for something else?

[Mark Bolam]

We shouldn't be placing ourselves in a 'fall arrest' situation, but we have to live in the real world sometimes....

 

Big swings seem to generate a bit of G.

[scotspine1]

Can the Treemotion be used for rescues then? Rescues where the victim is attached to the rescuer's harness due to the victim's harness being damaged beyond use?

 

 

Shade over 28 stone still climb everyday just having lunch in my pic forgot i had my hard hat on:lol:

 

you could put a mast on that burger and sail it down the Thames -

[Rupe]

Can the Treemotion be used for rescues then? Rescues where the victim is attached to the rescuer's harness due to the victim's harness being damaged beyond use?

 

 

-

 

Yes they could, you would still be well within the MBS, but you would be in the "cycles to failure" area so its possible the harness might have to be chucked after the rescue, or immediatly inspected by a loler inspector, who would add up the weights of the victim and rescuer and possibly condemn the harness, but as long the vitcim lost a whole leg or two, and those losses were included in the calculation then it would probably be ok!!

[Chris Cowell]

The ring on the bridge of a treeMOTION is rated at 30kN. Assuming both rescuer and casualty are connected to this ring, the harness continues to be subjected to a one person load. It is the work positioning system of the rescuer and the bridge ring of his/her harness which carries a 'double' load. For this reason, the ring has a rating which is double the rating required by the work positioning harness standards.

 

Chris

[scotspine1]

The ring on the bridge of a treeMOTION is rated at 30kN. Assuming both rescuer and casualty are connected to this ring, the harness continues to be subjected to a one person load. It is the work positioning system of the rescuer and the bridge ring of his/her harness which carries a 'double' load. For this reason, the ring has a rating which is double the rating required by the work positioning harness standards.

 

Chris

 

thanks Chris, that info is worth remembering.

[b101uk]

Harnesses are to arrest falls,

 

Are they? I know that "fall arrest" harnesses are designed to "arrest falls" but I was always under the impression that "work positioning" harnesses were for something else?

 

If no falling was involved or no shock loading was involved then it would be pointless in putting KN values on them when just a weight limit would do.

 

Granted its been 17 odd years since I climbed but I seam to recall my Willans t22 was 30KN and a maximum drop of 2m

[scotspine1]

If no falling was involved or no shock loading was involved then it would be pointless in putting KN values on them when just a weight limit would do.

 

Granted its been 17 odd years since I climbed but I seam to recall my Willans t22 was 30KN and a maximum drop of 2m

 

A fall of 2m in a work positioning harness would see the human skeleton start to break up - broken pelvis, snapped spine, severely torn ligaments etc we really shouldn't be talking about fall arrest when it comes to treeclimbing but I get your point re Kilonewtons.