Hauling systems - (Split from: Win lots of shiny kit!)

[andrewmcleod]

There was a discussion about the effectiveness of a 3:1 Z rig pulley systems on here some time ago. The photo I posted of the 3:1 configuration with the ID and low efficiency Fixe pulleys is regularly used for 100kg rescue practice on oil rigs with only 1 person doing the pulling over a 30m haul distance. They do get a bit of a sweat on mind.

What's the set-up for that though? Do they just stand at the top and pull?

Even when I did do such things, I could only squat about 60kg (at least more than a few times), so I am going to really struggle to pull 49kg repeatedly in a good situation. In a cramped awkward cave, I'd always try and go for a counterbalance because I am weak. I know people who I would estimate can only pull about 25kg (max) upwards when hanging on a rope. Big beefy oil-rig guys, or rope access workers used to pulling on things, will do significantly better than weedy student cavers trying to lift their fat mate (and I say that as one of the weedy albeit not student any more).

If you have a length of 5mm dyneema (5m or so), this has a pleasantly low coefficient of friction and combined with a microtraxion, small pulley e.g. Partner and an ascender, one more crab to make a 3:1 counterbalance makes an easy way to break into a loaded rope for people who can't use the Spanish pendulum chain-of-crabs route (because they are too weak/their partner is too heavy). 1:1 counterbalance is great unless you weigh 55kg and you are trying to lift 110kg...

Nothing, of course, is likely to work unless you have tried it. My first attempt at building a 3:1 at the top of the Wessex tower (a simple microtraxion 3:1 with a krab redirect) ended in total failure as I was too weak, from the slightly awkward position leaning in, to lift a relatively skinny student.

 

[mikem]

Redirecting through another pulley & using counterbalance / pulling up on their rope is probably quickest fix for you (even a krab would reduce your effort, as using body weight, rather than muscle power).

 

[Mark Wright]

There was a discussion about the effectiveness of a 3:1 Z rig pulley systems on here some time ago. The photo I posted of the 3:1 configuration with the ID and low efficiency Fixe pulleys is regularly used for 100kg rescue practice on oil rigs with only 1 person doing the pulling over a 30m haul distance. They do get a bit of a sweat on mind.

What's the set-up for that though? Do they just stand at the top and pull?

They will generally stand at the top and attach their chest ascender to the haul line and pretty much use their entire body weight to haul with.

Another exercise that was regularly used in IRATA training centres some years ago was called the 'Bastard Haul'. This was the same 3:1 configuration but from a suspended position with the rescuer attaching themselves to the haul line so using their entire body weight on the haul line. We used to do it at our training centre over a 10m haul distance and then attach the casualty, which was usually a 76kg Ruth Lee dummy fully kitted to around 90kg, to some structural steel where they, or someone else, would carry out an aid climb rescue and either lower the casualty to the floor or descend with them.

I'm not suggesting this rescue was easy, hence the name.

There are a number of 'off the shelf' rescue hauling systems on the market.

The Petzl 4:1 Jag system,

https://www.youtube.com/watch?v=Acj9X_eBZhk

The Spanset 4:1 or 5:1 Gotcha system that Wardy invented,

https://www.spanset.com/au-en/products/RescueEvacuation#long_description

and the +/- 6:1 Rescue Genie that an old pal of mine and me invented to try and compete with Wardy's system.

https://www.arcoservices.co.uk/equipment/working-at-height-and-rescue-equipment/rescue-genie-rescue-kit

Despite the Rescue Genie winning a British Safety Industry Federation award for innovation, the Gotcha is probably the most commonly seen system in industry.   

Mark

 

[Fjell]

If you have a long enough rope for you to get down with them, all you need is a knife for the one they are hanging on. All you need then are nerves of steel.

 

[Mark Wright]

If you have a long enough rope for you to get down with them, all you need is a knife for the one they are hanging on. All you need then are nerves of steel.

Using a knife is generally considered to be very much a last resort.

https://www.youtube.com/watch?v=gaH7pK-6n84

 

[Fjell]

I would be prepared to do it, and I def would if they were hanging in water. I am very likely to be on my own with someone when caving, and am not carrying a quick to use picking system. Doing a manoeuvre in water is very unfunny. I lifted someone off the rope on the final pitch in Diccan once on 9mm and that was sobering - in fact the only time I have done it for real.
And the absolute number 1 top tip in Alpine Caving is not to forget the other guy has a descender you can use to pass rebelays without using cowstails.

 

[Mark Wright]

I would be prepared to do it, and I def would if they were hanging in water.

Me too, but always remember to cut away from yourself.

I watched the former technical director of one of the UKs largest height safety companies cut towards himself during a pick-off rescue on an electricity pylon. He not only cut the casualty's attachment lanyard but also cut through the safety lanyard that connected the casualty to the rescuer. Luckily it was only a demo and only 1m from the ground. He was using a V shaped 'Safety Knife'.

They don't use knives in any of their rescue systems anymore.

Mark

 

[PeteHall]

They don't use knives in any of their rescue systems anymore.

What is used instead?

 

[Mark Wright]

They don't use knives in any of their rescue systems anymore.

What is used instead?

Gotchas and Rescue Genies.

Winch them up, disconnect their lanyard and lower them off

 

[PeteHall]

So no cutting at all, makes sense, much less chance of an accident.

I'd thought from your earlier post that perhaps they were using an alternative cutter that couldn't accidentally cut anything more than intended.

 

[Mark Wright]

So no cutting at all, makes sense, much less chance of an accident.

I'd thought from your earlier post that perhaps they were using an alternative cutter that couldn't accidentally cut anything more than intended.

No cutting required.

 

[mikem]

Although, in the video he doesn't cut his own attachment, he's on a strop around the pole, which is held in place by him pushing back against it. When he cuts the dummy's line, the shift in weight drags him inwards, so the strop disengages & everything heads down to ground.

 

[Mark Wright]

Although, in the video he doesn't cut his own attachment, he's on a strop around the pole, which is held in place by him pushing back against it. When he cuts the dummy's line, the shift in weight drags him inwards, so the strop disengages & everything heads down to ground.

In the video example, the rescuer introduces an unnecessary dynamic event by cutting the casualty's lanyard without ensuring the lowering rope is secure, resulting in dropping the casualty and subsequently causing his own attachment system to fail catastrophically with the potential for a multiple fatality.

https://www.lyonequipment.com/473/products/lyon-emergency-rope-cutter.aspx

If you do need to cut through a rope there's an argument for using something like the above instead of a knife as it cuts through a kernmantel rope in a more gradual fashion, rather than a sudden shock. The rope needs to be in tension for them to work effectively though. I've got one I made out of length of my old paraglider lines.

Mark



 

 

[mikem]

Not just the lowering rope - he is off to one side, allowing the load to pull him off balance, & strop is way too low (presumably below the casualty's attachment), so not remotely supporting him against pull.

 

[Mike Hopley]

I'd say be very, very careful using knives around safety ropes -- but do use them if they are the best option in the situation.

As Mark said, definitely cut away from yourself and away from the casualty. All slack should be taken up: there should be almost no movement of anyone or anything when the rope is cut. Cut calmly and gradually, not in a panic. Make sure you are cutting the right rope.

With any pickoff, especially rope-cutting ones, use backup precautions. Put a jammer on the rope well above the area you are wielding the knife, as an extra safety. Connect yourself to the casualty in such a way that you can definitely extract yourself from the situation if it goes wrong -- that applies to any pick-off method.

Yes, that means if you bungle a pick-off, you might possibly need to cut them loose. One death is better than two. Always have a way out.

Consider alternatives like a counterbalance pick-off on the long cowstail or footloop. All methods are difficult and require a lot of practice, and may never be used. Improvising a pick-off is likely to be a disaster. Study a good instructional book like the French Caving Technical Guide (Alpine Caving Techniques is somewhat outdated here).

Practise in a safe, relaxed environment with other people around to help, and ways to get down if you get stuck. If your mates are yelling "cut the damn rope Goob! Hurry up!", then they are morons and should not be allowed anywhere near this kind of practice.