Which Pulley?

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Simon Westgarth
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Re: Which Pulley?

Post by Simon Westgarth »

Mark Dixon wrote:I used a figure of 8 on doubled up end of my throwline as when I was fishing for Sams boat over the side of Newbridge I couldnt see thegrab handle with the bag in the way, so used the other end. That way I could attach the clip 15ft below me.
I havent a photo but will try and sort one out sometime, but I'll explain and maybe you might understand it.
1. put end of throwline through rescue pt.
2. attach sling to tree with caribiner on
3.feed end of rope through caribiner.
4.feed end of rope through caribiner on end of throw line.
5. pull towards tree.
6. When bag reaches convenient place keeping all tight pull main line up while bag goes back towards boat.
7. pull towards tree until boat free or where you want it to be
This is identical to having bag attached to boat, caribiner / sling at tree then prussic/caribiner and pulley to create mechanical advantage.
Tried and tested by top level 5 coach and works a treat. Hope this helps.
This is called a roving 4:1, which is an internal 4:1 system and all the rave with a certain ilk of provider. But without the pulleys you lose 40% per caribiner / contact point, so with 3 contact points that's really a maximum of 2.8:1. Plus the roving 4:1 means you need to feed the end of the throwbag through the grab loop, which is kinda mad, as it's both rope hungry and it would mean getting to the boat that is pinned in the first place and returning to shore to start the rescue. Your possible exception of dangling a weighted line of a bridge, to thread the rope through, clearly worked in that situation, but experience would suggest it's a very rare option.

Beyond the realms of a small group of diehard BCU WWS&R Provider's, the classic roving 4:1 is not at all used. Mainly because, within this grouping, they were determined to have a mechanical advantage system that does not use prusiks & pulleys on the Basic WWS&R course. In most boat pinning, you would try to get a rope attached to the boat, and pull, and then try a vector pull. After which you are highly unlikely to venture back out to the boat, to un clip the throwbag to then feed it through the caribiner and throw the throw bag back ashore, it's pretty impractical, time consuming and there are better more effective options. Other options where you could use an internal 4:1 system, is where you simply loop the rope several times around the spine of the bank end binder after attaching the line to the boat. And then set up a PigRig as above, simple.

Most river professionals the world over prefer external systems to internal ones though, simply because you can attach another line ti the pinned boat/raft, and set your initial rigging on that, without losing the tension from the first rigging set up.

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Re: Which Pulley?

Post by Mark Dixon »

There are lots of different scenarios, as you said dangling a caribiner off a bridge is a rare occurance yet it worked on that occasion. On the West a couple weeks ago where a boat was stuck in a tree it was reachable but we could not pull it up, but could reach it easily from a big branch, its not one I plan on using much and prefer clipping up, but you asked me how to do it with 2 crabs a sling and throwline and I merely answered your question.
If it works surely its better to use the quickest and simplest way to get the job done?

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Re: Which Pulley?

Post by Simon Westgarth »

Mark Dixon wrote:If it works surely its better to use the quickest and simplest way to get the job done?
All that matter's is it works.

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Re: Which Pulley?

Post by Mark Dixon »

http://www.flickr.com/photos/72747745@N03/8345548072/
As promised a photo of quick rescue set up with 2 caribiners, 1 rope and a sling, its a bit crude as I set it up in garage.

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Re: Which Pulley?

Post by Simon Westgarth »

Mark Dixon wrote:http://www.flickr.com/photos/72747745@N03/8345548072/
As promised a photo of quick rescue set up with 2 caribiners, 1 rope and a sling, its a bit crude as I set it up in garage.
Yes the roving 4:1, try and do it with the boat 10m away......

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Re: Which Pulley?

Post by Adrian Cooper »

When the rope running through the grap handle slides across to the edge, doesn't it jam between the handle and the boat at a pinch point?

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Re: Which Pulley?

Post by Chalky723 »

Out of interest, are there diagrams/guides for any of these around? I'm looking to do the WWSR later on this year but would be interested to see different solutions etc. before then...

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Re: Which Pulley?

Post by Simon Westgarth »

Image

Get it here or at any good kayak shop.

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Re: Which Pulley?

Post by Mark Dixon »

Before dissing it go and try it. I have

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Re: Which Pulley?

Post by Wilf »

Against my better judgement, I shall enter this debate. No doubt a certain Scottish gentleman will be chuckling to himself wherever he is today. It all seems a bit "Right or Wrong". I don't see it lake that at all.

The roving technique has been used for a while now (at least 5 years) and does work, but has its limitations.

There is not much point in teaching it when this system does the same thing.
Image

The main point here to remember is. DO NOT set up a roving system directly on the boat. It is better to attach a line (with bag if you like) directly at its end to the boat. The world is then your oyster. Use the line as an extender, then set up whatever system you like.

The sling technique shown is essentially the same roving system and the prussick allows it to be reset - nice. As always, to some who go on a BCU WW Safety course, the prussick is a bridge too far (it may be the first experience they have of using coils of rope of any type) and they will be on overload by the end of a weekend. Simple is good.

My points?
1. Alan (OP) no need for pulleys in general.
2. When setting up a recovery system, always try to attach a rope to the boat at its end (ie not roving directly to the boat)
3.The roving system does work, but has its limitations
4. The roving sling works very well.
5. There are many types of people who go on BCU courses, those who enjoy discussing the benefits of a clove hitch rather than an overhand not will not bat an eyelid at the introduction to a prussick, but those who are new to outdoor activities involving ropes will, on a weekend course, find it difficult to remember.

Thanks for the post Alan and Mark I'm glad you have enjoyed your course with whoever it was.
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Re: Which Pulley?

Post by Simon Westgarth »

Mark Dixon wrote:Before dissing it go and try it. I have
If this is aimed at me?

Well I have tried it, one would hope so given my career.

It's cons:
  • It's massively rope hungry, so limited in application.
    Kinda pointless to go out to the boat to loop the rope through the grab handle and come back to shore.
    Needs a crab on the boat and a pulley's on each crab to work effectively
It's pros:
  • Uses less kit
    Can be reset quickly, once you initially pulled in the throwbag
In essence you understand the pig rig, as it's complexity is similar to the roving 4:1. Simply attach a line to the rope, take it to the shore, then add the pigrig on a separate system, and if you use a tape instead of a rope on the separate system, there is no need for pulleys.

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Re: Which Pulley?

Post by Mark Dixon »

Simon its quick and easy and has its place, if a boat is 10m away then another method would be used, if its 5m away then bang! 1minute and your set up, for me its a no brainer.

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Re: Which Pulley?

Post by Chalky723 »

Simon Westgarth wrote:Image

Get it here or at any good kayak shop.

Thanks Simon, I'll get a copy.

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Re: Which Pulley?

Post by tobym »

Simon, in your post here http://www.unsponsored.co.uk/press/?p=401 you mention you wear a second Palm rescue tape sling tied round the waist, under the outer spraydeck cover, for boat towing, how would you recomend safely attaching this to a boat, and still being able to release, if snagged?. 'Scuse my ignorance, I'm pretty new to paddling.
thanks

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Re: Which Pulley?

Post by morsey »

Simon doesn't say the tape is tied around his waist. He says it is a tied tape, that is carried under the waist deck closure.

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Re: Which Pulley?

Post by Rhod »

I think what Mark is getting at is that is anything quick and easy that works, does the job (as we all agree).

I would add, direction is often more important than force, you can pull it as hard as you want, but if it is in the wrong direction because you are fixated on finding a tree to use, the boat is going nowhere. Most pins can be removed by either pulling it, pulling it harder with a couple of people, vectoring the line, lifting the back of the boat by hand, or pushing it.

The advantage of the sling system is a smart arse can set it up, with enough time for thought about direction, while the group are trying other options. It does not require re-setting the line after initial attempts, or setting up a system with ma in mind initially. One person can set this up independantly with the kit in their ba pocket, allowing the group to multi-task. Anything that works quickly is fine surely, the more methods we know the more addptive we can be.
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Re: Which Pulley?

Post by garya »

tobym wrote:Simon, in your post here http://www.unsponsored.co.uk/press/?p=401 you mention you wear a second Palm rescue tape sling tied round the waist, under the outer spraydeck cover, for boat towing, how would you recomend safely attaching this to a boat, and still being able to release, if snagged?. 'Scuse my ignorance, I'm pretty new to paddling.
thanks

The tape is tied in a loop and a carabiner is attached.

When towing you clip the carabiner to the boat and put one arm through the tape loop. you then paddle away and tow the boat from your shoulder. Should you need to realease the tow you simply take your had off your paddle and shrug the tape loop off your arm freeing you to paddle away.

To carry the tape and crab just fold it up a couple of time into a short 2.5 foot length. Tuck it under the the front of outer tube of your cag where it goes over your spray skirt, Leave a small finger sized pice of tape expose if you want so you can quickly pull it out when you need it... should it snag on anything whne carried like this which is unlikely the tape will just pullout and leave you free..

!!!!!! NEVER Wrap the tape around your whole body or clip it around your body with a crab, this creates a deadly snag hazard !!!!

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Last edited by garya on Fri Jan 04, 2013 11:54 am, edited 1 time in total.

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Re: Which Pulley?

Post by tobym »

Sorry, my mistake, any reason why this has to be tied tape and not a stitched sling, if it is not attached to you?

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Re: Which Pulley?

Post by garya »

Rhod wrote:I think what Mark is getting at is that is anything quick and easy that works, does the job (as we all agree).

I would add, direction is often more important than force, you can pull it as hard as you want, but if it is in the wrong direction because you are fixated on finding a tree to use, the boat is going nowhere. Most pins can be removed by either pulling it, pulling it harder with a couple of people, vectoring the line, lifting the back of the boat by hand, or pushing it.

The advantage of the sling system is a smart arse can set it up, with enough time for thought about direction, while the group are trying other options. It does not require re-setting the line after initial attempts, or setting up a system with ma in mind initially. One person can set this up independantly with the kit in their ba pocket, allowing the group to multi-task. Anything that works quickly is fine surely, the more methods we know the more addptive we can be.
This is absolutly right ... ;-)

That is why I like the three step idea.. It break things down into smaller tasks making it simpler and is a progressive approach..

1 line on boat and pull (everyone can do this)
2 set up anchor (no knot with spare bag or sling arounnd somthing solid, fairly easy)
3 use external or internal MA depending on situation ( the only bit that needs some practice )

These step can be done in sequenence or paralell depending on how big your group is.

Gary A
Last edited by garya on Fri Jan 04, 2013 12:17 pm, edited 1 time in total.

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Re: Which Pulley?

Post by garya »

tobym wrote:Sorry, my mistake, any reason why this has to be tied tape and not a stitched sling, if it is not attached to you?
Tied tape is only tied together to make a loop. This makes it more flexable to use in a rescue as you can untie it to thread it through somthing or use in an MA system. With a sewn loop you can't always do this.


To be honest I carry a 5meter unsewn sling and screw gate crab in my BA pocket, and a shorter 240 sewn nylon sling and wire gate crab for towing only under my cag.

I tow stuff a lot as I am usually working with beginners on lower grades. I find the wire gate easier to handle and quicker to clip to things. The 240 size sling brings the towed boat in a big closer making it easier to control the direction when towing it, I find the 5 meter tape loop just a bit too long for this.

In an emergancy if I needed and extra unsewn sling I would cut the looped one open next to the stiching.

Gary A

.... ps. I think the Petzl Fixe is the best pulley ... ;-)

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Re: Which Pulley?

Post by Dougie Shannon »

Creating mechanical advantage in order to recover equipment can be useful; more so with canoes and rafts than kayaks, but on occasion it is required with kayaks. It's a shame this thread has become a bit of a debate on which system is the most useful because in my experience all of the systems, so far discussed, have pros and cons and more importantly none of them can do everything
From the discussion so far there seems to be consensus that the 4:1 system is the way ahead, either set up with a 5m sling or with a throwline. I would agree with this, but don’t completely discount the “Z” drag. Simon is correct that a certain amount of advantage is lost due to friction although the figures he quotes will only be valid for specific ropes, diameters of rope and karabiners. What he doesn’t point out is that the same applies to slings running over crabs, so friction robs us of some of that advantage whatever system we use, although it does seem to be slightly less with slings, and I suspect there are some advantages to be gained from the lack of stretch in slings as opposed to polyprop rope (I’ll come back to that in a moment).
Using pulleys in a rope system uses less friction than slings running over crabs, therefor more efficient. The pulleys need to be in the correct place though, if you’ve set the system so that the person pulling on the system is pulling away from the river then the pulleys go at the boat and the bag, if you’re pulling towards the river then they go at the anchor and the bag. Although to further complicate this, it is sometimes useful to put pulleys at all 3 points, loading the system while holding the rope running through the pulley that you do not want to move, releasing your hold on this pulley allows resetting of the system while still under load therefor dealing with the “stretch” issue (see next paragraph), this was suggested to me by Tom Sibbald at a recent providers update and it seemed to work really well. The amount of benefit from use of pulleys depends on the pulleys. Pulleys with large wheels and good bearing are better, but are cumbersome to carry for the amount of use they are likely to receive and don’t like being exposed to water on a regular basis so, in my opinion, are not that useful. The compromise of small wheel and nylon bush bearing reduces friction significantly are reasonably easy to carry and don’t mind getting wet (I hope that answers big henry’s original question) oh and bye the way Henry, there is not generally a need for prussic friendly pulleys unless you are working against gravity over longer distances than approx. 5m (with a 15m rope), and even then only if you are short of knowledgeable help, so I don’t think they justify the extra cost.
Anyway, back to mechanical advantage. If you use a sling and the rope you are attached to is of significant length, say 15m or so, the amount of stretch in a polyprop rope (approx 10% at 20% of the breaking load) is 1.5m. That is the maximum amount of movement that can be created using the sling system, therefor you may need to reset it several times using a locking knot like a friction hitch (as shown in Simon’s picture)or an alpine clutch before you take all the stretch out of the system and start applying significant force to the boat. This is a footer and it’s much easier just to create a bigger system using a rope. Even this system needs reset sometimes to accommodate stretch, but as mentioned above introducing a 3rd pulley accommodates this easily. Another disadvantage of the sling system is that it can be so close to the anchor that it can be difficult to pull at the correct angle because the anchor gets in the way (see Simon’s picture for an example) this makes a big difference. This can be resolved by inverting the system so that you are pulling towards the river; mind you don’t fall in the river when it all starts moving though.
The rope system has it’s disadvantages as well – if the kit is more than approx. 4m from the anchor and you are using 15m ropes, you’re gonna need more rope.
As you can see it’s complicated (and I’ve not mentioned the pros and cons of the “Z” drag, use of mechanical devices, prussics as opposed to clove hitch, the dilemmas around hoisting etc etc ). Including the 4:1 system in the WWS&R syllabus was definitely a compromise, but we were trying to find a system that paddlers not familiar with rope systems could remember a year after they had been on the training, and which could be used in most situations.
I hate to advertise, but all of these systems are included in the recently released White Water Safety DVD. Chapter 10 “Recovering Kit” shows it all in HD detail. Downloadable version coming very soon. Follow the link at the bottom of the page.

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Re: Which Pulley?

Post by Simon Westgarth »

Dougie Shannon wrote:Creating mechanical advantage in order to recover equipment can be useful; more so with canoes and rafts than kayaks, but on occasion it is required with kayaks. It's a shame this thread has become a bit of a debate on which system is the most useful because in my experience all of the systems, so far discussed, have pros and cons and more importantly none of them can do everything
Great reply. The mantra of all rescue is all that maters is it works, still there is room for debate about effectiveness of some systems over others. The much over looked Z drag, is worth knowing and practising, as most paddlers especially from a far will use this system. Yet most internal systems have obvious limitations, of committing most of the kit on that specific solution. I do not like the roving 4:1 as its a terrible compromise to avoid the obvious use of prusiks.

In understanding the need to keep matters simple, the work flow for getting a boat off a pin should be straight forward, clip, pull, anchor, vector pull and then mechanical advantage. If you choose to undo the anchor to set a Z drag or worst still head back out the boat after the vector pull did not work, this is disruptive, to adding a single prusik and setting the pigrig.

There are of course other options and opinions on the matter.

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Re: Which Pulley?

Post by Mark Dixon »

Dougie Shannon wrote:Creating mechanical advantage in order to recover equipment can be useful; more so with canoes and rafts than kayaks, but on occasion it is required with kayaks. It's a shame this thread has become a bit of a debate on which system is the most useful because in my experience all of the systems, so far discussed, have pros and cons and more importantly none of them can do everything
From the discussion so far there seems to be consensus that the 4:1 system is the way ahead, either set up with a 5m sling or with a throwline. I would agree with this, but don’t completely discount the “Z” drag. Simon is correct that a certain amount of advantage is lost due to friction although the figures he quotes will only be valid for specific ropes, diameters of rope and karabiners. What he doesn’t point out is that the same applies to slings running over crabs, so friction robs us of some of that advantage whatever system we use, although it does seem to be slightly less with slings, and I suspect there are some advantages to be gained from the lack of stretch in slings as opposed to polyprop rope (I’ll come back to that in a moment).
Using pulleys in a rope system uses less friction than slings running over crabs, therefor more efficient. The pulleys need to be in the correct place though, if you’ve set the system so that the person pulling on the system is pulling away from the river then the pulleys go at the boat and the bag, if you’re pulling towards the river then they go at the anchor and the bag. Although to further complicate this, it is sometimes useful to put pulleys at all 3 points, loading the system while holding the rope running through the pulley that you do not want to move, releasing your hold on this pulley allows resetting of the system while still under load therefor dealing with the “stretch” issue (see next paragraph), this was suggested to me by Tom Sibbald at a recent providers update and it seemed to work really well. The amount of benefit from use of pulleys depends on the pulleys. Pulleys with large wheels and good bearing are better, but are cumbersome to carry for the amount of use they are likely to receive and don’t like being exposed to water on a regular basis so, in my opinion, are not that useful. The compromise of small wheel and nylon bush bearing reduces friction significantly are reasonably easy to carry and don’t mind getting wet (I hope that answers big henry’s original question) oh and bye the way Henry, there is not generally a need for prussic friendly pulleys unless you are working against gravity over longer distances than approx. 5m (with a 15m rope), and even then only if you are short of knowledgeable help, so I don’t think they justify the extra cost.
Anyway, back to mechanical advantage. If you use a sling and the rope you are attached to is of significant length, say 15m or so, the amount of stretch in a polyprop rope (approx 10% at 20% of the breaking load) is 1.5m. That is the maximum amount of movement that can be created using the sling system, therefor you may need to reset it several times using a locking knot like a friction hitch (as shown in Simon’s picture)or an alpine clutch before you take all the stretch out of the system and start applying significant force to the boat. This is a footer and it’s much easier just to create a bigger system using a rope. Even this system needs reset sometimes to accommodate stretch, but as mentioned above introducing a 3rd pulley accommodates this easily. Another disadvantage of the sling system is that it can be so close to the anchor that it can be difficult to pull at the correct angle because the anchor gets in the way (see Simon’s picture for an example) this makes a big difference. This can be resolved by inverting the system so that you are pulling towards the river; mind you don’t fall in the river when it all starts moving though.
The rope system has it’s disadvantages as well – if the kit is more than approx. 4m from the anchor and you are using 15m ropes, you’re gonna need more rope.
As you can see it’s complicated (and I’ve not mentioned the pros and cons of the “Z” drag, use of mechanical devices, prussics as opposed to clove hitch, the dilemmas around hoisting etc etc ). Including the 4:1 system in the WWS&R syllabus was definitely a compromise, but we were trying to find a system that paddlers not familiar with rope systems could remember a year after they had been on the training, and which could be used in most situations.
I hate to advertise, but all of these systems are included in the recently released White Water Safety DVD. Chapter 10 “Recovering Kit” shows it all in HD detail. Downloadable version coming very soon. Follow the link at the bottom of the page.
Thanks Dougie,
thats useful information, I prefer the Z drag set up and toyed with the Prussik brake by the anchor but when practising it went over the crab and snagged the wrong side messing it up, would I need to put a pulley on the anchor to stop that or maybe 1 less loop on the prussik or could it just be our rescue object was not full of water so a bit loose? (I only have 1 pulley though).
Thanks,
Mark

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Re: Which Pulley?

Post by TechnoEngineer »

Excuse my ignorance, but what exactly do you mean by the term "roving"?
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Re: Which Pulley?

Post by Scots_Charles_River »

Look at the pics, it's on a loop not actually clipped on the extender - I think.

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Re: Which Pulley?

Post by Adrian Cooper »

Answer jargon with more jargon?

What is an extender?

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Re: Which Pulley?

Post by Dougie Shannon »

Mark Dixon wrote: Thanks Dougie,
thats useful information, I prefer the Z drag set up and toyed with the Prussik brake by the anchor but when practising it went over the crab and snagged the wrong side messing it up, would I need to put a pulley on the anchor to stop that or maybe 1 less loop on the prussik or could it just be our rescue object was not full of water so a bit loose? (I only have 1 pulley though).
Thanks,
Mark
Mark
You should only need to place a prussic at the anchor if you are working against gravity. The idea comes from the systems used to haul climbers that have fallen into a cravasse or need hauled up a cliff for some reason. In boat recovery we are not normally working against gravity so when you need to reset the system just release the pressure and slide the other prussic back along the rope to reset. Having said that, if you find yourself needing to use one it needs to be looked after, as you've discovered. Either a person needs to manage it or a pulley that is designed to catch the prussic (usually referred to as a prussic minded pulley) needs to be used.

Hope that is usefull, but please remember that most throwlines are not suitable for hauling people where if the system fails the person will fall (normally ok to catch a slide down a muddy bank at most). There are some throwlines that can be used in this way, and there are a few more on the way, but they are few and far between at the moment and currently much more expensive than normall polyprop lines.

Dougie

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Re: Which Pulley?

Post by Dougie Shannon »

TechnoEngineer wrote:Excuse my ignorance, but what exactly do you mean by the term "roving"?
I wouldn't get too bogged down in the name. It's a term we started using in the WWS&R working group to differentiate it from another 4:1 system that had previously been advocated, where there is another knot in it that's not really needed and stops the system being easily reset (see the piggy back system shown in Franco's book).

If you're not sure about the system think about the way most of us use roof rack straps to tie boats on, that's a roving 4:1


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Re: Which Pulley?

Post by Scots_Charles_River »

Adrian Cooper wrote:Answer jargon with more jargon?

What is an extender?
Wilf mentions it and shows one in his pic, it's a sling that is connected to he boat strong point. Comes from the climbing world. It's the RHS spectra green sling, boat out of shot.
Wilf wrote:Against my better judgement, I shall enter this debate. No doubt a certain Scottish gentleman will be chuckling to himself wherever he is today. It all seems a bit "Right or Wrong". I don't see it lake that at all.

The roving technique has been used for a while now (at least 5 years) and does work, but has its limitations.

There is not much point in teaching it when this system does the same thing.
Image

The main point here to remember is. DO NOT set up a roving system directly on the boat. It is better to attach a line (with bag if you like) directly at its end to the boat. The world is then your oyster. Use the line as an extender, then set up whatever system you like.

The sling technique shown is essentially the same roving system and the prussick allows it to be reset - nice. As always, to some who go on a BCU WW Safety course, the prussick is a bridge too far (it may be the first experience they have of using coils of rope of any type) and they will be on overload by the end of a weekend. Simple is good.

My points?
1. Alan (OP) no need for pulleys in general.
2. When setting up a recovery system, always try to attach a rope to the boat at its end (ie not roving directly to the boat)
3.The roving system does work, but has its limitations
4. The roving sling works very well.
5. There are many types of people who go on BCU courses, those who enjoy discussing the benefits of a clove hitch rather than an overhand not will not bat an eyelid at the introduction to a prussick, but those who are new to outdoor activities involving ropes will, on a weekend course, find it difficult to remember.

Thanks for the post Alan and Mark I'm glad you have enjoyed your course with whoever it was.

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Re: Which Pulley?

Post by Adrian Cooper »

RHS = Rolled hollow section

Surely the green sling is a tape prussik.

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