Braking descenders and backup

TheGrave

New member
Hi,

I recently graduated the caving course in Bulgaria and feel fairly confident using a Petzl Simple descender. However it has some limitations which you are all familiar with and descending fast or muddy ropes is no joy with this gear.

Some background for what I need to deal with - short drops (rarely above 30-40m), narrow profile, lots of mud, lots of re-belays due to the morphology, ropes mostly in the range 9-11mm with 10 and 10.5mm most common. Racks not popular around here as everybody screams they twist the rope so I have to exclude them as an option (at least for the moment). I personally don't think that's the case with modern high quality 6-bar steel racks based on what I read but they are an overkill for our caves and not sure how suitable for the tight vertical restrictions.

I read quite some articles/reviews by cavers on single and double brake descenders but the problem is they are on outdated gear. Here is what I found interesting on the market as of today:

SRTE (now Capital Safety) regarded by many as the Mercedes of the descenders have stopped offering a double brake in their most popular model and now has a single brake:

http://www.capitalsafety.com/aunzadmin/Pages/ProductDetails.aspx?prodId=3276

They have this gadget now which looks questionable at best for muddy pits with all these wholes that will get filled very quickly and probably become inoperable so I'd count it out unless somebody shares a different experience:

http://www.capitalsafety.com/en-us/Pages/ProductDetails.aspx?prodId=3273&visitID=016269e778c7000d40881ca0efa90107c00aa07400818

The original Anthron DSD was quite superior outside caves but got repeatedly stuck when mud was introduced. Same story with the Plus?

https://www.anthron.si/index.php/dsd-plus.html

Camp have a product on which I can't find anything as well:

https://www.camp-usa.com/safety/product/i-block-evo/

This one looks promising too:

https://www.iscwales.com/Products/Descenders/RP810-A-B-Descender/18924/

I haven't made my mind on single or double brake so I'm open to suggestions on both types. Also, I'm trying to select a (mechanically) simple device cause if, God forbids, I get knocked unconscious somebody else should be able to easily take it off-rope without sending me down the pit :LOL: That and cooperation with mud, too :)

Now, the way we use Petzl Simple around here is quite common I guess - your upper ascender attached above it in semi-open state and controlled with your left hand, your right hand holding the rope tight to your thigh to control descending speed/stop. I found some stuff about backup techniques for braking descenders but I'm not sure how usable they would be in our narrow pits as they involve the usage of various knots above/below the descender which could complicate passing restrictions. Is this the common way you backup a single or double brake descender? How about gadgets like Petzl ASAP (Lock)? I've heard people in Bulgaria use a Petzl Shunt with Petzl Stop (the most popular braking descender around here due to economic reasons) in a similar fashion on a single rope:

https://youtu.be/7wEHSvEjVMs?t=69

I read this post as well before someone mentions it :)

http://storrick.cnc.net/VerticalDevicesPage/Misc/RappelSafetyPost.html

Also, borrowing to test on a tree/wall not an option at the moment due to vacation season and the few people having anything but a Petzl Stop are untraceable :)

Appreciating any input.
 

Chocolate fireguard

Active member
I think TheGrave is asking what we use to back up a simple.
The people I know in Britain who use a simple don't have any safety backup, and the ones who worry about being knocked unconscious mostly use a stop or sometimes one of the more modern alternatives.
I suppose some might use a shunt as backup to a simple, as once it was used to backup a rack (but not commonly in my experience).

The backup method involving the upper ascender is not one that I have heard of being used, although from what TheGrave says it is common in Bulgaria.
If you accidentally allow the ascender to engage then getting unhung might be a bit of a faff.
 

Mark Wright

Active member
I do have quite a bit of experience with all the devices you mention.

Firstly the Sala Stop Descender and the SRTE Noworries descenders. These were designed primarily for an industrial application and whilst they both do everything it says on the box they are quite cumbersome and the SRTE device is very very very heavy and some of the moving parts are very likely to get clogged up with mud.

The DSD device is one of the most complicated to load a rope into and isn't that smooth a descent when compared to other devices.

The I-Block Evo is the same as the DSD but with a different name on the front.

The ISC A-B device has been around for years and has had a number of different names. Its first incarnation was the SAR Scarab, later changed to the SAR Sarab. ISC manufacture them for a number of different companies.

I was involved to a small extent in the development of this device, carrying out long descent trials as part of the requirement for determining the maximum descent distances before they get too hot. If a device claims it can be used on, e.g. 200m decent with a 140kg load then this test would have been carried out with a 140kg test weight with a non-stop 1m / second descent rate for 200m.

If you are looking for a descender device that is good for using as a locking rescue pulley then I'm not aware of anything better. Unfortunately it isn't a very good descender.

During one of the recent International Berger expeditions we had some Bulgarians join the trip and they used a toothed ascender above their Stop / Simple descenders. We had to replace most of the ropes in the entrance series due to the sheaths being seriously damaged due to this technique being used.

If you could be sure you would let go of the Shunt if you lost control of the descent then this could be a useful method, however, it is most unlikely you would let go. You would more likely squeeze the Shunt or its towing cord even tighter and never let go.

Using a Shunt as a back-up device as is being shown on the videos is generally considered to be very dangerous. Most of the fatalities in the rope access industry have been down to not letting go of the device.

I've never heard of a Rack twisting the rope but it has been over 30 years since i've had a go on one.

The ASAP and ASAP Lock devices were again designed for industrial use. I wouldn't recommend using either devices in a muddy cave environment due to the many moving parts. They are also very expensive. ASAPs are the only devices that can't be overridden by the user, i.e. they will still work if you lose control of the descent and grab them or grab the rope above them.

If a Petzl Simple is a bit quick on new and/or thin rope then simply use a breaking carabiner.

Personally I would go for a Petzl Stop every time. If you aren't in a rush there will soon be a new version of the Petzl Stop on the market, I'm currently trialling a prototype.

Mark
 

Ian Ball

Well-known member
Mark Wright said:
Personally I would go for a Petzl Stop every time. If you aren't in a rush there will soon be a new version of the Petzl Stop on the market, I'm currently trialling a prototype.

Mark


Ooo interesting!
 

nearlywhite

Active member
tamarmole said:
Petzl Stop.

*Vomits*

In all seriousness I don't see the issues with just using a simple normally - stops have just as many safety issues i.e. clutch and plummet vs rockfall. If it's properly much then a long frame micro rack will cope (as will a simple - I've only had one situation where it was so muddy I opted for a figure of 8 and it was the only workable solution).

PS Racks don't twist ropes.

 

pwhole

Well-known member
Outside descenders. the Raumer Handy braking carabiner is the cheapest way of ensuring a trouble-free descent, as its top slot is so small that it will stop any rope simply by lifting the tail end above 90?. On a fat or very dirty rope you can reverse it and use the wider end. They've gone up a bit recently (probably Brexit), but at ?21 they're bomber, and last for years. I use a Kong Banana (with stainless bobbins) with a Handy, and everything is sweet.
 

tamarmole

Active member
nearlywhite said:
tamarmole said:
Petzl Stop.

*Vomits*

In all seriousness I don't see the issues with just using a simple normally - stops have just as many safety issues i.e. clutch and plummet vs rockfall. If it's properly much then a long frame micro rack will cope (as will a simple - I've only had one situation where it was so muddy I opted for a figure of 8 and it was the only workable solution).

PS Racks don't twist ropes.

My descender of choice is a homemade , stainless, 4 bar (with hyperbar) micro rack.  They are not for everybody; the OP appears to have been looking for a recommendation for a braking descender.  My thinking is that the Petzl Stop, issues aside, has pretty much been the go to braking descender since the year dot for good reasons.
 

nearlywhite

Active member
Fair enough, I perhaps thought that given they were considering racks that simples and racks were included in braking descenders - I mean what's a non braking descender? But yeah I see the point with handled - there's no other real choice.
 

TheGrave

New member
Chocolate fireguard said:
If you accidentally allow the ascender to engage then getting unhung might be a bit of a faff.

It's a pain in the ass, indeed. Especially when you reach a re-belay, clip your short cowstail, and forget to move down the upper ascender so it gets fully loaded. It's an experience you remember for a lifetime:)

pwhole said:
Outside descenders. the Raumer Handy braking carabiner is the cheapest way of ensuring a trouble-free descent, as its top slot is so small that it will stop any rope simply by lifting the tail end above 90?.

It's probably the best braking carabiner on the market but will it stop you from falling if it takes a serious hit?
Mark Wright said:
If you are looking for a descender device that is good for using as a locking rescue pulley then I'm not aware of anything better. Unfortunately it isn't a very good descender.

During one of the recent International Berger expeditions we had some Bulgarians join the trip and they used a toothed ascender above their Stop / Simple descenders. We had to replace most of the ropes in the entrance series due to the sheaths being seriously damaged due to this technique being used.

If you could be sure you would let go of the Shunt if you lost control of the descent then this could be a useful method, however, it is most unlikely you would let go. You would more likely squeeze the Shunt or its towing cord even tighter and never let go.

I've never heard of a Rack twisting the rope but it has been over 30 years since i've had a go on one.

If a Petzl Simple is a bit quick on new and/or thin rope then simply use a breaking carabiner.

Personally I would go for a Petzl Stop every time. If you aren't in a rush there will soon be a new version of the Petzl Stop on the market, I'm currently trialling a prototype.

Mark

First - much appreciating the time you spent writing this post and sharing your experience. I'm sure it will be quite useful for many fellow cavers.

Now on the points:

Locking rescue pulley is something like this I guess?

https://www.iscwales.com/Products/Progress-Capture-Pulleys/RP704-One-way-Locking-Single-Progress-Capture-Pulley/3303/

I assume this is used in rescue operations when you need to lift somebody below you?

Single and double break descenders can replace an upper ascender as well as far as I'm aware.

I'm surprised ropes in Berger got damaged because if you use this technique properly and you are an experienced caver the upper ascender should never be engaged and fully loaded during a descend. I can only imagine rope diameter too big for the ascenders they had cause I highly doubt rookies would attempt a cave like Berger :)

Also, it's interesting how you can use a Stop with an upper ascender having in mind you need your left hand to press the lever and your right hand to control the speed of descent. As for a Simple I think it's good practice, especially for beginners. First time they taught us how to rappel with a Simple a huge icicle fell on my braking hand just after I unlocked the Simple and was about to descend. I managed to hold the rope despite the pain but I can't tell you how glad I was the upper ascender was attached. Can't imagine using a non-locking descender without some sort of a backup. Not to mention they tell us every 5 minutes we need to clipped on the rope in at least 2 points at all times from day one :)

This rope twisting story is repeated by many around here. So far I've seen only 1 guy using a (quite possibly) micro rack and he descended very quickly. Rope had no noticeable deformations. I guess it's one of those things somebody read somewhere and started repeating without checking himself first.

Petzl Simple we always use with a braking carabiner. As for the Stop all you guys are recommending I have a few things against it:
  • aluminum bobins - seen many of those quickly worn out
  • rated up to 100kg - I'm 85 bare naked. Put a caving suit on me, enough mud, and 2 caving bags I'm easily reaching this limit
  • It's Petzl. I'm sure you read all the recent stories of quickly worn out newer generations Petzl ascenders and descenders

Mentioning Scarab - there is another product on the market with the same name:

https://www.conterra-inc.com/products/scarab-rescue-tool

It looks interesting but I think it would take quite some time getting used to the way it should be operated properly.
 

Ian Ball

Well-known member
I've heard of Fig 8 descenders twisting rope, but the fact they can't be attached to the rope without being removed from your harness is what really counted against them in caving?

It's interesting TheGrave,  I can't think of an occasion I've seen a secondary system in use on a caving descent.
 

Fulk

Well-known member
I've heard of Fig 8 descenders twisting rope, but the fact they can't be attached to the rope without being removed from your harness is what really counted against them in caving?

Fig 8 descenders definitely twist rope (although racks don't; I've no idea where the notion that they do came from). As for your second point, I remember ages ago doing a through-trip in Swinsto Hole using a Fig 8 and dropping it down a pitch, so your second point is (in my opinion) a very valid one.
 

mikem

Well-known member
Fig 8 can be used without disconnecting, if it is clipped to harness the wrong way around then it can be threaded before switching it to the correct configuration...

Mike
 

Mark Wright

Active member
The Progress Capture Pulley is certainly one example of a locking pulley system. Whilst using a pulley, particularly a ball bearing pulley, and a toothed ascender is the most efficient method it doesn't allow you to lower a casualty without introducing an additional device. If you were to, e.g. half load a Petzl Stop, you would still achieve a good efficiency but would be able to easily lower a casualty if required. They won't show you that method on their instructions as it would never pass the EN341A standard in this configuration. Until the introduction of the Petzl I'D and later the Rig descenders, the industrial rope access industry used the method for many years without incident.  There weren't many real life rescues but the method was used extensively during training.

The nature of the damaged ropes in the Berger, which were 9mm, was a combination of descending too quickly and glazing the ropes and large chunks of sheath pulled out through 'safety ascenders' being used inefficiently. I watched them do it. There were hardly any ascents on the ropes before we had to change them out for something a bit thicker.

There are plenty of rookies visit the Berger, we are taking a few with us next week.

I think there are 20 Bulgarian cavers joining us down there this Sunday when our permit starts.

The caver I saw using the technique was actually using a Simple but you can easily turn a Stop into a Simple. You could of course abseil a bit and then move the ascender down.

If you had been using a Stop during your icicle incident you could have just let go of the tail rope and you wouldn't have gone anywhere, or if you did it would be relatively slowly.

I've heard all the arguments for learning SRT with a Simple but to me this is simply ridiculous. An auto locking device is definitely safer and when you get proficient at smooth descents in all conditions and thicknesses of rope then you can either clip a carabiner in the hole of your Stop to deactivate the auto lock mechanism or buy yourself a Simple.

Backing up any descender device on a single rope is most uncommon, except of course in Bulgaria.

Aluminium bobbins will wear out but at least a Stop only has one, unlike the Simple.

If you read the user information for the Stop it actually rates them for up to 200kg subject to additional breaking being employed and suitable and appropriate training.

The main reason the new generation of Petzl ascenders wore out quickly revealing sharp edges on the stainless wear plate was because cavers thought they knew better than the manufacturer and ignored the wear indicators. You can buy a 4mm version again now. I'm not aware of any Petzl descenders wearing out quickly.

I think the reason the SAR Scarab changed its name to Sarab was possibly because Conterra actually named their device first. 

Mark
 

Kenilworth

New member
Fulk said:
I've heard of Fig 8 descenders twisting rope, but the fact they can't be attached to the rope without being removed from your harness is what really counted against them in caving?

Fig 8 descenders definitely twist rope (although racks don't; I've no idea where the notion that they do came from). As for your second point, I remember ages ago doing a through-trip in Swinsto Hole using a Fig 8 and dropping it down a pitch, so your second point is (in my opinion) a very valid one.

Racks with a hyper-bar engaged do twist. Not as badly as 8s. It is very easy to use a fig8 without detaching.
 

mikem

Well-known member
The latest versions of the Grigri seem to be wearing much faster than the originals did, I wonder if the new stop will be made of the same grade of alloy?

Mike
 

andrewmcleod

Well-known member
I use a Petzl Rig for caving, which works happily enough. The old model (not the upcoming new model) is only rated for 10.5mm for 11.5mm rope, so it is entertaining that:
a) it works much better on 11mm rope than a Stop, with no problems descending, and
b) it works much better on 9mm rope than a Stop, actually stopping reliably!

I haven't had any problems with mud personally. I would not use any other industrial device though as all the ones I've looked at are too heavy/bulky/complicated/don't allow you to easily pull rope through/have an irritating 'safety' catch.

And putting a toothed ascender anywhere near a moving rope is a terrible idea, no matter how many people do it.
 

TheGrave

New member
Mark Wright said:
The main reason the new generation of Petzl ascenders wore out quickly revealing sharp edges on the stainless wear plate was because cavers thought they knew better than the manufacturer and ignored the wear indicators. You can buy a 4mm version again now. I'm not aware of any Petzl descenders wearing out quickly.

4mm - are you referring to the bobbin thickness? Not sure where you can find a different version of the Stop online, will be glad if you can point me to a one.

Btw, a couple of Facebook posts from worn out Stops (might require membership in groups called Cavers of Facebook and Crappy Caving):

Code:
https://www.facebook.com/groups/caversgroup/permalink/10155237096503639/
https://www.facebook.com/tony.canike/videos/10155637297321542/
 

Mark Wright

Active member
TheGrave said:
4mm - are you referring to the bobbin thickness? Not sure where you can find a different version of the Stop online, will be glad if you can point me to a one.

I was referring to the Petzl Croll ascenders wearing out quickly and Petzl now producing a 4mm thick body instead of the 3mm.

Mark
 
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