lightweight (and cheap) rap line

http://www.mountaingear.com/pages/product/product.asp/imanf/PMI/idesc/7+mm+Perlon+Cord+Accessory+Cord/Store/MG/item/614808/N/1049

is this too thin to use for raps? I would use it both in combination with a 60m single for full length raps but I would also like to be able to make 30 m raps without having to haul a half rope along. I'd be using a safety backup and extend the belay device. is this a stupid suicidal idea?

Be sure to buy it about 10% longer than your climbing rope. Climbing ropes will stretch when you are rappelling but a static rope will not.

Be careful not to rap over sharp rock edges with the smaller diameter rope.

sorry for the tangent, but what would be the best knot to tie in this case? I don't think I would use the edk.

would a 6 mill work? or the risk of getting cut be too great? dying really would put a big hole in my summer climbing plans.

I've used 8mm Mammut ProCord with my 9.6 dynamic and it worked pretty well. The once I've done it, it was <200' so I didn't have to worry about the stretchy dynamic vs low stretch static issue. I think besides the worry of severing/damaging your thin line would be is your rapp device rated for 6 or 7mm rope? Also the rate of feed is different and I think it might be a little awkward to control that big of difference between lines. just my $.02.

Phil Lauffen wrote:sorry for the tangent, but what would be the best knot to tie in this case? I don't think I would use the edk.

The double sheet bend is the best I know of for 2 different thickness ropes. The thinner line goes around a bite of the larger one. PM me if you would like some more instruction on it.

7mm and 6 mm are definetly strong enough to rap on. There are two issues to be concerned with.

1. Thinner cords are less cut/abrasion resistant. The thinner you go, the more susceptible the cord is to rubbing and sharp edge damage.

2. There will be les friction. Both of these would be FAST rides on an ATC. I'd recomment building in extra friction and using a back up.

You can mitigate the uneven feed speeds and risk of cutting the thinner cord on 60 meter raps by using the cordalette as a pull line rather than a rap line.

For you, its a question of what you're comfortable with. For what its worth, 7mm is the minimum accepted cord by the AMGA for rigging. Personally, I'd use an 8mm minimum; that is just the first diameter that feels like a rope to me.

Evan

I used one for a long time, back when 50 meters was the standard rope length. 7 mm cords tangle easily, abrade quickly and get caught in cracks more quickly than thicker ropes. I would also be a bit nervous about rapping on two strands of 7 mm, just because it would be such a fast ride.

I use a 6mm pull cord / tag line, what ever you want to call it, all the time. I setup a biner block at the top anchors and do a single line rappel off my main rope, and pull it with the 6mm one. Works like a champ.

With that being said, I am going to be switching over to a twin rope system and not using my tag line anymore.

Phil Lauffen wrote:sorry for the tangent, but what would be the best knot to tie in this case? I don't think I would use the edk.

A thread on the subject with pointers to previous threads.

Wheling wrote:The double sheet bend is the best I know of for 2 different thickness ropes.

Do you mean this one?

For me it would not be worth the stress of thinking about such a thin line while rapping. Back in the day people used to just used to trail another 10.5 for the other rap line. I dont like dealing with two ropes anymore than anyone else but on the way down it nice to know both ropes are the same strength. What if you pulled your main 60 and it got stuck out of reach. Would you lead up on the 7mm accsessory cord to untangle it?

saw a famous aid climber carrying around 200' of spectra webbing last year for the rap. it got him down.

I just make my second carry a normal old beater rope on their back. havent heard many complaints yet.

I use a 6mm x 65m length of Mammut Pro Cord as a pull line on raps. Single rope goes through anchor, figure eight on a bite, figure eight follow through the Pro Cord to the bite in the lead line. First rapper has biner block at the bite, when they reach lower rap station they pull snug on pull line and clip it to lower anchor, second rapper removes biner block (reduce chance of getting ropes stuck on pull), and raps on lead line only. Figure eight on bite is like stopper against rap rings, anchored pull line is back up in case rapping off biners. (6mm pro cord has 7.8 kN strength when new).

I keep the pull line in a stuff sack, with the lead end tied into a loop of webbing I sewed inside the bottom sack. The stuff sack has a main tie-in loop and this is clipped to the harness of the first rapper - as they descend, the cord feeds out of the bag. When both rappers are at lower anchor and ready to pull, one person focuses on pulling cord while the other focuses on smoothly re-stuffing the cord into the stuff sack. If the cord is just left to dangle or pancake on ledge, it will cluster guaranteed. Feed lead rope through next anchor (from the far end), and repeat process.

I only bring this setup for alpine routes where I need the option for emergency raps in case of storm, or when the descent only has a couple raps. Pro Cord is stronger than standard perlon for each given diameter, and the 6mm weighs just 21g/m, which makes for a 3 lb pull cord - light enough that you don't have to question "should I bring it, should I not."

brenta wrote: Do you mean this one?

Yes, and then back up both ends with a barrel knot/half'a double fisherman's. Its very strong and relatively easy to untie after loading.

Ditto the comment about using the thin line as a pull line - make sure you always thread the "real" climbing rope through the rap rings (or whatever you're rapping from) and then tie it to the thin line. If you ever lose control of the thin line, or if the thin line gets cut, the knot will (hopefully) jam against the rap ring and prevent you from decking.

Alternately, start climbing on doubles or twins... but that's another topic altogether.

Does anyone have any experience rappelling with 5.5mm Titan cord? Its a lot more expensive, but the high strength and cut resistance sure does give me a warm fuzzy feeling.

I've used 7mm cord for years, but its time to retire and replace mine.

Chris Sheridan wrote:Does anyone have any experience rappelling with 5.5mm Titan cord?

Ask Steve House on Thursday, I think that's what he uses. Probably still as a pull-line only.

I thought about the titan cord when I was deciding for my pull line. My main reason for steering away from it was how slippery it is, and what a nightmare it would be to have to rap on a section of it if my lead line got perma-stuck when pulling the lines (definitely not prusiking up on 5.5mm static) and I had to chop the titan cord and descend on the remnants.

Not that the 6mm Pro Cord I now have would be super easy as the only rap option, I just envision (perhaps foolishly) that it would be considerably easier than titan cord.

Optimally they'll get the twin ropes down to 7mm in the coming years, then I'll just have one of those in the bottom of the pack for raps. Dynamic and grippy... much better.

Chris Sheridan wrote:Does anyone have any experience rappelling with 5.5mm Titan cord? Its a lot more expensive, but the high strength and cut resistance sure does give me a warm fuzzy feeling.

I wouldn't rappel on a cord made from Dyneema. Very low melting point. Especially a thin cord, which would need to be rigged for more friction, hence, more friction will equal more heat.

Melts at 144 to 152C with a critical temp of 55C (when it starts to lose strength). That's not very high.

Another thing to keep in mind with using thinner diameter perlon for rappeling, is, its not designed for that. I've seen the sheath on some of these cords "pigtail" and shrug making the cord a mess to the point where it won't feed through an ATC. Would suck to get stuck on a thin rappel line.

Edit to add: another thing to consider for using thin perlon to rappel on, is, if need be, how would you either back it up or ascend it? You'd have to have a bit smaller Prusik cord to ascend and the margin with knots and safety starts to get a tad thin. House of cards? Maybe.

Pull cord? No problemo. Thin cord can be very hard to pull to retrieve though and if the sheath is rough, can really bite into your hands.

I use a pull cord all the time. Currently its 6mm Kevlar. Had an Espirit "alpine escape" nylon cord they made that was 6mm that worked great (kinda bitey on the pull as the sheath was way rough). Destroyed in a bit of rockfall or I'd probably still be using it. Durable as heck.

Cheers.

I think John has the best idea. Using a biner block and rapping down your climbing rope while keeping your 7mm for a pull cord is safe and easy. I've rapped off of 7mm accessory cord before and I don't recommend it. It's not very cut-resistant and you need to add massive amounts of friction.

You can get good canyon rope for 77 cents a foot for an 8mm. It's tough and much more pleasant to rap down. I've got no qualms about using an edk to tie the knots together. As long as you leave the tails long (12 inches or so), you're just fine. If you're nervous you can even throw a second overhand on for backup.

canyoneeringusa.com/shop/pr…;cat=0&bestseller=Y

Austin Baird wrote: ...canyon rope...

I seem to remember canyon rope having a much lower melting point than climbing ropes. Could be wrong about that, but it rings a bell.

Erik W wrote: I seem to remember canyon rope having a much lower melting point than climbing ropes. Could be wrong about that, but it rings a bell.

Depends on the rope. I think Tom's Imlay canyon rope is nylon, while BW's canyon pro has a core of dyneema, with a sheath that's able to handle higher temp's.

For myself, instead of purchasing an 8mm static canyon rope, I'd just get a dynamic double or twin. At least if you stuck your main rope, and, had to climb up to retrieve it, you'd be on a dynamic rope instead of a static one.

Cutting corners isn't without risk (!).

Erik W wrote: I seem to remember canyon rope having a much lower melting point than climbing ropes. Could be wrong about that, but it rings a bell.

If you're using it as a pull cord / tag line, it's not going though the device, so melting point isn't important.

Just one note, if you buy one, make sure it's static cord. I accidentally bought a dynamic one because it was cheap and it really sucked pulling it on a 180' rappel.

And on another note, on single line (or double in my opinion now after an "incident"), I would recommend using an autoblock/prusik, or something when rapping, you can get zipping down really well. Of course, I just might be knee jerk-ish after that one rap... :-) I look at them like a seat belt in a car, hopefully you'll never need it, but if you do, you're glad you have it.

Oh, and another note. Ok, I can't think of anything else to say.