Single line rapping - another rope question

[Jud]

Related to my other topic/post about rope length (i.e., when is 60m too long, i.e., how to trade off the weight savings of a shorter rope, say, 50m vs. the utility of having a longer rope 'just in case') --how do you make the decision to carry a retrieval line for single-rope rapping? Is it based on what you would know beforehand about the descent part of a route (i.e., that areas for rap anchors are far apart, so rapping on a single rope is the best option), or because of the desire to rap down as quickly as possible b/c of objective danger on the route? (rock and ice fall, bad weather, etc.)

 

I suspect this latter criteria is the reason for Steve House/Vince Anderson's decision to lug up a 55m 5mil. cord all the way to the top of Nanga Parbat, something they only used on the descent...presumably so that they could rap long sections quickly and get the hell off the face. E.g., see: http://www.youtube.com/watch?v=oIkmYiwbZWg Just a guess...I'd like to understand how/where one decides to (1) bring a retrieval line; and (2) how one decides to rap on a single line on the descent.

 

Thanks...Jud

[DPS]

I bring a tag line or double ropes only if I plan on rappeling a large route.

 

The utility of a tag line or double ropes are realized on big, steep, technical descents. I once descended this route in Alaska making 22 60 meter, double rope rappels. If we had only one rope we would have had to make at least 44 rappels, using twice as much gear for anchors and taking much more time.

[Jud]

Good point...lot more gear for anchors needed if not rapping on double ropes...slings, pitons, etc.

 

That hadn't occurred to me...I can see how that could be a fairly important consideration since it would mean carrying more gear (anchor material). And, of course, more time. But I can see how the extra anchor gear would be a very important consideration, maybe more than the extra time required for lots of single rope rappels.

[Bug]

I climbed alpine on twin 9mm 50m ropes for years.

I found them to be the optimum length and weight coupled with the requirement for gear to run a full pitch and rope management on small ledges and hanging belays.

If the "Norm" had not become 60m and 30m rap stations and anchors, I would still be using 50m twins.

[mattp]

If the "Norm" had not become 60m and 30m rap stations and anchors, I would still be using 50m twins.

 

I agree. 50m is plenty long for pitch length and a coil of rope that is 50m long is a little easier to handle - fits in my hand better - than a 60m.