Climbing on single and double pros and cons

[Bashby91]

Can someone please tell me the the pros and cons are of double and single rope climbing?thanks

 

[JeffGu]

Moving rope (DdRT):
+ some mechanical advantage that helps returning from limb walks, short ascents, etc.
+ rope actually only sees half your weight
+ more rope in the system, between you and the anchor point, shock loading mitigation
+ plenty of effective devices/techniques for ascent/descent with long, time proven history
+ The ZigZag! The Spiderjack! The Hitchclimber System!
+ easy canopy anchor placement, install and retrieve from ground
- although effort is reduced, travel up the rope is halved... each foot of rope travel through the ascender only gives you half a foot of ascent
- doubled rope can be harder to manage in the tree.. bulkier, heavier
- redirects usually involve using a double-sheave pulley, especially if there is more than one redirect, due to large amount of friction from the moving, doubled rope
-----------------
Stationary/Single rope (SRT):
+ rope travel is 1:1 ...a foot of rope going through the ascender translates to a foot of travel up the rope
+ rope carries all of the load (not a problem for modern ropes)
+ lots of new technology and devices on the market, with more coming
+ The Akimbo! The Bulldog Bone! The Rope Runner!
+ multiple redirects don't add friction to the climbing system, as far as effort required to ascend/descend
+ redirects are easy and can help mitigate shock loading by spreading anchor point forces
+ rapidly evolved rope walking devices/techniques allow larger leg muscles to do most of the work ascending
+ less rope clutter, single line while ascending/descending and work positioning is easier to manage
+ using a base anchor is easy
- a base anchor seriously increases loading/shock forces at the TIP
- canopy anchors that you can install/retrieve from the ground takes a bit more thought and planning
- less rope in the system, between you and a canopy anchor, so shock loading is higher, requiring more awareness about fall mitigation
- new multicender devices are rather costly

This is certainly not a complete list... there are more pro and con items, but it gives you an idea about the many advantages/disadvantages of both techniques and systems.
Remember... a lot of this is highly subjective when it comes to real world climbing. Every climber will find that one system or the other is right for them for the way they prefer to climb. There is no law saying when and how you utilize the different methods, and experimenting with both usually yields the best system for whatever you are trying to accomplish at the time!
The fact is, some folks (myself included) will find that both systems are absolutely the best... depending on how you are going to climb that day, and the tasks you want to get done.

Hope that helps.

 

[Del_]

Doubles the load placed on the tie in point.

Anchor point side subject to entanglement.

Anchor line exposed to being cut by ground crew and climber.

 

[Adamgaspo]

Moving rope/halved rope/Ddrt,
+ ease of vertical movement when performing removals or climbing (especially when on gaffes,stepping up the tree one hand can hold the tree and other can feed rope through system.
+ a simple redirect learned form a colleague
when climbing to a far flung tree leader preferably 45* to 90* (vertical) when you have reached the top you can connect your second tie in ( safety first folks) then disconnect your spliced eye and drape over an branch union of your preference, Then re connect spliced eye on your hitch climber system.
This type of tie in is very useful, abilities include vertical and horizontal movement by pulling on either side of system.
Caution is to be exercised, the amount of deflection this type of redirect loading will be similar to a canopy (tip) SRT. this technique will take time to understand in entirety.
+ A variation of system from above is to capture the top line with a Carabiner and attach it to the third eyelet on a hitch climber system.
+ Can be used in conjunction with a SRT system.
what I mean by this is that with a canopy anchor SRT isolate your Static line to desired branch place Anchor ring on throw-line then attach to rope, set your rope then use alpine butterfly with ring in middle loop of the knot. pass other end of rope through the ring and pull to the top of tree.
At that point you can attach your double to the ring and pull both systems to the top or attach the Ddrt system to the end of rope and pull up to climb through the tree.
And not to mention there are a multitude of variations to this to this setup.
- Rope angles are very important with Ddrt, every deflection of your rope angle either over or under other branches greatly decreases your ability to move throughout the tree.

Single Rope/SRT/Rope walk/smokin prussicks
+ Vertical ascent with SRT has been a true breakthrough to tree access systems
+ when used in conjunction with a Ddrt system the Srt system provides effective and expedient access to the climber in the event of an life threatening event (there are basil lower systems and ill get to those further down)
+ Provides retrieval device for advanced Ddrt canopy systems.
-bulk...lots and lots of shiney devices that will either make you look kind of weird. or do like me and find ways to minimize the equipment that you need by making everything multi use.

Canopy High line systems/ basil anchors/
I'm not going to rate the pros and cons of these systems, there are So many Variations and also they require Boat loads Rope, Gear,Knowledge and also the need to actually use it to be honest.

Adam

 

[Phileroo]

SRT
+If you take small fall during ascent, say a twig 8" above your tie in point breaks out, you will most likely be standing vertical so you wont hurt your back as much. Opposed to hip thrusting and being horizontal. (your legs will help absorb shock drop)
+You can manage your tail length with a base anchor, this helps decrease getting it caught in brush and in a worse case scenario the chipper. (mostly during pruning)
+Can tie into multiple branches, backing up your TIP or taking weight off of it
+If doing a base tie there's no need to fully isolate TIP. If worried about getting your base tie cut just put it up and out of the way or have a no cut zone around the base of the tree. If they need to make a cut i tell them to let me know so i can lanyard in first.
- May have slower setup. Especially if you're not good at throwline
-Slow to ascend TIP


DRT
+Quick setup for short trees. Tie in low and just go.
+Easy to change TIP
-Friction builds up fast
-Lots of slack tending

+In worst case scenario all u need is rope and you can get out of the tree. This one is kinda separate because you can convert to it if your doing SRT. Your usually not going to climb a tree without any hardware. Its more of a thing just to know how to do.

Neutral stuff
As far as base price goes, i would say they're close to even if you don't cheap out on stuff. Friction saver vs rope wrench. 2 Carabiners, eye to eye and a pulley are usually needed in both systems. A foot ascender is good to have in both systems.

DRT has more rope in the system, SRT has more weight in the rope so it can stretch more. I don't know if there's much difference depending on what rope you have.

As far as cutting your rope in the tree, you have the same amount of lines that you can cut in a base tie system as in a normal DRT system. Anchor side and friction side (drt) v.s. down rope and friction side (srt). The difference is your downrope isn't located right next to your friction device. Only way you come out ahead here is with a canopy anchor.

Both can get expensive very fast.

 

[beastmaster]

A side from all the pros and cons of each technic you do well to master both. Each has its place. I interchange using both. I always access tall trees SRT. You can isolate a branch that might be time consuming, going straight up to it avoiding a long difficult climb, with SrT. You can shoot your line or redirect from up at the top so you can work the outside of the tree quickly. Ddrt i prefer for limb walking or doing work in a section of tree. I switch back and forth. don't limit your self to just one.

 

[greengreer]

Doubles the load placed on the tie in point.

Anchor point side subject to entanglement.

Anchor line exposed to being cut by ground crew and climber.

All of these are only issues on a basal anchor.

Jeff made some great points in his list.
I will add ddrt for crane work (no other real way to ride the ball).
Srt for spar work is much faster than setting and retrieving friction savers.