Post by dougsanders on May 22, 2014 9:19:40 GMT -8
I could not find taglines in F8? So, to get started...
A tagline extends a rappel rope from 1/2 up to full length. The goal is to provide a safe rappel system that weighs less (or is less bulky) than carrying a second climbing rope. Generally, a tagline would be carried in the Cascades for 'just in case' or infrequent use, especially on trips lasting several days where weight is crucial. For example, a party of 3 on a week long trip might have 1-2 rappels where a tagline would eliminate carrying a second rope.
With new materials, such as superstrong superlightweight and supersmall diameter dyneema, taglines may get renewed interest. While my old 6 mm tagline was 3 lb., my new, longer, 2 mm dyneema tagline, is less than 8 oz. However, I suspect there will be unintended consequences to the small diameter.
Tagline material properties trade-offs:
Bending the rappel rope and tagline together tradeoffs:
Where the tagline has a very small diameter compared to the rappel rope one might tie both the tagline and rappel rope to a rappel ring or locking carabiner (stoppers) under the presumption that there is too great of diameter difference to assure a secure bend just between the rope and tagline. This hypothesis maybe invalid.
Configuration trade-offs:
Safety
The anchor ring is typically a small loop in webbing or a rappel ring. The stopper can be a tie, rappel ring or carabiner. There should be a substantial difference in diameter between anchor ring and stopper to assure the stopper cannot pass through the anchor ring.
One commonly described method of rigging a tagline is to pass the rappel rope through the anchor ring, tie it to a carabiner which is clipped back onto the rappel rope. This seems to be very secure as safety is independent of the bend. A tagline is tied to the same carabiner, and after rappelling, used to pull the carabiner down the length of the rappel rope. (Wrapping the cord 3-6 times around the carabiner, in the manner of a high strength tie-off (no-knot,) will preserve strength, otherwise reduced with a knot.) However, this method pulls the carabiner down the rappel rope. It subjects the tagline to more friction, abrasion and less freedom of movement than other configurations where the carabiner is not clipped into the rappel rope.
Other considerations/technique descriptions:
An unweighted temporary anchor let from a butterfly knot on the rappel rope to a second anchor makes the rappel anchor system SRENE; the butterfly is removed before the last climber rappels.
The stopper is placed on the other side of the anchor ring from the rappel rope.
The rappel is on a single strand of the climbing rope. Larger diameter taglines may also run through the rappel device like a double strand rope as in a typical rappel. Smaller diameter taglines may tangle or run unevenly when placed through the rappel device. As such, laying out the cord from a “rope” bag while rappelling will prevent tangling. With small diameter cord a pocket may serve as a rope bag.
Since the tagline is weaker and less robust than the climbing rope, care needs to be taken in pulling on it to retrieve the climbing rope to assure against parting of the tagline and stuck rappel rope. If possible, move away from the rock face to lessen the angle (friction) on the anchor ring. Assure the tagline is not dragging over a sharp rock or twisted around the rope. While pulling the tagline, small diameter cord may need to be rapped around an object such as a carabiner or ice ax to prevent digging into and cutting the climbers hands. Wrapping the cord 3 times around a smooth stock carabiner, in the manner of a high strength tie-off (no-knot,) will maintain the cord strength and provide a friendlier handle to pull on.
It may make sense for the tagline to be in place before the last rappeller in order to test pull with the tagline. If this is done it may also be prudent for the tag line to be held out of the way from the rope and rappeler while the last climber rappels.
Photo added with edit. 3 rap rings + overhand loop (only 1 used,) backup butterfly, 6 wrap dyneema -nearly high strength tie-off, 1/2 double fishermans -not pulled tight for illustrative purpose, carabiner not pulled tight to anchor for illustrative purpose. Variations possible.
A tagline extends a rappel rope from 1/2 up to full length. The goal is to provide a safe rappel system that weighs less (or is less bulky) than carrying a second climbing rope. Generally, a tagline would be carried in the Cascades for 'just in case' or infrequent use, especially on trips lasting several days where weight is crucial. For example, a party of 3 on a week long trip might have 1-2 rappels where a tagline would eliminate carrying a second rope.
With new materials, such as superstrong superlightweight and supersmall diameter dyneema, taglines may get renewed interest. While my old 6 mm tagline was 3 lb., my new, longer, 2 mm dyneema tagline, is less than 8 oz. However, I suspect there will be unintended consequences to the small diameter.
Tagline material properties trade-offs:
- Weight
- Length (static v. dynamic)
- Strength
- Diameter
- Elasticity
- Durability
Bending the rappel rope and tagline together tradeoffs:
- Bulk
- Security with different diameter cordage.
Where the tagline has a very small diameter compared to the rappel rope one might tie both the tagline and rappel rope to a rappel ring or locking carabiner (stoppers) under the presumption that there is too great of diameter difference to assure a secure bend just between the rope and tagline. This hypothesis maybe invalid.
Configuration trade-offs:
- Bulk
- Simplicity
- Speed
- Probability of getting stuck on retrieval
Safety
- Assuring stopper bend cannot slip through anchor ring
- Enough friction on single strand to assure controlled descent
- A functioning autoblock on single strand
- Possible loss of rope if tagline parts
The anchor ring is typically a small loop in webbing or a rappel ring. The stopper can be a tie, rappel ring or carabiner. There should be a substantial difference in diameter between anchor ring and stopper to assure the stopper cannot pass through the anchor ring.
One commonly described method of rigging a tagline is to pass the rappel rope through the anchor ring, tie it to a carabiner which is clipped back onto the rappel rope. This seems to be very secure as safety is independent of the bend. A tagline is tied to the same carabiner, and after rappelling, used to pull the carabiner down the length of the rappel rope. (Wrapping the cord 3-6 times around the carabiner, in the manner of a high strength tie-off (no-knot,) will preserve strength, otherwise reduced with a knot.) However, this method pulls the carabiner down the rappel rope. It subjects the tagline to more friction, abrasion and less freedom of movement than other configurations where the carabiner is not clipped into the rappel rope.
Other considerations/technique descriptions:
An unweighted temporary anchor let from a butterfly knot on the rappel rope to a second anchor makes the rappel anchor system SRENE; the butterfly is removed before the last climber rappels.
The stopper is placed on the other side of the anchor ring from the rappel rope.
The rappel is on a single strand of the climbing rope. Larger diameter taglines may also run through the rappel device like a double strand rope as in a typical rappel. Smaller diameter taglines may tangle or run unevenly when placed through the rappel device. As such, laying out the cord from a “rope” bag while rappelling will prevent tangling. With small diameter cord a pocket may serve as a rope bag.
Since the tagline is weaker and less robust than the climbing rope, care needs to be taken in pulling on it to retrieve the climbing rope to assure against parting of the tagline and stuck rappel rope. If possible, move away from the rock face to lessen the angle (friction) on the anchor ring. Assure the tagline is not dragging over a sharp rock or twisted around the rope. While pulling the tagline, small diameter cord may need to be rapped around an object such as a carabiner or ice ax to prevent digging into and cutting the climbers hands. Wrapping the cord 3 times around a smooth stock carabiner, in the manner of a high strength tie-off (no-knot,) will maintain the cord strength and provide a friendlier handle to pull on.
It may make sense for the tagline to be in place before the last rappeller in order to test pull with the tagline. If this is done it may also be prudent for the tag line to be held out of the way from the rope and rappeler while the last climber rappels.
Photo added with edit. 3 rap rings + overhand loop (only 1 used,) backup butterfly, 6 wrap dyneema -nearly high strength tie-off, 1/2 double fishermans -not pulled tight for illustrative purpose, carabiner not pulled tight to anchor for illustrative purpose. Variations possible.