No.44 Access Lines
Key words: Access, Access Line, Stationary Rope System (SRS), Moving Rope System (MRS),
Bottom Anchor, Top Anchor, Access Anchor, Working Anchor, Rescue, Anchor Leg, Elongation,
Configuration, Unicender.
I define my climbing act into Access, Work and Retrieve and day to day each of these can have many degrees of difference. Access may be via spur, rope or mechanical platform. Spur may be with a lanyard, or two lanyards, or lanyard and high-line and may incorporate basic techniques or a combination of basic and advanced. It may be a crane lifting one into the tree or setting a top anchor via throw-line. Delineating this into an act of access ensures that whatever the means,
those on site will understand set parameters within the activity. Access means 'a way to obtain a working anchor' and not 'the act of upward movement'.
An anchor may be a top anchor or a bottom anchor, this is at your discretion but should be a safety led decision.
Accessing with an SRS bottom anchor opens risk of cutting the 'anchor leg' and so climbers may leave their chainsaws at ground level. All cutting should be left to a minimum of 'clearance of a path' for the accessing climber and can be achieved with a handsaw in most cases and always with a second point of attachment.
The 'anchor leg' side of the bottom anchor can be set with higher or lesser safety parameters and this must be done with consideration of loading forces, falling objects, ground-worker awareness.
Vigilance is a must when the climber is using or even just carrying a cutting tool.
I try to leave my chainsaw at the ground throughout my access.
All good arboreal teams will take as part of the working act that rescue is planned for and without this planning lends itself toward amateurism. It shows ones capacity for rope work skill and is professionally and ethically vital.
Arboriculture is the only industrial rope work discipline that remotely sets anchors and those that do it understand the difficulties, risks and time involved in doing so.
It goes without saying that an installed access line helps when planning for rescue.
It becomes the teams 'nylon highway' and increases team play, productivity and safety.
The access line is not just for rescue, in-fact it may be disingenuous to even call it a rescue line. The access line serves the purpose of access, whatever the call to access may entail.
Find a way to delineate the acts of access and work. It may help to use a separate rope and device to ensure that access and working activity do not become mixed up.
There are many low elongation 10mm and 10.5mm lines that work with a number of devices.
In most cases a 60M length ensures easy installation of a bottom anchor and the lighter weight line will be easier to pull over branches.
Illustration
The RED line is the access line. Because the anchor leg is close to the climber, cutting is kept to a minimum of clearance and always with a second attachment point.
Chainsaws are carried with a scabbard or left at the floor.
The anchor leg may be tied away from vertical to keep it a safer
distance from cutting tools but must never run through the drop zone.
The rope is tied at the base of the tree with a Double Loop Running Bowline and there is an Alpine Butterfly one metre
above for rescue purposes.
The device is carefully configured to the type and size of line and care is taken to follow established climbing guidelines.
Any tooth-cam type device will be used with a back-up on the
line because a leaf entering the cam will cause it to malfunction. A smooth cam type may be used alone.
The BLUE working line is carried and a top anchor created. The access line then becomes free for others to use.
“Conservative risk assessment and a solid climbing
methodology can be made as alive as the trees that you climb. Without them it would be a blind act.”
A rope is loaded to 10% of its MBS to give the elongation data.
There are differences in how companies obtain this figure so it must be taken lightly although it gives an approximation at least.
Anything below 2% is very static and shock loading must be carefully considered.
Above 3.5% will be too stretchy for efficient upward movement.
Liros Torpedo has a Dyneema core and would be great for ascents since it transforms all invested energy into the upward 1:1 movement.
Yet because of its very low elongation (less than 1%) these ropes cannot be certified to the European rope testing standard EN1891 and without additional shock absorbers should not be used for PPE.
Additionally, the slippiness of the Dyneema core means that tooth-cams will not configure safely to a rope like this, any shock load causing the cover to rip would plummet the climber to the ground.
Unicender
Rock Exotica's Unicender is designed for SRS and MRS, has a smooth cam, is lightweight and very fast to attach midline. The specification states 11-13mm but it successfully and safely works on 10 and 10.5mm (not endorsed by Rock Exotica). That the Unicender configures to so many types of rope is very unique for a mechanical device.
It is an adaptable tool that can happily sit on ones harness ready for a multitude of tasks.
1. If the Unicender is kept at a distance from the bridge it allows a variety of interesting
techniques.
The most popular devices are clipped directly into the bridge ring and slack tending is
done with an upward motion; that is, the rope below the device is lifted upwards to remove
slack.
When tethered at a distance the Unicender can be slid up the rope, the difference from the
former being that the climber need not needlessly lift the heavy standing part of the line
each time they slack tend.
2. Using the tether allows the chest harness karabiner to attach directly to the rope (below
the Unicender). The climber will be close to vertically upright and is as ergonomic and
efficient a climbing posture as can be when using the Rope Rocket ascent system. The
Unicender can pushed up by hand or tended automatically by the karabiner.
3. With the addition of a Petzl Rollclip the Unicender can be used for a traverse system.
