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No.11 Climbing System-A Riggers Approach

This article is describes an idea for setting up a climbing system.

Please seek professional training to learn climbing techniques.


We should be inspired to climb with particular systems for the following reasons;

non-invasive to the trees cambium -

freedom of three dimensional movement -

security from falling -

ergonomics -

an ability to easily access trees of all shapes, strengths and heights -

climbing systems that do not hinder working (tree cutting) processes.

Ways of climbing have evolved and been written into 'best practice' guidelines in many countries.

'Standards' demand that climbers use a 2:1 climbing system for work positioning.

2:1 is usually called Ddrt.

Ddrt means that the rope has been Doubled over a branch.

It enables a climber to lift half of their weight when ascending, it gives them a 2:1 power ratio.

The following photos describe several 2:1 systems.

The 3 Knot system ascending with Body Thrust technique


The Split-Tail system ascending with Body Thrust technique.


The Split-Tail system with foot-clamp assisted Body Thrusting


The Hitch Climber system with foot-clamp assisted Hand-Over-Hand technique


The Lock Jack system with foot-clamp assisted Hand-Over-Hand technique


2:1 technique enables the climber to 'self belay' and gives safe and controlled access to all parts of a tree.

It is a simple and safe way to work and with application of technique and tool contains many creative possibilities.


Industrial access and caving practice have influenced 'tree access' techniques (not descent or work positioning).

1:1 is usually called Single Rope Technique, its acronym is SRT and a style of ascent called 'frog walking' or 'rope walking' has been used extensively by arboreal workers the world over because of its fast and ergonomic style.

Many non-converts challenge the safety of a system that has so many 'parts' to be successful.

What is potentially a fluid and ergonomic access technique can become physically difficult and potentially dangerous if not set-up correctly.


Possibly the most ancient technique, I would guess dating back to when man needed to ascend anything(!), is the 'foot-lock' ascension technique.

Equipment wise it is simple and when the climber is proficient becomes a fluid way to access trees.

Foot-locking has been polarised by the ISA competitions to those that find it physiologically detrimental and those

that swear by its virtues.


More recently tools have been designed that enable workers to ascend and descend with the same tools on a 1:1 system.

It is called Single Rope Work Positioning and while not yet included in 'best practice' guidelines it is garnering a huge amount of interest the world over.


All of the above techniques tick my original boxes when used with sensitivity to ones own body and the tree.


At present Japan doesn't have a safety standard for arboreal workers and it is an interesting time in terms of tree climbing culture as there are, from around the world, a wealth of technique and tool.

As we learn more about how we can physically interact with a tree, safety guidelines and equipment will alter to best suit our needs.


The Victorian Tree Industry Organisation (VTIO) recognises that although working in trees is an inherently dangerous activity, comprehensive prescriptive regulation of best practice is unfeasible as the unique challenges posed by each tree mean that no single universal approach can be successfully prescribed.

In addition, the differing skill sets and experience of each individual climber allow for a number of different valid approaches to each tree.”


Something that I have come to use recently borrows aspects of 1:1, 2:1 and inverted 2:1 (triple leg) rope systems, after-all there are tools that work effectively with the 3 systems so why not integrate different ideas to achieve something greater than a stand alone system?

I chose not to say Ddrt or SRWP or RADS or the multitude of different acronyms in use, I simply use rigging solutions to achieve my objectives.


non-invasive to the trees cambium -

freedom of three dimensional movement -

security from falling -

ergonomics -

an ability to easily access trees of all shapes, strengths and heights -

climbing systems that do not hinder working (tree cutting) processes.


I found that a 2:1 system performs better than a 1:1 at:

moving the tie-in-point -

climbing in the 'alternate lanyard' style -

walking IN from a limb walk -

rope and cambium protector retrieval.


and that a 1:1 system performs better than a 2:1 at

climbing long vertical distances -

more easily 're-directing' -

utilizing the trees inherent strength through re-directing -

consistent friction in the climbing system which enables a greater range of movement.


It seems obvious to me that Arboreal Workers should unite the virtues present in each rope system and I am happy to explain how this may be possible.

Modified Ring and Ring & 34mm large ring


At the heart of this flexible system is the Ring and Ring cambium saver.

A simple change in the large ring size enables a 2:1 rope system to be knotted on the splice side and safely cinched against the large ring, thus turning it into a 1:1.

A standard sized large ring is too big and the knot will pass through it.


Modified ring and ring uses a Large ring size of 34mm and a Small ring size of 28mm.

A Choice of 3 tools

The Unicender

The Unicender was the first tool used for 1:1 work positioning and its smooth aluminium plates act as a shock absorber by slipping at higher loads.

Its mechanical design ensures that the plates will always grab the rope in a fall event.

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The Rope Wrench

Hitch cord is usually 8 or 10mm and around 70cm long.

The pulley is multi purpose; 'slack tending' the hitch is its main function but the Hitch Climber pulley features a rigging plate (3

holes) and can be used for many different techniques : 1:1 traversing - equipment hauling flexible alignment of hitch and karabiners for strength .... the list goes on.

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The Rope Wrench 'tether'.

A hard tether keeps the Wrench from pressing against the top of the hitch.

A hard tether spliced or stitched onto the pulley means that the Wrench doesn't have a 'flopping connector'.

A flopping connector drops the Wrench toward the top of the hitch which potentially descends the climber.

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The Hitch Hiker

The newest tool and possibly the best 1:1 device. A climber needs to have 'fluidity' for crown movement and the HH excels at this.


The Spliced/Stitched Eye

The 2:1 set-up has a compact connection with a spliced or stitched eye. Ring and Ring retrieval is made easier with a spliced eye.

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Additional Items

'Rope Walking' on 1:1 systems are fast and ergonomic when set-up right. The foot-loop length needs to be tailored.


A foot-locking hitch can be placed on a single or twin rope.


A foot clamp helps with 1:1, 2:1 and 3:1 systems, truly an indispensable tool!


Lanyard for 'changeovers' and 'work positioning'


Helmet, Safety Glasses and Gloves


Shock Absorption

A trunk anchor (see article 12-11-30) potentially lets more rope become 'active' in a climbing system and so aids shock

absorption through its stretchiness.

The trunk belay does not enable a worker to switch between rope systems as the rope is tied at ground level.

Choking a knot to the ring and ring causes two areas of thought. Firstly that less rope is available for shock absorption and that the stopper knot can creep away from the ring when the rope is not loaded and a careless move may result in a fall and shock load.

We are designing a drop test for the 'cinched ring and ring' which will be carried out at a research facility in April. We plan to find a set-up with the most shock absorbing qualities and we will look at different types and age of rope as well as midline knots.

A trees flexibility will also aid shock absorption especially if the climber has set redirects. It is hard to quantify these things, a climber must get used to 'feeling' a tree.

A climbing system and climbing style must be prepared to negate shock loading scenarios.

A Climbing Scenario

The following photo story shows how easily a climber may change between 1:1 and 2:1 systems to achieve different objectives in a work scenario.

The following photo's describe a small amount of rigging possibilities and I hope that you may begin to see a larger amount of rigging potential and how you can apply these ideas for a smoother and safer job.


Initial access

Throw line is isolated on a branch, rope is pulled over and cinched against branch with a

running bowline. Osaka san access' with 1:1.



Check anchor point and set a ring to ring with 2:1 system.

Osaka san chose to access with a foot-clamp and he used his lanyard to hold his bridge ring higher which helped slack

tend the Hitch-Hiker.


Limb walk to crotch and tie alpine butterfly changing 2:1 to 1:1.

Osaka san needs to climb through a natural crotch to maintain a good rope angle and decides to change to a 1:1 system to reduce wear on the tree and reduce friction in his climbing system.

A midline knot is tied as high as feasible above the hitch and the splice is clipped to it.

He attaches his lanyard to a strong branch before un-clipping his climb line.


Drop through crotch and re-ascend to alpine butterfly.

The climbing move is easily accomplished and Osaka san returns a happy man.


The next work station is below and there are no obstructing limbs so Osaka san changes back to 2:1 and descends.

He attaches his lanyard to a strong branch before un-clipping his climb line.


His final work station is above him so Osaka san tie's a midline knot above his splice, clips a karabiner to it and pulls it up to choke on the ring and ring and ascends on a 1:1.

He attaches his lanyard to a strong branch before un-clipping his climb line.


He can tie the midline knot at any point above the splice. If he lets the splice hang downwards he can position it at any height on the tree.

A climber should position it in reach from the next work station for an easier changeover later.

If a traditional large size ring and ring is used the knot will pass right through the ring. The modified ring and ring uses a large ring size of 34mm which is smaller than normal.


Ascend to splice eye, change back to 2:1 and descend to floor.

He attaches his lanyard to a strong branch before un-clipping his climb line.


Retrieve rope and ring and ring.


This scenario shows an example of a climber who repetitively alters the rigging on his life support system.

While these techniques are far from complicated it is IMPORTANT to understand the consequences of poorly executed rigging.

Shop K are open for anybody to come to talk and climb, we run workshops that introduce safe climbing practice and can advise on the whereabouts of bonafide professional courses.

Please do get in touch as all of this is for your benefit.....(and for the trees!)




A Hauling System

This rigging technique enables a climber to transfer weight into an object, it gives mechanical advantage to help with the hauling of ... anything.

The ease of raising a person is astounding. It has rescue capabilities.

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