RR668 Rigging Explained | Tree Surgery & Arborist Training

What the RR668 Rigging Research Really Means for Arborists

Practical lessons for tree surgery training, rigging, and safer decision-making

Rigging is a core part of modern tree surgery, yet it remains one of the most misunderstood areas of arboriculture. Over the years, the HSE research report RR668 has been widely referenced — and just as widely misinterpreted.

At Ground Up Training, we believe research should inform better practice, not create confusion or fear. This article explains what RR668 actually tells us, what it doesn’t, and how arborists can apply its findings sensibly through proper tree surgery training and rigging education.

Whether you’re a working climber, ground staff member, or involved in arborist training, this is about understanding forces — not memorising numbers.


What Is RR668 and Why Does It Matter in Tree Surgery Training?

RR668 is an HSE-commissioned research report that examined the forces generated during rigging operations, particularly where dynamic lowering techniques are used.

Its aim was to:

  • measure forces under controlled conditions

  • understand how variables such as drop distance and system stiffness affect load

  • improve awareness of rigging-related risk

It was not written as a set of rules for arborists — but as research to inform safer decision-making.


What RR668 Was (and Wasn’t) Testing

Understanding the context of the research is critical for arborists.

RR668 used:

  • controlled test rigs

  • known weights

  • measured drop distances

  • fixed anchor points

This allowed researchers to isolate variables and study force behaviour.

RR668 did not test:

  • flexible tree unions

  • natural damping within living trees

  • varied timber shapes

  • human factors such as communication and timing

This distinction matters greatly in tree surgery training.


Key RR668 Findings Arborists Should Understand

Dynamic Forces Increase Rapidly

Small increases in slack or drop distance can cause large increases in force. This reinforces:

  • careful cut planning

  • minimising free fall

  • understanding how rope systems behave

System Stiffness Plays a Major Role

Stiffer systems typically generate higher peak forces. Rope choice, configuration, and technique all influence how energy is absorbed.

This is why rigging training is about understanding systems — not just equipment.

Anchor Points Experience Significant Loads

RR668 confirms that anchors can experience forces greater than the weight of the load, especially during poorly controlled catches.

This highlights the importance of:

  • anchor selection

  • union inspection

  • positioning and load path awareness


What RR668 Does Not Say

One of the most important lessons for arborists and trainers:

RR668 does not:

  • ban dynamic rigging

  • provide universal safe working limits for trees

  • replace professional judgement

  • account for every site-specific variable

Research supports best practice — it does not replace experience or competence.


Practical Rigging Takeaways for Working Arborists

For Climbers

  • Reduce unnecessary slack wherever possible

  • Choose anchor points deliberately

  • Think about load path, not just weight

For Ground Staff

  • Smooth, controlled catches reduce peak forces

  • Communication timing matters

  • Poor technique increases load unpredictability

For Supervisors and Trainers

  • Teach why techniques matter

  • Encourage planning and discussion before cuts

  • Focus on decision-making, not rigid rules

These principles sit at the heart of professional tree surgery training.


Why Proper Rigging Training Matters in Tree Surgery

Reading research alone does not make anyone safer. Applying it through training does.

Courses like our Aerial Tree Rigging Course help arborists:

  • understand forces intuitively

  • apply research to real trees

  • develop safer rigging habits through practice

Good rigging comes from knowledge, experience, and structured training — not fear of figures.


Rigging Within a Wider Arborist Training Pathway

Rigging skills sit alongside climbing, aerial rescue, and machinery operation.

A typical progression includes:

Understanding research like RR668 fits naturally within professional arborist training.


Research Informs Judgement — It Doesn’t Replace It

RR668 reinforces one key principle:

Safe rigging is about informed decision-making, not fixed limits.

Trees vary. Sites differ. Conditions change. That’s why education, training, and planning remain essential.

At Ground Up Training, we train arborists to understand why techniques work — not just how to copy them.


Frequently Asked Questions (FAQ)

What is RR668 in arboriculture?

RR668 is an HSE research report examining forces generated during rigging operations. It helps arborists understand how loads behave during dynamic lowering.

Does RR668 ban dynamic rigging?

No. RR668 provides research data, not rules. It highlights how forces behave, not what techniques arborists must or must not use.

Is RR668 relevant to everyday tree surgery?

Yes — when used correctly. It improves understanding of forces, anchor selection, and planning, but must be applied alongside training and experience.

Why is rigging training important for tree surgeons?

Rigging training helps arborists apply research safely, understand system behaviour, and make better on-site decisions.


Final Thoughts

RR668 is valuable research — when used responsibly.

Its real value lies in:

  • reinforcing good rigging practice

  • supporting structured tree surgery training

  • encouraging thoughtful, informed decision-making

Used correctly, it helps raise standards across the industry — exactly what professional arborist training should do.


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