Level 3 Aerial tree pruning

Started on April 23, 2024

C&G NPTC assessment unit 003931 (formerly CS40)

This two-day, field-based course is aimed at climbing arborists looking to improve their understanding of pruning techniques following current industry good practice, specifically BS 3998, or any arborist wanting to achieve an industry recognised qualification in the aerial pruning of trees.

This course has been developed to give a better understanding of how, where, when and why tree pruning may be required and a better understanding of tree physiology and how pruning affects the tree as a living system. This course will also provide the candidate with all the theoretical knowledge and practical skills required to undertake the C&G NPTC Level 3 Unit 003931 assessment. Reference will be made throughout the course to the most up-to-date research on this topic.

Learning objectives

Upon completion of this course, the candidate will

  • understand the specific industry legislation and safety guidelines relevant to aerial tree pruning
  • have gained a better understanding of current industry good practice for aerial pruning, especially adherence to BS 3998
  • be competent in performing a hazard evaluation of the tree and a working-at-height assessment
  • understand how trees’ species, their condition and the time of year can affect the work carried out
  • be able to define pruning prescriptive terms and measurements in order to comply with BS 3998
  • understand the principles of natural target pruning and the effects, both positive and negative, that pruning operations can have on trees
  • evaluate the advantages and disadvantages of a range of pruning tools
  • be able to demonstrate competence in both crown reduction and crown thinning techniques and understand the principles of a range of pruning operations.

Equipment required

Pruning tools, including hand saw (silky saw), secateurs, long reach loppers or pole tools; top handled chainsaw optional (petrol or battery, maximum bar length 15” but preferably smaller).


Chainsaw trousers Class 1 type C, boots, mountaineering-style arborist chainsaw helmet with ear and eye protection and chin strap, cut-resistant climbing gloves, full climbing kit (work positioning harness, minimum of two climbing ropes, of which one must be at least 35 m and one at least 25 m, minimum of eight auto lock triple action karabiners, adjustable strop/lanyard, one tape sling of around 120 cm, pair of climbing irons (spikes), wire core flip line, four prusik loops or equivalent friction cords, rescue knife with retractable/folding blade), first-aid kit with haemostatic dressing, large wound dressing and whistle. An in-date thorough LOLER examination certificate (or certificate of conformity/receipt for items less than six months old) will be required for all items of climbing equipment. All equipment is available to hire at an additional cost, including PPE. Please enquire for details.


Cross-cutting and chainsaw maintenance (003920 or CS30), Small tree felling (003921 or CS31), Climbing and aerial rescue (003922 or CS38), Chainsaw from a rope and harness (003923 or CS39).

Course duration

Two days training with an assessment on a separate day.


Training cost: £300 per person plus VAT. C&G NPTC assessment cost: £250 per person.

Refresher courses are also available, either with or without assessment. Please enquire for details.