Bobbin Head Road Lightning Strike

North Turramurra

2 days

Lightning damage to a mature Norfolk Island Pine Araucaria heterophylla causing a section of trunk to explode outward and undermine tree structure, posing a significant safety risk.

A 60-tonne crane with traffic control was needed as the tree could not be climbed above the area of the wound. A high-traffic and pedestrian area made not only the tree but also the remedial work a safety risk. The tree was found to be at the highest risk level, requiring Ku-ring-Gai Council approval for crown reduction.

The safe and successful dismantling of a gigantic 26m Norfolk Island Pine tree, where 8m of tree top canopy was removed 1.5m below the wound area, following a thorough aerial inspection and risk assessment.

A high-stakes commercial job at North Turramurra where a 26-metre-high Norfolk Island Pine Araucaria heterophylla had been struck by lightning in a passing storm. Located next to the footpath at the front of the strata property on Bobbin Head Road and close to the nearby public school, safety was of paramount importance with high traffic, both cars and pedestrians, passing below on a regular basis.

The first step was an extensive survey of the tree in question, which entailed one of our qualified arborists climbing the tree to just below the wound and inspecting the damage. A large section of the tree had been blown apart by the suspected lightning strike with delamination of the trunk and exploded sapwood exposing large sections of the internal heartwood. In one particular area, daylight could even be seen running through a vertical split in the trunk and the tree was rated as ‘Very High Risk’ according to the VALID Tree Risk/Benefit method.

An aerial survey of the tree was also carried out via drone, with initial footage capturing the extensive damage caused by the presumed lightning strike and allowing for a decisive plan of action to be formulated. The plan was taken to the strata management, Strata Insights, with the strata committee agreeing to the emergency work pending council approval. Ku-ring-gai Council was contacted by our qualified Level 5 Arborist, after which, the emergency process started with permission subsequently granted by council for us to remove the top of the tree down to 1.5-metres below the wound – approximately 8-metres in total.

Traffic control was booked in for the day with one lane of Bobbin Head Road closed along with the pedestrian access below the tree. Traffic management was organised through TTC Traffic Control for the duration of the job. The team prepared the site for the work and the 60-tonne crane arrived as expected. Our skilled arborist climber was hoisted up with his full climbing gear and harness attached to the hook of the crane, which swung him high above the street below and safely into the tree. The top section of the Norfolk Pine was then secured before it was cut free and lowered back to the ground along with our qualified arborist himself – quite amazing to see really!

This was repeated a second time with our arborist remaining in the tree as the second much more substantial section – a 5-metre-wide canopy in some parts – was lowered to the ground. With the trunk now brought back below the level of the wound, some tidying up of the cut was undertaken to allow for healthy regrowth before our arborist was assisted safely to the ground by way of crane.

The team on the ground was busy dismantling the sections of the tree as they were lowered, with the diameter of some sections of the trunk up to 78cm wide. Removed tree branches were fed into the woodchipper to be recycled into mulch. Clean up work was carried out with the overall result being an excellent example of a job being completed skilfully and efficiently. Arbor Pride finally advised the client that the health of the remaining tree should be monitored for signs of any defects and a Visual Tree Assessment (VTA) carried out annually.