Hazard trees, borderline trees, tree limit, line clearance, assessment of hazards… Trees are not only of good – they can actually present serious risks for people and property!


Hazard trees, borderline trees, tree limit, line clearance, assessment of hazards… Trees are not only of good – they can actually present serious risks for people and property! Regular, preventive risk assessment and utility vegetation maintenance is necessary to reduce the safety risks involved. Falling trees are one of the most common causes for electricity breakdowns, and especially so when the weather makes it tough to handle service interruptions. Hard wind and heavy rains, ice and snow are all typical reasons to why trees fall over.


There are many different names for similar functions and measurement needs. All such functions aim to prevent accidents from happening, and trees from falling over power lines, buildings and roads. Many of the advanced and specialized functions that you would normally pay extra to get – or even have to purchase a special instrument for – are incorporated as standard functions in some of Haglöf Sweden professional instrument systems.

The Hazard Tree (Tree Limit and Line Clear) function in our VL5, L5 and Vertex Laser Geo and Laser Geo instruments has been developed, following specifications and demands from professional users. With their valued feedback, we have fine-tuned the functions and added usability. Our hazard trees function is easy to get to, and the control measurement operation is not complicated. The instrument processes data, and gives you on-hand reports on which tree is OK to keep. Easy – and money-saving!

The function in the instruments enables the operator to estimate the safety distance from a tree top to, for example a power line, a road or a construction site. It is always recommended to work with a security margin, given that the measurements include uncertain factors that can have effects on the results. Certain calculations will presume that the object, for example a tree, is standing straight when you measure a height. Trees that are leaning in the opposite direction from the operator’s position may be given a lower height measurement value. Other factors of uncertainty can affect the results, such as cold/warm temperature, power output in the power line, etc. If you are unsure whether the laser beam actually hit the correct spot when measuring, it is recommended to verify results with at least one more measuring operation.