In a recent refresher / update course, we covered the use of speedlines in arboriculture operations and I thought it might be interesting to take a look at the how’s and why’s of using them. Speedlines are definitely not for use every day, but when you encounter a situation when you could use them, you’ll be glad you had it in your ‘toolbox’.
Speedlines have a number of advantages:
- Perfect for dismantling trees that have ‘targets’ under them, such as a shed, fence, garage, pond, car or similar… things where dropping the timber straight down is not really an option.
- They provide a safe, controlled method of lowering timber.
- Speedlines allow crews to lower timber to a specific point on the ground, delivering wood near to a chipper in-feed chute is a classic example.
…however, they do have a number of disadvantages that can limit the number of times you’d use them…
- they can be complicated and slow to set-up, needing careful planning and installation.
- they require a greater level of competency from climbers and ground crew.
- communication between ground crews and the climber is paramount.
- they require more equipment than a simple rigging system.
Applications For Speedlines
Speedlines can be installed for a number of reasons, but the type of installation will depend on the application that it is going to be used for…
- Light-weight applications
- Medium-weight applications
- Heavier-weight applications
In this scenario a speedline can be set up, tensioned and used to transfer small branches from the stem to the ground. These branches will be lightweight and their low mass coming on to the line will have little effect on the system, or the climber in the tree.
In this scenario, we may well be lowering larger branches, or stem sections where more control is required and due to their mass, these sections would not be rigged directly on to the speedline. In this case speedlines would be de-tensioned during rigging and then tensioned for lowering.
This is the most critical system to set up and system components must be carefully selected to avoid overload situations, and in addition the use of guy-lines on the stem may be required due to the lateral loading when lowering timber down the speedline.
In the next article of this series we’ll take a look at the elements that make up a speedline system.
We offer aerial update courses that can cover climbing and aerial rescue techniques, as well as rigging methods. If you still need your aerial rigging ticket then we can run the City & Guilds NPTC Level 3 Award in Aerial Tree Rigging. Contact us for more details.