Your internet browser is not using current security protocols.
This will soon affect your ability to use the ISA website.
To update your security protocols, turn on TLS 1.2 in Advanced settings or contact your system administrator.
ISA Logo
About ISA  •  Find an Arborist  •  Newsroom  •  Job Bank  •  Contact Us  •  LOGIN
Join ISA
    Tree Biology CD in Spanish
    ISA Members: $59.95
    Non-Members: $69.95
    Price in US Dollars

    Climbers' CornerTree Academy

    Throwline Installation: A Survey of Techniques


    This presentation will look at and discuss techniques used for installing throwlines in trees. The techniques discussed will include: Double Throwline, Double Ended, Bottle or double throwball saw, Walk Down or Walk Up, Strum, Flipstick, Sending a Loop, or the Mid-line Knot.
    Three arborists from Minnesota have recorded data on throwline installation techniques of approximately 200 trees in production settings. The data recorded includes: Height, Placement (upper, middle, lower third of total tree height), Time, Tree Species, Tie-in (DdRT, SRT), and Special Techniques.  The recorded data has shown an average of just over three minutes to set the throwlines an average of 42 feet.  The most common techniques in the survey were the double throwline technique (26%), the double ended (14%), and midline knot (12%). The survey found 10% of throw-ins to be bullseyes.  The fastest throw was 0:18, and slowest 20:44.

    Conference Proceedings Documents


    Pierce Wasmund is an ISA Certified Arborist and Certified Tree Worker Climber Specialist. He is a graduate of the University of Minnesota Urban Forestry program. Pierce is a production Arborist for Northern Arborists in Lake Elmo, Minnesota. 

    Taylor Hamel is a contract climber and the owner of Taylor Hamel Arborist Services. He is an ISA Certified Arborist and two-time Minnesota tree climbing champion. Taylor has traveled around the United States and Europe working with and climbing trees. 

    Climbers' CornerTree Academy

    ©International Society of Arboriculture 2009-2018
    PO Box 3129 • Champaign, IL 61826, USA • +1.217.355.9411

    Email comments and questions to ISA
    Saturday, February 17, 2018 10:53:27 PM (CST/ISA Headquarters Time)
    Please click here to view our privacy policy.