Home          Your notes are welcome: Editor@UpperWindpower.com             Most recent edit: Sunday August 31, 2014

Line Encyclopedia Project (LEP)
for kite systems, K3, tethered aviation, AWES, kite energy systems

  • This encyclopedia is an open project. All interested persons are invited to send notes, links, corrections, images, terms, descriptions, uses, reports of experiences, etc.    The LEP will be separate from the main Kite-Energy Glossary.  
  • Mission statement: LEP is to be a free Internet-based encyclopedia about lines for the purpose of increasing the safety and success of kiting activities in all scales and for all purposes including special applications of working or tasking kite systems. .
  • Status of the project: September 2012 in an embryonic stage reaching for the stars....  We have no pages to launch yet in the project, except this introductory index page.
  • Funding for the project? Maybe AWEIA?  Foundations? Suppliers?  Cordage industry?  Right now: sweat equity by EnergyKiteSystems.net      Funding identification? Some $200 per month for five years would be generative until project effectiveness is widened cooperatively in caring industries; split to 20 entities: $10 each per month. Do you want the LEP to advance?                    [Contacted: PJ, C, D, AWE group,      ]
  • What is already accomplished by others for a similar purpose? Links to kin resources.  Folder started, unlinked yet.
  • What is a "line" for the purposes of kite systems? A line is very high aspect ratio material object used in tension in a kite system. A line is to be distinguished from tensioned coverings of low-aspect ratio; though a covering may embed lines.
  • Lines are with many uses in kite systems, the most prominent use being a tether that couples wing and anchors; however, lines are used in bridles, control systems, structural systems, covering constructions, staying systems, kite-killing systems, energy-transfer systems, safety systems, nets, parachutes, anchoring systems, kite applications, kite tasks, etc. 
  • Some common forms of lines: fibers, threads, strings, cord, rope, cable, wire, wire rope, chains, fibrous rope, ...
  • Aspects of lines? Lines are either found in nature or manufactured from materials provided by nature. Lines are used. During the useful life of a line there will degradation of properties. Awareness of the current quality of a line will permit operators to make better decisions that may affect the life of humans and animals, as well as the integrity of a kite system or properties in the operational environment.  Aspects of lines will affect ROI in AWES.
  • Manufacturing and construction of lines:  ________
  • Decommissioning lines from a specific use and finding a following secondary use for a line will be part of projects; secondary use could be letting a line be feed stock for soil-making processes; a decommissioned line's quality for a secondary use ought to be managed for safety purposes. A line with gross appearance of integrity might be thoroughly degraded by ultraviolet light, rot, or fatigue. Freshly purchased product is not a guarantee of quality of line sample in hand, as errors in manufacture and supply and handling may bring defects in lines freshly purchased; the user is responsible for inspecting and verifying the needed aspects and qualities of a line for an immediate purpose. When would it be best to make a line not a line?
  • Risk management is ever part of line use. Perfect knowledge is never available. Costs for fuzzy action and operation vary. Sharing critical safety knowledge is part of a professional ethic that makes the world better. Using the services of experts may be appropriate. Inspection schedules and incident analysis are part of the core costs of responsible use of lines.
  • Line terminations, couplings, joinings, splicing, knots:  Lines frequently join other parts. Line segments may join other lines. The beginning and end of lines may receive various treatments. Specifying these matters, describing the craft procedures involved, illustrating, tip giving, failure-mode disclosure, inspection methods, testing,
  • Testing lines may be by destructive or non-destructive means.
  • Inspecting lines.   Logs, inspection tools, experience notes,
  • Tools involved with lines:  _______
  • Understanding and engineering "tension" in line usage:  shock, load limits, age, hours of tension, creep, effects from reeling and drumming,
  • Line dynamics?  Line in moving systems? Line in wind? Long-line dynamics?  Short-line dynamics? Simulation programs? Expert knowledge?  Experience reports?
  • Line handling, reeling, spooling, using, storing:  _________________ 
  • Circle coiling versus figure-of-eight coiling? 
  • Line-handling and line-operating errors and error effects? _______________
  • Lines of choice in particular projects?  
  • Line patents.  
  • Line products.    Cordage, cables, nets, textiles, reels, spools, winches, lubricants, treatments, tools, etc.
  • Line engineers.  
  • Line manufacturers.   
  • Line supplier. 
  • Standardization and standards affecting line manufacturing and line handling.
  • Safety:   For example in crane literature: "Each and every lift must be planned carefully to avoid the risk of serious and costly accidents."  No less for kite systems!  Training of involved handlers and technicians is part of projects.  Errors made in line making, handling, storing, operating, ...?
  • elastomer line, elastomer lines,     | as turbine  |    |
  • Stringing


LEP:  A B C D E F G H I J K L M N O P Q R S T U V W X Y Z   : LEP

Project steps:  Most recent on top
  • Started folder on books about lines. Not linked yet.
  • Started folder on suppliers of line products. Not linked.
  • Folder started to hold wiki links that address LEP topics.
  • letter pages, not linked, have been constructed. Oct. 1, 2012.
  • PJ noticed.  Oct. 1, 2012
  • This index. page. Oct. 1, 2012.
  • Project conception occurred during the growth of the Kite Energy Glossary.
Project To Dos:
A curious technical issue arose as our designated large kite area was sporadically invaded by parents and kids flying toy kites; Gary was hyper-vigalant against the threat that the cheap thin lines of the toy kites could slice his larger professional kite lines, which is an interesting asymmetric threat that recalls Thai Chula-Pacpao kite fighting.   ds    May 8, 2013       AirborneWindEnergy/message/9149
Classification of Tethers
  • Dave Santos
    Today at 2:30 PM  January 27, 2016
    Dave Lang is the father of AWE tether science, having pioneered AE theoretic, simulated, and tested tethers during his long career, over many years challenging AWE researchers to look deeper. His involvement with actual Space Tethers and forward-looking Space Elevators even inspired new conceptual hybrids of the kite principle in planetary science. In the last decade, open AWE also scours academic literature and commercial sources for tether knowledge, especially in key high-TRL applications like fishing, rigging, and related practices.

    New AWES tether conceptual frontiers emerged, such as sonic relativity in long-line control inputs (variable c in tension-modulated tether), and 3D tether lattices on a vast scale. A profusion of tether types and methods were rediscovered or newly invented. Advanced tethers range from pure super-polymer at highest power-to-weight and lowest-drag, to composite structure with diverse added functions. Below is an incomplete list of tether types and concepts in raw-note form, awaiting others to someday bring due order to the engineering classification of the complex AWES tether space.

    Load Bearing Tether- eg. the common kite tether

    Primary Load Tether- a line bearing the preponderance of a tensile load from a wing set.

    Plain Tether- a single tensile material

    Composite Tether- any combination of materials and construction for multiple functions

    Conductive Tether- metallic electrical, RF coaxial, or salt-contaminated tether

    Secondary Load Tether- leader, bridle, riser, killer, tagline, pendant, PTO (power-take-off), etc

    Control Tether- steering line, trim-tether (AoA "brake" or D line), kill-tether, trip-line, etc

    Lifter/Drougue/WECS Tethers- specific to basic AWES modules

    Slack Tether- unloaded in nominal operation, perhaps as a backup or stop

    Moving Loop Tether- rope-driving, payload transport XC and local pick-and-place

    Pumping Tether- low-stretch oscillating load

    Shock Tether- elastic, damped, 

    Snubber- a tensile shock absorber, often elastomer with backup rope

    Stationary Anchor Tether- most common primary tether

    Mobile Anchor Tether- drag-line, FF connecting tether

    Horizontal Tether- (surface-tether, aloft-tether, (cableway, guide-cable)

    Multi-Tether- identical tethers acting in parallel

    Gangline- branching from a primary tether, a tether with multiple payload units along it

    Star Tether- a multi-tether of shroud lines, lattice junctions, etc.

    Chafing-Gear- ruggedized tether sections at bearing zones (capstans, pulleys)

    Segmented Tether- serial tether segment

    Graded Tether- serial tethers of progressive variance

    Tether Lattice- 3D geometries

    Cutting Tether- fighter kites, kill method

    Dragline Tether- usually chain or wire rope; drags while creating a load for a kite to act against

    Tether-Set- a group of tethers in the same AWES

    Hot-Swappable Tether- the tether part of a system for changing lines without AWES interruption

    Light-Air Tether- thinner and lighter section for weak wind

    Working Tether- normal section for average or most-probable wind

    Heavy-Air Tether- heavier and thicker section for strong gusty to storm conditions

    Modular Tether- standard fixed length interchangeable units

    Renewable Tether- fresh sections unrolled from storage reel as needed

    Monofiliment Tether- previous state-of-the-art in polymer tethers; non-scalable

    Twisted-strand Tether- right or left handed, with a varying torquing moment according to load; swivels commonly added

    Braided Tether- no torquing by pumping, in its untwisted state

    Cored-rope Tether- twisted or braided cover over a core of load bearing fibers; the outer layer protects the core

    Heat Resistant Tether- in supposed descending order; tungsten, fiberglass, carbon-fiber, steel, kevlar, nylon

    Chain Tether- made from small links, capable of indexing.

    Ballast Tether- ie. anchor rode steel chain

    Lightweight Tether- ie. floating UHMWPE or PP

    Wire Rope- steel cable for heavy-duty surface operations

    Natural Tether- hemp, flax, cotton, sisal, etc.

    Artificial Tether- various polymers and metals

    Water Tether- low absorption typical, undersea, all-weather

    Beaded Tether, Toothed Tether- non-slip indexed (ie. timing belting)

    Tapered Tether- smooth graduation

    Coated Tether- electrical insulation, UV protection, abrasion protection, absorption reduction, color-coding,

    Fiber-Optic Tether- normally composited with structural fibers

    Long-line Antenna Tether- normally composited with structural fibers or a metallic tether with both strength and conductivity

    Stoppered Tether- Cody used graduated rings and stoppers to sequence train launches.

    "Flying-rope" Tether- Culp's idea of a self-flying tether as a soft-train made of many small lifting units

    Variable Mechanical Advantage Tethering- a tri-tether whose variable angles manipulate the "rigger's triangle" (bow-string angles)

    Rat-Tail Tether- wrapped on a long-line as needed to create a haul-end at any point

    Spliced Tether- maximal strength line link joints

    Knotted Tether- quick, often reversible, but weaker linking

    Kite Tail- an extended kite drogue that is its own tether

    Tow-line Tether- pulling loads XC

    Rated Tether- tested for yield and failure numbers; derated according to logged and inspected wear

    Guy-Line Tether- a bracing-line to stabilize a tensile structure along a given axis        
  • Add the following:
  • Grappling Tether
  • Hose Tether,
  • Ribbon or Belt Tether

General Kite-Energy glossary in the online book Airborne Wind Energy

Let us know you and your interests.
News, notes, documents, files:  Editor@UpperWindpower.com
~~Kite Energy Community~~