line
something (as a cord or rope) that is long and thin and flexible
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
Researched by: Codex + Grok
Purpose and description
Enable an AI agent to recognise a physical line, assess its condition and arrangement, and determine which handling or load-bearing actions are supported by available evidence.
A line is a slender, flexible tensile member - built by twisting, braiding, laying, jacketing, or extruding fibres or wires - whose working role is to carry tension, to lash, to hoist, to moor, to tow, or to fish, as distinct from a rigid bar, a flat strap, or a chain of links.
It can be Trace, measure and mark the line or a selected segment.; Coil, uncoil, route or untangle it while accounting for attached ends and tension.; Tie, untie, splice or terminate it using a method supported for its construction and intended use.; Attach, pull, tension or release it within evidenced limits for the complete arrangement.; Inspect and isolate a suspect segment, or remove the line from a proposed use pending assessment.; Cut it into separately identified pieces after accounting for stored tension and connected objects..
Distinguishing features
It is a tangible article with a traceable length and physical cross-section, rather than a geometric line or surface mark.
Its longitudinal extent substantially exceeds its transverse dimensions; the boundary for short cut pieces remains to be settled.
It can bend along its length during intended handling, distinguishing it from an article intended to retain a rigid shape.
Its identity fits a cord-like or rope-like flexible article; a hollow passage, conductive core or broad flat profile requires checking the boundary with hose, cable or strap models.
An individual line has traceable material continuity, including any joints; several contacting or tangled lines do not automatically constitute one line.
Scope
+ The physical extent, ends and continuity of an individual line
+ Material and construction relevant to bending, stretching, gripping and wear
+ Length, cross-section and changes along the line
+ Knots, splices, terminations and local attachments
+ Current routing, slack, tension, tangles and contact points
+ Condition and evidence supporting a proposed use
- Geometric lines, drawn marks and abstract paths
- Queues, production lines and communication services
- Rigid rods, poles and structural beams
- Fluid conduits whose defining function is carrying a flow
- Electrical or optical cables whose defining function is transmitting power or signals
- Complete lifting, climbing, mooring or restraint systems and their operating procedures
Characteristics
- Material and construction
- Recorded material; laid, braided, monofilament, other or unknown construction Construction informs interpretation of flexibility, wear, grip and compatibility with terminations.
- Length
- m, with measurement method and tension condition Available reach and cut length depend on how the line was measured.
- Cross-sectional dimensions
- mm diameter or width and thickness, with position and measurement condition Cross-section affects fit through guides and fittings and helps locate deformation.
- Bending behaviour
- Observed bend radius in mm under stated conditions; documented minimum bend radius if available A line that can physically bend around an object may still lack evidence that the bend is acceptable.
- Extension under load
- % extension at a stated force in N, duration and environmental condition Stretch affects reach, restraint and the interpretation of a tensioned arrangement.
- Continuity and end configuration
- Open-ended, closed loop, joined, cut or uncertain; free, knotted, spliced or fitted ends Continuity and end treatment determine how the line can be threaded, attached or separated.
- Routing and contacts
- Ordered endpoints, guides, supports, crossings and contact locations The route determines usable reach and locations where friction, bending or abrasion may occur.
- Tension distribution
- N at a stated segment and time, with measurement or estimation method A local tension reading does not necessarily describe every segment across knots or contact points.
- Local condition
- Observed fraying, cuts, flattening, stiffness, contamination, discoloration or no visible anomaly; location and inspection coverage Condition must be located along the line, and an unobserved interior must remain distinguishable from an inspected surface.
- Documented use limits
- Applicable manufacturer information, test evidence or procedure, with configuration and conditions A proposed use requires evidence applicable to this line and arrangement, rather than an inferred rating from appearance.
Analytical facets
- substance
- material
- origin
- manufactured
- agency
- inert
- mobility
- portable
- scale
- handheld
- affordances
- graspable
Also called
+110
Where this came from
oewn:2024 · CC BY 4.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 5 bundles · 9 layers · 16 findings · 28 questions.
Physical identity and extent Establish which flexible article is being modelled and where its material extent begins and ends.
Coils, loops and tangles can obscure whether an observer is seeing one continuous line, a segment or several lines.
Line recognition
Record the evidence that this article belongs to the registry's physical line concept.
Cord-like flexible form
Capture observable slenderness and bending behaviour without assuming that every elongated flexible article is a line.
- What observations establish a long, thin, flexible physical article of the cord or rope kind? definition
- Does its profile, construction or defining function place it instead with a strap, hose, cable, wire or rigid rod? boundary
Continuity and segments
Resolve individual identity through ends, joins, loops and selected working portions.
Traceable material extent
Record the continuous path of the article and distinguish physical boundaries from temporary working-segment boundaries.
- Can the line be traced between its physical ends or around a closed loop, and where are any joins or obscured portions? boundary
- What are its total and selected working lengths, and under what tension were they measured? measurement
Construction and response Describe the line's material makeup and its evidenced response to bending and pulling.
Similar-looking lines can behave differently when bent, gripped or tensioned, so appearance alone cannot support handling decisions.
Material and cross-section
Characterise strands, core, covering and dimensions where these can be established.
Verified line construction
Separate observed construction from identification supplied by labels or product records.
- What material, strand arrangement, core and covering are established, and which remain unknown? definition
- Which markings, product records or examinations support that identification? provenance
- What cross-sectional dimensions occur along the line, and how were compression and irregular shape handled during measurement? measurement
Bending and extension
Record mechanical response under specified conditions without converting observations into unsupported ratings.
Conditioned mechanical response
Describe bending, extension and recovery using applicable documentation or bounded observations.
- What evidence describes extension and recovery at stated loads, durations and environmental conditions? provenance
- What bend-radius constraints apply to the intended guide, knot or storage arrangement, and where are those constraints documented? action
Routing and force transfer Represent how the line is arranged, connected and carrying or awaiting tension.
A line's usable function depends on its route, terminations and local tension as well as its material properties.
Route and slack
Trace the working route through guides, contacts, crossings and stored portions.
Working path and obstructions
Distinguish useful free length from length occupied by coils, knots, wraps, snags or inaccessible sections.
- Which ordered contacts and guides define the route, and which crossings are actual entanglements? boundary
- How much slack and free working length are available between the relevant connection points? measurement
Terminations and tension
Record local attachments and the force-transfer configuration of the line.
Connected and loaded segments
Identify knots, splices and fittings and associate tension evidence with the segments it actually describes.
- How is each working end or intermediate attachment secured, and what evidence supports compatibility with this line? provenance
- Which segments are slack or tensioned, and what measured or estimated force applies at each assessed location? measurement
- What connected objects or tensioned segments would move or unload if a selected attachment were released? action
Condition and use decisions Connect inspection evidence and service history to a particular proposed action.
Visible condition, hidden portions, previous exposure and configuration-specific limits must remain distinct when deciding whether a line is fit for a use.
Wear and inspection coverage
Locate observed changes and state what the inspection could establish.
Located condition evidence
Record anomalies by position and distinguish absence of observed damage from evidence of remaining capacity.
- Where are cuts, fraying, flattened areas, stiffness, contamination or other changes, and how extensive are they? measurement
- Which surfaces, interiors, knots and covered sections were examined, and which could not be assessed? boundary
- What is known about prior loading, abrasion, heat, chemical exposure and storage, and what supports that history? provenance
Use limits and interventions
Evaluate a proposed operation against applicable evidence and record the effect of any intervention.
Evidenced action eligibility
Record whether a specific use is supported, unresolved or excluded, including the consequences of cutting or changing terminations.
- Which documented limits and rejection criteria apply to this line's identity, condition, terminations and proposed operation? provenance
- Does the available evidence support the proposed action, or is inspection, replacement or another assessment needed first? action
- If the line is cut, spliced or reterminated, which length, identity, condition and use-limit records must be reassessed? action
Evidence and external alignment What the world already says about this thing, gathered so the model can be checked against it.
A model that cannot be lined up against existing standards, identifiers and practice cannot be adopted by anyone who already uses them.
Reported evidence
Findings from the breadth pass, kept separate from the structural claims.
Kinds and varieties
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Laid (twisted) fibre rope, typically three-strand or cable-laid
- Plaited and braided fibre rope (eight-strand, twelve-strand, solid braid, double braid)
- Kernmantle rope with a load-bearing core and a woven sheath (dynamic and low-stretch/static)
- Wire rope and wire line (stranded steel or other metal wires, sometimes fibre-cored)
- High-modulus synthetic line (HMPE, aramid, and similar low-stretch, high-strength constructions)
- Natural-fibre cordage (manila, hemp, sisal, coir, cotton)
- Fishing line (monofilament, fluorocarbon, and braided superline)
- Small stuff: cord, twine, marline, and accessory cord below ordinary rope diameters
- Which of these kinds and varieties hold for the sense of line this model covers, and on what evidence? provenance
Identifiers and schemes
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Wikidata - Q11010 - Item for rope; English "line" in the cord/rope sense is usually treated as rope or cordage in use, not as a separate item.
- Harmonized System - 5607 - Twine, cordage, ropes and cables, whether or not plaited or braided and whether or not coated or sheathed.
- ISO vocabulary - ISO 1968 - Defines the fibre-rope and cordage terms used in product standards; it is a vocabulary, not a product code.
- Harmonized System - 9507 - Fishing rods, fish-hooks and other line-fishing tackle; fishing line as a retail/fishing-tackle article is classified here rather than under 5607 when put up as fishing tackle.
- Which of these identifiers and schemes hold for the sense of line this model covers, and on what evidence? provenance
Standards and regulation
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- ISO 1968 Fibre ropes and cordage - Vocabulary (International Organization for Standardization)
- ISO 2307 Fibre ropes - Determination of certain physical and mechanical properties (ISO)
- ISO 9554 Fibre ropes - General specifications (ISO)
- ISO 1140 / 1141 / 1346 and related material-specific fibre-rope product standards for polyamide, polyester, and polypropylene (ISO)
- EN 892 Dynamic mountaineering ropes (CEN)
- EN 1891 Personal protective equipment for the prevention of falls from a height - Low stretch kernmantel ropes (CEN)
- NFPA 1983 Standard on Life Safety Rope and Equipment for Emergency Services (National Fire Protection Association)
- Cordage Institute CI-1500 and related CI fibre-rope test, inspection, and retirement guidelines (Cordage Institute)
- OCIMF Mooring Equipment Guidelines, MEG4 (Oil Companies International Marine Forum)
- IMO SOLAS regulation II-1/3-8 and associated circulars on ship towing and mooring equipment (International Maritime Organization)
- OSHA 29 CFR 1926.251 Rigging equipment for material handling (U.S. Occupational Safety and Health Administration)
- UIAA 101 Dynamic Ropes, aligned with EN 892 (International Climbing and Mountaineering Federation)
- Which of these standards and regulation hold for the sense of line this model covers, and on what evidence? provenance
Real-world use
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Ship and boat mooring, towing, and sail handling (hawsers, warps, sheets, halyards, painters, anchor rodes)
- Lifting and rigging: block-and-tackle, crane tag lines, slings, and winch lines on construction and industrial sites
- Climbing, caving, arboriculture, and rescue: belay, rappel, and life-safety ropes
- Cargo and equipment tie-down, guy lines for tents and masts, flag and clothesline halyards
- Commercial and sport fishing: handlines, longlines, and reel line
- Theatrical and stage flying systems
- Oilfield wireline and well-logging cable as a specialised wire line
- Binding and whipping with small stuff in sail lofts, packing, and traditional rigging
- Which of these real-world use hold for the sense of line this model covers, and on what evidence? provenance
Typical measurements
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Diameter - About 0.1-2 mm for fishing line; about 3-24 mm for general working cordage; up to about 80-120 mm for large hawsers - mm
- Minimum breaking force / minimum breaking load - From roughly 0.05-0.5 kN for light cord, through tens of kN for climbing and mooring lines, to well above 1 MN for large synthetic or wire hawsers - kN
- Elongation at working load or at break - About 1-5% working elongation for HMPE and many wire ropes; about 5-15% for polyester; about 10-25% or more for nylon; dynamic climbing ropes are specified by peak impact force and sheath slippage rather than a single stretch figure - %
- Linear density (mass per unit length) - On the order of 1 g/m for light cord, tens of g/m for climbing and dinghy line, to several kg/m for large hawsers - g/m
- Length as supplied or as fitted - Coils and reels commonly 30-220 m; ship mooring lines often around 100-200 m; climbing ropes commonly 50-80 m - m
- Number of strands or braid pattern - 1 (monofilament) through 3 (common laid rope) to 8 or 12 (plaited/braided); kernmantle is core-plus-sheath rather than a strand count - count
- Which of these typical measurements hold for the sense of line this model covers, and on what evidence? provenance
Failure modes and hazards
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Abrasion through on chocks, fairleads, winch drums, rock, or cargo edges
- Tensile rupture with snap-back; stored elastic energy in nylon is a known killing hazard on mooring decks
- Ultraviolet, chemical, and heat damage to synthetics (polypropylene is notably UV-weak; friction can glaze or melt fibres)
- Rot, mildew, and embrittlement of natural-fibre cordage when stored wet
- Hidden core damage under an intact sheath on kernmantle rope
- Strength loss at knots, tight splices, and sharp bends, often on the order of 20-50% depending on knot and fibre
- Wire-rope broken wires, birdcaging, kinking, crushing, and corrosion
- Overload, cyclic fatigue, and shock loading in towing, lifting, and fall-arrest service
- Incorrect retirement: a line that still looks serviceable can have lost a large fraction of rated strength
- Which of these failure modes and hazards hold for the sense of line this model covers, and on what evidence? provenance
Regional variation
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- In English maritime practice, manufactured cordage is "rope" in the coil and becomes a "line" once it is named and put to work; a few shipboard pieces keep the word rope (bell rope, bolt rope, tiller rope). Ashore, "rope" and "line" are often used interchangeably.
- Traditional British and older American sizing was by circumference in inches; modern catalogues and ISO product standards use diameter in millimetres.
- United States fire and rescue service splits "life safety rope" from "utility rope" under NFPA 1983; that split is not universal outside North American emergency services.
- Coir and other local vegetable fibres remain ordinary marine and agricultural cordage in parts of South and Southeast Asia, where manila/abaca and sisal also have long trade histories.
- Large towing and mooring pieces are still called hawsers in many fleets; high-modulus synthetics have replaced much steel wire for tanker mooring under OCIMF practice, but steel wire remains common elsewhere.
- Climbing rope certification is effectively EN 892 / UIAA 101 in Europe and in much of the global market; North American rescue rope is more often bought to NFPA 1983.
- Which of these regional variation hold for the sense of line this model covers, and on what evidence? provenance
Neighbouring kinds and how to tell them apart
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Rope - Rope is the manufactured cordage as a product; a line is that product assigned a job. In non-marine English the two names overlap, so construction, diameter, and rated strength - not the name - decide what you have.
- Cord / small stuff / twine - Same family, smaller diameter and usually not load-rated as working rope. If it is sold as twine or accessory cord and is below ordinary rope sizes (typically a few millimetres), it is cord, not a working line.
- Cable - Either an electrical conductor, a very large fibre rope made by laying three hawsers together (cable-laid), or a shorthand for wire rope. A line is not an insulated conductor; cable-laid fibre is identified by that three-rope construction.
- Webbing / strap - A flat woven textile. The cross-section is planar rather than approximately round, and hardware (buckles, ratchets) differs from rope fittings.
- Chain - Articulated rigid metal links, not a continuous fibre or wire strand assembly. It does not knot like a line and fails by link deformation or weld/pin fracture rather than fibre rupture.
- Yarn - A constituent strand used to build rope or cloth, not the finished tensile member. If it has not been laid, plaited, or braided into cordage, it is yarn.
- Solid wire or rod - A single rigid or only slightly flexible metal element. Wire rope is built from many wires in strands; a rod is meant to take compression and bending as well as tension.
- Hose - A hollow flexible tube whose job is to carry fluid. A line is solid (or a fibre assembly) in cross-section and carries tension, not a fluid.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of line this model covers, and on what evidence? provenance
Sources
- ISO 1968: Fibre ropes and cordage - Vocabulary - Specialist terms for rope, cordage, construction, and related line types; basis for the definition and the construction kinds.
- ISO 2307: Fibre ropes - Determination of certain physical and mechanical properties - Measured quantities used on fibre line: diameter, linear density, elongation, and breaking force.
- ISO 9554: Fibre ropes - General specifications - Product classification of fibre ropes by material and construction, and general performance specification.
- CI-1500 Test Methods for Fiber Rope - Industry test methods and the quantities (breaking strength, elongation, linear density) recorded for fibre rope in trade.
- NFPA 1983: Standard on Life Safety Rope and Equipment for Emergency Services - Life-safety rope as a distinct kind; inspection, retirement, and failure practice in rescue and fire service.
- EN 892: Mountaineering equipment - Dynamic mountaineering ropes - Safety requirements and test methods - Dynamic kernmantle climbing rope as a regulated kind, with impact-force and elongation criteria.
- Mooring Equipment Guidelines (MEG4) - Ship mooring and towing lines in steel wire and high-modulus synthetics; snap-back hazard and in-service retirement practice.
- 29 CFR 1926.251 Rigging equipment for material handling - Workplace use and inspection of fibre rope and wire rope as lifting and rigging gear in the United States.
- The Ashley Book of Knots - Traditional English distinction of rope, line, and small stuff, and the working constructions still named in marine practice.
- Rope - Overview of fibre and wire constructions, materials, and the ordinary range of uses against which the specialist sources sit.
What the second pass must settle
- Where does the registry place the boundaries between line, string, thread, wire, cable, strap and hose, especially for articles with multiple functions?
- Does a short offcut retain line identity, and how should closed loops, joined lengths and branches be individuated?
- Which construction-specific inspection methods and rejection criteria can support decisions about condition beyond visible surface observations?
- Which authoritative sources establish use limits for knots, splices, bends, environmental exposure and repeated loading for each identified line product?
- How should an agent assess an unmarked line with unknown service history when its proposed use requires dependable load capacity?