Definition
A tripping line is a secondary rope or cord used primarily in nautical rigging to release, disengage, or “trip” a primary line, sail, or piece of equipment quickly and safely. The term derives from the verb “to trip,” meaning to cause something to become disengaged or to fall away.
Nautical usage
- Sail handling – On sailing vessels, a tripping line is often attached to a sheet, halyard, or the tack of a sail. By pulling the tripping line, the crew can release the main line without having to handle the heavier or more critical line directly, facilitating rapid sail changes or emergency douses.
- Gaff and spritsail rigs – In traditional gaff‑rigged vessels, a tripping line may be secured to the gaff or peak halyard. When tensioned, it pulls the gaff out of the gunwale or releases the peak halyard, allowing the sail to be lowered or taken down quickly.
- Winches and block systems – Small tripping lines are sometimes wound around a winch or run through a block to act as a backup release mechanism. If the primary line jams, the tripping line can be pulled to free the system.
Industrial and safety contexts
Outside of sailing, the phrase “tripping line” is occasionally used in industrial settings to describe a cord or wire that, when pulled, activates a safety device or initiates the shutdown of equipment (for example, a tripping line on a conveyor belt to stop motion). Such applications are not standardized and the term is largely descriptive rather than technical.
Design characteristics
- Material – Typically made of durable, low‑stretch synthetic fibers (e.g., nylon, polyester) or natural fibers (e.g., hemp) to withstand marine conditions.
- Length and diameter – Chosen to provide sufficient leverage while remaining manageable; common diameters range from 4 mm to 8 mm, with lengths varying from a few metres to the span required by the specific rig.
- Attachment – Connected to the primary line or equipment via knots (e.g., a bowline or figure‑eight) or dedicated hardware such as shackles, eyes, or dedicated tripping‑line cleats.
Operational considerations
- Redundancy – Tripping lines are employed as a redundancy to ensure that a sail or piece of rigging can be released even if the primary control line fails.
- Ease of access – They are positioned where crew members can reach them quickly, often leading back to a central cockpit or deck area.
- Maintenance – Regular inspection for chafe, corrosion, and UV degradation is required to maintain reliability.
Etymology
The word “tripping” in this context originates from the Old English trypian meaning “to stumble, cause to fall,” which evolved into the modern sense of “to cause to disengage or release.” The compound “tripping line” thus literally denotes a line used to cause a release.
See also
- Sheet (sailing)
- Halyard
- Sail furling
- Block and tackle
References
- Admiralty Manual of Seamanship (UK) – sections on sail handling and rigging.
- “The Art of Sailing” by John Rousmaniere, 1999 – discussion of auxiliary lines for sail control.
- International Maritime Organization (IMO) guidelines on emergency sail release systems.
Note: While the term “tripping line” is well documented within nautical literature, its usage in non‑nautical industries is informal and lacks a standardized definition.