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Furlers

Specifications for continuous line furling systems used for Code Zeros (Bottom-Up) and Asymmetric Spinnakers (Top-Down).


Continuous line furlers allow for the handling of flying sails that are not attached to the forestay. The system consists of:

  • Drum (Swivel): A continuous line driver at the tack.
  • Top Swivel: A free-spinning swivel at the head.
  • Torsion Cable: Transmits torque from the drum to the head (critical for Top-Down).
  • Continuous Line: An endless splicing line for operating the drum.

  • Mechanism: The tack is fixed to the drum. The sail rolls from the bottom up.
  • Cable: The sail luff often encloses the cable, or the cable is integrated into the luff tape.
  • Application: Code Zeros, Staysails, Drifters.
  • Requirement: Sufficient luff tension to furl effectively.
  • Mechanism: The tack is free-rotating on the drum. The drum drives the torsion cable first, transferring torque to the top swivel. The sail starts rolling from the head down.
  • Cable: Essential “Anti-Torsion” cable (AT Cable) separate from the sail luff.
  • Application: Asymmetric Spinnakers (A2, A3), Gennakers.
  • Benefit: Allows furling of sails with deep draft and loose luff.

Critical for the function of the system.

TypeConstructionApplicationTorque Transfer
Standard ATPolyester/Spectra core + braided coverCruising Code 0Good
High-PerformanceDyneemaSK78/99 core + Technora coverRacing Code 0Excellent
Top-Down DedicatedMulti-layer braided coversTop-Down SystemsMaximum (Critical)

Common specification reference for UBI Maior FR series furlers.

ModelSafe Working Load (SWL)Boat Size (Ref)Drum ØLine Ø
FR 871300 kg20-30 ft87 mm8 mm
FR 1002200 kg30-38 ft100 mm8 mm
FR 1254000 kg38-45 ft125 mm10 mm
FR 1505000 kg45-55 ft150 mm10 mm
FR 1758000 kg55-70 ft175 mm12 mm
FR 20012000 kg70-90 ft200 mm12 mm

Features:

  • Rewind®: Ratchet system (available on some models) to prevent accidental unfurling.
  • Top-Down Adapter: Optional tack swivel attachment for converting a standard drum to Top-Down.

(Note: Other common brands include Karver (KF), Facnor (FX), Selden (CX/GX).)