Furling Drum

The rotating lower component of a furling system that winds or releases the control line to turn a sail foil or stay.

In a headsail furler, pulling the furling line rotates the drum and foil to roll the sail; unfurling the sail rewinds the line onto the drum. Some systems use continuous-line drums rather than storing turns conventionally.

Correct line lead, number of turns, halyard angle, bearing condition and load control prevent overrides, halyard wrap and incomplete furling. Reefing loads may exceed those for furling a fully eased sail.