Recent Blogs
Hermaphrodite Brig: Sail-Area Coordinate Calculator | FIRGELLI
Compare an entered sail-area centroid with a lateral-resistance coordinate. This geometric comparison does not predict helm angle, sailing behavior or a suitable rig.
Full-rigged Ship: Yard Bracing and Geometry
See a three-masted square rig and how its yards turn. Compare two brace angles and calculate yard-end movement and angular allowance.
Full-rigged Brig: Sail Plan and Yaw Moments
Explore a brig’s two square-rigged masts and aft spanker. Compare yaw moments from two entered sail-force resultants and their lever arms.
Brigantine Sailing Rig Explained: How the Two-Masted Square and Fore-and-Aft Mechanism Works
Explore a brigantine’s square foremast, gaff mainsail and headsails, then compare sail area and displacement using the dimensionless SA/D ratio.
Barkentine Sail Plan Mechanism: How a Three-Mast Square-and-Fore-Aft Rig Works
Barkentine sailing rig explained — how the square-rigged foremast and fore-and-aft main and mizzen work together for shorthanded ocean trade and sail training.