Sven Yrvindvideo
Cheap line tensioner for my inside steering.
August 12, 2026 · 3 min · 2K views
What this video covers
Sven Yrvind demonstrates a low-cost line tensioner built for inside steering on a small boat.0:17 The device uses a weighted line tensioned by a sweat-and-tail method against a camcleat, a knob, and a hole that keeps the line positioned correctly when pulled sideways.1:11 The capstan equation governs the design: friction over an angle in radians reduces the input force to one-tenth, so a 150-kilogram working-load component can hold 1.5 tonnes.0:48 Pulling the line sideways across the knot multiplies force by a further factor of three, achieved by offsetting the attachment point 2 centimeters over a 6-centimeter span.1:57 The arrangement replaces four rope clutches — two per side — that would otherwise be needed for the steering system.2:54 Yrvind notes the solution is primarily intended for his next boat, where eliminating rope clutches reduces cost significantly.2:33 The capstan equation's mechanical advantage makes a simple, cheap fitting adequate where an expensive clutch would otherwise be required.
More from Sven Yrvind
From Sven Yrvind — see the channel’s boat, crew, and every analyzed video.
The Sailing Directory Newsletter
One email with the fleet's best finds — the moments, boats, and stories worth your watch time. Enter your own address to get your own copy.