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Canting keel

How does a canting keel work? · Standard part · basis: Design rules and figures from the cited sources; example geometry by Xem Studio

Also called: cant keel, swing keel ballast, VO70 keel, IMOCA keel, canting keel rc, canting keel daggerboards, keel cant angle

Exact dimensions. True size, with no printing tolerance added.

sizes
3 in table

Notes

  • A canting keel swings its ballast bulb to windward on a strut, giving righting moment with the boat nearly level; separate daggerboards then provide lateral resistance (Wikipedia).
  • The VO70 cants up to 40 deg; its 6.5-ton bulb gives over 176,000 N m of righting moment with the hull level. Failures of rams and seals have caused sinkings (Wikipedia).
  • Used on: Volvo Open 70, Wild Oats XI, Hugo Boss.
  • The file is a reference example built by Xem Studio from the numbers above (Cant 40 deg (VO70); size from IOM fin reference.). Sizes the sources do not fix are illustrative; scale the example to your own vehicle.

Canting keel size chart

parametervalue or rangesource
VO70 cant angleup to 40 degWikipedia (Canting keel)
VO70 righting moment level>130,000 ft lbf (176,000 N m)Wikipedia (Canting keel)
Banned in America's Cup class2007Wikipedia (Canting keel)

Where the files are

Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.

WikipediaCanting keelwebPublisher's page; dimensions are facts

Free files

★ Free files 1 parts. Xem Studio design: free to use, print and sell things from; not to be republished as files. Xem Studio Design License. index.json

canting-keel-appendagecanting keel: 420 mm deep, 60 mm chord, NACA 00-series foil, bulb Ø40 × 180 mmSTEP · STL
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Plain text: sheet.txt · JSON: /api/geometry?object=canting-keel

Canting keel, isometric render of a generated part
Render of canting-keel-appendage from the free STEP; not to scale.

Fits with

Fin keel with ballast bulb, isometric render of a generated part
Fin keel with ballast bulb5 sizes★ 1 file
Spade rudder, isometric render of a generated part
Spade rudder6 sizes★ 1 file
Skeg-hung rudder, isometric render of a generated part
Skeg-hung rudder2 sizes★ 1 file
Daggerboard, isometric render of a generated part
Daggerboard2 sizes★ 1 file
Centreboard, isometric render of a generated part
Centreboard1 sizes★ 1 file
Rigid wing sail1 sizes★ sheet

Questions

Why daggerboards too?

The canted fin no longer gives enough lateral resistance (Wikipedia).