bilge keel

shipbuilding

Also known as: bilge piece

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Last updated

June 22, 2026

Quick Summary

A bilge keel is a projection, similar to a fin, that extends from the hull of a ship or boat on either side, near the turn of the bilge. These keels run parallel to the main center keel and are designed to reduce or check the rolling motion of the vessel. They are a common feature in shipbuilding, particularly on larger ships where their projections might be slight, and on smaller yachts where they can be more pronounced.12

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ship
Ship motions in response to the sea
…ships are fitted with “bilge keels” in an attempt to dampen roll. These are long, narrow fins projecting from the hull in the area where the bottom of the hull meets the side. Bilge keels are effective in reducing roll, but they are much less effective than other measures.…
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…ships are fitted with “bilge keels” in an attempt to dampen roll. These are long, narrow fins projecting from the hull in the area where the bottom of the hull meets the side. Bilge keels are effective in reducing roll, but they are much less effective than other measures.…
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keel
A “bilge keel” is one of a pair of longitudinal plates that, like fins, project from the sides of a ship or boat and run parallel to the centre keel. They are intended to check rolling. On large ships the outward projections of the bilge keels…
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A “bilge keel” is one of a pair of longitudinal plates that, like fins, project from the sides of a ship or boat and run parallel to the centre keel. They are intended to check rolling. On large ships the outward projections of the bilge keels…
Read More

William Froude
…be reduced with a deep bilge keel, a finlike projection stretching horizontally along both sides of a ship below the waterline. The device was adopted by the Royal Navy.
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…be reduced with a deep bilge keel, a finlike projection stretching horizontally along both sides of a ship below the waterline. The device was adopted by the Royal Navy.
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