why are there windows in the keel of a 540e
Printed From: myHanse.com
Category: General
Forum Name: Chit Chat
Forum Description: Talk about anything to do with your boat
URL: https://www.myhanse.com/forum_posts.asp?TID=15533
Printed Date: 27 March 2026 at 01:44
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Topic: why are there windows in the keel of a 540e
Posted By: GerardR840
Subject: why are there windows in the keel of a 540e
Date Posted: 21 February 2026 at 15:07
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After sandblasting the 2,9 meter keel of my Hanse 540e (2007) we found two larger windows in the keel (approx 65 cm x 30 cm ). We cleaned them and filled them with XPS (expended polystyreen) before closing with epoxy. the question is : why were these installed ? original or later ? see pictures. Thanks Gerard 
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Replies:
Posted By: Arcadia
Date Posted: 21 February 2026 at 17:57
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I believe the purpose was to minimize the weight of the upper iron portion while concentrating the weight lower in the lead portion. This effectively lowers the center of gravity of the overall structure. A much better result than the newer all iron keels we have now. Your design certainly was more costly and as usual was changed by the accountants. ------------- Leon / ARCADIA 2018 Hanse 588 Sag Harbor, NY |
Posted By: Black Diamond
Date Posted: 21 February 2026 at 22:43
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I'm obviously not a naval architect, but isn't there an opportunity to improve sailing performance and perhaps make a stiffer boat by filling it with something heavier than epoxy? It certainly wouldn't change the draft. For that matter, a while ago I looked into a MARS keel for my 575 to reduce draft but preserve sailing performance. Never did anything, but isn't this a similar opportunity? I get that having it the way it is lowers the center of gravity, and that it was designed that way, but that was also a cost decision by Hanse (not making it all lead). Do other options present themselves? Curious..
------------- Rick S/V Black Diamond Hanse 575 Build #192, Hull# 161 Newport, RI |
Posted By: Arcadia
Date Posted: 21 February 2026 at 22:56
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The total weight of the keel is a fixed amount set by the design of the hull shape, rig and other design factors. The only options for the builder is how to get it as low as possible getting the righting arm as large as possible for a given weight. An all lead keel would only raise the CG. That’s why ultra performance boats often have lead bulbs hung from light weight foils. ------------- Leon / ARCADIA 2018 Hanse 588 Sag Harbor, NY |
Posted By: Arcadia
Date Posted: 21 February 2026 at 23:19
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To put it another way, the less you put up high means the more you can put down low. Iron, especially with windows cut out is less than half the weight of lead, making it a good inexpensive choice for the foil. ------------- Leon / ARCADIA 2018 Hanse 588 Sag Harbor, NY |
Posted By: Arcadia
Date Posted: 22 February 2026 at 06:51
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Just curious Gerard. What were the original windows made of and was the void empty ? ------------- Leon / ARCADIA 2018 Hanse 588 Sag Harbor, NY |