Centaur Keel strengthening

[Guest]

Ok .... here we have a reasonable Centaur with rebedded bilge keels. The silly little transverse stringer fillets fitted to the keel area have delaminated and 'another' surveyor has also recc'd glassing in extra bigger transverse stringers to take grounding loads on a tidal berth......... (Note I do not disagree with him - its another guys boat anyway - but have also other ways to do it etc.)

I have a few ways to strengthen the keel areas - having inspected enough over years to see others ways of doing it.

a) Remove nuts and protect threads - while glassing in heavy matt that is spread longitudinally and transverse easing out to sides to spread load. Set and use larger stainless steel bearing washers etc. to wind nuts onto.
b) Fashion a stainless steel long plate to fit - passing through any stiffeners - the keel bed and wind nuts onto that.
c) GRP rope and matt used in a ctas cradle to increase GRP around all nuts and keel area.

Now for the Centaur owners and others out there - lets hear your solution to it .......

For those not aware - this is a common item on Westerlies ... and immense experience is out there - with some traditional and not so traditional solutions !


<hr width=100% size=1>Nigel ... and of course Yahoo groups :
http://groups.yahoo.com/group/gps-navigator/

 

[wooslehunter]

I have a Centaur that's been done in the traditional way - larger transverse webs. I looked at several boats before I bought mine that had and hadn't been fixed. All the ones that had, had additional webs added.

I can PM you some pics if you want. That's after I've taken them this weekend.

The problem is that the Centaur keels are spread at quite an angle compared to some boats where they are parallel. Hence when the boat grounds, there's an outward force imposed. This is increased when the boat settles into mud. When the boat is pulled out of the mud, the force is reversed. Hence a Centaur on a mud berth will bend the keels in and out. This has the effect of bending the hull in the transverse direction and also stressing the mounting faces and bolts themselves. The fix for the hull is to strengthen the it in the transverse direction. Hence the additional transverse webs.

If I understand your description, you propose beeffing up the hull inside but not including any webs. This would certainly inprove the keel mounts with the larger washers. The additional webs normally add strength over a far larger area to reduce any flexing of the hull.

The idea of the webs is to add a strong T section in the transverse direction. This spreads the load over the entire hull area around the keel bolts as far out as possible. To get the same with just glass and flat steel plate would probably involve more work. Also the steel would have to be shaped to fit a far larger area than just around the bolts which are set into small wells anyway.

I'd go for replacing the delaminated glass and adding nice beefy transverse webs. Like you I'd be interested in any other solutions though. Might be an idea to post on the Westerly owners site.

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[jimbouy]

Hi

Nigel and i are kind of working on this together.

Can you expand on what you mean by Larger Transverse webs.

As the boat is at the moment it has and small webs added.. Triangular webs of around 10" .

The survey or has suggested a much larger web should be added... one in the galley area extending up the hull as far as poss.. ditto opposite.

Is this what has been done to yours?

<hr width=100% size=1> "It is a pleasure to give advice, humiliating to need it, normal to ignore it"

 

[Guest]

I know about the transverse web idea and that it is recc'd by some.

I also am aware of the keel situation having been involved in surveying for quite a few years.

The post was to help a pal of mine to decide what he should do and best approach - as I have ideas and also observations that differ in solution to the problem.

I / we are interested in seeing how many differing solutions come forward - so as to make an informed and intelligent decision to get best result ..... as many are aware - this is a common problem with all BK Westerlies and the different actions all have merit ....

<hr width=100% size=1>Nigel ... and of course Yahoo groups :
http://groups.yahoo.com/group/gps-navigator/

 

[AndrewB]

The two boats I've known that had this done both used method (a). Never owned a Centaur myself, and when I considered it was put off precisely by this problem - some even leaked from new. (Not that there weren't worse examples among the bilge-keelers of the 1970's).

This seems like such a fundamental structural problem that I'm amazed by their continuing high reputation and second-hand value, compared for example with other very similar bilge keelers of the time like the Kingfisher 26 which spread the load and so don't suffer from this problem.

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[Guest]

Most of the boats that don;t display similar problems or splay keels are those that have generally moulded in keels - instead of bolted on.

Even with a vertical keel bolted on - you can still get tremendous pressures exerted in that space between the keels when they take ground in mud etc.

Westerly are not unique in this area and I have witnessed many another marque with weeping keel joints to hull and them out of line / splayed etc. But yes - the Westerly has a known reputation for it. The Griffon I have seen some pretty awful examples of underhulls and strengthening - but they suffered changes in models - like the Club etc. each one addressing different issues.

Now I do not want now an inundation with irate Griffon owners berating me about their wonderful boats ..... EVERY boat manufacturer has its good and bad examples ...... its just that westerlies are so popular and law of averages says .... the more there are - the more you'll see problems ....

I agree with another post that there are many other boats out there with good accommodation etc. similar size and less problems in this area. In most cases less price too ...so what is this phenonemum the Centaur and why does it command such following >>>>?


<hr width=100% size=1>Nigel ... and of course Yahoo groups :
http://groups.yahoo.com/group/gps-navigator/

 

[[448]]

Re Kingfisher 26. We have had one here for 35 years that that has dried out twice every day apart from maybe 2 or 3 winters when she has been ashore for her 10 yearly checkup. Bottom is firmish sand. The harbour is not particularly well sheltered, and apart from a quay/breakwater is wide open to SE gales. She has had absolutely no problems with keels. Built like brick s***houses these boats.

Cheers, Dave

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