----- Original Message -----Sent: Wednesday, April 15, 2009 1:25 PMSubject: Re: [harryproa] Rare Bird's Race and stainless rudder pin failureHi,
Titanium is strong and light and resists corrosion very well.
It is expensive, but these are vey important parts, so why not titanium??
-Arttu
Hi all,
>
> We gave the fleet 5 minutes start off Manly and followed them out of
Moreton Bay. The big dedicated race boats steadily drew away from us
cruisers. All the other boats had down wind sails
(genoas/genniker/screechers) and the breeze was either too gentle or too
far abeam for us to use the kite, so we were immediately at a
disadvantage. Despite this we caught and overtook the Seawind halfway
out of Moreton Bay, and overtook Catalina on a broad reach before they
overtook us again downwind with their extra sail.
>
> After that we kept Catalina in sight for the next 80 miles, before her
sternlight faded in the distance off Fraser Island. Rob hit the sack at
8pm and for the next 3 hours I enjoyed blasting north through the night
in 1-2 meter seas with 1-2 meters chop, in a 15-20 knots Easterly, speed
ranging from 9 to 13 knots. Front rudder was left to do its own thing
(swinging 5 degrees maximum) and the aft rudder easily steered, mainly
by foot, as I sat on the comfy seat.
>
> When Rob took over he reefed both main and jib, as the winds were
forecast to increase. He still was doing 8-9 knots and was still
steering only with the aft rudder. He'd only been at the helm less than
an hour when he heard a small bang, and though the boat was still
steering OK, he took a look around and discovered the forward rudder
hanging sideways. The 19mm stainless rudder pin had broken at the lower
mounting point (where it passes through an incredibly fine carbon mount
- it is about 1 cm x 1cm in cross-section, and there are two of them).
The mounting point was still intact! The top quadrant ( see pictures on
harryproa.com) was broken when the cassette went sideways. It is
repairable.
>
> We had to retire , and when we had motored back to Mooloolabah,
discovered that the shaft was corroded almost completely through. The
reasons? The best suggestions I've heard are
> 1. Stainless of less quality than specified, and/or
> 2. Galvanic action between stainless and carbon
> Any comments?
>
> I think I will replace both pins with carbon fibre rod - or maybe go
for 321 stainless - boatbuilder comments?
>
> Despite the failure I'm very impressed with the Visionarry's overall
performance:
> - very comfortable motion in messy seas (my other half had only
previously had ONE gentle sail on Moreton Bay, and she still wants to do
more sailing)
> - easy sail handling, just a couple of steps from the cockpit
> - quick shunting ( our best time about 30 seconds )
> - excellent upwind performance (45 degrees off true wind)
> - easy control downwind
> - very fast on reach - close to wind speed in ideal conditions
> - could easily handle a lot more power and be seriously competitive
> - well suited to short-handed cruising
>
> Cheers,
>
> Col Campey
>
>
>
> --- In harryproa@yahoogroups.com.au , Mike Crawford <jmichael@...> wrote:
> >
> >
> > My guess is that the posts are the vertical axles for the two wheels
> > (not sure "wheels" is the right word) on which the rudder cassettes are
> > mounted. The rudder would certainly fail if one of these fail.
> >
> > I can't see this being a flaw in the design, though. Because they are
> > so short, and handle very little bending moment, these posts should have
> > lower loads than a normal multihull rudder stock. And anything that
> > fails due to corrosion is likely to... fail due to corrosion.
> >
> > That said, I do look forward to seeing how the new beam-mounted design
> > works on Blind Date this summer. It's a nice way to handle kicking up
> > in both directions, balancing the rudder forces as they are raised, and
> > concentrating forces on a very strong structural member.
> >
> > - Mike
> >
> >
> > Doug Haines wrote:
> > >
> > >
> > > so it was 316 SS? rare bird was the board in case design lasts i recall.
> > > was it changed to a post?
> > > or you mean the shaft in the board was steel? very strange.
> > >
> > > --- On *Tue, 14/4/09, Robert /<cateran1949@...>/* wrote:
> > >
> > > From: Robert <cateran1949@...>
> > > Subject: [harryproa] rare bird.
> > > To: harryproa@yahoogroups.com.au
> > > Date: Tuesday, 14 April, 2009, 9:28 PM
> > >
> > > Rare bird suffered a corroded rudder post. It was supposed to be
> > > stainless 3.6.1. The posts are going to be replaced with carbon
ones.
> > > The owner reckons it was remarkably comfortable at 13 knots in a
> > > bit of a sea
> > >
> > >
> > >
> >
>
>
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