International 14 Mailing List
| 14 | ||
From: Ted Rogers (twrogers@earthlink.net)
Date: Thu 29 Jul 1999 - 18:33:00 BST
Pete -
By adding a trap-able gantry you ended up finding that the optimum position
for your weight was about 250mm aft of where you were standing on the boat.
But I just cut the corner off the racks on my B2 at nearly 45 degrees, so
we get 2 footloops on the angled part, and suddenly my CG is about a foot
(250mm!) aft of the transom and I don't have to keep my back leg bent. (No
more Elvis leg on the long reaches!) So there are often multiple ways to
achieve the same goal, and some of them will fit within the 14 foot box.....
In terms of real proposals for rotating rig rule changes, it occurs to me
that our masts are round or nearly so because they don't rotate. If they
could rotate, they might get big front-to-back, at some point adding area
to the rig. Perhaps we should simplify the rules by 1) measuring real sail
area, 2) adding the mast area of any rotating mast/double-luffed sail, etc.
to the mainsail area, and 3) eliminate all restrictions on mast & boom
configuration. This would allow us to experiment with new rigs, and give
anyone with a fixed rig about a 2% advantage in total rig area, meaning
that a new rig would need to be significantly superior. (And thus be
something we'd all want to adopt.)
As I watch our class race and evolve, it is apparent that the people who
win regattas are the best sailors, those who have put in the most sailing
time. Some of them are quick to evaluate new developments and make use of
them, but they're usually not the ones actually doing the innovating. With
that in mind, I'd like to see us loosen up the rig rules and turn loose the
techno-wizards of the fleet to see what they come up with. My guess is that
it will take a couple years of experimenting before anyone can come up with
a rotating rig that will give talented sailors like Grant, Charles, or Zach
any reason to switch from their current configurations. And when they do
switch, the rest of us will have something new to seriously consider.
Ted
<p>At 09:47 PM 7/29/99 +1000, Peter Rundle wrote:
> > who would like to see racks extending behind the transom, to allow us
> > to really drive the boats downwind.
>
>About 18 months ago I put a gantry on my boat 12' skiff style that
>could be trapezeed off. This caused a lot of contraversy at the
>Perth nationals and in the end it was one of the reasons why I sold
>my 14. However, I learnt a lot and none it was really all that
>surprising
>to anyone who's stopped to think about it.
>
>It made a huge difference to the nose dive factor. The gantry was built
>so that you could get up to 400mm behind the transom. The idea being to
>do the 12' thing with the skipper entirely on the gantry and the crew
>interlaced with aft foot on the gantry and front foot in the last
>fruttie
>on the hull. This was way way too much. At first we often made the
>mistake of standing too far aft and stalling the boat on the backs of
>waves. In the end we just used to sail with only my rear foot on the
>gantry and my crew had her rear foot in the last fruttie on the hull
>front foot well forward. I think that a 300mm or even just 250mm
>extension is plenty far enough. I doubt that the rule needs to limit
>this as if you stand too far aft it's safe but slow slow slow.
>
>Getting on to the gantry is dead easy and after a while you don't even
>notice you're doing it. The comfort factor too was great, the two of
>us weren't on top of each other, she could work the kite without
>giving me an upper cut to the jaw, and I was no longer always on the
>verge of losing steering control with her pushing me off the transom. We
>still tended to interlace our feet for windage and security though.
>
>It doesn't make the boat go faster in terms of top speed, it just lets
>you keep the hammer down when you might otherwise back off. We did a
>sprint with another 14 in Perth, starting in the very flat water near
>the windward shore and heading out into the bay. The wind was 25-30kts.
>We were neck and neck until it got choppy, then we just left them for
>dead as we kept the peddle down and they had to flag the kite.
>
>The boat also starts to do this kinda scarry thing where it literally
>leaps from wave top to wave top, there's this split second of silence
>and a floating sensation, then a WAM as you hit the top of the next
>wave. But you get used to it.
>
>Observers on the shore said that our boat was pitching back and forth
>more than the others. I think you need to learn where the fine line is
>between safety and speed. Too far aft is slow, the pitching energy is
>wasted boat speed.
>
>The top mark bearaway in strong winds becomes a delight you just step
>back and pull on the tiller extension. The boat pivots on it's transom
>and then takes off.
>
>Hovever there is still a limit, you can't cross Manly ferry wakes with
>impunity. Whilst we never cartwheeled or nosed the boat in, we still
>flagged the kite to cross the big wakes, but we never one wired
>anywhere again and that included a 30kt plus southerly on Sydney harbour
>against the 12's. Man that day was a hoot, these 12's rounded beside
>us and thought that they'd take us downwind and they stood back on their
>gantry's and then we stood back on ours and they just couldn't pass us.
>
>As to the fact that it will lead to finner, flatter hulls I don't accept
>that. The hulls are already as fine as the rules will allow, and fine
>hull are less nosey than fat ones anyway. Dead flat is not fast. I don't
>think anyone would suggest that a boat with a hogged bottom would
>be fast so if you chart speed on the Y axis against rocker on the X
>axis then there must be a point somewhere that will be the best for
>all round performance. That point obviously ain't hogged so unless you
>think that the curve has a sudden sharp drop when the rocker becomes
>dead flat then the optimum point must be somewhere back from that
>spot. In my opinion it's quite a way back. I have raced boats with as
>little as 1" of rocker and they are obviously too far on the flat side
>of the optimum. Very flat boats are not a good all round shape, sure
>they
>can be really quick in narrow ranges, typically just on the edge of the
>planning magins, but upwind speed is the key to winning races and flat
>boats just don't have a good enough range especially when it's light,
>but
>generally upwind is a planning semi-displacement proposition and you
>need
>subtle lines forward not flat as a tack.
>
>Anyway for what it's worth I still think that it was the best $200 I
>spent on my boat and insurance from cartwheels and mast breakages
>alone makes it worth it. But as a 12' footer said, "Hell if you want to
>one wire downwind why don't you buy a Cherub."
>
>rgds
>
>Pete
>
>
This archive was generated by hypermail 2.1.4.