Subject: [harryproa] Schooner vs. Telescoping |
From: "Mike Crawford mcrawf@nuomo.com [harryproa]" <harryproa@yahoogroups.com.au> |
Date: 11/18/2018, 6:50 PM |
To: harryproa@yahoogroups.com.au |
Reply-to: harryproa@yahoogroups.com.au |
<<Perhaps Robs telescoping masts makes sense, as the masts can
fit on the trailer. Also the shorter mast is perhaps easier to
wield.>>
Erutan,
You've zeroed-in on the largest remaining question about what I
would choose.
SCHOONER RIG
Being the conservative kind of guy that I am, I'm currently in the
schooner rig camp for the following reasons:
- Steering. You can steer and shunt the boat with the
schooner rig even if both rudders are taken out. You could even
beach the boat, fix it, and launch it back through (calm) surf
without rudders, and then sail it home. Depending upon skill and
weather.
- Emergencies. You could carry two short masts in the
hull space between the beams, which could also double as lifting
masts to hoist the primary masts into place. So you could: a) have
two emergency masts on-hand, if you need them for some reason, and
b) you could beach the boat and remove the masts for work with just
one or two people. The emergency masts would be slow, but they'd at
least be present. Or maybe fasten the short masts to the beams
themselves if it's too hard to find a way to get them in and out of
the hull. Or just make the emergency masts in four sections each
and assemble them when needed.
- Accommodations. That space between the masts could
also house one or two pipe berths and/or a second head. Or at
least a compositing toilet with a curtain. A great place for the
kids to stay up late and talk too loud about boys, girls, or Call of
Duty.
- Stresses 1. Putting the masts right next to the beams
lets you build a much stronger boat with much less material --
handling torsion over the distance between a central mast and
outboard beams is not trivial, particularly if you want to
incorporate one or more openings.
- Stresses 2. While the total heeling moment won't
change, each mast would only be applying half of the total force to
the boat, and would be putting that force much closer to the beam
that resists it.
- Sail area. You can put up a honkin' amount of sail
area while still fitting under the ICW bridges and/or staying within
trailer limits. With a lower COE than a single rig.
- Shipping. Twin 46' upper masts (stub mast in the lw
hull) would easily fit into a 48' high-cube shipping container.
Maybe 50' masts in an extra-long 52' container -- because an EX48
maxiTrailer would need a container larger than 48' unless the lw
hull bows are removable. Assuming the ww hull fits into the
high-cube dimensions, which is probably the real limiting factor.
- Shade. How cool would it be to string up some dyneema
lines from the cabin roof to the two masts and run a tarp between
then while at anchor? A half-acre of shaded deck/tramp space.
- Simplicity. You'll never have to worry a about a
non-telescoping mast jamming in the up position during a storm.
There's also no joint to deal with when figuring out how to get a
bolt rope, mast track, or mast hoops to transition from the lower
section to the higher section.
- Righting. It's possible, in theory, to right a
weight-to-windward proa in a knockdown, depending upon the sea
state. Sealed unarig masts would offer more stability and flotation
than a single telescoping rig.
TELESCOPING RIG
Yet despite all those reasons, the convenience of a single mast
still calls.
- Sail area up high. Okay, I just said that I like
having a lower center-of-effort with a schooner rig. Which is true
when the wind picks up. But when the wind is really light, there's
more of it the higher you go, and a super-tall mast is a great way
to consistently move across the water with wind in your face on days
when a normal rig might leave you just sitting still.
- Single mast for shunting. It's possible that with
deep enough rudders, the right hull rocker, and backwinding the
"jib", a schooner rig will tack. Or not. In which case shunting a
single taller telescoping rig takes half the effort of shunting a
pair of shorter rigs.
- Sail area at anchor and in storms. A single retracted
telescoping mast will probably present less of a heeling moment
under bare poles than the pair of fixed masts on a schooner rig.
---
Basically, since I want to eventually go places in the boat, the
schooner rig is really the only option that fits my safety criteria.
But because it's about five miles out to open water for me,
through an inlet that ranges from 1/4 to 1/2 mile wide, the
telescoping rig still calls to me. That's a lot of short-tacking
today in the catamara, and wold be a lot of short-shunting in a
proa.
The good news is that with the proa I'd never have to worry about
blowing a tack to close to shore and then heading into the rocks.
But the thought of shunting one sail instead of two is still
attractive. I can see why someone else would choose it.
- Mike
| My goal is the largest transportable boat at 10' to 12' wide on the trailer (no lead or tail "wide load" vehicles required), that can be folded safely while on the water, and trailered by two adults.
This is probably exactly my desire. I might add quick set up and take down. But that speed might come from refinement through experience.
I am hoping I can tag along with your mods to the EX40. I think it would be great for HP's to have a pair of sister HP's. Also, I don't know enough about sailing to know what I want, or where I want it, or why.
| The proa would be much faster, safer, more seaworthy, and also less stressful to trailer with mast-raising assist poles that hoist the masts up at their center of gravity and allow you to drop them into their casings. I like the mast-raising setup on the trimarans, but it only works on the trailer, and it involves huge horizontal stresses on the mast bearing in the early phase of raising it up.
Perhaps Robs telescoping masts makes sense, as the masts can fit on the trailer. Also the shorter mast is perhaps easier to wield.
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