Multi Sailing - Second hand multihulls - 25840 Pulsar 50
Multi Sailing - Second hand multihulls - 22971 M Pulse
Here are two boats I really like for the title of "Ultimate cruising Tri" Both the outside look and the interiors look very functional.
So far I am resting in the 50' area as best length to shoot for to get waht you need as far as functional, carry some stores, brilliant performance etc. Sailing comes first. Good shots of sailing on the second URL.
I recently came across this blurb. I thought I would post it. There are some things I do not quickly agree with, but it is good "food for thought"
. A primer
To achieve real speed and comfort in a ship, the aim is, as Tony Armstrong puts it, "long and thin. But the problem with long and thin is they tend to fall over. They lack what naval architects call stability, which is the ability to come upright. Catamarans get around that beautifully, of course, by putting two long thin hulls side-by-side. And even though there are two, they still have less drag than the equivalent monohull
The inherent stability of a catamaran
is, however, also its biggest drawback - it rolls very quickly and uncomfortably. "If you're not careful with the design of the catamaran, the roll period becomes very similar to the pitch
period and then the boat tends to operate like a corkscrew as it goes along, which is most uncomfortable."
"The trimaran is a slightly different approach in that it's long and thin but to stop it from falling over we've put two training wheels on the side like a kid's bicycle. You're very slippy in the water with low drag, but you don't have the high roll accelerations that a catamaran would have. It combines the wave cutting ability of a mono-hull with the stability of a multi-hull."
** The unexpected pleasures of the trimaran
In developing the trimaran, Austal discovered a number of unexpected pluses along the way. "It's got greater speed for the same cargo weight and the same power compared to a monohull and a catamaran. It's got better passenger comfort, by which I mean less sea-sickness. It's got a better sea-keeping ability - able to operate in higher sea states without something breaking."
Austal also found the trimaran could operate at high speed in much higher wave heights. "When you go out in waves as opposed to a flat, calm water it's better than a catamaran, " says Tony. "And, of course, that's a practical application because, in reality, most boats are operating in waves."
There also proved to be less slamming - water hitting the hull
- which causes huge loads on a catamaran's structure and leads to a very noticeable 'bang' and the whole structure vibrating. "It's just not an issue on a trimaran because we don't have that cross-structure."
Curiously, the trimaran turned out to produce very little wash. "The waves that it makes - which, of course, impacts on the environment
when they come into shore - were fractions of those made by a catamaran. Maybe one-third, one-quarter, something like that. So it's got that big environmental advantage."
Tony can think of only one disadvantage to the trimaran: "It's a little more complex shape to build which, of course, reflects in an increased cost. We're talking five percent more to build it."
from the Benchijigua Express
When Austal delivered the world's fastest and largest aluminum
boat to the Canary Islands in 2005, the work didn't stop there. Benchijigua operated for over a year with a lot of instrumentation on board, gathering data. And, fortunately, the same operator runs two catamarans in the same area, so Austal could make direct comparisons.
"Now, you've got to appreciate that Austal sell both, but we found that power consumption
is reduced about 20% when operating in a seaway compared to a catamaran in that area. And reduced by as much as 50% when compared with a monohull operating in waves. Which is substantial, because all those power reductions equate directly to fuel consumption
"We found the vertical accelerations, which are related to motion sickness, reduced about 30% over a monohull. And this one is a sort of non-scientific comparison but one that I'm sure the general public can identify with - the general store of the ship operator issues only one tenth of the sick-bags to the trimaran that it does to the catamaran."