Thursday, March 20, 2008

Melonseed



This is a photo taken by Andy of Mike sailing Pepita. It is clear how Mike must use his body mass to balance the force of the breeze on the sail. Most small craft have no ballast other than the mass of the hull plus the live weight of the crew.

Melonseeds are a typical local small craft, rising to perfection in the 1800's, indigenous to the bay and marshes of NJ. They are thin water boats that can skate over mud flats and be poled over marsh grass & weed. They show sustainable practices in several ways; structure, continuity of community, materials, and uses and aesthetics. There are still builders of both the wooden ones and plastic versions. Pepita, above, is a wooden version off Chappelle's plans, strip built by Carl W. of red cedar using Titebond III adhesive, a waterbased glue. Strip building produces a clean (not lapstrake) hull which is commonly sheathed in glass to produce a monocoque structure. Wish you could see Pepita close up. She has some beautiful details in her decking and spars.

Urchin, by contrast is an open lapstrake boat. She has no decks. She was designed as a pulling boat for the Salibury River in Massachusetts. The loosefoot lug sail has quite a bit of twist sailing to windward which makes it lose power. The sailmaker has provided two rucking lines on the leech and foot of the sail so in light air I can change the shape of the sail by adding fullness. In strong breezes I flatten the sail by letting them loose. In actuality this system is almost self tending as a stronger gust will blow out the lines from the small jam cleats on the clew of the sail.

1 comment:

Professor Fleming said...

Hi, can a building be self tending - that is react in a low energy way to changes and flucuations in weather, wind, temp, etc..
or do people have to do some work i.e. typical sailing, or should we have computers make measurements and have the building adjust automatically...

i suspect that you will say people can "sail" a buildng adjusting windows, blinds and other settings as needed...so each person in such a building has to learn to sail in order to get maximum performance - but where is te incentive otehr than maintaining human comfort???