Multihull Structure Thoughts

[skaraborgcraft]

Not a Hirondelle 20, but a "cracksman"

Cracksman 20 - Wikipedia

en.wikipedia.org

 

[oldmulti]

Skarabougcraft. The Hirondelle 20 and "Cracksman" sold very well at the time. The Hirondelle was extended and subsequently widen in later production versions. The Chacksman had a bigger cabin put on but both cats suffered the same problem. They were good cats but the cost of building them increased to the point where they were uneconomic to produce at an affordable price. People were prepared to pay twice the price for a cat EG 4 foot longer cat with more space or performance, but a solid smaller cruising catamaran needs to be as cheap as a Hobie 20 or I will choose the Hobie 20 type thinking.

Reality there is a market for a smaller cruising catamaran but only at a price people can afford, and our society is dividing into a few people with a lot of money and many with a little money and many expenses.

 

[HelmutSheina]

Back in 2019 we published a small catamaran design by Mark Grumpecht. Mark built the design in a year himself but I could not find any plans for the design. The cat was later sold and no further details came forth. A small request and hopefully someone can lead us to the plans of this cat. I do not know if Mark is still active or someone has a copy of the plans. If they do, could they please advise us as the design looked good.

Mark Grumpecht small cruising catamaran is 22 x 8.5 foot weighing 1900 lbs with 24 foot wing mast as used on his Drifter 17 trimaran design. The cat has a lifting centreboard and central rudder. Mark designed and built the cat in one year. It is plywood with light e-glass cloth outside. It uses mahogany wood on the interior and for some framing etc. I do not know any structural dimensions. The cat has aft sugar scoops with steps.

The cat is trailable on a 3500 lbs capable trailer (the trailer weighs 700 lbs). The engine is a 6 HP long shaft outboard. The custom mast raising rig, uses trailer winch. The cat has two single speed winches mounted on the cabin top. The cockpit is 5.5 x 6.5 foot and the cat has a micro galley with a 2 burner propane cook top and small sink. The cat has a custom private head with door on port side and a thetford porcelain marine head. The cat has a double berth with 2 child single berths. The front mini tramp can have 1 adult or 2 children on it is very comfy and cool to be on while sailing or at anchor. The cat is a coastal cruiser that is claimed to perform well.

The jpegs give the idea but we need more detail please.

OM, Mark Gumprecht did a 17' Drifter Tri also that had a small cabin, and I cannot find any plans for it. i sent an email to an address he had on plans for a smaller Tri and heard nothing back, but old emails die too.

Building the Drifter 17 Trimaran – Interview with Mark Gumprecht

The Drifter 17 trimaran is a fabulous-looking craft built by Mark Gumprecht. Having previously designed, built & sailed smaller tris, Mark has spent recent months building this beauty, which features both cockpit and small cuddy cabin for camp-cruising. And it's all set upon a platform with a...

smalltrimaran.co.uk

 

[brian eiland]

Both the world’s largest sailing multihull (58m) and what is rumoured to be the largest ‘proper’ sailing monohull (as opposed to sail-assisted) at around 120m, are in fit-out today and will sport DynaRigs. First seen on Maltese Falcon 25 years ago, these freestanding masts rotate so the yard arms and soft sails can be set to suit the wind angle.

Southern Spars the proven DynaRig is the answer for certain sizes and applications, especially with the 3 latest projects it has in production. In cost and practical terms, it makes much sense – for vessels over a certain size (around 65m+ LOA) and for passage making, it is hard to match.

I was also much inspired by the dynarig development as it was introduced on MF.
This was my interpretation on a catamaran,..
DynaRig MotorSailer https://www.runningtideyachts.com/dynarig/

 

[brian eiland]

 

[jamez]

Hi folks,
While rummaging through some old files I found the following which I think I got from a member called Oldsailor (hope your still out there mate) many moons ago. Anyway I know some of you are interested in the older 1960-70s trimaran designs. There are a bunch in this document which looks to be compiled from a number of old plans catalogues. Enjoy.

 

[HelmutSheina]

Hi folks,
While rummaging through some old files I found the following which I think I got from a member called Oldsailor (hope your still out there mate) many moons ago. Anyway I know some of you are interested in the older 1960-70s trimaran designs. There are a bunch in this document which looks to be compiled from a number of old plans catalogues. Enjoy.

Thanks for this, there is even a couple of tris by some Skip Johnson bloke who just happened to like your post.

 

[Skip Johnson]

Thanks for this, there is even a couple of tris by some Skip Johnson bloke who just happened to like your post.

Ah but not that Skip Johnson ;-)