Free design for a canoe style boat.

[Guest625101138]

Originally Posted by fishy1

What program are you guys using to generate the green designs of boats I keep seeing, and where can you get it? Just seems like a pretty useful tool.

It is called DelftShip. There is a free version here:
http://www.delftship.net/
Log in and download it. It will be the best 5 minutes you will spend if you have an interest in boats.

I have attached an fbm file of a boat that sort of matches your needs. This can be opened with Delftship. It is a good place to start if you want to design your own. It would be suitable for stich and glue. It would only need to be glassed on the outside and in the cockpit as the hull is self bailing with the cockpit. The enclosed sections give good structural rigidity even with light sheeting.

You can produce sheet developments using Delftship. Takes a bit of work but much faster than laying sheets over a frame.

The boat has not been built but it will perform well. It is not super stable but fine for sitting and OK for standing if careful. You could make it wider but this will reduce performance somewhat. Depends on what ballance you want to strike between speed and stability. It could be lengthened if you want two rowing positions.

Rick W.

[Gilbert]

I don't think anyone mentioned that a second pair or oars is a significant expense in a small boat and they also take up room when not in use.

[fishy1]

But when not in use, the oars don't need to be taken along. Price of 2 oars is not much compared to total price of boat.

[kengrome]

I have attached an fbm file of a boat that sort of matches your needs. It would be suitable for stitch and glue.

Rick, how refined is this hull shape? Have you run it through michlet / godzilla or is this just a starting point?

I downloaded your .fbm file and made the layer transparent, turned on the station visibility, and took a look at it more carefully. It seems this would be a very easy boat to build by carving the shape out of a big foam block, then covering the whole thing with epoxy and glass to create a monocoque structure -- kind of like a "surfboard canoe" or maybe a "surfboard rowboat" ... or a "sit-on-top rowboat" perhaps?



The transom should be wood for the outboard of course. Wooden gunwales pre-drilled for oarlocks every 6 inches (and glassed into the hull) might be an ideal way to provide both multiple and adjustable rowing stations, too. My thought here would be to use full length bowstem to transom wooden gunwale logs and glass them into the hull to add longitudinal strength to the hull, even though the added strength probably wouldn't be necessary.

What do you think about this type of construction?

[Guest625101138]

Ken
It is a Godzilla optimised shape for a transom and stability criteria suitable to stand in (with care) - KMT = 0.6m. I cannot remember the design speed but it will do 4.6kts with 100W into an efficient prop or maybe with 120W using paddles.

It has rounded edges for glass moulding over foam but could also have hard edges for stitch and glue. As it is, it was designed for total displacement of 120kg. Would need to be increased in volume a bit to carry two.

Polystyrene foam is OK but you need to use epoxy resin with this. I find polyurethane foam too flexible for long hulls but if it was solid or with plenty of ribbing it would be adequate as well - a timber keel and timber gunwale as you suggest would help keep the shape during layup. Polyurethane foam with three layers of 200g/sq.m should be a nice strong boat. You might want to lift the transom a bit for an outboard.

Rick W.