Capsize test Northeaster Dory

Builder's Forum
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Well, I finally got around to a controlled capsize in the dory. The first flip is with standard under seat flotation specified in build manual. Pretty much had to stand on the rail to send it over. Positive buoyancy from the under seat foam is pretty impressive.

The one problem I had was the screws holding the forward most seat pulled free. That’s a pretty good indicator of the buoyancy generated by the small blocks of foam under that seat. I’ll replace the original #8 screws with longer #10s. Will also probably have to drill the pine cleats and epoxy in hardwood dowels for a better grip. The pine just isn’t hardy enough.

Second test has more flotation added. Beach rollers are lashed in at aft gunnels. While not specifically designed as flotation they add lots of buoyancy and are made of white water raft material - very tough. I lashed an air bag designed for the bow of a white water canoe. Being designed in a 3D shape it fits the dory’s bow section fairly well and provides a substantial amount of flotation.

Dagger trunk top is clear of the flooded boat by two inches with just the standard flotation. The boat is also pretty stable. Addition of auxiliary flotation raises the trunk top an additional inch or two above water level in flooded boat. Additional flotation also makes it a bit harder to capsize. It tends to hang on the gunnels longer before going the rest of the way over. The boat is stable enough to easily stand in when flooded. Aux flotation increases stability a bit. Bailing the flooded boat took ten minutes with a canvas bucket. I tried several techniques before settling on a good method (for me).

A most surprising finding is the ability to keep water flooding out after the boat is righted. Upon righting the boat is pretty full. Healing a bit to one side allows the buoyancy under the seats to keep lifting the boat as water slips over the side. Patience is your friend, at least in calm water.  

Posting photos here is a pain and I’m lazy so here’s a link to a Flickr album. Click the thumbnails to read description of what’s going on.

https://www.flickr.com/photos/feetwetphotos/albums/

Hope this helps someone.

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   I would be interesting to see this tried in rough water - maybe close to a sandy beach with some on shore wind.

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Here's a subset of the photos (so I'm bored, what can I say?).

Looks like you're ready for an electric pumping system.

Good seeing you at O-fest, wish I'd realized then that that was your boat.

Laszlo

   

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   Thanks Silver Salt for the post and Lazio for the pics from it. I did find the captions helpful so would reccomend going to the link. I have the beach rollers but keep them uninflated since they take up lots of space but haven't tried them where you lashed them. Have you sailed with them lashed on? If so, how did it impact using the boat?  Are you planning a capsize with sail up and rudder attached?

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   Thanks for posting pics Laszlo. Good to see you too. I guess it’s an unusual boat, now you know! How 'bout I drop you a line next time I'm on the South River?


Bearnkar: rollers don’t affect sailing at all. Having anyone in the sternsheets disrupts trim too much and gives me a funky helm. Besides, the mizzen partner and mast do a good job blocking the seat. My Julie and I went out Sunday for what turned into a bob and bake and we decided napping was better than rowing. She reclined back there and noted the rollers make a nice arm rest. There are photos in the Mizzen Retrofit album showing attachment points for rollers.


<“Are you planning a capsize with sail up and rudder attached?”>
No, but it’s inevitable ;-)  


Actually yes at some point. I need to get my front seat secured and finalize some other things like securing the anchor and rode before I do the full cruising outfit test. It will be very interesting to see how the masts and gear affect righting ability.

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   https://www.youtube.com/watch?v=cCwRUwG7JbI