NE Dory Capsize Test

Builders,

I just posted a video of a capsize test we put our Northeaster Dory through this summer.  It was not our first such test, but the first one we tried to film.  I know when I was preparing to build and go out on the Maine Island Trail, I spent a fair amount of time searching for demonstrations of how the flotation held up.

Although it was under ideal conditions (what would you have to do to capsize in a dead calm?), I think our test went well.  Even with me in the boat, there was still some distance between the rail and the water.  Below are the points I put in the video caption, repreduced here for general discussion:

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

- I think (hope) that our dry bags, if well tied down would actually add buoyancy. They float and are large.
- with standard under-seat flotation as called for in the NE Dory plans, we had the topmost plank above the water after righting.
- even with this freeboard, it was very tippy and strong chop would make bailing much more challenging
- I used a 10 quart paint bucket to bail and it took under 3 minutes of bailing to get the water down to safe levels
- based on other swamping tests not included in the video, those small bailers (clorox bottle and small scooper) were nowhere near as effective as the bucket
- the importance of tying everything down was clear. Even with a virtually empty boat, stuff (paddles, sponges, bailers) went everywhere immediately. Not tying down my bucket resulted in a lot of cursing (edited out in post-production) even in a calm test run.
- Finally: could the sail be used as a kind of sea anchor if made fast to the bow!? The way it was floating next to the boat in this video made me think it could be used to keep everyone head to wind if the seas got up. This could make bailing easier and might prevent re-capsizing. Just a thought.


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RE: NE Dory Capsize Test

Interesting video. Would have been good to see the actual re-entry, though. Was the water over your head or were your feet on the bottom?

Laszlo

 

RE: NE Dory Capsize Test

 

From my expedrience the sail adheres to the wate surface by surface tension and makes the capsized boat a little harder to right. One needs to make sure the main sheet and any other sail sheets are running free. A secured sheet can cause the sail to to locked in a position where the boat starts to sail and if the tiller or rudder jams you can end up with pilotless sailboat going off into the sunset withou you.

I wold lower the sail by using the halyard and make sure the mast is secured to the boat or you may watch your sail float away.

If you turn turtle so the mast is pointing down under the boat, the raise sail will act like a giant center board or dagger board. If you need to tow the baot try to right boat or get the sail and mast parrallel to the water surface. You do not want to see what happens when the mast is rammed into the bottom.

 

   

RE: NE Dory Capsize Test

   I would not try that. Water is 600 times as dense as air and with just moving air the sail is not olhy pulling the boat but also the passengers and gear. Just consider how much force the sail can genterate in a current. Large boats have what appear to small sea anchors ant they can hold or slow the boat in some strong winds.

I do not know if you have ever been under a sail while a boat has been capsized, but form sailing sunfishes and sailfishes I can tell you even that small of a sail can ber very disorientating when your head comes up under the sail and all you see in all directions is water below you and white cloth all around you.

 

 

RE: NE Dory Capsize Test

Fascinating. I've wondered about bailing the boat in the event of a capsize. Climbing back in before bailing seems to work in calm water, but I'll probably go over when it's white-capping. I can imagine that waves might lap in over the gunwales, adding water as fast as I could bail it out. . . . At least you've convinced me to carry a 10-quart paint bucket (a good place anyway for holding some rope for anchoring).

Btw, thanks for posting all your other videos. They are helping me survive as I wait for a warm day for varnishing the inside of my new North Easter Dory.   

RE: NE Dory Capsize Test

 

 

 

   Thanks everyone for the interesting comments.  A few points of clarification:

The water was well over my head.  I had to kind of seal/squrim over the rail to get in.  It was really not very hard, but it was awkward looking.  In an earlier test, I did try to "pre-bail" before entering.  Not useful at all.  Entering alone puts the rails under the water and negates any prebailing you might do.  Once sitting on the bottom, the boat doesn't float much lower than without me in it, so I really don't think a pre-bail is the way to go.  

Regarding the sail issue.  This test was very specific to the NE Dory.  I can't imagine a circumstance when you are going to be able to turn turtle in the NE Dory with the mast still stepped.  As long as you are using the wooden mast in the kit, it really really does not want to turtle with the mast there.  I would always free the halyard, etc., before righting the boat (as done in the video) to avoid it sailing away or a recapsize.  In this circumstance, you will almost always have the sail in the water once the boat is up.  In the video, you can see that the yard and boom float while the sail sinks.  This creates significant drag.  If not tied off, I would think you wouldl quickly seperate the boat from the sail in any kind of wind or waves.  

My thought is that if you made off the sail to the bow, the drag on the sail might help keep the bow into the wind while you bail.  Without a way to keep your bow to weather you will take on much more water and be at greater risk of a re-flip.  Probably the safest thing would be to have a real sea anchor on hand for this situation.  Maybe there is a kayak version available.  

The larger question, which has been debated on many internet fora already, is how much flotation is enough flotation.  It is hard to safely test a capsize in real conditions, so most of us are just guessing about whether we would be able to bail faster than water splashes in.  All in all, I was impressed by how high the NE Dory floated with standard under-seat foam.  I was also impressed at how quickly a bucket was able to significantly improve things.  There is no doubt you could still bail even with *some* water coming in.  How much (or at what rate) is the key question.  I can't imagine that there is any open boat (save one entirely filled with foam) that could always be bailed in any sea state. 

Maybe next year I'll find a group of people willing to spot me while I test-capsize in weather.

 

RE: NE Dory Capsize Test

One more thing!

We also tried to shake, thrust, or slosh some of the water out before reboarding as has been advocated in some circles.  The idea is that from a position at the bow or the stern, you can aggresively push the boat and catch her, thus sloshing some of the water out.  This did not work in our tests (again, just tested the NE Dory).  The bulk heads limited flow, so very little water came out.  In the end, entering the boat brings more water back in.  It seems clear to me that the best move is to get back in as soon as possible.  This is probably also the safest option.  Even if you can't bail, sitting half out of the water in a swamped boat is far safer than spending exessive amounts of time in the Gulf of Maine.

Since everyone seems to be ending posts in Latin these days, I thought I would change things up with some Classical Chinese: 水能载舟,亦能覆舟 (shui neng zai zhou, yi neng fu zhou).  "the water can float your but, but it'll also sink her."

RE: NE Dory Capsize Test

   updated video link:  https://youtu.be/cCwRUwG7JbI

RE: NE Dory Capsize Test

Thanks for the update. Seeing the actual re-entry process gives a much better idea of just how safe the boat really is. It's also encouraging that it's that easy to get back into.

Good point about how quickly open boats flood.

As far as the shake, thrust and slosh method not working well - did you remember to shout "Killick you mumping villain! Empty ---- you, empty if you want to keep the skin on your back!" ? I've read that's a necessary ingredient in dealing with Killicks :-)

Finally, 舟 means "boat", not "but", right?   :-) (We really need a way to edit our posts, though in this case, floating our butts is something we all do, so it works).

Have fun,

Laszlo

 

RE: NE Dory Capsize Test

Small sea anchors:  

 http://www.jimbuoy.com/pages/marine/anchors.htm

The small one they recommend for horseshoe buoys is much bigger than the one supplied with my horseshoe, so may be big enough, as buoys have a lot of "sail area".

RE: NE Dory Capsize Test

My EP swamped in seconds.  Once righted and I was back in, the shear dipped below the waterline, making bailing a moot point.  I was rescued by a racing sailboat who used their halyard to haul her aboard.  Since then, I bought two 66# buoyancy bags by Holt for Optis, but which fit great in the cutouts under the center thwart, next to the trunk.  I will test righting it once Green Lake warms up a little.

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