Capsize Test

Welcome to PocketShip.net! This bulletin board is for builders of the Chesapeake Light Craft-John C. Harris "PocketShip" design, a 15-foot micro cruiser sailboat built from a kit or plans.

For more information on PocketShip, click here: http://www.clcboats.com/pocketship

This site gathers PocketShip builders in one place. Here you can share photos, tips, questions, and---eventually---your sailing adventures in PocketShip! CLC will also post design updates and tips here as they come up.

We'll try to knock down spam as quickly as possible.

Moderator: John C. Harris

Forum rules
Spam or commercial posts will be deleted.
This is a civil forum: no flames or drunken tirades.
Please stay on-topic.
PocketShip's Web Page: http://www.clcboats.com/pocketship
If you need CLC customer service: http://www.clcboats.com/forms/contact_us.html
We'll try to delete spam as soon as it appears.

Capsize Test

Postby jdhseville on Thu Apr 30, 2020 11:25 am

Hello all!

Contemplating a Pocketship build. Has anybody ever done a capsize test on a Pocketship? I know that John Harris mentioned in a thread a decade ago that he might try one. Anybody know if it happened and what the results were ?

Also curious what factor the weight difference between a Sapele build like Pocketship#1 and an Okoume build might make - if the extra weight in a Sapele or Meranti build would improve or worsen the capsize recovery.

Thanks!

John
jdhseville
 
Posts: 8
Joined: Wed Apr 22, 2020 9:06 pm

Re: Capsize Test

Postby craig on Thu Apr 30, 2020 1:55 pm

It was tried by one owner, but we are still waiting for the report - last sighting by Coast Guard was 50 miles SE of Charleston, SC.







Seriously though, I don't think it has been done. With as much freeboard as Pocketship has, and being decked, I don't see how it would be possible without a wave.
Titania, launched January 2015
craig
 
Posts: 271
Joined: Fri Feb 21, 2014 1:04 pm
Location: Chapel Hill, NC

Re: Capsize Test

Postby jdhseville on Thu Apr 30, 2020 3:57 pm

Ha! Thanks Craig!

I saw the pic from the capsize test CLC did on The Guider, so had me curious as to how high Pocketship might sit in the water on its side (hopefully higher than an open companionway hatch) , and how much water she might take on in a worst case scenario. Can't blame anybody for not wanting to put their boat through it though! But would be very interesting to see the results.
jdhseville
 
Posts: 8
Joined: Wed Apr 22, 2020 9:06 pm

Re: Capsize Test

Postby karlstatt on Fri Feb 26, 2021 5:54 am

We did a capsize test last year - but not voluntarily. There is a report on my blog at https://www.konfido.info/pocketship/gekentert/, but in German. Here in a nutshell: The cause was a mixture of carelessness, natural conditions caused by a sudden huge gust in a jet and far too little weight in the boat. Important to know: Nothing happened, it was almost fun and the water was warm.

The boat was in the water up to the mast, the sails were slightly under water, the hull floated completely on its side and very high up. Not a drop of water got into the cabin or the cockpit. As some of the water flowed off the sails, the boat righted itself in less than a minute. With more weight in the bilge, the boat probably wouldn't have capsized at all and would have righted itself immediately.

If you get knocked over by a wave somewhere, you probably have completely different problems. But on inland waters, it was a harmless affair.

I may be wrong. My impression is that if you have enough weight on the keel, you're more likely to fall out of the boat when it's leaning than to tip it over.

Damage: Wind vane floated away and tree fitting bent. Mobile phone gone, glasses gone. Otherwise all healthy.
There is nothing good unless you do it.
User avatar
karlstatt
 
Posts: 16
Joined: Sat Jun 28, 2014 1:42 pm
Location: Hoya / Germany

Re: Capsize Test

Postby craig on Fri Feb 26, 2021 1:46 pm

Oh fascinating, I'm glad you were OK! Sounds like about the best performance as you could hope for with a capsize: no water onboard and self-righting.

So you didn't fall out of the boat when it went over? Did it come back upright with you still in the cockpit?

Another question I have is ballast. I used google translate to read your blog and I think it was saying you hadn't added any ballast at all to the bilge. I guess the boat was sitting pretty high in the water? I've seen people claim to use a pretty broad range of weights, from maybe 100 up to 300 pounds (from memory). Sounds like having weight down there is pretty important.
Titania, launched January 2015
craig
 
Posts: 271
Joined: Fri Feb 21, 2014 1:04 pm
Location: Chapel Hill, NC

Re: Capsize Test

Postby mark48 on Sat Feb 27, 2021 9:14 am

Greetings,

Great story, and thank you for sharing. Builds confidence among us all.

Just a note or two about ballast: John Harris is quite prescriptive in this Forum on ballast amounts, both for the "empty" weekend day-sail, and for those who intend to "cruise." And you'll want the ballast below the floorboards; don't just stow it in the cabin in the interests of shoving off more quickly. And don't ask me how I know. :-)

Stay well, all,
Mark
mark48
 
Posts: 152
Joined: Fri Jun 28, 2013 9:55 pm

Re: Capsize Test

Postby Mflyer65 on Thu Mar 11, 2021 11:27 am

Thanks Karlstatt,
Great information regarding the need for bilge ballast.
As I understand your German blog you did not have any ballast in the bilge because you thought it was optional, and you did, of course, fall out of the boat rather quickly but were able to stand. You also stated, I think, that the centerboard was fully up as well.
This is a great help to those of use wondering if we have enough ballast weight. I have about 190 pounds in the bilge myself and wondering what others have placed in that location.
Thanks all,
Mike
Mflyer65
 
Posts: 67
Joined: Thu Nov 15, 2018 12:09 pm
Location: Durham, NC

Re: Capsize Test

Postby karlstatt on Tue Apr 06, 2021 3:29 pm

Hi Craig, You can now go back to my blog https://www.konfido.info. I have added a translation tool, which makes it easier.
We didn't fall out of the boat, we were thrown out. As described, it was incredibly fast. In the blog I describe, among other things, the mistake that we didn't have any ballast in the bilge at the time, there was no battery yet, and since we were only going on a trip for a few hours, there was hardly any luggage as ballast.
There is nothing good unless you do it.
User avatar
karlstatt
 
Posts: 16
Joined: Sat Jun 28, 2014 1:42 pm
Location: Hoya / Germany

Re: Capsize Test

Postby karlstatt on Tue Apr 06, 2021 3:37 pm

Hi Mark48, I would have been very surprised if I had been the first ;-)

I have described elsewhere (here in the forum and in my blog) that I built my cabin floor in such a way that I have convenient access to the entire bilge along the entire length of the floor. As well as being able to clean well everywhere and store some food in a reasonably cool place, I can now also accommodate ballast very easily and change the trim at any time.

I was able to get lead ingots very cheaply, which are very easy to store. So that I don't have to touch the lead when trimming and so that any bilge water doesn't wash lead out into the bilge, I have coated all the bars thickly with liquid rubber. This has the added advantage that the bars do not scratch the paint.
There is nothing good unless you do it.
User avatar
karlstatt
 
Posts: 16
Joined: Sat Jun 28, 2014 1:42 pm
Location: Hoya / Germany

Re: Capsize Test

Postby karlstatt on Tue Apr 06, 2021 3:46 pm

Hi MFlyer65, If I remember correctly, John Harris recommends 100 to 150 kg, depending on the luggage. I was only able to get 60 kg of lead shortly after the capsize. That already made the boat more stable, but it's not really enough. I'm aiming for 120 kg of lead and an additional battery of around 15 kg.

I have to add one thing: you can actually sail the boat without the centreboard extended. In Germany, we had little water in the last two years, so it was too shallow for the centreboard in many places at my home port. In the short distances that you can sail straight ahead on this very winding river, I have not noticed any drift. With the small long keel, John Harris has obviously managed a very good design.
There is nothing good unless you do it.
User avatar
karlstatt
 
Posts: 16
Joined: Sat Jun 28, 2014 1:42 pm
Location: Hoya / Germany

Next

Return to PocketShip Forum

Who is online

Users browsing this forum: No registered users and 2 guests

cron