Ballest for a Marben

[Northern Spy]

When I get home I'll take a look at my GM calculations. Mine was pretty snappy when relaunched and empty after repowering. After a few years of re provisioning (placing useless crap back in the lockers) her roll is more gentle.

That is 180 degrees opposite of intact stability. A "too stable" vessel has a large GM and will roll quickly. Adding weight will lower G and unless there is a large change in draft, the GM will only increase and the boat will roll (snap)even faster.

I had also thought about putting some lead in the bilge (keel box) but I think she'd just get snappy again with the hard chines on my boat.

That is the way it works. Adding weight down low increases static stability but increases roll rate. If you want a slower roll, take weight out of the bilges or add it higher.

You're absolutely right, it was more likely the removal of railroad track down low and adding the weight back up high (kayaks on pilothouse roof, restepping the mast, building an overhead console) rather than the minor increase in draft that raised G, lowered GM, and lessened the righting arm.

 

[Al]

Mark, I see that you are online. Could you respond to me if the photo I am adding to the text comes through? Thanks, I have no sense on how to transfer photos from my phone to add as an attachment. I read the 'Newbie' column but I am just not up to speed and all of my Granddaughters are absent. Thanks, AMJ

I am posting this to reflect the size of our 27' Marben along side a 26 ' Tolly. gives a prespective in the recent discussions. One can see the difference. Again, we have a 3'6" draft.
AMJ

https://mail.google.com/mail/?hl=en&shva=1#inbox/13a0095932e186cd

 

[Al]

Nope, I can see its not going to work. Thanks, AMJ

 

[Rambler]

I have no sense on how to transfer photos from my phone to add as an attachment. I read the 'Newbie' column but I am just not up to speed and all of my Granddaughters are absent. Thanks, AMJ

I see that you are as technological competent as I am. Might we be related?

I suspect this site help can't tell you how to get pics off your phone. That'd be on the phone help site though. Probably have to copy it or send it to a computer then take it from there and post it to this site.

 

[Nomad Willy]

Now that I've seen a pic of the Boat in question I'd recommend some ballast but a NA will probably be the only one that can tell you how much and where. I've seen Ballest recommended up under the decks at the gunwales to dampen roll on a light boat. We have 4,000lbs ballast in Willy as it came from Willard so have little idea what she would act like w/o it. Many boats have newer and much lighter engines than original and that could or should be taken into consideration as well.

I haven't read all the posts but I'd recommend finding out all that could be discovered about ballast as original equipment or as specified by the designer.

Beyond that one could/should spend some time on BoatDesign.net.

 

[Al]

Hi Eric, (It is Eric as I recall). See you are or were back in Thorne Bay with your advertisement for home sale. I trust you have dotted all the i's and crossed your t's.
Having K-Town as my life long home base, I have seen so many throw up their hands, or for any number of reasons, sell their home in South East Alaska and then, within two or three years, back swearing never to move South again as the (You fill in the blank) traffic, taxes,schools,crime, weather. all become factors that have them back into our part of the world.
Anyway, I know your model of Willard. I would think your draft is equal to our 3'6". Your center of Gravity will be lower just by the nature of deck levels in the two boats.
Our craft comes with 1500 # poured into the keel at construction. You indicate you have not read all the post. I believe you will agree, the sister boat to ours carries 200 gallons of fuel vs. our 75 gallons. Water on theirs is 85 gallon and on ours 48 gallons. Right there is a huge difference in full tank status. When you look at that difference in light of your indicating a 4000# ballast in the Willard, It would seem there is room for adding a couple hundred pounds in the bilge area.
We shall see, and will give a report.
Take care- Good luck on the home sale, It appears very well built and attractive to the eye.
See you in a couple of years (Maybe
A.M.Johnson-Ketchikan

 

[Al]

Greetings, Test,Test, attempting to post a photo. Seems a whole lot of letters and numbers!! The purpose is to reflect the height of our 27 foot Marben alongside a 28 foot Glasply and a 26 foot Tollycraft. in relationship to the ballast conversation.

Cheers- A.M.Johnson

https://mail-attachment.googleuserc...id=0.1&disp=inline&realattid=1414140486964215

 

[Al]

Nope, o well, best to close the thread- Thanks to all
A.m.Johnson