RickB
Guru
- Joined
- Oct 20, 2007
- Messages
- 3,804
- Vessel Make
- CHB 48 Zodiac YL 4.2
"If you tell someone to do something very dangerous and stupid and I read it I will post the reasons why it is dangerous and stupid. Too bad if it offends you."
RickB wrote:
*
Delfin wrote:
Next, we'll get a lecture from RickB on the subject, to be sure.
Okay, I could look this up but being inherently lazy I'll ask here instead.* It sounds like my description of the sloshing of a liquid in a tank, hold, etc. can be a stability*problem but it's NOT the definition of Free Surface Effect.* If fish and ice can cause a Free Surface Effect the definition must be different than my assumption since fish and ice don't really*"slosh."RickB wrote:
The difference in it being a hold rather than a tank is that, except for fishing vessels that use a refrigerated seawater fish hold like you see on the Bering crab boats, the boat is not designed to operate with the hold completely full of water and "batter boards" are used to prevent fish and ice from causing a free surface effect.
RickB is RickB but I trust his answers above most others folks PC or not.sunchaser wrote:
*I am not one bit bothered by RickB's statements. Picture your teachers or profs of yesteryear rising to the moment.*I am puzzled though as to why Ancora never weighs in on*this stuff - does he really exist or is he just afraid to get pinned down on tech issues?*
I recently read a very interesting book about the Edmund Fitzgerald called Mighty Fitz by Michael Schumacher.* As I recall from my reading there were two main contributors to the loss of the ship.* The biggie was the ship's brief grounding on Six Fathom Sound which momentarily hogged the ship and split bottom plates apart if not actually breaking the ship's back.sunchaser wrote:
Free surface effect is alive and well. In my business we transport ore concentrates*(copper, zinc, or lead primarily), coal and iron ore in ships up to 80,000 dwt. Each product must meet specific % moisture tests to insure it is "stable" in a rolling sea. If the hold covers become dislodged, seas can enter and render the "dry" products wet and subject to liquid like behavior*with real potential for capsize.
I am puzzled though as to why Ancora never weighs in on*this stuff - does he really exist or is he just afraid to get pinned down on tech issues?
What I know about vessel stability and how to determine or correct it wouldn't fit on the head of a pin.* But I can mention something I've read that may have relevance to your situation.* A number of years ago I read a book called Lost at Sea. An American Tragedy by Patrick Dillon.* It is the story of two of the "A" boats owned by the same company in Anacortes, WA, the crabbers Americus and Adair, that were both lost on Valentine's Day in 1983 in relatively calm seas in Alaska.* (All their boats' names started with the letter "A", hence the term A-boat.)skipperdude wrote:If the center of gravity is lowered by adding weight.
How does that effect the center of*boyancy?*
Would it make her less tippy?
Sounds similar to the story about the King of Denmark who ordered that another deck be added to a ship about to be launched.* The deck was added and when the ship was lanched it turned turtle and sank in the harbor.Sailor of Fortune wrote:
After several years the shipyard workers were interviewed and it was determined that the painted waterline was not where it was supposed to be. The waterlines were raised on those boats
on the orders ( architects unaware) of the owners.
I think that is what the P.O. did by filling the fish hold with tubs of sand.Delfin wrote:, replicating the design weight as originally intended would help answer the question for you.