rva1945

Last Saturday some members of our association (www.camne.com.ar, in Spanish but with hundreds of pics) spent a day at a lagoon in the Province of Buenos Aires, but none of the boats touched the water: high winds, waves, etc. No way. Not even the guy windsurfing there could remain afloat more than a few seconds.

So we decided it would be a nice idea to create an unsinkable boat: no matter the weather conditions, even if it takes some water (the water will somehow find the way in), not only will it remain afloat but also, if capsized, it will naturally recover.

The idea is to install an inner watertight hull with all the electronics and electric stuff inside, and the volume between the outer and inner hulls filld with expanded polyestyrene, as much as possible.

We have the hulls (on of our members moulds 26 in. PT-like fiberglass hulls), the question is, should you install a rudder for this project? It seems to be the weak part of the boat, which must stand bumps and shaking among stormy waters.

Two ducted props would be fine, but steering should be achieved by independently controlling the motors.

As it has to recover from capsizing, I don't know which shape the deck and superstructure should be: flat or rounded?

Any help?

Regards
Robert

LtDoc

Robert,
The only thing I can think of that would tend to be true in (almost) all cases would be to keep weight towards the bottom of the boat. Sort of a 'no-brain'er, huh? It also sort of follows that any flotation 'bubbles' ought to be at the top of the boat. That's with either the hull full of water or completely dry, and means that the hull will tend to rotate right-side up if at rest. From there it's more a matter of imagination. Lots of possibilities...
- 'Doc

Umi_Ryuzuki

They already make such boats,
It is just a matter of incorporating the water tight features you are considering.

They're called Life boats and used by the US, and Canadian Coast Guard, and the RNLI
Browse this page. [8D]
http://www.44mlb.com/model-lifeboats-photos.htm

http://www.44mlb.com/

Any of the Coast Guard or RNLI boats would be canidates for the weather you describe.


Trent Class
http://www.modelslipway.com/trent.htm
Tenby class
http://www.modelslipway.com/tenby.htm

Seems like someone makes a Severn Class Life boat also...

USCG 47 foot
http://www.midwestproducts.com/item_...asp?item_id=98
http://www.youtube.com/watch?v=ibPLFkEpMrM

merc1500

build it out of foam no matter what you do it wont sink

Poppa

Umi is right about the RNLI lifeboats, there was also another one that had self righting abilities it was the "Brede Class" that ended service in 1998 i believe.
They self righted by using pumps to move water from one side to the other if i'm correct.
I just finished a model of one at 1/12th scale approx built totally from scrap, (Pics in Gallery).
Ive always been fascinated by these sturdy boats, and the guys that go out in them in all weathers deserve medals in solid platinum.

herrmill

Subs make great unsinkable model boats, especially the earlier unterseebooten!

merc1500

still like my idea of a foam boat would never sink

Tachikaze

Hmmmm.....
Seems to me someone once built an unsinkable ship called the Titanic.

subsinker

My Feedback: (61)

I thought Harland and Wolfe built a ship many years ago labeled "unsinkable" can't think of the name off the top of me head...

patmat

From the above link:

Tachikaze

Damn,
Now I have another project to start!

crazy yank

I built a Dumas plank and frame model of the 44' lifeboatover 25 years ago and have continued to update with more scale features, not in the original kit, such as: operable radar antenna, running lights(operated from transmitter), home built speed control, swiveling boatswain's chair, below deck's hatch, operable winch, docking fenders, transmitter operated horn, crew of four members and as I see new things, will add them. In general, it's still a work in progress. The running lights I originally used were filament type and have since been replaced with LED's.
Lynn Leaich

foodstick

Lots of flotation, with th ballast way down low should work,

and man it must have been windy that day! I used to sailboard alot in my younger days, and have been out in wind gusting into the 40's! you wanna talk about a wild ride ! If I remember correctly it was during hurrican hugo and it had the wind stoked up even in the midwest usa.. Ruined my only good sail that day, but the jumps between the crash's were out of this world for flatwater sailing...not quite like sailing THE GORGE..but hey what is !

Umi_Ryuzuki

Neil, of Fleetwood,Lancashire, UK, did a couple of custom
Pilot boats for a Marine Architect, and owner...

[8D]

Here is his video of tests...

http://www.youtube.com/watch?v=IeNc3rDT7gM
.
.

Justaddwata

My Feedback: (3)

Well this thread is a blast from the past (2007)

While more on the unsinkable side than boat side I get a laugh out of this boat/bottle on Youtube

[youtube]http://www.youtube.com/watch?v=iB-2f6Pbkak[/youtube]