# Is it possible to combine a sailboat, motorboat and submarine?

Discussion in 'Motorsailers' started by tahroo, Sep 14, 2012.

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1. ### dskiraPrevious Member

1833

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### YobarnacleSenior Member

What would you name it?
"GLUB GLUB glub" ?

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### allwetJunior Member

slightly submersible?

What about a surface boat that can go down to 50' or so to ride out a storm instead of bouncing around on the surface? There would be some rolling but much less than at the surface.

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### NavalSArtichokeSenior Member

There was a chap on these forums who wanted to combine a submarine with a train, locomotive and all, so I guess anything's possible. Whether or not anyone would want it is another thing entirely.

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### Mik the stickSenior Member

My ad vice is DON'T DO IT.Its just not worth it.
My preliminary very ball park calculations predict 22hp for 5kt underwater speed in a 48*14*12ft boat. Which with a 24v motor is 684 amps or 149 amps with an inverter giving 110 volts. Diesel electric drive is the sensible way to go.

Problems
Assumming batteries are 60amp/hr three connected in parallel give 180Amp/hrs which would run for an hour at Max speed which is usually the best a WW2 sub could do.

As a sub goes under it must be kept stable, to go down to 50ft (measured to the keel) I will say takes 50 tons of water. As depth increases the sub is crushed so that 55 tons of water starts the boat sinking again. But at 65 feet the boat displaces less water than before. So to stop the boat diving perhaps 7 tons of water will need to be pumped out.

WW2 subs could dive to 200-300ft which generally equaled their length. So a reasonable dive depth would be perhaps 90ft with double that as an absolute crush depth. If 55 tons of water caused a dive speed of 10ft/sec, then 5 seconds after the start of the dive your dive speed will increase and if you don't get some water out of the boat you won't be able to stop diving and you could reach crush depth before you can react to the situation. A failed compressed air valve is a death sentence.

The required training to get that right I think is beyond most people. The need to have someone to help you compounds the problem. That is why submariners tend to be a very elite group in any navy.

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### upchurchmrSenior Member

Not true.
I was on a US sub (missile) in 1985 at 300' taking 50 degree rolls.
It was a really big typhoon. Upset my poor tummy quite a bit.

Actually it was probably a lot less than on the surface, it just didn't seem like it at the time.

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Sleeping beauty..

Actually during WW2, a one man wetsub was developed in UK that could be sailed and paddled as well as powered electrically. Google "sleeping Beauty" as was its codename.
Only barely a sub of course, but interesting enugh. One specimen is on exhibit in the Naval Muesum of Horten, Norway.

A malicius canoe if there ever was one

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### Umi_RyuzukiNew Member

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### Jamie KennedySenior Member

US Submarines are boats, with motors, and a sail, but they are not motor-sailboats. ;-)

10. ### exp30002Previous Member

How about a submersible catamaran type of vessel, that
could flip like the Scripps vessel, the Flip? It could probably ride out a storm.

11. ### whitepointer23Previous Member

Do they have a sail

12. ### exp30002Previous Member

Not yet.

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### NavalSArtichokeSenior Member

Yes, they do. The big sticky up thing with the periscopes and whatnot is called a 'sail':

14. ### whitepointer23Previous Member

Ok i thought it was a conning tower.

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### Mr EfficiencySenior Member

Probably an alternate, informal description.

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