RE: [PSUBS-MAILIST] I new here, I need advice

["Alec Smyth" <Asmyth@changepoint.com>]

Thomas,

 

I hope you're not offended by this, but if you are interested in Naval Architecture the right sequence is to do the studying first and the building later. Wooden subs have been built successfully, but not to my knowledge of plywood (unless you're talking about an ambient sub). Be aware flat surfaces are to be avoided like the plague, for structural reasons. In addition, even if you were only shooting for a depth of 5-7 feet, you will probably find that a buoyancy imbalance takes more than that depth to correct. 

 

If I were you, I would invest the $350 in a SCUBA course. If you've already done that, great! In that case use the $350 for building an underwater tow-sled. You can put wings on it and have a wonderful time. I did that when I was about 18, and I think my current sub-building endeavor is a direct result. 

 

rgds,

 

Alec

PS: To answer your question, displacement is simply the submerged volume multiplied by the density of water.

-----Original Message-----
From: Thomas C. Brown [mailto:tombro77@optonline.net]
Sent: Friday, February 28, 2003 2:44 PM
To: personal_submersibles@psubs.org
Subject: [PSUBS-MAILIST] I new here, I need advice

Hello my name is Thomas Brown from NYC.

 

            I have the desire to make a small 1 man submarine out of wood with a depth of max 10feet. Basically just to see if I can make it and to test my skills. My interest in submarines comes from a desire to join the Navy and serve in a submarine and also to pursue a degree in Naval Archeitechure. I figured out mostly everything from rudder control,ballast control(I was going to use a water bladder in a compartment,I would use 2 pumps; 1 to pump in and sink, the other to pump out and rise.)the total weight of the sub will probably be no more that 100-150lbs and I weigh 200lbs so a total of 300-350lbs when im in it. I went over costs and this shouldn’t cost more than $350 USD. 2x4 wood frame, with plywood hull. I will caulk inside and out to waterproof, and on the outside I was going to epoxy for further strength. I planned to have ¼” thick plexi glass windows. My Main problem is how to figure out the displacement of it, so I know whether or not I will be able to dive and surface. Please take into consideration that this is a plywood(no curves, flat edges) submarine being made by a 17 year old(with an excellent understanding of science and submarines.) I want my normal depth when im under the water to be 5-7 feet. Please tell me how to figure displacement, if this will work, and how many hp electric engine should I expect to need to propel an 350lbs submarine 2knts with a depth of 7 feet.

                                   

                                                                                                                                                                                                                        Thank you for your time.