Personal Submarine Build

Correct, that would probably be the easiest way to hook everything up and also the simplest to operate.

Nice man! Such a cool project!

Just remember to load a clutch stick before setting out.

Nah no "clutch stick" this time. lol

My dad almost built one of these in high school and he tells me every time we get on the topic of it that he is glad he never built it.

Whys that?

Well he never really said but I think he was worried about dying

Yeah fair enough. It would probably feel strange being a metal tube in water. Gotta make sure it's all sealed!

or claustrophobia.

Hopefully it won't bother me too bad. I don't think it will be too big of a deal though. If for some reason something goes wrong, there will be about a 200 lb safety weight on the bottom which you can release. If you happen to get snagged in something or can't drop the weight, you have to flood the submarine through a valve to equalize pressure before opening the hatch. When submerged, water pressure holds it closed. That's a last ditch thing of course.

What is the exact plan for sealing this tin can up

Knowing mr.mod, Flex Seal. loooooooooool

Flex seal? Is that the stuff in the spray can?  Actually....The hatch is the main problem to seal. On most other mini subs, they use a rubber o ring in a groove. On mine I plan on having a groove on the sub filled with some kind of silicone. The hatch edge will fit into the groove and seal against the silicone. As for other things such as the shaft seal and shafts for other things like rudder, dive planes, and valves will be sealed with a normal rubber seal like an engine shaft seal. You can buy seals for pretty much any application, I just need to find out what I need. Probably something with a flange that fits a seal, I don't know yet. I'll have a couple of small 4" windows. They should be easy to just silicone up before tightening the bolts which hold them in place.

That was my next question if you were going to have a window or not

I didn't realize it had been over a year since I worked on this, I thought it was only a few months. Anyway, I'm back on it and hoping to finish up this model soon so I can move onto the next thing on the list, whatever that may be. I pretty much finished the structure for the forward deck. I still have to make the nose, tail section, rudder, dive planes, simulate the hatch hinge and port holes, and re-do the exhaust which I have a different idea for now.


Same idea as the aft deck.


Snorkel has to end up about here. Still need to weld it on. This would not be for running the diesel submerged, but only for replenishing breathing air without having to come completely to the surface. More explanation on this later.

I forgot about this neat little thing. Looks good mr.mod! I like the little knob on top, hahaha.

Looking cool mr.moo! Scale models are always pretty dope. How are you planning to actuate the rudder/elevators?

Hehe, I don't suppose you're not doing the daily weld test that naval/some other professional welders do every day to determine if they're fit to weld that day?

He just wanted an excuse to build a massive RC sub.

Ooooooohhhh....better start saving those 18650s! Although having a tank full of lithium batteries might not be such a great idea...

Thanks people. The rudder and dive planes will be moved with hand operated levers. I'll have a linkage rod going to them. I imagine they will have some sort of friction device or notches so that you can set them in any position and not have to hold it in place.

And no, no welding test lol. I will have to work carefully on the real one though. Your life kinda depends on it.

What actual batteries I will end up using is up in the air. I was planning on regular lead acid car batteries, but glass mat/AGM might be the way to go for safety.

I'd definitely go with some gel cells. A lot safer that way.

A couple Optima batteries would do the trick, LOL.

Yeah I may end up going that route. I want a decent amount of reserve power though so I may end up with 5 or more batteries. I'll figure all that out later on. For now the main thing is figuring out the pressure hull and what size it needs to be to fit the sort of equipment I need to be self sufficient. I was thinking I would like to be able to go on a 2 day trip without re-fueling. We'll see how that goes.

Anyway, some more work on the model. Now fabricating the nose. On the real one it will bolt on. For the model it's welded to the forward deck and is removable as a unit.


Basing the deck off the design of the UC3 Nautilus submarine and also the Euronaut, which both have similar deck ideas.

New exhaust with muffler. Not finished yet.

Welded on the rest of the exhaust


When on the surface, the main exhaust shut off valve is open to allow the engine to run. The exhaust drain valve is closed to prevent exhaust from getting into the submarine.

When diving, the diesel is shut down and the exhaust shut off valve is closed. As the submarine submerges, the exhaust system is flooded all the way up to the shut off valve.

When the submarine surfaces, some water will naturally drain out of the exhaust from the goose neck out. But some will remain in the pipe between the shut off valve and the goose neck.
The exhaust drain valve is opened and then the main shut off valve, allowing this trapped water to drain out into the bilge. Once drained, the exhaust drain valve can be shut and the diesel engine started.

The air snorkel tubes will have to be drained in a similar way and a small amount of water might need to be pumped out of the bilge from time to time.

Part of the deck side finished