Hey dudes, so I was prepping for my usual sunday nightmare series last night (H.P. Lovecraft and Nicorette gum just before bed), and had an interesting thought regarding the engineering problem in the hobby surrounding submarines. With the advent of digital milling/3d printing, and the rest of that digital tomfoolery, I was thinking that perhaps the solution to the problems of low mass and space could be addressed using a combination of these devices with a mentality similar to that behind the Vac-U-Boats. This is just an abstract though experiment. I'm not inclined to build a combat-ready sub in the first place, but since I'm just hanging out making unemployed noises in my cabin until Forestry season starts and more boat parts arrive for my Texas, it can't hurt to spend time thinking about the problem. So what I was thinking on the sub topic is to use a snap-together-like-legos design for the ribs and keel, in which the motors, ballast tank system, servos, etc. were mounted to a wide keel which could be cast in a mould with a similar snap-on bow and stern plate. The ribs could be prototyped using a 3D printer and used to make moulds (you'll see why the mould would be needed in a moment) The deck system could be similarly prototyped and cast, in which the subdeck is "lego snapped on" to the top of the pertinent ribs. Something like an Avenger Cannon could be designed specifically for the submarine application, possibly with the magazine integral to the keel system, some of the gun fittings integral to the deck, or both. I dunno, I keep hearing about people casting/printing guns, so it's a possibility I guess? you guys are the experts, shoot it down if the idea is a flying washing machine. Back to the structure: So the Keel and top deck system would be the only parts of the boat that will be built to endure punishment. the ribs could be made strong enough to withstand something like a glancing bb impact, a ram, etc. but light and small enough to facilitate maximum internal space. their only purpose is to retain hull form and some semblance of watertight integrity. Since even a single BB hit may be a sink for a sub, there's no point in building her ribs tough enough for an assault role. So. these little buggers are strategically useless, have glass jaws, and are naturally suited by design to people who are A: super-clever, B: highly experienced, C: are naturally inclined to being the battlefield clown who delights in playing pranks on his or her opponents, and D: has a ton of time on their hands. With that supposition, a sub captain would be suited to doing a modular replacement regime in the event of a catastrophic rib failure, and the "snap-in Lego" ribs would allow them to cut out a section of the hull, replace the offending rib by pulling the remnants out and snapping a new one in place followed by a re-skin. In this way, even if one of these fragile glass-jawed little jokers got pummeled by a major combatant, ground into the bottom, etc. it could be rebuilt using the keel and deck components with an entirely new suite of bow and stern plates, as well as ribs. with comparatively little effort. And with moulds available for the expendable structural components, you could crank out enough parts to keep up with the combat demands. similarly, the moulds could be manufactured and sold as a kit of some sort. If such a thing were to occur, it might be possible to expand the number of boats in the hobby, and the classes available for building due to reduced mass and increased versatility. It'd be like Vac-U-Boat Fletchers/Gearings, but for madmen! Alright, guys, shoot some holes in the idea and let's see what comes out on the other side.