Diaphragm Pumps?

Are Diaphragm Pumps not allowed by rules? Everything seems to address impelled pumps.

 

Correct, all positive displacement pumps are illegal. It's the first rule in the pump section.

 

Positive-displacement pumps are prohibited because they are (theoretically) capable of putting the same quantity of water through any diameter outlet, thus negating the purpose of the standard 1-unit and 1/2-unit pump restrictors used in Fast Gun ships. Unfortunately this removes them from service as ballast pumps aboard submarines, a purpose for which they are ideally suited.

 

What about air pumps?

 

Alas, the current phrasing of the rules for submarines specifies that submarine pumps must pump water into and out of a ballast tank. No air, no positive-displacement, etc. This prohibits both air compressors (because they're positive displacement), and air pumps (because they pump air, not water). The Fast Gun rules regarding submarines are very poorly written, making any such project significantly more difficult than it needs to be. I would be more annoyed by that but I have too many surface ship projects to try rewriting the rules.

 

That can’t be exactly true because the I-400 I saw (Franks?) used co2 to blow the tanks.

I thought about bellow tanks, but it can be argued that they are essentially diaphragm pumps anyway, so why crowd out the cabin with extra complexity and moving parts.

My concept is basically a snorkeling sub with a little diaphragm air pump to blow the tanks using surface air drawn through a snorkel. Then a bleeding valve to dive.

At this point I’m Damn the Torpedoes! Full speed ahead. If I show up a NATS and they want to toss out the coolest ship there even if it meets the intent of the rules, then so be it. I’ll call ‘em a bunch of Fraidy Cats scared of a little 1.5 unit novelty store clearance rack special.

.... hopefully NATS will be at Saranac so I won’t have so far of a drive of shame home. Lol

 

Type type type type type. A wise voice once said, ‘build it and they will come.’ The number of keystrokes for a post typically exceeds the number of key strokes for a rule proposal. Most would recommend building a capital ship that doesn’t shoot its load in a few seconds, putting a sub in the MI lake would have a similar recovery rate as the mars rover

 

Shoeless Joe Jackson said that. Not sure how wise he was considering the tactical advantage of shoes.....

No worries Kevin. The modelshipsahoy surface fleet will be there in force.

 

Guessing it would be a high priority target?
Lol. That says a lot.

 

Not your standard “Typist” attire.

 

Saranac's pretty deep. it's super clear, but it gets deep really fast. I think that's their point. The alternate site would be pretty decent though. but if you brought a sub to Saranac, you'd really have to be careful not to accidentally hit crush depth or something.

I dunno, I think swimming at Saranac would be pretty pleasant in mid july. But I'm weird, I guess? am I the only guy that brings swim trunks or something? Definitely don't want to sink there in september or october though. Kas and the gang let me get the boat back to the dock before Will swung in for the coup de grace during the October scrap.

that would have been a long cold drive back to Wisconsin if it had gone down where the Baden and Derf had it clobbered.
But next year.... Oh next year..... we shall see.

 

Need to consider the muck factor, during nats randy’s boat lawn-darted (as we’d say in the real sub driving world) and had about half of the 50” length visible above, lodged vertically. The MI pond (and others) has a few feet of muck. The MI pond specifically gets over head depth within about 3-4 steps from shore, which is way deeper than the typical nats ponds. I spent 20ish minutes looking for a prop in the muck a few feet (and neck depth) from shore. I found it miraculously by moving my hands through the gunk on the bottom, I also was sick for a week following (not sure if causation or just correlation)

 

Hoping to set the neutral buoyancy of the sunk model at about 4 feet. Operational dive depth will only be 12” lest it drowns it’s snorkle.

 

I’d love to see your fluid dissolved solid and temperature mapping capabilities

 

Lol. ABOUT. We’re talking a 31” model. Variables are negligible.

I’m pretty sure I can keep it from spiraling down 20 feet to the abyss.

 

Also considered a seaplane float on a self retracting bobbin. Would stay on the surface as the model dives, retract back upon surfacing and keep paying out on a sink. Thoughts?

 

Out of everything you’ve said, having a prop fouling device would probably be the only thing that people would raise concern about (and would not be allowed)

 

Good to know. Maybe release by a pressure trigger set for 2 psi (4.5 ft typically in freshwater)

 

I respectfully disagree;-) Mud-dart was the term of choice with us Torpedoman’s Mates at one point many moons ago.

Edit: In addition to... avoid becoming a 8000t mud dart there is also no water in the people tank and a 1 to 1 ratio of dives to surfaces to be maintained.