While I don't know how much effect anything we come up with will have on our actual design since we relegated it to a "generic" sub, I think our first domestic design should be on the conservative side so that we can build up institutional experience and be better able to deal with inevitable cost overruns before trying to go crazy with new technology. We're going to be making at least one more new submarine design after this when we finally get our hands on nuclear power plants anyway, since nuke subs are just so much more than diesel-electric.
- I agree with you on the hull and the AIP. The benefits of titanium are unlikely enough to outweigh the trade-offs, so we can just stick with the regular steel. While Stirling AIP is a bit ahead of time since IIRC it started being seriously worked on in the late 80s I think it's reachable for us. Stirling engines themselves have been around for years at this point, and AIP work started in late WW2. It was mostly sidelined just because nuke subs could do everything AIP does but better. And while LOx is going to be tricky to work with, it's still probably going to be safer than hydrogen peroxide which is the other major type of AIP currently.
- A extendable bridge like the one in the photo is just going to eat into more of our limited internal space, and if we're putting a fixed dorsal fin on the top anyway why not just make it a particularly streamlined sail and use the saved internal space for more fuel, torpedoes, or machinery?
- It wasn't a shrouded propeller on those designs, it was a full on pump-jet. It's got more going for it than just speed, and they're used on non-nuclear boats since the 30s.
- The rotating autoloader for the 400mm lightweight torps is cool, but I thought we were focusing on sub-launched heavyweight torps useful against ships and subs if we're doing sub design over surface buildup, and that autoloader only carries 6 with no reloads. Also that design forced the Swedish to put their both the passive and active sonar equipment in the sail because it took up all the space in the nose, and that same article you got the image from had this to say about the autoloader.
- One of the big goals we were working towards was a purely electric torpedo so that we could do quiet "swim-out" launches as standard. That would have prevented most of the problems you mentioned about blinding our sonar and also make it much harder for us to be found, since the loudest noises during launch would be opening the tube and the torpedo motor itself. A CAPTOR style system with the torpedo held in a gas is going to prevent that unless we roll even higher than what we need and manage a workaround. A simple electric torpedo with internal reloads is going to be cheaper and easier to design and produce while being almost, if not just as, effective a weapon.
- Once again on the sonar in the nose, we aren't going to be able to get both that and the rotary autoloader in there.
- I agree the anhedral forward dive planes sound cool, and as long as they don't protrude down past the bottom of the submarine they shouldn't impact our shallow water operations. I still think we'd be better off with a full sail on top instead of the 3rd fin to save internal space.
- While we can probably do the multiple watertight compartments, there's no way I think we can get that nitrogen system you want in there. Not only is it going to take up more of our internal space with the pressurized storage tanks for the nitrogen and air, unless you want to upgrade the bulkheads to full on airlocks and send the crews in with personal oxygen it's going to need a very strong system to pump all that nitrogen back into the higher pressure tank, otherwise you risk asphyxiating whoever goes in there and the rest of the sub every time you open the door to that section.
- Not to mention the idea of building something with the idea of "we can't do maintenance or repairs except for in specific circumstances" just sounds like it's asking for something to go wrong. I'd much rather try to design something reliable that doesn't need much maintenance, and have easy access to it for repairs anyway in case I fail at that first part. Especially since the sections flooded and inaccessible except for at the surface are going to contain things like large amounts of high explosives, fuel, and the engines/battery systems we use to run life support and maintain control of the sub.
Let's just try to make a sub that actually works and isn't a deathtrap first before we go crazy with the technology, alright? We aren't the Soviets, we have very little to no experience making more modern submarines. At most we may have had a few early U-boat equivalents but I haven't seen anything of that mentioned, all our naval history seems to be in our surface fleet.
An extendable bridge doesn't necessarily have to eat into our internal volume - unlike project 673, we're building a single hull submarine, which means the pressure hull is going to be bracketed by the ballast tanks. This bridge tube could be housed in the forward ballast tank so it doesn't eat into any out our internal volume.
I'm not aware of non nuclear subs with pumpjets beyond that one experimental conversion of a Kilo. What subs are you referring to?
Sorry, I wasn't clear: I'm not suggesting copying the Swedish design exactly. Rather, I'm proposing omitting the six non-reloading tubes and making the rotating magazine carry heavyweight torpedoes inside a free-flooding compartment at the
rear of the submarine.
I was debating going for a thermal torpedo because my reading suggested that electrical torpedoes tend to be much shorter ranged. Modern electric torpedoes seem to be in the same performance regime as thermal ones, but I'm not sure how much that has to do with modern battery construction. A cursory search hasn't turned up a good source for the historical energy density of
Aluminum-Silver-Oxide batteries. :/
I'd
prefer electric torpedoes, but it all depends on the battery.
Mind you, we have very good electric actuators, a linear motor type piston for pushing torpedoes out would also be pretty quiet.
You're right about the nitrogen system - that was pure sleep deprivation talking.
Hmmmmm, ok, alternative idea to the rotary torpedo rack: We commit to electric swim-out torpedoes that can stay in a free flooded compartment, remove the rotating part, and mount 16 heavy corps all around the forward ballast tank (ahead of the deployable sail). Each torp is mounted in a simple launch tube that just guides it out. To fire, a single actuator hinges the front of the launch tube out.
This way we eliminate the torpedo room and all the complex bits that go with it, and because each tube comes with its own wire, it allows for this frankly hilarious specification:
Max Torpedoes: 16
Max Torpedoes Guided at Once: 16
Edit: Do not do this, you will tangle literally all the wires and have a deeply unfun time.
I'll make a diagram this evening to illustrate what I'm talking about.
Edit: I'm coming around to a more traditional sail for something like this - expanding the forward ballast tank to fit the deployable one would push the fin sail too far back I think.
Awww, come on. I really want to make something of least a
little wacky. 🥺
Maybe we can gather building experience by making civilian designs too? For science and research uses maybe?
Unfortunately there's not a lot of crossover between civilian and military submarines. Science wise you're typically better off just using ROVs tethered to a surface ships.
edit: The way I see it, what ends up making it into the sub will be based on the roll chart. Now, our cumulative bonus is +14 (+4 from 7th Hex's Tigerstripe, +4 from my Tigerfish, +2 from my Tigerstripefish, and +4 from abominable's omake). According to the Roll chart, that means we start at 'improvements over baseline design'.
0- = Utter failure, completely unusuable.
1-3 = A pretty bad piece of equipment. Faulty, unreliable, prone to explosion/jamming/not working.
4-8 = Eh-Level weapon/equipment. Minor faults, some things don't work right, but "good enough" all things considered.
9-11 = You wanted it, you got it. Whatever "it" is.
12-16 = Improvements over baseline design, adjusted to fit some things, but better than nothing.
17-20 = Covers failures, improves in one area far ahead, but has experimental issues that can be resolved later.
20+ = You wanted a bolt-action rifle? Too bad, here's an automatic gun! Basically, jump in technology and capability for the thing you wanted.
Here's how I see this chart relating to our submarine:
9-11 = A baseline design: sail, automation, anechoic tiles, diesel generators and batteries + IT weirdness: good electronics. (100% Chance)
12-16 = Starting to see hints of the future: x-rudder, towed array, rafted machinery, quieter propeller + IT weirdness: electromagnetic piston torpedo launch (similar to what the French use). (100% Chance)
17-20 = Jumping into the next generation: Stirling AIP with some teething issues, flank sonar arrays + IT weirdness: photonics masts (feasible with our current electronics tech according to people on Discord who know way more about electronics than I do). (85% Chance)
20+ = The future is now, old man: rim riven thrusters, conformal sonar array + IT weirdness:
Extendable sails and folding masts. (70% Chance)
