Using Radar to Search for Submarines

[TLAM Strike]

Originally Posted by SeaQueen

That is true. Covertness is definitely the submarine's advantage. None the less, the Airforce, at the present time, doesn't seem to have much trouble surpressing air defenses sufficiently to allow their B-52s, B-1s and B-2s as much access as they need. The other thing about submarine mining is that it basically takes a submarine out of the game. That one submarine is dedicated to mining, and that's pretty much it. After it lays it's mines, it has to go all the way back to wherever they've forward based it. Then it'll most likely be weeks until the submarine can begin transiting back to the theatre. At that point, things will be pretty much over. Unless you just happen to have a spare submarine in the theatre, still I wouldn't do it.

Well I have to disagree with you on the USAF's ablity to conduct SEAD in this case. To lay mines they would need to fly at low altitude a to avoid damage to the mines when the enter the water. So unless they fly far off the coast they are voulnerable to MANPADs and other light SAMs not to mention small arms fire ("Every cousin with a rifle" to quote Flight of the Intruder).

The Swedes and Germans have gotten around the whole taking a sub out of the game thing. They use GRP mine cratles to haul dozens of mines around in additon to their torpedo armorment.

[bottomcrawler]

I could easily imagine a hull-conformal mine storage. I don't know the size of a typical mine, but I'm certain a fair number could be hauled along outside the pressure hull. But it would make for a slightly noisier sub, and a slower one.

[TLAM Strike]

Originally Posted by bottomcrawler

I could easily imagine a hull-conformal mine storage. I don't know the size of a typical mine, but I'm certain a fair number could be hauled along outside the pressure hull. But it would make for a slightly noisier sub, and a slower one.

A mine is roughly half the size of a torpedo (torpedoes are about 533mm wide 8 meters long). It woudn't nessarly be much noiser if the storage girdle was streamlined, the sub would lose some speed. Also the storage girdle could be jettisoned after the mines have all been deployed.

[bottomcrawler]

Perhaps not much noisier, but I'm pretty sure one noise component is the water flowing over the surface, and if the wetted area increases, that noise component should increase as well. Seams and ports would also produce some noise due to flow disturbance, I would imagine.

Perhaps I'm wrong here, but I tend to think of drag-inducing factors as noise inducing as well. But I'm really mostly into aviation, not subs...

[SeaQueen]

Originally Posted by bottomcrawler

I could easily imagine a hull-conformal mine storage. I don't know the size of a typical mine, but I'm certain a fair number could be hauled along outside the pressure hull. But it would make for a slightly noisier sub, and a slower one.

Actually, one of the things people in engineering circles are looking at for future submarine designs is weapons storage external to the hull.

[bottomcrawler]

Ah!

Well, as I said, my main interest is aircraft and aviation in general, and conformal fuel tanks and sensor packages are becoming more common there. It just made sense to me to have something similar under water.

Carefully designed, CFTs only add around half the wetted area compared to a pylon-mounted drop tank of the same volume. In addition to that, they free up pylons for missiles and bombs.

For a sub, I figure faster reloading and an increased load capacity would be the main advantage. Having torps in long tubes that are already flooded, outside the pressure hull, would make for quieter launches. I don't know if it's possible, but gently pushing a torpedo out, then have it "hover" silently until the launching boat quietly swims away to a safe distance, would allow very stealthy engagements.

[SeaQueen]

My understanding is that with future 774 class flights you'll see more experimentation with various ideas. Rickover did a lot for the nuclear Navy in terms of safety, but at the expense of quashing innovation with weapons systems and sail designs in particular. There's all kinds of things on the books for future versions.

Originally Posted by bottomcrawler

For a sub, I figure faster reloading and an increased load capacity would be the main advantage. Having torps in long tubes that are already flooded, outside the pressure hull, would make for quieter launches. I don't know if it's possible, but gently pushing a torpedo out, then have it "hover" silently until the launching boat quietly swims away to a safe distance, would allow very stealthy engagements.

[LoBlo]

Originally Posted by bottomcrawler

Ah!

Well, as I said, my main interest is aircraft and aviation in general, and conformal fuel tanks and sensor packages are becoming more common there. It just made sense to me to have something similar under water.

Carefully designed, CFTs only add around half the wetted area compared to a pylon-mounted drop tank of the same volume. In addition to that, they free up pylons for missiles and bombs.

For a sub, I figure faster reloading and an increased load capacity would be the main advantage. Having torps in long tubes that are already flooded, outside the pressure hull, would make for quieter launches. I don't know if it's possible, but gently pushing a torpedo out, then have it "hover" silently until the launching boat quietly swims away to a safe distance, would allow very stealthy engagements.

Sounds like your thinking along the lines of the the Navy's "Tango Bravo" research project http://www.darpa.mil/STO/maritime/tango.html

I love speculating about future designs as well.

Conformal would make sense if it looked similar to the Ohio Class subs fairwater area [above the missile tubes]. That would be the only way to make them conviently reloaded otherwise the weapons would need be loaded underwater [awkward at pierside and with a 1 ton torp]. Not sure how many torps you could fit at a 'read to launch' position in such a small space though. I say, storage in the ballast tanks would be better.

[bottomcrawler]

I'm not so sure. The easiest way to load them would be through the ports, and all that's required is something to align the loading tube with the storage tube, make the connection and gently push the torp over. Surely that would be possible underwater, and fully automated as well.

If torps are made to swim out, then you could have a rail system inside the storage tube, so that when the first torp is away, the next in line is moved forward to the launch position. If the sub itself is 400 ft long, for example, the storage tubes could maybe be 250 ft, and that's eight torps in line. Imagine three such tubes stacked vertically on each side... 48 extra torps. Not sure how that would work with regards to buoyancy, though.

Added a simple illustration. The big black circle is the pressure hull, and the grey is the outer hull, with the six black circles as torp tubes. This would be for a new hull design, though.

[Dr.Sid]

Launched torpedoes would be replaced by sea-water, same as with VLS, so there should be no problem with buoyancy.
Also VLS is in fact such system. It's not accessible from inside, though I'm not sure if it's inside pressure hull or outside.
Problem I see is that no maintenance would be possible. But then VLS missiles don't need any, or it is done by wire (I guess).
Then there is problem that you have explosives outside your hull, and they do not work as good bumper.
Which reminds me .. hey ! Russians use external tubes for some time now. All problems solved.

[LoBlo]

Originally Posted by bottomcrawler

I'm not so sure. The easiest way to load them would be through the ports, and all that's required is something to align the loading tube with the storage tube, make the connection and gently push the torp over. Surely that would be possible underwater, and fully automated as well.

If torps are made to swim out, then you could have a rail system inside the storage tube, so that when the first torp is away, the next in line is moved forward to the launch position. If the sub itself is 400 ft long, for example, the storage tubes could maybe be 250 ft, and that's eight torps in line. Imagine three such tubes stacked vertically on each side... 48 extra torps. Not sure how that would work with regards to buoyancy, though.

Care for some debate/critique? In the spirit of debate, I see a few issues with that design.

1) One is that it would be cumbersome to load front hatches/ports while they are underwater. Even the Akula had its external tubes on the dorsal surface to allow easy loading.



You would either need divers to ease the torps into their ports (awkward for a floating diver manipulating a 1 ton torp being supported by a crane and having to repeat it 48 times), or special support platforms to load the torps; meaning only ports with the special support platforms can load torps whereas currently any port with a simple crane will do (good for wartime improvising).

2) that profile would make the boat non-axissymetric, meaning more drag and all the pitfalls of more drag. If its made to be axis symetric, its now essentially a double hull a.k.a increased building expense, whereas most Navy's are looking at ways to build things cheaper.

3) The launch needs not only to gently push, but also needs be able to forcibly eject the weapons outward while the sub is a flank speed, meaning that the system would need a the same load and latch systm currently in all subs now. They would then be outside the boat chronically exposured to seawater at months at a time, unavailable for diagnosis and repair of any malfunctions unless returning to port/pier. Remember that seawater is the most corrosion medium on the planet and anything chronically exposed will have an increase risk of malfunction (relative to being in air). When you think about it, we've essentially taken the loading/rail/hatch system of any current sub, moved it outside the hullr, exposed it to seawater for months at a time, and made it completely off limits to maintenence for months at a time as well.

All and all, not sure we're getting much bang for the buck there with all that's required in the name of having a few more torps in the loadouts.

A simple solution would be to replicate a 'VLS' approach for torps. Preload the torp into their launch tubes off the boat. Drop the preloaded tubes from the top into the ballast tank horizonally and secure them to the correct angle. Ready and done. No extra moving parts to break, malfunction, or matain. I would probably go with a 'quad-canister' arranagements (like used by the harpoon missiles) at the 4 quadrants of the ballast tanks angled forward. Just open the door and shoot when needed. Simple, easy, reliable.