Using Radar to Search for Submarines

[SeaQueen]

I've been playing with the P-3 lately. I created a scenario where I was the pouncer for 3 CVOAs located in the Philippine Sea, and I had to make sure a CVN didn't get sunk. Interestingly, my most effective search sensor wasn't the sonobuoys at all. I used them mostly for prosecution. It was the radar!

Up at 2000ft, the radar horizon is pretty long so I could search large portions of the ocean relatively quickly. When I saw a radar contact vanish from my screen, I knew it was a submarine submerging. I'd fly to the last location and just drop a torpedo on the MAD hit. I'd get 'em every time.

[Molon Labe]

A little surprising. I know there's a hardcode that makes D-E subs run their diesels on occasion, but I think they usually do it snorkeling. Did you set up the mission to force them to surface on some interval?

[SeaQueen]

A little surprising. I know there's a hardcode that makes D-E subs run their diesels on occasion, but I think they usually do it snorkeling. Did you set up the mission to force them to surface on some interval?

I know, that's why I posted it! :-)

I just let the AI do it's thing. There was no coding at all in it. Something I've noticed, and this goes back to my usual axe to grind, is that people don't make missions with the correct distance and time scales in mind. Out of 24 submarines in the whole scenario, I only saw 2 pop up in 3 hours. Part of that was due to the limitations of my radar horizon at 2000ft too. There might have been more and I just didn't see them.

None the less, if you throw enough submarines in there, eventually, you'll see them surface. Another thing I've noticed is that submarines at periscope depth will go deep when a helo goes near them. I guess they're trying to avoid the MAD. There's actually a lot of interesting behaviors built into the stock AI, but they're realistic ones, which means that yeah, the submarines won't pop up a whole lot, but they do pop up.

[LoBlo]

Care to share the scenarios? I played your RIMPAC scenario. It was challenging. You should make more and share them. :D

[SeaQueen]

Care to share the scenarios? I played your RIMPAC scenario. It was challenging. You should make more and share them. :D

I'm glad you liked RIMPAC. NATO EXWAR exercise is pretty similar but with an ESG instead of a CSG. I sent in a scenario called NATO ISR exercise to Bill Nichols but it seems to have vanished into the void. He doesn't seem to be updating his site like he used to be. I guess with the Democrats in power he has things to do again.

The mission I'm playing with now is still in the works, but it is definitely promising as one to send in. I actually want to make a campaign some time. I just can't figure out how to make that part of the scenario editor work.

[Molon Labe]

A little surprising. I know there's a hardcode that makes D-E subs run their diesels on occasion, but I think they usually do it snorkeling. Did you set up the mission to force them to surface on some interval?
I know, that's why I posted it! :-)

I just let the AI do it's thing. There was no coding at all in it. Something I've noticed, and this goes back to my usual axe to grind, is that people don't make missions with the correct distance and time scales in mind. Out of 24 submarines in the whole scenario, I only saw 2 pop up in 3 hours. Part of that was due to the limitations of my radar horizon at 2000ft too. There might have been more and I just didn't see them.

None the less, if you throw enough submarines in there, eventually, you'll see them surface. Another thing I've noticed is that submarines at periscope depth will go deep when a helo goes near them. I guess they're trying to avoid the MAD. There's actually a lot of interesting behaviors built into the stock AI, but they're realistic ones, which means that yeah, the submarines won't pop up a whole lot, but they do pop up.
I can assure you, helos going deep with air contacts in the vicinity is not hardcoded, but controlled by doctrine.

EDIT: it turns out I'm wrong about the snorkeling; that is also doctrine.

I'm glad you liked RIMPAC. NATO EXWAR exercise is pretty similar but with an ESG instead of a CSG. I sent in a scenario called NATO ISR exercise to Bill Nichols but it seems to have vanished into the void. He doesn't seem to be updating his site like he used to be. I guess with the Democrats in power he has things to do again. Well at least I know he's not just pissed at me.

[LoBlo]

Maybe a a PM to him would be in order to check that everything is cool?

Of course... subguru.com is the only repository for DW scenarios... if the site ever went down all the scenarios would be lost... hmm..

[SeaQueen]

Of course... subguru.com is the only repository for DW scenarios... if the site ever went down all the scenarios would be lost... hmm..

That's not true. Now there's CADC too. I just put NATO ISR exercise up on that one. Hopefully someone enjoys it. It's a little bit different from the usual scenario.

[Molon Labe]

Of course... subguru.com is the only repository for DW scenarios... if the site ever went down all the scenarios would be lost... hmm..
That's not true. Now there's CADC too. I just put NATO ISR exercise up on that one. Hopefully someone enjoys it. It's a little bit different from the usual scenario.

Gave it my first runthrough today and you'll be happy to know I flunked. Question, did you design this with LWAMI in mind? Because normally you seem to prefer stock DW, but the placement of some of the stuff in here seems like it was meant to take advantage of a certain LWAMI feature. I'd say more but I don't want to throw a spoiler out. But if it was intended, it's very devious. :dead:

[SeaQueen]

Gave it my first runthrough today and you'll be happy to know I flunked. Question, did you design this with LWAMI in mind? Because normally you seem to prefer stock DW, but the placement of some of the stuff in here seems like it was meant to take advantage of a certain LWAMI feature. I'd say more but I don't want to throw a spoiler out. But if it was intended, it's very devious. :dead:

Oh good! I'm glad you enjoyed it. I designed it with stock in mind, but there's no reason why you couldn't play it with LWAMI that I can think of. If you can make it past the surface ships undetected and take a picture of those bunkers, you're all good. There's nothing database dependant about all that. If I remember correctly, I designed the anti-submarine barriers to a 0.9 effectiveness, so just by random chance you should win about 10% of the time.

There isn't really anything devious about it. The surface ships behave pretty brainlessly. It's tough because you've got to quickly make decisions in the face of great uncertainty, which is the real challenge of being a submarine officer. You never really know how far away the surface ships are exactly, so how do you evade them? They come up awfully quick. If you're smart you can make some good guesses but even then it's not easy.

[LoBlo]

A 10% probability of survival? Now that's just plain wrong...:shifty:

*goes off to try the mission*

[SeaQueen]

A 10% probability of survival? Now that's just plain wrong...:shifty:

*goes off to try the mission*

It's not a 10% probability of survival. It's a 10% probability of remaining undetected assuming you're behaving randomly in the sense that you start off at a random position and then drive in a straight line. You all are pretty smart people so I'd HOPE you all put a little more thought into things than that. It's also important to notice that in DW detection is not the same as classification. Just because the AI has determined there's a submarine there doesn't mean they've determined there's a hostile submarine there.

If I was writing a subsim, I'd want to have some control over the classification criteria as a scenario designer. In one scenario, detection might be classification, in another it might be something else. I've noticed that the AI is very slow to call something a hostile sub, and giving the scenario designer some control over that might help.

But anyhow, if you can remain undetected you'll probably do pretty well because the minefields aren't terribly effective against submarines.

[TLAM Strike]

Care to share the scenarios? I played your RIMPAC scenario. It was challenging. You should make more and share them. :D

I'm glad you liked RIMPAC. NATO EXWAR exercise is pretty similar but with an ESG instead of a CSG. I sent in a scenario called NATO ISR exercise to Bill Nichols but it seems to have vanished into the void. He doesn't seem to be updating his site like he used to be. I guess with the Democrats in power he has things to do again.

The mission I'm playing with now is still in the works, but it is definitely promising as one to send in. I actually want to make a campaign some time. I just can't figure out how to make that part of the scenario editor work. Just played ISR and liked it although it was a little long, returning to the ESG area there wasn't much to see (no shipping or biologics).

[Molon Labe]

Gave it my first runthrough today and you'll be happy to know I flunked. Question, did you design this with LWAMI in mind? Because normally you seem to prefer stock DW, but the placement of some of the stuff in here seems like it was meant to take advantage of a certain LWAMI feature. I'd say more but I don't want to throw a spoiler out. But if it was intended, it's very devious. :dead:
Oh good! I'm glad you enjoyed it. I designed it with stock in mind, but there's no reason why you couldn't play it with LWAMI that I can think of. If you can make it past the surface ships undetected and take a picture of those bunkers, you're all good. There's nothing database dependant about all that. If I remember correctly, I designed the anti-submarine barriers to a 0.9 effectiveness, so just by random chance you should win about 10% of the time.

There isn't really anything devious about it. The surface ships behave pretty brainlessly. It's tough because you've got to quickly make decisions in the face of great uncertainty, which is the real challenge of being a submarine officer. You never really know how far away the surface ships are exactly, so how do you evade them? They come up awfully quick. If you're smart you can make some good guesses but even then it's not easy.
Try it with LWAMI installed and you'll see why I said it was devious. One of the DB objects is not the same as what it used to be.

edit: ah hell, if you designed it for stock I don't have to worry about spoilers. The minefields are CAPTORS, and they're positioned such that they're likely to catch the sub when he has to put on a little bit of speed to traverse the Krivak route.

[SeaQueen]

Just played ISR and liked it although it was a little long, returning to the ESG area there wasn't much to see (no shipping or biologics).

That's fair. I've come to the conclusion that really, to do a realistically scaled mission, it's probably going to be kinda long. My own experience with warships is that, frankly, a lot of time at sea is spent sailing around looking at nothing.

[LoBlo]

I don't know much about that part of the globe, but how about some merchants transiting out of the port? Unless all merchant shipping has been halted owing to the minefield? (maybe a corridor thru the minefield that merchant shipping uses and a SSK sitting right in the middle to ensure only merchants (not enemy subs) use it.:hmmm:

By the way. Great mission. Got thru it the 1st time and wasn't until I turned on the replay did I see all those mines! Yikes!. Talk about lucky sailing.

[SeaQueen]

I don't know much about that part of the globe, but how about some merchants transiting out of the port?

You're right, Trondheim is a major port.

Unless all merchant shipping has been halted owing to the minefield? (maybe a corridor thru the minefield that merchant shipping uses and a SSK sitting right in the middle to ensure only merchants (not enemy subs) use it.:hmmm:

I thought about it. I didn't think it was really essential to the mission and it might lead a player to think there was a "right" way to get through, and I don't like to do that. I like things to be more open ended.

By the way. Great mission. Got thru it the 1st time and wasn't until I turned on the replay did I see all those mines! Yikes!. Talk about lucky sailing.

The mine barriers shouldn't be terribly effective. It's such a large area to mine that it's hard to put out enough mines out there to be even 80% effective. They might make a decent deterrent, though, if one ship got hit. I threw them out there in a way that would probably be typical of a minefield intended to deter amphibious assault. The hard part of that, though is deciding how much preparation the enemy has to plant mines. I assumed they didn't have much time. A less favorable assumption would be that they had months.

[LoBlo]

By the way. My experience with the DW AI is that it automatically classifies any human target it encounters, meaning that it automatically knows whether it is hostile or friendly the instant it is detected (if you look at debug view while the game is running).

Can anyone else confirm?

[TLAM Strike]

I don't know much about that part of the globe, but how about some merchants transiting out of the port?

You're right, Trondheim is a major port. I just noticed that the depths for it in DW seem just about right for a Kilo to pull a harbour pentration mission... :hmmm:

Unless all merchant shipping has been halted owing to the minefield? (maybe a corridor thru the minefield that merchant shipping uses and a SSK sitting right in the middle to ensure only merchants (not enemy subs) use it.:hmmm:

I thought about it. I didn't think it was really essential to the mission and it might lead a player to think there was a "right" way to get through, and I don't like to do that. I like things to be more open ended. Unless of course the shipping channel has CAPTORs or other mines that discriminate. :yep:

[LoBlo]

Unless of course the shipping channel has CAPTORs or other mines that discriminate. :yep:

A little off topic (not to hijack the thread), but were Captor's ever deployed?

[SeaQueen]

Unless of course the shipping channel has CAPTORs or other mines that discriminate. :yep:

I'm not sure that'd serve the right purpose. For an amphibious assault, you want to deter the assault by insuring that ANY platform that approaches the coast stands a chance of getting hit. Ultimately your minefield isn't really targeting submarines at all, it's targeting grey hulls and any commercial shipping being used to haul military forces (MPF ships).

You'd use mines that discriminate if you were narrowly targeting specific types of vessels, but to deter amphibious assault, I'd want floating mines in the deep, teathered mines as it got more shallow, right on up to bottom mines in the shallows. I'd want to send out a big loud message "STAY THE HELL AWAY FROM HERE, EVERYONE!!!" Bare in mind, even a small speedboat could contain special operations forces.

[SeaQueen]

A little off topic (not to hijack the thread), but were Captor's ever deployed?

Yes. But mine warfare is sort of the ugly stepchild of the US Navy. Both mine sweeping and mine laying are not considered high priorities by them.

Honestly, I'm doubtful that US Navy will ever really use mines on a wide scale. There's reasons that range all the way from the laws of war and humanitarian issues, to the generally risk-averse mindset of Naval officers. If they did lay mines, it'd be very interesting, because it's a really complicated question regarding what they'd be trying to accomplish.

For example, suppose you were mining a harbor, if it was a commerical harbor then you'd be targeting merchant shipping. The thing is, mines don't discriminate between neutral shipping and targeting shipping. These days it's especially important because the shipping industry is so globalized. The shipping companies are TRUELY multinational, changing flags and registries as convenient. So, even if you were targeting, say, Iranian shipping, you'd be most likely hitting vessels belonging to almost every seafaring nation of the world. Since in the US we like to try to obey international law (the previous administration aside), the legalities of this would be complex. The political angles might be every more complex. Suppose you hit a Ukrainian container ship, pulled into an Iranian port, filled with everything from arms to Algerian terrorists to microwave ovens intended for consumption in the US. It gets weird fast. Naval officers don't like weird. They like easy, straightforward and minimal risk. Hence, I'll be amazed if the US ever employs mines in any large quantities.

And if we did use them, they'd most likely be layed by B-52s, B-1s and B-2s. The Navy MIGHT lay a few of them for ceremony's sake, but all by themselves, they can't lay a minefield of any real effectiveness. I mean... come on... if you filled a 688 with mines that'd be only 24. You need more than that to lay a good barrier. Quickstrike mines are the way to go.

[TLAM Strike]

I mean... come on... if you filled a 688 with mines that'd be only 24. You need more than that to lay a good barrier. Quickstrike mines are the way to go. Actualy it would be about 50 since in general 2 mines can be carried in the place of one torpedo unless its a SLMM which is just a torpedo that functions as a mine. 50 Captors would be fairly nasty off a Bandar'e Abas. :ping:

[SeaQueen]

Actualy it would be about 50 since in general 2 mines can be carried in the place of one torpedo unless its a SLMM which is just a torpedo that functions as a mine. 50 Captors would be fairly nasty off a Bandar'e Abas. :ping:

That depends on what their actuation radius is and what you're trying to do.

[TLAM Strike]

Actualy it would be about 50 since in general 2 mines can be carried in the place of one torpedo unless its a SLMM which is just a torpedo that functions as a mine. 50 Captors would be fairly nasty off a Bandar'e Abas. :ping:

That depends on what their actuation radius is and what you're trying to do.

Valid point.

However the closer you can get to where ships are coming from (a port) the less mines are needed to isolate/destroy them. So a submarine with fewer mines can do more damage than aircraft(s) or ships can with more. Since the aircraft risk being shot down (and their pilots bailing out in enemy airspace) and the ships risk being attack by costal defenses.

[SeaQueen]

However the closer you can get to where ships are coming from (a port) the less mines are needed to isolate/destroy them. So a submarine with fewer mines can do more damage than aircraft(s) or ships can with more.

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.

[TLAM Strike]

However the closer you can get to where ships are coming from (a port) the less mines are needed to isolate/destroy them. So a submarine with fewer mines can do more damage than aircraft(s) or ships can with more.

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]

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]

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.

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]

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.:cool:

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.:yep:

[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.

http://img25.imageshack.us/img25/2719/xtratorps.gif

[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.

[TLAM Strike]

Which reminds me .. hey ! Russians use external tubes for some time now. All problems solved.Yes and the US Did it in WWII. Between the world wars it was trendy to have a set of external tubes that were trainable like the mounts on destroyers.

http://img6.imageshack.us/img6/733/wwiisub.th.jpg (http://img6.imageshack.us/my.php?image=wwiisub.jpg)
^USS Stingray with two external tube mounts.

[LoBlo]

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.

http://www.nancarrow-webdesk.com/warehouse/storage2/2008-w45/img.402827_t.jpg

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.

[Dr.Sid]

I like the 'not for public use' watermark :arrgh!:

[bottomcrawler]

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).


We live in the 21st century. An automated loading system with self-alignment would be an easy matter to design and build. You start with a crane and then add a rigid lift mechanism that lowers the loading tube (carrying the torp) into position. A docking mechanism then engages the edge of the storage tube inside the port, aligning and securing the loading tube. A rail system would then push the torp into the storage tube, where it transfers to the internal rail. Done!


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.


When you say more drag, do you simply refer to the increase in wetter area (surface friction drag) and the slight increase in frontal area (form drag)? Or is the another factor that comes into play?


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.


Well, there are several ways to solve that problem. One is to simply evacuate the tubes (which would require pressure-resistant storage tubes, i.e. a bit heavier) and only slowly flood them right before hostilities are expected. They could then be flushed with fresh water at a later time, to prevent large-scale corrosion.

Or, the tubes could be flooded with fresh water permanently and then flushed again (like above) after "use".
I'm not sure what the realistic production capacity for fresh water is in a modern sub, though.

Or, have encapsulated torps, where they each have their own, snug, storage capsule that is jettisoned at launch (this capsule could also have an ejection mechanism to solve the high-speed ejection issue).

My mind is always looking for problems to solve and imperfections to improve on. Some ideas are good, others, not so great... :D

[LoBlo]

We live in the 21st century. An automated loading system with self-alignment would be an easy matter to design and build. You start with a crane and then add a rigid lift mechanism that lowers the loading tube (carrying the torp) into position. A docking mechanism then engages the edge of the storage tube inside the port, aligning and securing the loading tube. A rail system would then push the torp into the storage tube, where it transfers to the internal rail. Done!
When you say more drag, do you simply refer to the increase in wetter area (surface friction drag) and the slight increase in frontal area (form drag)? Or is the another factor that comes into play?
Well, there are several ways to solve that problem. One is to simply evacuate the tubes (which would require pressure-resistant storage tubes, i.e. a bit heavier) and only slowly flood them right before hostilities are expected. They could then be flushed with fresh water at a later time, to prevent large-scale corrosion.
Or, the tubes could be flooded with fresh water permanently and then flushed again (like above) after "use".
I'm not sure what the realistic production capacity for fresh water is in a modern sub, though.
Or, have encapsulated torps, where they each have their own, snug, storage capsule that is jettisoned at launch (this capsule could also have an ejection mechanism to solve the high-speed ejection issue).

Sure, those things are achievable, but are they efficient? My impression, is that the rail system itself would be the maintenance headache [as oppose to the torp], meaning that all the moving parts of the rail would need to be 100% malfunction proof, be able to sit in seawater for months between maintenance cycles without any malfunctions, and be able to sit in seawater for years before dry dock/dry maintenence (even in port they would be in the seawater and the maintence would have to be done in the water by divers, unless its expected that the sub would be in dry dock quite often). Is that doable? Yes. But is it worth it in terms of capability/maintenence/reliability/and cost? That's the tough question.

Hm... I'm not sure how often submariners haul the subs into dry dock or go into the ballast tank for maintence. I'll ask in the RL submariner's thread.

In terms of drag, I believe an elipsoid form have a higher coeffient of dray than a cylindrical form, meaning higher drag coeffience = higher drag per surface area.

My mind is always looking for problems to solve and imperfections to improve on. Some ideas are good, others, not so great... :D

Here's a challenge then. How would you solve these problems? http://www.darpa.mil/STO/Solicitations/tangobravo/proposers.htm :hmmm: :yep:
The Defense Advanced Research Projects Agency's (DARPA) Advanced Technology
Office (ATO) announces the joint DARPA/United States Navy TANGO BRAVO
program. The intent of this effort is to overcome selected technological
barriers that are judged to have a significant impact on submarine platform
infrastructure and cost. DARPA and the US Navy together plan to execute a
technology demonstration program to enable design options for reduced-size
affordable submarines with full nominal capability, while simultaneously
decreasing platform infrastructure and the cost of future design and
production. Five technical areas will be solicited under a Broad Agency
Announcement anticipated to be published in the forthcoming weeks:

1. shaftless propulsion,
2. external weapons stow and launch,
3. hull adaptable sonar array,
4. radical ship infrastructure reduction, and
5. reduced crew/automated attack center.

A classified Proposers' Day Conference will be held on 8 November 2004
at the Executive Conference Center, One Virginia Square, Suite 600,
Arlington, VA 22203. A Proposers?Day Conference announcement will be
forthcoming with details on registration.

[bottomcrawler]

Well, the easiest way to avoid corrosion, is to use materials that aren't much affected by seawater. Plastics, for example. My idea was to use a system where moving parts are made of a suitable plastic material (also good for reducing mass and overall density), and actuate them using pressurised water (the pumps could be housed externally in an easily accessible compartment). Teflon-coated sliding plates/rollers work fine when wear is low. After all, such a system would not see much action (only during loading and launch, and how often does that happen?).

[LoBlo]

Well, according to the RLBTDT (Real Life Been There, Done That's), on the RL Submarine thread, guess 'in-water' equipment isn't as maintenence intensive as I thought... so what do I know (diddly squat!) :O:

Of course one could always go with the SSN 23 Jimmy Carter's Wasp Waist design combined with a rotary stowage to store torps. I believe the rotary idea was pioneered by a British engineer, Harold Armstrong by Babcock Defense Systems, according to a book I read. For a 40foot sub, you could probably hold about 30 torps on the rototary and could be loading from the top. If the sub sail was getting in the way it could always be moved to aft of the reactor compartment since subs are going for nonpenetrating mast now anway. Here's a pic. Critique?

http://img204.imageshack.us/img204/6071/extweapons2n.png

[bottomcrawler]

Another idea I have is for a recoverable mobile sensor platform. It could hold a passive 360-degree sonar array, optics ("remote periscope"), simple ESM and a comms system. A larger "spine" or a longer sail could house a couple of units.

This would probably be more useful for a smaller AIP/diesel-electric sub. It could lie in wait at the bottom, with a wire-connected mobile sensor bobbing at the surface, effectively giving the sub nearly the same situational awareness as if it had been at periscope depth with a couple of masts extended.

In an emergency, the wire would simply be cut and the "drone" left to its own. It could of course be programmed to quietly swim to a predetermined safe resting location, to be recovered later by a surface unit.