Having a problem with the deDaanan

Tanaka Kichigai · Post by **Tanaka Kichigai** » Tue Jun 15, 2004 9:47 pm

The boat Mithril is using is slightly...incompatible.

The problem is, basically, its size. Its length along the beam prohibits the diving and rising times needed by their operations. In order to dive or rise in any respectable amount of time, they'd have to plane down at such an angle it would throw the crew off of their feet, cause equipment to drop from racks, slam people into consoles, and other nuisances. Also, they'd have to spin their screws so fast that they'd cavitate (this is an anomaly which occurs on subs all the time - you spin your screws fast enough that you create an area of low pressure behind them, low enough to vaporize the water - resulting in extremely noisy bubbles). Boomers have the same problems, which they make up for by being extremely quiet, and diving/rising slowly.

Which brings us to the area of how quiet this thing is. It's so big, it has one of two problems. 1) it's horribly noisy, which has its own obvious problems 2) its entirely too quiet, leading to a "hole in the water" lack of sound, thereby allowing it to be located with ease. This is demonstrated in the Russian Typhoon class boat, a boomer which they love to sit under the ice of the Aluetians.

(Oh, forgot to add - jets are even noisier than screws, and cause more cavitation)
All in all, that's been bugging me for a small bit. Can anyone think of a solution?

HELLFIRE · Post by **HELLFIRE** » Wed Jun 16, 2004 6:12 am

@Tanaka
Question then becomes "what's the de Danaan's propulsion system." At a guess,
they probably use a cold-fusion reactor for the powerplant -- it was thrown
around that that is what powers the latest generation of AS -- but it's
never revealed what kind of propulsion system she uses, conventional
screws or otherwise. During the refit ep, Mardukas makes some mention
of 'particle thrust propellers' or something to that effect -- I have to
rewatch that ep -- yet the animation clearly shows a conventional screw.

Some interesting points you've raised... the best way to explain it is
it's all BlackTech, or some of the VERY latest cutting edge USN sound-isolation
systems yet devised... the stuff that goes under the heading "if I tell you,
I have to kill you."

Regards

Andrei Burnside · Post by **Andrei Burnside** » Thu Jun 17, 2004 2:26 pm

Palladium Reactors are mentioned in Fumoffu. Given the scarcity of the metal and it's value, I'd venture It has some pretty potent properties to be used in in three reactors of a sub. Given the fact the TDD-1 has actual screws, but also has a variable jet system (they can tilt). It might be possible to rise (combined with the princples of buoyancy in subs) without planar problems. Would make alotta noise, which is why they were so reluctant to rise in Khanka. The fins on the TDD-1 could be some sort of extra buoyancy tanks, or stablizers for that very purpose. In addition, the TDD-1 one is mainly a straightline sub and mainly stays at a relatively light depth in deep seas. It would certainly make the problems associated with rising easier. In addition planar problems are shown, in the anime. When Kaname takes control of the sub and dives, the whole sub shifts. And cables/ linkages holding the harriers break. Black Technology does also play a apart in this. So assume Tanaka they're using a TL-8 sub in an TL 7.5 world.

Tanaka Kichigai · Post by **Tanaka Kichigai** » Fri Jun 18, 2004 12:35 pm

Don't you love GURPS tech designations? They make everything SO much easier.

Hmm...I think one of the best explanations might be it isn't quiet. And it has quite a waterswell when it surfaces...it makes up for those things with a) being faster than torpedos (aka, Akulla II) and packing enough firepower in a quickly deliverable package that it's not a sitting duck when it surfaces.

Post by **Taurec** » Fri Jun 18, 2004 2:17 pm

it's a kind of magic ......

laws of nature don't apply in animation ...

episode numbers would help ...

Tanaka Kichigai · Post by **Tanaka Kichigai** » Fri Jun 18, 2004 3:36 pm

Post is just speculation. However, I'll look through episodes to see where we can get a clear shot of it surfacing, and perhaps being shot at.

HELLFIRE · Post by **HELLFIRE** » Sat Jun 19, 2004 8:00 am

Quiet or not, she definately has a unique sound signature: ref Gaulun's
ToyBox disc, and the Pasedena's XO's comments about a ghost sub.
Maybe a la Hunt For Red October and generating a sound that sounds
like "whales humping, or some other seismic anomaly, ANYTHING but a
submarine."

N doubt about her firepower, conventional and unconventional. From what
we can tell, 6x 21" tubes, 5 VLS for BGM-109s, nevermind at least a platoon
(~50) of SRT members + heavy air and mech support

Regards

Tanaka Kichigai · Post by **Tanaka Kichigai** » Sat Jun 19, 2004 9:48 am

Perhaps I'll look into it and draw up some designs. She would have a unique sound signature, whether or not she wanted to; she's shaped way differently than anything else in the water.

Post by **Taurec** » Sat Jun 19, 2004 10:11 am

@TK if you can get me a vector, i would be very grateful.

Dannan · Post by **Dannan** » Sun Jul 18, 2004 12:23 am

in episode 7, around 13.5 mins in they make a dive while being shot at. the speed that they dive at is only slightly higher than acceptable. I think it's the designer's lack of research making it that shape. (and it seems like a fad to make ships that shape; it looks like a spaceship!

Guest · Post by **Guest** » Tue Jul 20, 2004 8:07 am

Actually it reminds me of the airplane the xmen uses.

Post by **Taurec** » Tue Jul 20, 2004 10:39 am

Dannan wrote:in episode 7, around 13.5 mins in they make a dive while being shot at. the speed that they dive at is only slightly higher than acceptable. I think it's the designer's lack of research making it that shape. (and it seems like a fad to make ships that shape; it looks like a spaceship!

Seaquest DSV ??? fluid dynamics aren't my cup of tea

Dannan · Post by **Dannan** » Wed Jul 21, 2004 3:08 am

lol only serving beer here sir! but the real question is not the engine power (although big factor) , but the material the hull and stern are made of... *seeks answers*

HELLFIRE · Post by **HELLFIRE** » Wed Jul 21, 2004 7:09 am

There's been talk about the Russkies developing pliable anechotic<sp?> tiles
inlaid with airbubble pipes to reduce the friction moving thru a liquid
medium generates, and I think current US subs use a special polymer-based
paint that'll give an extra knot or two. Beyond that, that's REALLY
specialized materials engineering stuff - WAAAY beyond my level
of knowledge

Regards

terran empire · Post by **terran empire** » Tue Nov 16, 2004 2:40 pm

The official us Full metal panic site claims
that the Dannan uses some thing called "EMFC" and a Super conductive propeller. but what those are and how they do what they do are a mystery to me.

Another interesting question would be "where is the Dannan's sonar?" all modern subs have a ball shaped sonar mounted in the nose (bow) but the Dannan's Bow is a flight deck there would be no room as far as i can see.