NationStates Jolt Archive

With older ship classes being decomissioned and newer, more powerful ships replacing them, it has been decided that the standard ADCAP has been used beyond its years and should be replaced. As such, we announce that the new Centaur class DDGN will be the first ship class to be armed with the likewise new Pirhana MkIISS supercavitating torpedo, once they both officially enter service. Here are the stats for the new sub:

Pirhana MkIISS
Range: 20 Miles
Propulsion: Water Ramjet
Max Speed: 400 Knots
Guidance: Blue-Green LIDAR array
Manuverability: Four retractable fins and thrust vectoring, as well as variable cavitator
Warhead: 650 Pounds
Diameter: 21 inches
http://invisionfree.com/forums/The_Allied_Powers/index.php?act=Attach&type=post&id=376896

It should be of some note that all new ship classes will have the necessary systems to fire these torpedoes. Once all new classes come into service, we will also update our submarine's fire control.

[Credit goes to our ally New Empire for the pic and the modification to his originally unguided torpedo.]

Um, excuse me... but... uhhh.... Hydrogen ramjet?

20 Miles range?

Apple Zero, your point is...? The ADCAP has a range of around 6-10, depending on who you believe. The Shkval II is rumored to have up to 20 miles of range.

Raysia-
http://www.sciam.com/article.cfm?articleID=000CA29B-0EA6-1C70-84A9809EC588EF21&pageNumber=3&catID=2

It should be a water Ramjet, (I was thinking of my new Hydrogen rocket torpedo when I was rewriting the stats for the upgrade. Sorry Scandinavian.) . The US Navy is working on them.

Actually, a ADCAP has a vastly greater range, I believe about 40km or so. It is comparable to the RN Swordfish in terms of range.

A Hydrogen ramjet would burn through fuel much quicker and so have a much shorter range, even if it is faster.

NE: It sounds like a rocket booster with a gas bubble around it... where does the ramjet come in?

FAS and Globalsecurity put it between 6-10 miles... Maybe I need some new sources...

NE: It sounds like a rocket booster with a gas bubble around it... where does the ramjet come in?
To Quote Sci American

Most existing and anticipated autonomous supercavitating vehicles rely on rocket-type motors to generate the required thrust. But conventional rockets entail some serious drawbacks - limited range and declining thrust performance with the rise of pressure as depth increases. The first of these problems is being addressed with a new kind of high-energy-density power-plant technology; the second may be circumvented by using a special kind of supercavitating propeller screw technology.

"Getting up to supercavitation speeds requires a lot of power," says researcher Savchenko. "For maximum range with rockets, you need to burn high-energy-density fuels that provide the maximum specific impulse." He estimates that a typical solid-rocket motor can achieve a maximum range of several tens of kilometers and a top speed of perhaps 200 meters per second. After considering propulsion systems based on diesel engines, electric motors, atomic power plants, high-speed diesels, and gas turbines, Savchenko concluded that "only high-efficiency gas turbines and jet propulsion systems burning metal fuels (aluminum, magnesium or lithium) and using outboard water as both the fuel oxidizer and coolant of the combustion products have real potential for propelling supercavitating vehicles to high velocities."

Aluminum, which is relatively cheap, is the most energetic of these metal fuels, producing a reaction temperature of up to 10,600 degrees Celsius. "One can accelerate the reaction by fluidizing [melting] the metal and using water vapor," Savchenko explains. In one candidate power-plant design, the heat from the combustion chamber would be used to melt stored aluminum sheets at about 675 degrees C and to vaporize seawater as well. The resulting combustion products turn turbine-driven propeller screws.

This type of system has already been developed in Russia, according to media reports there. The U.S. also has experience with these kinds of systems. Researchers at Penn State's Applied Research Laboratory are operating an aluminum-burning "water ramjet" system, which was developed as an auxiliary power source for a naval surface ship. In the novel American design, powdered aluminum feeds into a whirlpool of seawater occurring in what is called a vortex combustor. The rapid rotation scrapes the particles together, grinding off the inert aluminum oxide film that covers them, which initiates an intense exothermic reaction as the aluminum oxidizes. High-pressure steam from this combustion process expands out a rocket nozzle or drives a turbine that turns a propeller screw.

Frankly, it's a rocket and a propeller. Why they call it a Ramjet, not so sure.

Well, according to FAS the listed range of the ADCAP is 45,000 metres, and as this is what they work with in the RN I feel it is safe to say that estimate is pretty accurate, especially as most modern torpedo strikes are usually practised at about twenty miles in order to avoid escorts.

20km for the Squall is reasonable seeing as it is just a warhead and rocket fuel, but for a complex guided torpedo, in reality the range would be just about four or five kms. The Ramjet, though providing lots of range, does need lots of fuel.

This is the problem with supercav and the reason I dont adopt it. They are relatively ineffective at causing more damage and light up the firing submarine on sonars for hundreds of miles, meaning within minutes the submarine is being hunted by every helicopter in the area. Not good.

The Omzian Navy Public Affairs Department truly congratulates our fellow ally for their great achievment in the field of Naval Weapons Engineering. While Omzian engineers at the Omzian Navy Weapons Labs are currently working on a similar helicopter-mounted mine-clearing system, we are also seeking such technology.

While we have a small amount of foreign-designed Type 62 series of supercavitation torpedoes in service, we express our great interest in this weapon system, and the compatibility with 21" TT is a big plus.

Very good...so, in terms of years, about what range of technology level is this?

Well, I'm going on what's been said in the articles and such. The LIDAR system doesn't weigh all that much, neither would thrust vectoring. The Water Ramjet is more efficient than the Shkval rocket, though.

But if you don't wanna use supercav, don't. We've used it because, with our tech level, the subs can get away.

Very good...so, in terms of years, about what range of technology level is this?

About 2010. The technologies all exist physically, but were just slightly too large.

While the Pirhana IISS was designed by the UCSNE, it will be Scandavian State's decision on whether or not he wants it exported.

2010...Nice, that's still within my technology level. Actually, it's only six years off...I'll have to research this technology on my own, although I know little about it except that it creates an air bubble in the sea, which frees the torpedo from water resistance and allows very high potential speeds - given the right propulsion. The problem with supercativation would be that it's hard to get a steering vessel to do it...but ah well...all the same, I'm glad its modern tech.

/end of rant.

Off to research!