Comments on: A SUPER FAST, (SUPER LOUD) MINISUB

By: John

John — Mon, 03 Aug 2009 17:35:25 +0000

Sounds good. Now all they have to do is spend $18 billion dollars on it, build 3 and cancel the program.
Then it will be a *real* US military program.

By: Oblat

Oblat — Sat, 01 Aug 2009 11:54:10 +0000

Seems a lot of trouble to go to when a zodiac loaded with a marching band playing at full volume would be just as effective.
But it is hilarious after the years of poo-pooing Russian and Iranian supercavitating torpedoes as being too noisy only to see the same people comment that the same technology used for stealthy seal mini-subs would be cool. Talk about snake oil customers.
If ever there was a project that held up both hands to be canceled this would be it.

By: Jean

Jean — Fri, 31 Jul 2009 12:31:03 +0000

The wildlife argument is quite interesting, especially when turned the other way around. What would happen to a manned sub hitting a whale, a great white shark, a whale shark, a manta ray or a big tuna at 100kts? I know such moderate risks are part of the business for the military but so far as considering this an acceptable mean of civilian transport, I guess i'd still prefer, and by far, flying a respectable 500kts at FL390, even if I'd be scared to death of flying, than blindly cruise this "slow" into what I can't see nor detect, if I understood you guys correctly. But OTOH, since every sides have better and better listening devices to detect the ennemy, this does sound (no pun intended) to me like an excellent way of "scrambling" those listening means and hide one's own subs moving onto a target. They may not even have to be near the attacking sub (or a spying one) if they're so noisy and could be cruised routinely anywhere to hide the "real moves". Does it "sound" like military strategy now? Jean

By: M167A1

M167A1 — Thu, 30 Jul 2009 21:26:59 +0000

I wonder at the manned requirement too.
Would make a heck or a torpedo and it might be a good way to project mines into a harbor if you don’t mind the other sid knowing you did it.
It might be a very rapid type SDV. Get a seal team ashore asoon as possible for a raid, they jump out raid the brewery or whatever they are there for and dash off while ther other side is wondering why the waterfront is burning..
Small change and a perhaps useful tech. Lets do it.

By: gsak

gsak — Thu, 30 Jul 2009 19:13:12 +0000

We need this for clearing datum after an SLBM launch, to avoid counter-battery fire. Assuming we work smaller solid propellant motors into a Virginia-sized hull.
Additionally, this could be useful for fast transit from the 100-fathom curve to the area of operations.

By: joe buff

joe buff — Thu, 30 Jul 2009 13:02:19 +0000

Tom et. al.: You give a very good summary of what DARPA is and isn’t trying to accomplish with the Underwater Express project w. GDEB. While the article in THE DAY didn’t mention dual mode (high-speed rocket/low-speed batteries) propulsion, it did describe the GDEB design as 8 feet in diameter (beam) and 100 feet length. Notionally, this is like a 60ish-foot ASDS with a 40-foot supercavitating back-end. The ASDS had a battery-powered screw that could make 8 knots for 125 miles. The concept of the ASDS was stealthy ingress and egress. (The project was canceled because the actual test article was too noisy and vibration-prone, and had a bad fire during a battery recharge.)
Thus, an SST could be thought of, and used, as an “ASDS-Plus.” It could offer the option for a stealthy minisub ingress and egress — with another option for an “emergency exit” if the commando team during its mission on land were compromised, or the mission as planned involved having to “make a datum” that revealed the team’s presence to opposition forces. (In that case the loud egress signature does not further compromise the mission.) The fast/loud egress option could then be invaluable to team survivability. The utility of that emergency exit capability would be even greater if the mission parameters specified as vital to success the assured retrieval from hostile territory of some high-value personnel and cargo.
Make sense?

By: Tom

Tom — Thu, 30 Jul 2009 12:26:18 +0000

So what if it is noisy as long as the mission is properly planned to beat the enemy capability to respond!
Even among nations that do have robust maritime defenses and/or paranoid leadership, there are very few situations where an enemy could react quickly enough to catch or kill something moving 100 kts underwater.
The greatest potential drawback is that IF this system was used to enter the enemy location it might raise an alert that would interfere with any sort of clandestine mission. Of course, as someone else already noted, there is no reason why an OPERATIONAL version could not be fitted with dual propelsion systems to provide a low-noise entry combined with a fast exit.
Keep in mind that this is a DARPA research project, not an operational procurement. Although DARPA projects frequently do turn into operational hardware sooner than outsiders might expect, the bottom line is that most DARPA projects are research to address a single specific problem or closely related set of problems. DARPA is not designing a Seal Delivery Vehicle — they are working on technologies for fast underwater transport. What someone later does with that technology and especially how this technology is merged with other technologies is outside the scope of this project.
If this technology works out, I would bet that in a few years we will see a stealth sub with a 100kt dash speed capability.

By: DualityOfMan

DualityOfMan — Thu, 30 Jul 2009 04:38:10 +0000

This program seems a bit silly to me. The whole point of submarines is basically stealth. In the Cold War, this was so our submarines could tail Russian submarines. Now it has to do with keeping power projection secret and/or stealthy.
If we’re going to study supercavitation, torpedoes seem to be a better choice. If we want minisubs, stealth is probably better. Accelerating to 100 kts underwater is like holding up a giant “look at me, I just infiltrated your coastal waters” sign. If they can’t see you, who cares how fast you get out?
$38 mil is pocket change in the budget anyhow. I think it’s good that DARPA provides pretty inexpensive development of radical technologies for future use.

By: Ptsfp

Ptsfp — Thu, 30 Jul 2009 01:24:39 +0000

All right Joe, who are you trying to kid? According to your last article, “UFO IN OUR BAFFLES, COMRADE CAPTAIN!” the Reds already think we have something that does 230 kts…
We also have the cool underwater thingies that can fly too. I think Darpa is just blowing smoke. :)

By: joe buff

joe buff — Wed, 29 Jul 2009 23:07:52 +0000

WJS: Yes I think you hit squarely on the basic idea of Underwater Express. So long as you don’t crash into an old wreck or a sandbar, 100 knots underwater is a great way to “get out of Dodge.”