Unmanned Sub Hunter to Set Sail

They are still using sails?
Is that for stealth?
Del

......but, it has to slow-steam during its 'stalk' mode, less it blows its cover

less, lest

But won't they know the're being tracked by this above water ship? I mean all they need to do is blow it out of the water, hey no witnesses right? It's like tying a bell on the tail of a cat....how long will that last?

Agreed They would be smarter to have a submersible that can cruise up to 20 metres below the waves to make it invisible to planes or satellites , then surface and skim like a hydrofoil at speed to its next rendezvous , or slowly cruise in stealth mode on the surface powered by solar panels . Wot Wong wit dat ?

I agree that it should ride below the waves but if the submarine switches out of stealth mode it will be able to skip out of range at above 50knots so solar panels are not going to supply enough power to keep up.

Trimarans are inherently unstable vessels. If I was the sub captain I would steer to an area with short high seas and then race away beam on to the waves. If the trimaran follows it's lee hull will dip below the water and the sea will flip it over sand sink it, problem solved, or knowing this will happen and wanting to save $xxxx million of US tax payers money, the remote helmsman will steer strait on, problem solved. OK guys, back to the drawing board.

Yeah, not too stealthy!

And the opposition is assumed to have nothing to take this out? I think a remote operated drone would be fine in finding this, along with a supper tanker that would run over the top of it.

Heavy swells and rogue waves have a habit of breaking off the out riggers on tri-mirans, but it will be interesting to hear how the sea trial go. More debris to navigate around.

It is probably dropped from a tanker type vessel as the range of ninety days will not take it very far afield. I wonder how long it would last around the coast of Somalia. Handy spare parts donation I think and sharing of wealth.

I couldn't see any April fools references but hoo nose

It might come in handy for Sweden's navy when they need to locate the Russian mini subs that come up the rivers. Everyone sees them in the lakes and rivers and yet the navy can never find them. It may have a use for some countries and the drug smuggler may find this sub very handy.

Considering it is designed to stalk a specific fleet of diesel-electric subs, it is only good against third world navies, and perhaps drug traffickers. Good luck staying upright in heavy seas.

No bother then for chasing Swaziland, Lesotho, Ethiopia and Switzerland's navies then.

LOL

I am a little out of date but it use to be that diesel-electric subs were much harder to locate than an a reactor driven sub. They are just so much quieter it was frightening. The other advantage is that they are so much cheaper. If you are not wanting to fill it full of ICBMs then a diesel electric boat makes perfect sense.

The target of a diesel-electric boat is to sink ships. War ships, task groups and even merchant ships. It is also very good for intelligence gathering and depositing teams behind enemy lines.

They are highly maneuverable and have a shallow draft that makes them ideal for areas that a nuclear boat would find very testing.

If you were the purchasing officer for a navy and you had to choose between 10 diesel electric boats or 1 nuclear for an attack on a carrier battle group what way would you go?

If I were on the carrier I would prefer to take on the 1 nuclear boat any day or night of the week.

Another thought is that an unmanned vessel such as the proposed sub-hunter doesn't need to be that stable. There is no one to get hurt and machinery can be designed to cope with any angle. So long as the boat is self righting does it matter how many times it rolls over?

The additional hulls improve the stability and they also make a difference to the speed of the boat for the amount of horsepower driving it. It is to do with the perceived length of hull at the water line.

BAB

The problem with trimarans is that they are not self righting. Once the boat has flipped the outer hulls keep the center of gravity (CoG) inboard, so even though the CoG may be above the water line and the center of buoyancy the hull stays flipped.That means all the propulsion gear is out of the water and the remote driver has no control. If you were to examine Norwegian fishing trawlers you would find that the single hulls have a very deep V cross section. The CoG is a large distance from the center of buoyancy so even if knocked flat by arctic sea conditions they pop back up very quickly. It also allows them to turn 180° in fast flowing fiords that would flip any conventionally shaped hull that turned side on to the current. The penalty is a higher power:speed ratio but as you don't tow trawl nets at high speed and the power needed to pull a trawl is much higher than to drive the trawler that is not a serious drawback.

I think the nuke sub wins, simply because it can stand off out of fighter (or other) A/C range, and simply launch a missile (even while submerged), and continue on whatever course it needs. The carrier will be a smoking hole in the ocean, sorry.

The problem firing a missile like Harpoon from a SSN or SSK to attack a carrier will alert the carrier ASW Escort to launch it s chopper to drop a lightweight torpedo where the missile was launched, (left the water), sub gone! Also there is a good chance the anti ship missile will be shot down. A swim out torpedo will be far more covert than an air launched missile or torpedo, SSKs tend to use swim out torpedos like the quiet battery powered BlackShark. To put this post on track, this is a trail platform big enough for tests on sensors, comms and propulsion. The stability of the platform may be resolved by towing sensors from the outter hulls?

The reality of all this hype is that, the attacking force saves lives and saves compensation costs, while the enemy looses lives, pays out a fortune in compensations and not only looses the battle but goes bankrupt in the process, borrows madly fr,om the world bank, to stay economically viable, and is ultimately controlled by the lender, who's managers all have Panamanian accounts and live well off the profits of an unmanned submarine.

Which I add, is provided after use, to the illegal drug runners who keep the coast guards occupied. It is a win-win boat and no one gets wet in the process.

RMOFLMFAO!!!

I was referring to win/lose scenario, will no holds barred. A nuke sub can certainly nuke a carrier (long range air burst in the multi-megaton range) with no chance of shooting down the missile (IMHO). This stealth sub buster is a so-so idea, but I still hope the USN has good results with the intended purpose. Go Navy!

I understand the colour it is painted is the latest in tested camouflage and is virtually invisible to the naked eye, even in broad daylight. Nuclear orange and better known as speed trap camera yellow. The only give away is the port and starboard running lights.

This April Fool joke has gone completely out of hand...Seriously? Nuclear Orange is invisible at sea?

Obviously you have not seen it at all. Clearly it works quite well then!

How come the picture put out by DARPA shows a grey colored vessel? At least the Navy did not have to shell out big money for another truck load of "Battleship Grey".

Oh that! That was so that they could find it easily themselves without sophisticated detection equipment and of course it is a an artist rendition superimposed on a puddle of water. The actual ship is nuclear orange, (US Navy) and speed trap camera yellow for the UK and European waters, as it does not show up on a photograph. Only the running lights show up as a green and red dot on a photo. (If they are on that is). Near impossible to see this in a photo.

The order that has been placed by the Botswana Navy is Okapi Black, they will only sail it at night and South Africa has placed an order for two, one based in Cape Town and one based in Durban and they will be Great White Grey. These are easily seen when close up but rather well hidden from the naked eye at a distance. They can sneak up better on coastal ships in daylight hours.

The actual first unofficial sea trail has been done already along the coast of California, last year. Obviously the trail went well as no one reported seeing the 40m boat, 500m off shore. It was on You Tube about a mysterious wake on the sea and an orange buoy being towed and passing a sailing yacht. Cant find that clip right now. The buoy was so that the operators could find the boat.

Well I suppose the horizon and seas can play havoc on visual contrast. It does seem odd they colors fade out in the distance that easily. But even 400 yards from another aircraft, the markings on it could be hard to make out. (speaking of WWII era fighter planes).