gt0818a%prism@gatech.edu (Paul E. Robichaux) (08/31/89)
From: gt0818a%prism@gatech.edu (Paul E. Robichaux) In a recent issue of _Defense News_, I saw a small article claiming that the Navy is planning to offer contracts for antitorpedo systems. Presumably these would be carried on board subs (since New London was listed as the project office) and used to somehow kill or spoof incoming torpedos. I thought about it, but couldn't convince myself that an active system would be much use. The British dropped something like 85% of their torpedos on false contacts, and a common tactic of US ASW is to drop a torpedo just to see what the other guy does. Any passive system would probably be pretty useless; non-violence doesn't work too well against R533s. So what does that leave them with? How can a sub defend itself against torpedo attacks? (invisibility and getting the first shot aside) Are these systems likely to be useful? Would their activation increase the likelihood of enemy ASW being able to fix their location? Enquiring minds want to know. -Paul -- Paul E. Robichaux |"Collateral damage is the number of women Georgia Institute of Technology | and children you kill when attempting to do GT PO Box 30818; Atlanta, GA 30332 | something else."- Cap Weinberger. Internet: gt0818a@prism.gatech.edu | All opinions in this message are mine.
budden@manta.nosc.mil (Rex A. Buddenberg) (09/02/89)
From: budden@manta.nosc.mil (Rex A. Buddenberg) Countering a torpedo after it has been launched -- that is at the engagement stage of the combat cycle -- tends to be a losing proposition. Exactly the same reasons that close-in EW systems intended to break a terminal homing missile off don't work well either. Critical to engagement-stage countermeasures is detailed knowledge of the other guys' targeting system. First -- that requires GOOD intelligence input at the HUMINT level -- overhead satellites can't do that job. Second -- it's easier for the missile/torpedo designer to stay a jump or two ahead of the decoy/countermeasure designer. Hard lesson we're learning in SDI... In this regard, the submariners, with the stealth inherent to the environment, have a real advantage. With battle groups, the basic rules -- if you intend to be successful -- are the same. One: don't get detected. If the other guy doesn't know you are there, he won't attack you. Two: when detected, don't let him localize you to enable successful engagement. A general purpose good tactic to consider at this situation is make it look like the ocean is full of you and hope he attacks the wrong target or desides to conserve his ammunition. I've run a couple of these warfighting models, albeit in a surface, EW scenario rather than a subsurface one. When the next war breaks out, buy stock in the companies that make chaff. Rex Buddenberg budden at manta.nosc.mil
maniac@garnet.Berkeley.EDU (George W. Herbert) (09/02/89)
From: maniac@garnet.Berkeley.EDU (George W. Herbert) In article <27042@amdcad.AMD.COM> gt0818a%prism@gatech.edu (Paul E. Robichaux) writes: >In a recent issue of _Defense News_, I saw a small article claiming that the >Navy is planning to offer contracts for antitorpedo systems. Presumably these >would be carried on board subs (since New London was listed as the project >office) and used to somehow kill or spoof incoming torpedos. The correct one is Kill... The US Navy has been running around like a chicken with its head cut off since they realized that they didn't have any way to stop torpedos that were incoming on both ships and subs. It wasn't that anyone had thought it possible before, but once they realized that it might be possible, they immeiately decided it was necessary. Torpedo Decoy systems have been in use since late WWII and in the same form: a underwater speaker playing ship propellor noise towed behind the ship, hopefully distracting torpedos to home on it instead of Real ship. Currnet model is the 'Nixie' system, carried by just about everything in USN fleet. However, this is only good against 1 torp, and is no sure guarantee. Also, the navy has overcome its institutional fear of Backfires with AS-4's, and now thinks that the air threat to its carriers has been dealt with (by systems like Aegis, F-14's, etc.) and the Navy wants to fix the next most likely mode of carrier assasination. Submarines with torpedos. The primary use of the system is going to be for surface ships defending themselves. It will probably be in the form of a anti-torpedo torpedo. Going with this idea has been a whole spectrum of ideas transfered down from air and surface combat: Acoustic jamming, 'chaff' that blocks sonar, and all sorts of similar little things. The desired goal is that the fleet in the year 2000 will be able to stop any underwater weapon it detects with multiple layers of hard kill and soft kill (decoy/distract) methods. Most of this has been in the USNI _Proceedings_ magazine. Look it up there (over last ~2.5 yrs) for more details. George William Herbert maniac@garnet.berkeley.edu, gwh@ocf.berkeley.edu