Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!cs.utexas.edu!sun-barr!newstop!sun!amdcad!amdcad!military From: amichiel@rodan.acs.syr.edu (Allen J Michielsen) Newsgroups: sci.military Subject: Re: Torpedoing Battleships Message-ID: <1991Jun7.071828.7268@amd.com> Date: 31 May 91 17:51:14 GMT References: <1991May23.054849.13718@amd.com> <1991May31.061110.12964@amd.com> Sender: military@amd.com Organization: Syracuse University, Syracuse, NY Lines: 93 Approved: military@amd.com From: amichiel@rodan.acs.syr.edu (Allen J Michielsen) The design of anti-torpedo-torpedo's is a good idea. But there are some problems associated with them. I hope that my thoughts are complete enough that the big picture can be seen without explaining every word and assumption. Look at the following considerations.... 1. A Typical high-(or medium high)-performance torpedo has a speed that is much higher than submarine. Given typical sub speeds are, say, 30 MPH, that gives the torpedo a intercept speed about 60 (and I believe the mark iv is oficially rated at about 52 knots or something like 56 mph). While you can say that the speed of your anti-torpeo-torpedo device isn't important, and this is true as long as the target-sub is in a advantageous position. However, when the target sub is in a advantageous position, they would be able to launch a torpedo at the hostile sub (and would in this case). In this scenario, the planned hostile would be at extremely close range, more about that later. If the target-sub is NOT at a advantageous position, then the recovery or turn around radius and speed of the intercept torpedo is very important. 2. The precision location of ALL underwater homing devices in weapons is NOT terribly good. A small sub is the size of a football field, and quite loud. The torpedo's are much louder, but with a target size approaching 12 ft long, and 15 in dia, moving at 60 MPH, would be nearly impossible to IMPACT with any reliability. After all, +- 50 ft on a football field sized object @30 MPH is nothing compared to +-8 inches on a 1.5x15 ft object @60 MPH. 3. While precision impact would be nearly impossible (see above), it MAY be enough to use a proximity sensor, and explode as close to the torpedo as possible. Water is a terrible damper, using a explosive projectile weapon would be terribly ruined by the damping effect of the water. Short of that, the force required to damage a torpedo is great. Your best chance would depend on being close enough to yourself (the torpedo's target) for the torpedo to be armed, and activate the warhead in a contect charge. Remember that torpedos are loaded on and off subs from cranes on sub tenders, at sea under any conditions. If you saw this once during 'weather' you'd believe in god. They are dropped, banged, and mistreated in every respect. The outside case is about 1/2 in of steel. I would guess that something approaching a small tactical nuclear device would be needed at 50 ft underwater to destroy a torpedo that was NOT armed. Simply using something like that (an explosion) to 'throw' the torpedo off course and depth would be plenty of defense, at long range. When used at short range, it probably would no more effective than countermeasures, and would add a great deal on confusion. Further, is we made one, our enemy would also. The great confusion this would cause, would greatly increase the chance that the torpedo would turn on it's launcher and destroy 'mommy'. With both sides doing this, then,,,, And if we add more smarts so it can identify it's launcher or be disabled by it's lanucher, we add more counter- intelligence to it, more possibilities of more jamming for it, and most importantly, increase both the weight, size, cost of the weapon, and decrease it's max top speed, effectiveness, reliability. 4. Lastly, there is a myriad of social and economic and political reasons. The use of underwater explosive devices kills all the wildlife for a MASSIVE area. Remember also that EVERY launch tube in a sub is a dangerous place. The force from the water at depth is astronomical. Tube numbers are minimized to reduce this potential danger. Using existing tubes would require reallocation of required torpedo tubes. Current subs are built with a limited weapons stock availability and with certain clas weapons in mind. We can't just add another storage area or elevator handling mech for a new weapon. With multiple different platform weapons, getting the desired weapon in the desired tube is almost a feat byitself depending on man and machine. More different possibilities means more potnetial for error and disaster (think of the 16 in gun incident, and don't always believe what the government wants you to think...). Adding more tubes to new subs would require larger subs, causing a whole new list of different problems.... In the future, I can see this becoming more effective, and believe that eventually, there will such weapons. Increased computer speed and decreased size and power requirements, increased/improved sensor&electronics, along with newer higher powered synthetic explosives will eventually make these defensive tools a reality. The problem is that nothing is stagnent. Along with these steps MAY come something like satellite based MAD, DAD, IRAD, UVRAD or NAAD/NAD sensor systems. If/when some or all of these are functioning, then the effectiveness of the offensive use of submarines becomes zero. When this happens, no offensive or defensive submarine will be needed by either side. (In other words, subs cease to be a option for war, so these anti- torpedo-torpedos aren't needed) Of course, this can't happen overnight, and depends on some pretty finely located assumptions. -- Al. Michielsen, Mechanical & Aerospace Engineering, Syracuse University InterNet: amichiel@rodan.acs.syr.edu amichiel@sunrise.acs.syr.edu Bitnet: AMICHIEL@SUNRISE