RUSSIAN "ROCKET" TORPEDO ARMS CHINESE SUBS

Newsmax/Softwar ^ | 4/24/2001 & 10/8/2001 | Charles R. Smith

[Eagle74]

I heard about these torpedoes months ago, durring the surveillance airplane fiasco. While it's said there's no defense, these weapons have no guidance, the supercavitation prohibits the use of sonor guidance. So the fish is more like a bullet, unless the attacking sub uses active sonar to guide the torpedo(a sure death sentence). If the supercavitating torpedo doesn't give away your position, active sonar certainly will. Submarine warfare places a premium on stealth, anything that gives away your position will get you killed. An unguided torpedo thats 3 times faster but reveals your position, doesn't make up for the sneaky fire and forget type that leaves you alive to try again if you miss. I have heard that counter-torpedoes are under development, to be fired from exsisting countermeasures tubes.

Faster than the speed of sound? I don't think so, the speed of sound increases with density, the speed of sound in air at sea level is ~700mph, it's much faster in water.

[Snow Bunny]

Thank you for the thread Fighting Irish .

[boris]

Scientific American had an interesting piece on the "Squall" torpedo. Turns out it has trouble steering, and the "slapping" of the torpedo on the interface between the cavity and the water causes major aiming problems. The U.S. equivalent will be able to steer.

As for the speed of sound in water:

Speed of Sound in Water

R. J. Wilkes, 11/5/97

 

The literature on sound speed in water (freshwater and seawater) is rather confusing. There are 6 primary references in the literature (refs. [1]-[6] below). Treating them in chronological order, their content can be summarized as follows: 

Greenspan and Tschiegg (1959): Tables of c vs T for distilled water, 0 < T< 100 deg C; no pressure is given and it is presumably standard atmospheric P. Also given is a ploynomial fit with standard deviation 0.026 m/sec or 17 ppm. 
Wilson (1960a): Tables of c for seawater, -3 < T < 30 deg C; 1.033 (=1 atm)< P < 1000 kg/cm2; 33 < S < 37 ppt. Note that P is absolute pressure. A polynomial fit is reported with standard deviation 0.22 m/sec. 
Wilson (1960b): Tables of sound speed in distilled water, for 0 < T < 100 degC, 14.7 < P < 14,000 psia (ie, 1~1000 atm). The accuracy is 0.1 ppt. 
Wilson (1960c): A brief note giving an updated fit equation covering a wider range of parameters (especially salinity): -4 < T < 30 deg C, 1.0 < P < 1000 kg/cm2, 0 < S < 37 ppt. 
Del Grosso (1974): Provides a fit formula and tables of differences relative to results of previous formulas. Ranges are not given explicitly but tables in the paper cover 0 < T < 35 degC, 0 < S < 43 ppt, 0 < P < 1000 kg/cm2. Note that he uses gauge pressure, ie P=0 corresponds to 1 atm = 1.033 kg/cm2 absolute. 
Chen and Millero (1977): Tables and fit for 0 < T < 40 deg C, 0 < P < 1000 bars, 5 < S < 40 ppt. Note pressure is gauge pressure (P=0 corresponds to 1 atm). Standard deviation of fit is 0.19 m/sec. 
 

Attached is source code for Fortran-77 functions to compute the sound velocity for specified S,T,P using the fits described in refs. [1], [4] (which covers [2] and [3]), [5] and [6] within their valid ranges. The functions have been arranged for uniform input (T in degC, P in kg/cm2 absolute, S in ppt) and return c=-1 if input parameters are out of the range of validity for the fit coded. Naturally there is no warranty express or implied for the use of these functions!

 

Following the source code is a table of c vs T according to the various authors, for fresh water, and one point for seawater at T=1 degC, P=500 kg/cm2 abs, S=35 ppt.

 

References

[1] M. Greenspan and C. Tschiegg, (1959), JASA 31:75.

[2] W. Wilson, (1959), JASA 31:1067.

[3] W. Wilson, (1960a), JASA 32:641.

[4] W. Wilson, (1960b), JASA 32:1357.

[5] V. Del Grosso, (1974), JASA 56:1084.

[6] C. Chen and F. Millero, (1977), JASA 62:1129.

 

Fortran-77 functions to calculate sound speed in water

	double precision function greensp(T,P,S)
	implicit double precision (a-z)
c	calculate c(m/sec) in fresh water at 1 atm given t(degC)
c	according to m. greenspan and c. tschiegg, JASA 31:75 (1959)
	if (s.gt.0.or.p.gt.1.033) then
		greensp=-1.0
		return
		endif
	c=1402.736
	c=c + (5.03358)*t +(-0.0579506)*t**2
     #     + (3.31636e-04)*t**3 + (-1.45262e-06)*T**4
     #     + (3.0449e-09)*t**5
	greensp=c
	return
	end

	double precision function wilson(t,p,s)
c	find c(m/sec) in water with (T(degC), P(kg/cm2 abs), S(ppt))
c	according to wilson, JASA 1960
	implicit double precision (a-z)
	logical notok
c	test for in-range
	wilson=-1.0
	notok=.false.
	if ((t.lt.(-4.0)).or.(t.gt.30.0)) notok=.true.
	if ((s.lt.0).or.(s.gt.37.0)) notok=.true.
	if ((p.lt.0).or.(p.gt.1000.0)) notok=.true.
	if (notok) return
c	ok
	c0 = 1449.14
	ct1= 4.5721e00
	ct2=-4.4532e-02
	ct3=-2.6045e-04
	ct4= 7.9851e-06
	cp1=1.60272e-01
	cp2=1.0268e-05
	cp3=3.5216e-09
	cp4=-3.3603e-12
	dcs=1.39799*(S - 35.0)+1.69202e-03*(S - 35.0)**2
	cstp1=-1.1244e-02
	cstp2=7.7711e-07
	cstp3=7.7016e-05
	cstp4=-1.2943e-07
	cstp5=3.1580e-08
	cstp6= 1.5790e-09
	cstp7=-1.8607e-04
	cstp8=7.4812e-06
	cstp9=4.5283e-08
	cstp10=-2.5294e-07
	cstp11=1.8563e-09
	cstp12=-1.9646e-10
	dct=t*(ct1+t*(ct2+t*(ct3+t*ct4)))
	dcp=p*(cp1+p*(cp2+p*(cp3+p*cp4)))
	dcstp=(s-35.0)*(cstp1*t + cstp2*t**2 + cstp3*p
     #        + cstp4*p**2 + cstp5*p*t + cstp6*p*t**2)
     #        + p*(cstp7*t + cstp8*t**2 + cstp9*t**3)
     #        + p*p*(cstp10*t + cstp11*t**2)
     #        + p**3*cstp12*t
	c=c0+dct+dcp+dcs+dcstp
	wilson=c
	return
	end

	double precision function delgros(t,pa,s)
	implicit double precision (a-z)
	logical notok
c	returns c(m/s) in water with (T(deg C), P(kg/cm2 abs), S(ppt))
c	according to V. Del Grosso, JASA 56:1084 (1974)
c	convert kg/cm2 absolute to gauge pressure
	P=Pa-1.033
c	test for in-range
	delgros=-1.0
	notok=.false.
	if ((t.lt.0).or.(t.gt.35.0)) notok=.true.
	if ((s.lt.0).or.(s.gt.43.0)) notok=.true.
	if ((p.lt.0).or.(p.gt.1000.0)) notok=.true.
	if (notok) return
c	ok
	c0=1402.392
	ct1= 0.501109398873E+01
	ct2= -0.550946843172E-01
	ct3=+0.221535969240E-03
	cs1= 0.132952290781E+01
	cs2= +0.128955756844e-03
	cp1= 0.156059257041e00
	cp2= +0.244998688441e-04
	cp3= -0.883392332513e-08
	c1= -0.127562783426e-01
	c2= +0.635191613389e-02
	c3= +0.265484716608e-07
	c4= -0.159349479045e-05
	c5= +0.522116437235e-09
	c6= -0.438031096213e-06
	c7= -0.161674495909e-08
	c8= +0.968403156410e-04
	c9= +0.485639620015e-05
	c10= -0.340597039004e-03
	dct=t*(ct1 +t*(ct2 + t*ct3))
	dcs=s*(cs1 + s*cs2)
	dcp=p*(cp1 + p*(cp2 + p*cp3))
	dcstp=c1*t*s + c2*t*p + c3*(t*p)**2 + c4*t*p**2
     #       + c5*t*p**3 + c6*p*t**3 + c7*(s*p)**2
     #       + c8*s*t**2 + c9*t*p*s**2 +c10*t*s*p
	c=c0+dct+dcs+dcp+dcstp
	delgros=c
	return
	end


double precision chenmil(t,p0,s)	
c	* sound speed according to Chen and Millero (1977) JASA,62,1129
implicit none
double precision s,t,p0
double precision a,a0,a1,a2,a3,b,b0,b1
double c,c0,c1,c2,c3,p,sr,d,sv
c	convert from absolute to bars
	p = p0 - 1.033
c	test for in-range
	wilson=-1.0
	notok=.false.
	if ((t.lt.0.0).or.(t.gt.40.0)) notok=.true.
	if ((s.lt.5.0).or.(s.gt.40.0)) notok=.true.
	if ((p.lt.0).or.(p.gt.1000.0)) notok=.true.
	if (notok) return
c	ok
	sr = sqrt(s)
	d = 1.727e-3 - 7.9836e-6 * p
	b1 = 7.3637e-5 + 1.7945e-7 * t
	b0 = -1.922e-2 - 4.42e-5 * t
	b = b0 + b1 * p
	a3 = (-3.389e-13 * t + 6.649e-12) * t + 1.100e-10
	a2 = ((7.988e-12 * t - 1.6002e-10) * t 
     #    + 9.1041e-9) * t - 3.9064e-7
	a1 = (((-2.0122e-10 * t + 1.0507e-8) * t 
     #    - 6.4885e-8) * t - 1.2580e-5) * t + 9.4742e-5
	a0 = (((-3.21e-8 * t + 2.006e-6) * t 
     #     + 7.164e-5) * t -1.262e-2) * t + 1.389
	a = ((a3 * p + a2) * p + a1) * p + a0
	c3 = (-2.3643e-12 * t + 3.8504e-10) * t - 9.7729e-9
	c2 = (((1.0405e-12 * t -2.5335e-10) * t 
     #    + 2.5974e-8) * t - 1.7107e-6) * t + 3.1260e-5
	c1 = (((-6.1185e-10 * t + 1.3621e-7) * t 
     #   - 8.1788e-6) * t + 6.8982e-4) * t
		 + 0.153563
	c0 = ((((3.1464e-9 * t - 1.47800e-6) * t 
     #   + 3.3420e-4) * t - 5.80852e-2) * t
     #	 + 5.03711) * t + 1402.388
	c = ((c3 * p + c2) * p + c1) * p + c0
	chenmil = c + (a + b * sr + d * s) * s
	return
	end

 

Sample output

Fresh water, surface
  T,degC        Greenspan       Wilson          DelGrosso
       0         0.14027E+04     0.14024E+04     0.14024E+04
       1         0.14077E+04     0.14074E+04     0.14073E+04
       2         0.14126E+04     0.14122E+04     0.14122E+04
       3         0.14173E+04     0.14169E+04     0.14169E+04
       4         0.14220E+04     0.14216E+04     0.14216E+04
       5         0.14265E+04     0.14261E+04     0.14261E+04
       6         0.14309E+04     0.14306E+04     0.14305E+04
       7         0.14352E+04     0.14350E+04     0.14348E+04
       8         0.14395E+04     0.14392E+04     0.14391E+04
       9         0.14436E+04     0.14434E+04     0.14432E+04
      10         0.14476E+04     0.14475E+04     0.14472E+04
      11         0.14515E+04     0.14514E+04     0.14511E+04
      12         0.14553E+04     0.14553E+04     0.14550E+04
      13         0.14591E+04     0.14591E+04     0.14587E+04
      14         0.14627E+04     0.14628E+04     0.14624E+04
      15         0.14662E+04     0.14664E+04     0.14659E+04
      16         0.14697E+04     0.14699E+04     0.14694E+04
      17         0.14731E+04     0.14734E+04     0.14727E+04
      18         0.14764E+04     0.14767E+04     0.14760E+04
      19         0.14795E+04     0.14800E+04     0.14792E+04
      20         0.14827E+04     0.14831E+04     0.14823E+04
Seawater, p=500, s=35
  T,degC        Greenspan       Wilson          DelGrosso
       1        -0.10000E+01     0.15364E+04     0.15358E+04

In other words, the speed of sound in water is roughly 1500 meters per second; that is 4920 feet per second or 3356 miles per hour.

--Boris

[krodriguesdc]

I read here infowar.com that the russians have, "...a new highly secret weapon known as the 100-RU Veder missile, NATO code-named: SS-N-16A Stallion.

It utilizes silver battery driven propellers to send it out from the submarine to a safe distance before a liquid fueled rocket engine kicks in to send the missile to the surface.

From there it flies under rocket power at supersonic speed until just above its target, where it ejects a lightweight-torpedo with a parachute and a 200 pound explosive warhead, that slowly drops into the water, which then homes in on the submarine.

It can be armed with a mini-nuclear warhead and can engage targets at depths of up to 500 meters."

[athiestwithagun]

Nothing really new here. I read about this idea in the sixties. It was a two stage torpedo. The first stage was a 'conventional' electric torpedo that approached stealthily until close enough to launch the rocket powered second stage which closed at high speed. As I recall, the idea of venting gasses to reduce friction on the second stage was discussed at length in the article.

[krodriguesdc]

I sure hope you're right...

[Bill Rice]

"The Kilo 636 is said to be nearly as quiet as the early version of the U.S. Los Angeles class nuclear submarine,"...

We can thank Toshiba for this.

And many stupid Americans continue to buy their products!

[Capitalist Eric]

With respect, I didn't specify the ranges (w/speeds) of the '48, simply because I felt it was one more advertisement as to our capabilities... No sense parading our "goods," if you get my drift... And, assuming that can't find a Janes' Fighting Ships anywhere...

FReegards,

[Dan Day]

In other words, the speed of sound in water is roughly 1500 meters per second; that is 4920 feet per second or 3356 miles per hour.

Yes, that's about right. For an easier way to do it, see: http://www.npl.co.uk/npl/acoustics/techguides/soundseawater/content.html. It provides several alternative equations -- just press the "Interactive version" link next to your preferred one and punch in the parameters, it'll calculate the speed of sound for you.

I got 3,300 miles per hour using one equation.

So I'm very skeptical of the claims in the article. At the very least, it would take ENORMOUS forces to shove aside water fast enough to travel at 3000+ mph in the water. Not only is water quite heavy, by volume, but it's practically incomprehsible -- unlike air, you can't just "squeeze" it out of your way, you have to shove it aside, plus all the water that's all around it. That's why jumping off a bridge into a body of water is almost always fatal -- at high speeds, water is about as "hard" as concrete.

[My Favorite Headache]

As Louie Armstrong would say......what a wonderful world.........

Cue the Nuclear Explosion image.

[NY.SS-Bar9]

Don't forget these are also "dumb" straight line weapons. Which means you need to be close in and lucky.

[Jeff Head]

PING!

Amazing! This is getting scarier and scarier ... and uncanny. Breath of Fire is about to hit the street, and this (albeit and much improved model of the supercavitating weapon), it the lynch pin.

Should have to available for sale in the next 2-3 days.

[John Jamieson]

speed of sound underwater. I was going to say 5,000 ft per sec. Glad I didn't.

[Capitalist Eric]

Which means you need to be close in and lucky...

Compared to the Mk-48 (with snapshot capability), no amount of luck will be enough, with one of these russki fish.

It simply won't matter...

BTW, nice screen name.

FReegards.

[Mudboy Slim]

Thanks fer the heads-up, although much of this thread is simply over this CountryBoy's head.

How long do y'all reckon it'll take our Counter-Intelligence to get the specs on this torpedo...oooops, I fergot, Clinton gutted our Counter-Intelligence capability seein' as there was no longer any threat to the U.S. and all!!

LOL & FReegards...MUD

[Poohbah]

Uh, Jeff...this thing can go 7,500 yards, tops, and it's a straight-runner without any guidance. US torpedoes may not be as fast, but they can reach out a LOT further, AND they are just about unbeatable in the endgame. Kinda like blazing away with a shotgun at that sniper 800 yards away while he calmly lines up the crosshairs on your chest...not a move designed to enhance your longevity.

[goldilucky]

Yes, a very interesting thread. Especially post #23!

We should be building this same technology.

[Ross Amann]

Read the Scientific American article - several months old by now.

We are way behind in development.

And if it's traveling faster than the speed of sound, who the fcuk cares how noisy it is??? (You're dead before you hear it.)

[Ronin]

Wrong Doug.

Clinton was not indifferent to this. He was delighted by it. He never got more of a thrill then he did when crapping on anything American.

[Lazamataz]

We are way behind in development.

Finally we've got some adults in the White House. Hopefully this will help speed our development.