[ventana]

Good catch, Mr. Irish. And welcome aboard! V's wife.

[Diddle E. Squat]

I would hope that we have clearly stated to China and Russia that the use of one of these that sinks a carrier equates to the use of nukes.

[Ole Okie]

I will bet that our Navy isn't sitting on its hands. We know that the Russians have accomplished supercavitation. What keeps us from doing likewise?

[monkeywrench]

"The new technology "could mean a quantum leap in naval warfare that is analogous in some ways to the move from prop planes to jets or even to rockets and missiles."

[Red Jones]

bump

[RobRoy]

>>...and it is likely that we have no defense against it," stated Jack Spencer, a defense analyst at the Heritage Foundation.<<

Translation: "Please don't throw me in the briar patch!"

[Lazamataz]

I'm sure we've got these by now. We knew about these way back when.

[6ppc]

A bit hyperbolic, but the description of the technology sounds feasible. It's likely that reliability is a problem (Kursk?). Let's hope the R&D guys are on this one if it's real.

[krodriguesdc]

an interesting note on the name Shkval - this was the name of a soviet elint trawler that was of the coast of cuba on October 28, 1962...

probably no connection but interesting just the same...

[It'salmosttolate]

Posted way back here Russian 'Rocket' Torpedo Arms Chinese Subs

[doug from upland]

Clinton knew about this when it was in development and I'm sure he knew about it before. But he didn't give a damn. He spent his 8 years raising money for RATS, getting BJs, lying to grand juries, assaulting women, and covering his crimes. He had no time for the defense of this nations. My son in law in on a carrier in the Middle East right now. One more big salute of thanks goes to Bill Clinton.

[gkidman]

The Chinese navy has completed the acquisition of four Russian Kilo-class conventional submarines. The Kilo 636 is said to be nearly as quiet as the early version of the U.S. Los Angeles class nuclear submarine," noted Fisher.

Let's see, the Los Angeles class is divided into two groups, 688 and 688I. Kilo is "nearly" as quiet as a base 688 (most of which are being retired). The 688Is are significantly quieter, with the Seawolf and Virginia-class subs being much quieter still. And, all other things being equal, the USN and RN submarines are unmatched when it comes to the electronic wiz-bang necessary to detect and kill other submarines (Kilos may be quiet, but they are also completely deaf when compared to US subs).

Soooooo ... the chances of a Kilo with this torpedo getting close enough in to a US carrier (all US carriers travel with at least two Submarines riding shotgun) to take a shot (my understanding is that supercavitating torps are notoriously short ranged) is limited. In a shooting war, those Kilos would be sunk long before they had a chance to open their outer torpedo doors.

[michigander]

BA-111 Shkval underwater rocket

[Capitalist Eric]

6,000-pound Shkval rocket torpedo has a range of about 7,500 yards... The Chinese Type 093-class nuclear attack submarines are similar to Russian Victor III class first produced at the Leningrad yards in the 1970s... 5,000 tons and is over a football field in length....

***Yawn***

Big deal. A fish with a range of 7,500 yards, installed on a boat that you can hear (and kill) from well over three times that range... Victor boats are about as stealthy as a cat-burgler who, while trying to break into your house, is carrying two tin 50-gallon garbage cans...

He'll be rather lacking, with regard to the element of surprise...

FReegards,

[Non-Sequitur]

Let's see. On the one hand we have the Shkval with a speed of about 230 miles per hour and a range of 7,500 yards. On the other hand we have the U.S Mk 48 ADCAP with a top speed of 55 knots and a range of 42,530 yards, or a max range of 54,685 yards if you limit the speed to 40 knots. Can anyone else do the math here?

[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.