December 1, 2015

Long range torpedos and anti-ship missiles

The SEAHAKE Mod 4 ER long-range torpedo (aka DM2A4) (above and below) has a range of at least 140 km. It features an advanced electrical propulsion system and a fiber optic cable for torpedo guidance and communication, which, in conjunction with advanced signals processing and mission logic, makes the torpedo largely countermeasure resistant. Its long at 6.6m (22 feet) long. With that range it may be a viable torpedo tube deliverable medium-large UUV.

The following are parts of an article by Christopher P. Cavas in DefenseNews, November 27, 2015:

 [Retired Vice Adm. Michael Connor, a former commander of the US Navy’s submarine forces, spoke to House Seapower subcommittee on October 27, 2015] 


Connor specifically wants torpedoes with ranges of more than 100 miles. [the SEAHAKE Mod 4 ER long-range torpedo has a proven range of 140 km, achieved in March 2012. Since then improvements in battery and fuel cell technology would mean even longer ranges. Meanwhile the US Mark 48 torpedo may still be restricted to 50 km.]

“This is definitely doable with chemical-based propulsion systems and will likely soon be achievable with battery systems,” he said. Such a range also will need better command-and-control systems, including the ability to communicate with the torpedo, perhaps via manned or unmanned aircraft or by satellite, he said.

“The torpedo will come to be considered along the line of a slow-moving missile,” he said, “with the advantage that it is more difficult to detect, carries a much larger explosive charge and strikes the enemy beneath the waterline, where the impact is most severe.”


Connor also wants the US “to get back into the business of submarine-launched anti-ship missiles” with the ability to “confidently attack a specific target at sea at a range of about 1,000 miles [see two competing options: an update of the old, reliable Tomahawk or the new Long-Range Anti-Ship Missile] We should be pursuing this more aggressively than we are.”

Artist's vision of a Long-Range Anti-Ship Missile (Image on Breaking Defense)


Connor also wants better and more-capable undersea vehicles.

“We need to improve the endurance of the vehicles, expand the payload set, and get to the point where any submarine can recover the mission data, if not the vehicle. We need to do this while keeping the cost of the vehicle down. The cost should be low enough such that, while we would always like to get the vehicles back, it is not a crisis if we don’t. The value is in the data, not the vehicle.”

Bryan Clark, a naval analyst with the Center for Strategic and Budgetary Assessments, appeared alongside Connor and urged greater development in undersea sensors — onboard submarines, unmanned vehicles and weapons, as well as deployed [SeaWeb like] in the water and fixed on the seabed.

…Clark [as ever talked up large UUVs] urged continued development in a wide range of unmanned underwater vehicles (UUV), including looking at ways to arm some. He pointed to the compact, very lightweight torpedo — now under development — as having potential not only as a defensive, anti-torpedo weapon but also as a weapon that could be carried and launched by larger UUVs. See WHOLE ARTICLE



Anonymous said...

"He pointed to the compact, very lightweight torpedo — now under development — as
having potential not only as a defensive, anti-torpedo weapon but also as a weapon
that could be carried and launched by larger UUVs."

A new lightweight torpedo is interesting, since the current Mk-54 uses the same propulsion as the Mk-46, and has about the same performance.

As for the Mk-50, this weapon has higher performance but as this article states:

"Many components for the Mk 54 came from the older Mk 50, and production of that
model halted in the mid-1990s. Since then, old Mk 50s have been cannibalized for
parts but that supply is running out"

I wonder how many Mk-50s are still operational?

As for the newer weapon, it has already been tested in the anti-torpedo role:

The article at:

Contains the following tidbits:

"The small-diameter ATT currently under development also shows promise as a multimission weapon, useful against submarines and small ships and light enough to be deployed on unmanned vehicles."

"The ATT is 6.75 inches in diameter, 105 inches long, weighs approximately 200 pounds and is powered by a stored chemical-energy propulsion system — which uses steam created by chemical reaction — similar to that used in the Navy’s Mk50 lightweight torpedo. It is designed to operate in the noisy, turbulent wakes of ships, where it could intercept wake-homing torpedoes."

"The ATT also could serve as an antisubmarine weapon — a variant called the Common Very Lightweight Torpedo — fired from the same launcher."

"The Common Very Lightweight Torpedo could be carried by smaller platforms such as unmanned aerial vehicles. The Navy is considering fitting it to the RQ-8B Fire Scout unmanned aerial vehicle. The Fire Scout, which is similar to a helicopter, is being developed to operate from the Navy’s future fleet of Littoral Combat Ships. The very lightweight variant also could be adapted for MH-60R helicopters. In these roles, it would be renamed the Compact Rapid Attack Weapon."

"Bock declined to comment on the capabilities of the ATT versus a rocket-powered high-speed torpedo such as the Russian-designed Shkval, which reportedly can reach speeds of 220 miles per hour.

“That’s not currently part of the requirement we’re building against,” he said."

Note that the above article is dated 2006. After all these years of development, I hope it doesn't turn out to be a lemon.

Peter Coates said...

Hi Anonymous

The miniaturisation of weapons - including the ATT seems to be progressing quickly as are options for delivery platforms - including Fire Scout.

I suppose increased helicopter, Fire Scout and other UAV use (by China and Russia) may prompt the US to develop anti-aircraft missiles for SSNs?



imacca said...

One thing i have been wondering about. From my general reading of the very early history of submarine development, one of the things that made them practical was forward mounted hydroplanes. That enabled reasonably reliable depth keeping under-way.

So, torpedoes, that DONT have forward mounted hydroplanes? My guess is that the relatively high speed of a torpedo negates the need a bit, but how about when they get really long and relatively skinny like the 4 battery SeaHake in the article? There must be some kind of minimum speed below which they would be really inefficient to operate??

Peter Coates said...

Hi imacca [Re torpedo]

From this short Youtube depth keeping and guidance:

- occurs using a torpedo's onboard computer controlling

- Elevators and Rudders behind the torpedo's propellor/"rotor"

Also there would be computer controlled buoyancy/balance systems.

If the the torpedo has a fibre optic cable tethered to the submarine the submarine's combat system computers can also assist a torpedo's functions.



MHalblaub said...

A torpedo with a fiber link also works as a sonar UUV. With such an additional sonar a submarine gets far better firing solutions.


Anonymous said...

"The miniaturisation of weapons - including the ATT seems to be progressing quickly as are options for delivery platforms - including Fire Scout."

A sonobuoy-equipped version of Reaper has also been developed:

I can see something like that being equipped with the new mini-torp as well.


Note that ATT isn't the only anti-torp game in town, the MU-90 supposedly has that capability too:


"Pre-arrangements to cope with submarine-launched SLAAM threats have been incorporated in the weapon as well as Hard-Kill (anti-torpedo torpedo), continental shelf mine and submarine launching capability."

In addition, Atlas is working on something called Sea Spider:


"Basically a small rocket propelled torpedo homing in on incoming torpedos destroying them. Unlike the Israeli Torbuster it doesn't need to lure the torpedo to hit itself."


Anonymous said...


As for the ATT, Compact Very Light Weight Torpedo (CVLWT), Compact Rapid Attack Weapon (CRAW), or whatever they're calling it now. It looks like they're going to squeeze as much destructive power out of its smaller warhead by using a shaped-charge:

Even with the shaped-charge, I wonder how well a weapon of this size would do against a large double-hulled sub, such as an Oscar?

Also note that the weapon's smaller size means that, not only can it be carried by smaller platforms, such as UAVs, it also means more of them can be carried by existing platforms.

This is important, since the tactic of launching multiple torpedoes at a single
submarine may be coming back in style:


"In the past such tactics foresaw e.g. the near simultaneous launch
of two Mk44 torpedoes in order to increase the chances of success
against a submarine, that was trying to exploit the bathy-thermal
layers to hide itself. The limited sonar power and thus reduced
detection range of the torpedoes made this mode of operation
possible, without excessive risks of mutual interference. The
higher power available to 2nd generation torpedoes (Mk46, STINGRAY,
A244) forced this practice to be discontinued - but the growing
availability of torpedo countermeasures available to submarines is
now again changing the terms of the equation. In fact, the nearly
simultaneous launch of two LWTs degrades the survival chances of
a boat protected by countermeasures by a factor of three to four.
On the other hand, there is a significant risk of mutual
interference between the torpedoes, especially because the
reciprocal Doppler effect is relevant due to the wide array of
possible relative speeds.

The solution could lay in the use of IFF-like sound codes injected
within the active sonar pulses, allowing the torpedoes to reject
the acquisition of friendly torpedoes and widening the operational
chances, while eliminating firing restrictions (i.e., it would
even be possible to locate two torpedoes at the same search depth).
The A244S Mod3 is the very first LWT with embedded IFF code

Other quotes from the above article:

"A new specific sonobuoy-like communication device will be used to
ensure guidance of the CRAW towards the target, before stepping into
the small torpedo autonomous terminal homing."

"Lockheed Martin is currently developing the VLA-ER extended range
version, which will maintain 90% commonality with the existing
weapons but will be capable of four-five times the ranges through
the addition of a wing glide kit (a further increase to up to some
100km could be reached through spiral developments). The VLA-ER is
a potential weapon of choice for net-centric warfare operations,
in that it can exchange data during its flight and receive target
position updates."

Since the new mini-torp is so small, it's possible that 2 or more, plus the "sonobuoy-like communication device" can be carried on a single VLA-ER to increase kill probability.


Note that in addition to deployment on UAVs and UUVs, the mini-torp was also considered for deployment on swimmer delivery vehicles:

Proteus was cancelled, but I wonder if the idea will be (or maybe has been) resurrected elsewhere.