Monday, January 30, 2017

LCS ASW Update

Here’s an interesting tidbit from the DOT&E 2016 Annual Report (p.267) concerning the LCS ASW module development and testing.

“The Navy did not conduct any at-sea testing of the ASW mission package in FY16.”

Huh???  I thought the ASW package was settled and a vendor for the variable depth sonar, Thales, was selected and the module was in the final integration and testing stages.  I guess not.

What’s the hold up?  Apparently, it’s weight. 

“The Navy continued its efforts on a weight reduction program for the components of the mission package, including the handling system and support structures for the variable depth sonar and multifunction towed array.”

We’ve repeatedly noted that the LCS (both variants) are overweight and have no weight growth margins.  Every pound added to the LCS has to be balanced by a pound removed.  The LCS “growth” has become a zero-sum game.  In other words, growth is no longer possible for the LCS.

Regarding the VDS vendor selection, apparently that is not the settled issue I thought it was.

“The Navy anticipates downselecting to a single vendor for the variable depth sonar in FY17 and beginning a test program soon thereafter.”

To refresh your memory, the ASW module currently consists of

  • Lightweight Tow torpedo countermeasure (a Nixie-like acoustic decoy)
  • Multi-Function Towed Array
  • Variable Depth Sonar
  • MH-60R and MQ-8B/C Fire Scout VTUAV

The Navy hopes to begin testing in 2018 or 2019.  Assuming, optimistically, a typical few years of testing and a few more years to actually purchase production modules, we’re looking at 2025 or so before production ASW modules reach the fleet.  That’s a lot of time and effort for what will be a pretty anemic ASW fit.  Many LCS ships are going to live significant portions of their service lives without any modules.  


  1. Operational question: Why have a MFTA and a VDS? My understanding of the MFTA is that its long and angles downward as it trails the ship, so its going to get under the layer itself. Moreover, it has mics along a good chunk of its length, so you'll get a 'picture' through the water column; where as VDS has a set at the end. Is the VDS on a Helo? That might allow you to triangulate.

    1. I don't know the operational nuances of both systems well enough to answer that. I note that US Navy ships have not, at least of late, have opted for towed arrays over VDS. Don't know what that says, either. Finally, the LCS is intended for shallow water ASW and I don't know how either a towed array or VDS fit with that intent. Towed arrays are generally not considered effective in shallow water. Perhaps towed array is for deeper water and VDS for shallow? The Soviets and other countries have made extensive use of VDS. Towed array is usually passive and VDS is passive/active.

      Short answer: I don't know.

    2. The variable depth sonar IS a towed array. In really simple terms the end of the cable has a complex set of devices on it and this in tern has little hydroplanes on the side and positions itself where you want it. This "head" is the multifunction array usually.

      The Thales system looked like a very very nice system being a I believe a "lighter" version of what goes on the Royal Navy Type 23 ASW Frigate.

      Hull and Engine noise is a factor though.

      I suspect weight is going to be a huge issue. These Arrays and their associated machinery on a Type 23 represent 100's of tonnes as I recall.

    3. The whole thing is confusing to me. It seems silly to have both on a weight challenged ship, unless its the deep/shallow situation you mention CNO. Or maybe the VDS is an attempt to compensate for no hull mounted sonar?

      "Hull and Engine noise is a factor though."

      This really bugs me. Can water jets act in a 'quiet' mode? Every jet I've seen on a ferry or private boat are noisy as hell as they roil the water behind them. But I know nothing about the LCS jets.

      It just seems that if noise is a factor, you'd work on that first before any mission module.

      Maybe knowing the frequency of the LCS noise software filters can block it out; or maybe its not appreciably louder than a conventional screw. It would be nice to see them establish a sound benchmark though.

    4. The original ASW package was designed for shallow only and then the Navy tested in deeper water and didn't like the performance or the limitation that made on the LCS (I can't believe they said that with a straight face!).

      So once again because there was no CONOPS up front, the requirements changed. In the meantime the ship became an overweight pig, so now the exercise is to put lipstick on it.

      PEO LCS should be disbanded and ANYONE who ever worked in it or for it (Defense Contractors) should be bared for life from working Defense Contracts. Incompetent is the nicest thing you can say.

    5. ""Hull and Engine noise is a factor though."

      You're talking about self-noise and how it interferes with acoustic sensor receiving (as well as broadcasting the ship's location to any listening sub!). Self-noise is not just the external props (or water jets) in the water, it's also the internal ship's machinery vibrating against the hull and creating noise. This is why ASW ships (and subs!) are built with extreme acoustic isolation between the machinery and the hull. The Spruances were built this way. I don't know whether the Perrys were or not. I think they were but I don't have absolute proof. The LCS was not built this way and can never be a good ASW platform as a result. I've heard that the reason the LCS lacks a hull mounted sonar is self-noise interference. Don't know if that's true.

      The original concept did not call for the LCS to be the "hunting" platform so acoustic isolation was not needed. The unmanned vehicles were going to do all the hunting. Of course, that failed big time.

      In short, there's a lot more to "noise" than just the props/jets beating the water.

    6. "then the Navy tested in deeper water and didn't like the performance"

      No one outside the Navy knows the real reason why the entire ASW module concept was abandoned. The "official" story is that the Navy concluded that the unmanned vehicle approach wherein the LCS would "drop off" a group of vehicles to form a local sensor net - a point barrier, in essence - was the wrong way to conduct ASW and wanted to be able to conduct ASW on the move. You know, the way ASW has been conducted forever. Thus, they were left with a non-optimized platform with serious inherent flaws as regards ASW.

      A purpose-designed ASW corvette would be far more effective and cheaper than an inherently flawed LCS. The Navy, in their wisdom, believes otherwise.

    7. Yep.

      The Royal Navy spends incredible amounts of hull shape design and paint. To prevent hull noise.

      Not to mention the vibrational insulation you mention.

      Interestingly one of the Type 23 s favorite hunting teqniques is to accelerate to high speed on gas turbine. Then shut down everthing but the sensors and coast. ( I understand they can coast quite some way. )

      In this silent mode the sonar is most effective.

      Possably LCS will be able to hunt in this mode ok ?

      Ill be impressed if a 50kts speed hull is also a silent coaster though ?

    8. The tactic you're describing is popularly called "sprint and drift". The key, however, is that it uses passive listening during the drift portion which is ideal for open ocean sensing. For shallow water ASW, passive listening is not very effective. Shallow water ASW depends much more heavily on short range active sonar. Detections will occur at short range and the side that can respond quickest will survive. That makes the LCS' complete lack of on-board anti-submarine weapons baffling.

      I think the LCS will have to conduct ASW in groups of 3 or 4 to have any hope of success. They'll use active sonar to "sweep" an area as opposed to passive listening waiting for a sub to come to them. Once located, the other group LCS's will converge and herd the sub while helos attempt to localize and attack. Just speculation on my part.

    9. In WWII some DE's had diesel electric drive.

      I thought there was an Italian DE that could run on electric drive for a bit so it could listen relatively silently.

      We have experience with Diesel Electric drives. It might not be bad to have in a (relatively) inexpensive Destroyer Escort. The diesels give it range, and battery packs (along with the aformentioned acoustic isolation) could give it a silent hunting mode.

    10. ". I don't know whether the Perrys were or not. I think they were but I don't have absolute proof."

      At the very least I believe the Perry's had Prarie/Masker. Not sure if that is still an effective solution today.

    11. Prairie/Masker is fitted to the Burkes. You can see the three vertical tubes on the side of the hull.

    12. The towed array is only an acoustic receptor. It can operate passively, which is very unlikely to detect lurking diesels, or it can operate actively if combined with a hull mounted sonar, a towed variable depth sonar, or a helicopter dipping sonar. Depending on the conditions sonar detection range can easily quadruple by lowering the emitter 3-400 meter down in the water column.

      Most hull mounted sonars are placed in a bulbous bow or in a keel dome, but neither configuration is really compatible with the high performance semi-planing hulls of the LCS 1+2. That is probably the reason why it is omitted. In some ice strengthened patrol vessels, the sonar is put in a retractable pod, but these are usually medium frequency sonars made to operate in the shallows or in pack ice.


  2. I think the lcs will have a shorter then expected service life because of the weight margins. No room for the current modules, what happens when some revolutionary tech comes out that the navy must install on all ships? Just my opinion.

  3. For a ship intended for anti-submarine warfare, it's light on anti-submarine weapons. No ship mounted torpedo tubes. The only torpedoes are those carried by the MH-60R.

  4. The LCS ASW mission package competitive contracts placed in July 2015 with AAC (50/50 DRS & Thales company), L-3 and Raytheon for a reduced weight design cable winches using hydraulic or electric motor handling systems both for the Variable Depth Sonar (VDS) and the LM Multi-Function Towed Array sonar (MFTA) so as able to make the max. weight limit 105 MT of the LCS. The MFTA is GFE but the competition included the VDS which was required to be towed at higher speeds than normally used in normal frigates, ~ thirty knots (when non-operational), to new search area to save time from reeling in and then re-launching in new area.

    The quote below from Dr Gilmore's Dec 1 presentation to the SASC on the LCS infers that the selection has been made and it's different from that VDS (Thales CAPTAS ?) trialled, so far have seen so news on winning contactor, AAC, L-3 or Raytheon ?

    "Additionally much work has gone into a weight reduction program for the sonar and handling system, and a re-compete of the variable depth sonar. The Navy recently downselected from three vendors, selecting the variable depth sonar and handling system, and will begin ship integration efforts in the coming year. IOT&E is now planned for 2019. The Navy did conduct an at-sea test of an advanced development model of the variable depth sonar in September 2014 aboard LCS 1, albeit that test was conducted with a different sonar than was selected in the Navy’s recent decision. Those tests showed promising sensor performance in one acoustic environment, and demonstrated the potential of a variable depth sonar, which several other foreign navies already employ from their frigates. The operators were highly-cued in that test, since they were provided prior knowledge of the target submarine’s position, and the submarine did not execute evasion tactics. Given the significant departures from operational realism in that test and given the Navy has now chosen to go with a different design and vendor, I cannot provide any assessment of the expected effectiveness of the ASW mission package in a real-world combat scenario at this time."

    PS Side note note Ultra Electronics and Curtiss Wright /GeoSpectrum and others system mfg combining MFTA and VDS into a single Towed Array Active/Passive Sonars, for submarine, torpedo and surface-ship detection, so only one winch handling system required saving on weight and volume in stern of ship.

  5. Dutch navy Dec. 2016 press release for background info. on current state of art littoral sonar system, ship and helicopter combined, which if believable is hopeful, have previously mentioned.


    The Royal Netherlands Navy (RNLN) has successfully conducted trials of new low-frequency active-passive sonar (LFAPS) aboard its Karel Doorman-class or multipurpose (M–class) frigate, HMNS Van Amstel. The testing was carried out as part of the operational evaluation (OPEVAL) trial of the system. During the trial, the LFAPS demonstrated its abilities to mono-statically and bi-statically detect and track a diesel-electric submarine, in challenging environmental conditions, in littoral waters. The evaluation test was carried out along with a Walrus-class submarine and a NH-90 helicopter, which was fitted with a low frequency, dipping sonar. The Dutch Defence Materiel Organisation (DMO) received support from Ultra Electronics Maritime Systems in the development of LFAPS hardware, while the LFAPS processing software was developed by the Netherlands Organisation for Applied Scientific Research (TNO). The 123m-long frigate Van Amstel (F831) is equipped to engage in anti-submarine and surface warfare activities

    1. Just to add some perspective to that announcement, when has the US Navy ever released an announcement that was glowing in its unmitigated success? The reality is a bit different.

      I have no reason to disbelieve that announcement but neither do I have any reason to believe it.

  6. Here's a thought for anyone to ponder. The LCS has no ship-based ASW weapon. The only weapon the LCS has is the MH-60R helo which typically carries 2 Mk54 torpedoes. If a submarine is spotted, and assuming the helo is not down for maintenance or performing some other task, the helo can launch two attacks and then has to return to the LCS to rearm. Depending on distance from the ship, this is likely to be a few to several hour evolution. Is the LCS likely to be able to hold contact on a SSK for a few to several hours while the helo rearms? Is the LCS likely to still be afloat after a few to several hours of playing around with an SSK? For a non-optimized ASW vessel, that seems problematic, at best.

    One can't help but wonder if an ASW version of the LCS is really worth the cost?

    This also suggests that the only way an LCS can be successful at ASW is by operating as a multi-ship (four sounds about right) squadron in order to pool helos. Given that we will have only a single LCS ASW squadron on each coast, that's a pretty limited ASW effort - we'll get to patrol one and only one area!

    What do you think?

    1. In that case, unless the LCS had help from another ship, like a Burke, or a nearby patrol aircraft, it ought vacate the area as quickly as possible.

    2. The limited availability due to weather, maintenance, refuelling etc., time on station and payload of an ASW helicopter was the raison d'être of CNO Zumwalt 70's Sea Control Ship, a 14,000 t FL ship carrying 3 SH-2 Seasprite LAMPS 1 and 14 SH-3 Sea Kings to counter the cold war threat of the Soviet Union submarines. Similar thinking partially behind the 70's RN Invincible ASW Class of three, 22,000t carrying SH-3 Sea Kings, now all scrapped. The new JS Izumo Class of two, 27,000t FL costing $1.2 billion each carries 7 ASW helicopters and 2 SAR helicopters, 28 aircraft maximum.

      In the Falklands war the RN was paranoid about Argentine submarines attacking their CV's, mounted numerous attacks on suspected contacts using 50 MK46 LWT, depth charges and mortars. The only Argentine submarine a Type 209 San Luis only reported two attacks and used the WW2 tactic of hiding silently on bottom amongst the wreaks of whaling ships and whales.

      A few alternatives for a frigate to attack the submarine is a ship launched 12.75" LWT or the VLS ASROC introduced in 1961 with a reported range of only ~12 miles, the detection range of a TAS is much higher. The newly designed Italian Marina Militare PPA frigate has taken a different option, in the stern besides the TAS winch, RHIB launcher ramp it has twin 21" HWT tubes for the Black Shark 50 KM+ at 50 knots to take advantage of the TAS detection range.

      If the LCS the payload was not maxed out an option for NAVY would be to install the Anti Torpedo Torpedo, a 6.75-inch diameter interceptor for high-speed and maneuverability rapid attack on the threat torpedo, part of the suit of Surface Ship Torpedo Defense (SSTD) Systems under development and testing for installation on the CVN's. In 2006 a Chinese diesel-electric submarine surfaced near Okinawa within torpedo range of Kitty Hawk, without having been detected by that carrier’s escort of more than a dozen vessels and anti-submarine aircraft.

    3. In that light, no. Its not worth it. Its time and money spent doing a mission it can't do well; and indeed will likely get destroyed doing. In another comment you mention they'd have to do active sweeps. Not sure if that's just for the LCS or for anything in the littorals, but if so, that sounds like suicide. An SSK sitting beyond the active sonars detection range is going to be able to hear the LCS (or whatever) doing active pings and pop a missile (or two) at it; or even a heavyweight torp with a decent range.

      I wonder if sonar has the ability to pick up an SSK in the littorals with all the background noise anymore. The best hope might be to seed the littorals you know you need with some sort of SOSUS net.

    4. "seed the littorals you know you need with some sort of SOSUS net."

      You're still not quite grasping the shallow water environment. A SOSUS system is passive. Shallow water is an acoustic garbage dump. There's tidal flow noise over the bottom, flow noise from river discharge, turbulence and flow noise from water passing over, around, and through bottom wrecks, rocks, and debris, there's wave noise, seaweed movement noise, massive biologics noise, small craft noise, and many other noise sources. A passive sensor is overwhelmed with noise. Trying to pick one very quiet sub out of that cacophony of noise is difficult/impossible. An analogy is trying to pick one voice out of the crowd roar at a stadium.

      It couldn't hurt to try a SOSUS system but it's not likely to succeed.

      And yes, this is true of any ASW vessel.

      Remember, too, that all of this applies to the sub, as well. They're just as "blind" as the ASW ship. That's why short range, active detections will likely be the common result. That requires an ASW ship that is quiet, acoustically shielded from active sonar like subs are, and has a very capable, rapid, and deadly short range anti-sub weapon to respond with.

    5. For ASW, two helicopters would be better. But, with weight at a premium, maybe that's why the aviation detachment is a helo and a UAV.

    6. CNO: Yes, you're right. I hadn't thought of the sub side of it, nor realized the amount of noise.

      Anon: I also would guess that the flight deck probably can't handle two Helo's. It can handle two of the smaller firescouts in both classes, but just one Helo or one of the bigger MQ-8C's.

      The ASW aspect of the LCS is getting increasingly dodgy to me.

      Its best role at this point for me sounds more and more like a modern peacetime 'protected' or 3rd class cruiser. And if your going to use it for that I'd strip it of anything that made it expensive at all.

      We're going to need alot of bovine lipstick in the coming years.

  7. Question: if by some miracle the Final ASW module works as advertised, do we still need an LCS to put it on? If it is as self contained as it should be, and truly modular then it could be placed on nearly any ship.
    The LCs is only built to commercial standards not naval standards so shouldn't any ship do?
    It could be placed on an MSC cargo vessel...many of which have help helo hangers and CIWS...or an amphibious assault ship, or dozens of patrol vessels etc. So why waste money on an LCS when those funds could bring the modules to fruition. The modules should have been the first priority anyway since they were what made the LCS a combatant.
    If all the modules are brought to functionality then the Navy could put out the call for a inexpensive hulls with a fixed price of 100mill and Voila, an inexpensive DE.

    1. The modules are not truly modular, at least not entirely. The VDS, for example, requires hard mounting (welding) to the host ship in order to handle the massive strain imposed by towing the sensor and cable. That's a permanent mount, not modular.

      The equipment, alone, in a modular box, is useless. It needs to be integrated with a comprehensive combat software suite that integrates the ships radar, sonar, weapons, water temperature sensors, water salinity sensors, etc. to produce a complete "picture" of the battlespace and formulate a response.

      Also, beware of isolating on one aspect only. Even if you could mount an ASW module on a cargo ship (and you could if you also add the other necessary components) you've created a massively radar reflecting target of a ship. So, while you may create a substandard ASW vessel (still no acoustic quieting) you'll also create a ship that is a beacon to enemy missiles and won't last long. The LCS, for all its faults, does have stealth shaping and a reduced radar signature as well as AAW missiles. Sure, you could mount radars and an AAW weapons fit (and decoys and ECM) on a cargo ship but then you've essentially built an LCS and your "cheap" cargo ship is now expensive, just like the LCS only it's a hugely bigger target.

      The helo capacity would be nice and a modified cargo/helo ship might make for a good ASW mothership but that's another topic.

    2. Thales already supplies the entire system of towed array, variable depth sonar, winches, processing, and terminals in a set of ISO containers. The Royal Danish Navy has configured it's Iver Huitfeldt class AAW frigates with space for ISO containers under the helicopter deck, so the ASW capability of the platform can be boosted in a pinch.

      But this is only as a contingency. ASW is more than just a module, you need a well trained crew to go along with it.

  8. Just a few item I semi to recall from the news over the last couple of years,

    First, the congress cut the budget for ASW modules development work over the last few years.

    The DoD has taken delivery of a new unmanned submarine hunter equipped to find conventional submarine with hull mounted sonar.

    1. You're not suggesting that Congress is at fault for the LCS ASW state of affairs, are you????

    2. You don't believe that a small, unmanned vessel with a low power sonar is going to be effective at finding SSKs when our best platforms are only marginally effective, do you? This DARPA toy is a gimmick. It may or may not prove to have a useful niche value but it won't be a magic ASW solution! If it were, we'd be frantically converting every ship in the fleet to whatever magic small sonar this thing has.


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