Wednesday, March 28, 2018

PT Boat

Conversations about the LCS, even among professional Navy officers, often seem to equate the LCS to PT boats from WWII.  I don’t know about any official Navy position (I doubt they have any official position!) but many Navy leaders seem to believe that the LCS can operate like a PT boat – skulking about concealing islands and shorelines, springing forth to deliver salvoes of death and destruction, and then vanishing back into the littorals to repeat the cycle, impervious to enemy detection or retaliation.


“It can hide behind islands and in shallow waters, sniping at the enemy fleet — much like the PT boats of World War II …” (1)

Referring to operations in the South China Sea and surrounding areas,

“With 50,000 islands for LCS to hide among, “good luck finding me,” Gabrielson said. “I know I’m going to be able find you…and I’m going to hurt you.” (1)

What an appealing and, dare I say it, romantic notion?  This kind of naval guerilla warfare tugs at the heartstrings of Americans and appeals to our notion of heroic naval combat.

If we could rejoin reality for a few moments, though, let’s look at what the WWII PT boat really was, how effective it was, how it was used, and what lessons it offers us today.

What was a PT Boat?  Without boring you with specifications that are easily found on the Internet, in its original form the PT boat was a very heavily armed and very fast boat that was designed to sink larger enemy ships.  This is almost exactly today’s distributed lethality concept, isn’t it?  The PT boats were an expedient stopgap measure that, it was hoped, could provide cheap naval firepower to some extent until we were able to ramp up actual warship production.

Restored PT Boat


How effective was the PT boat?  Relative to its original anti-ship function, the PT boat was almost totally ineffective.  As far as I know, of the several hundred PT boats that served, there were only a very small handful of successful anti-ship attacks and many/most of those were found to have been false claims after the war.  I would estimate that there were perhaps a half dozen successful attacks.

As the war went on, the PT boat found other roles for which it was better suited and proved far more successful.  The two notable roles were early warning and barge-busting.

Early Warning – Due to their abundant numbers, PT boats were able to be deployed in strings across possible enemy transit routes and were often able to provide valuable early warning and monitoring of enemy movements.  In essence, they acted like a distributed sensor net, as we would refer to it today.

WWII was mainly an “eyeballs” sensor war.  Yes, early radar was present and often played a useful role, especially towards the end of the war, but most sensing was via eye.  It might be visual sightings from an aircraft, the lookout station on a ship, the periscope of a sub, or the hills of a coast watcher but the prevailing detection method was visual.  Aircraft were used to extend the range of our eyeball sensors and, in this role, the PT boat excelled.  It was able to extend the range of visual sensing and cover a larger area.

Barge-busting – Later in the war, PT boats were found to be ideal for interdicting resuppy barges.  The PT boats were loaded with all manner of ‘gunboat’ weaponry such as 40 mm guns, 37 mm anti-tank cannons, rockets, grenade launchers, etc.  Again, the boats were very heavily armed for their size.

Finally, let’s note that, as reported by Wiki, 99 of the 531 PT boats that served in WWII were lost to combat related causes – that’s 19%.  Given that many of the boats didn’t really see any significant combat, that loss rate is actually much higher, probably two or three times that among boats that saw significant combat.

How Was the PT Boat Used?  Early in the war, the PT boat was used as a stopgap means of applying disproportionately heavy firepower from a cheap, expendable, and inefficient/ineffective platform.  It was a necessity born out of our lack of real warships.  It achieved very few sinkings although it did cause a fair amount of doubt and confusion among the enemy.

Later in the war, the PT boat was used far more successfully as a remote sensor with strings of PT boats being deployed along/across suspected travel lanes and approaches of enemy shipping.  The early warnings that these boats supplied were invaluable.

The barge-busting role provided interdiction of desperation supply efforts and, again, were quite effective.

The PT boats were also used for myriad transport, search and rescue, and patrol functions.  The large numbers of boats allowed them to be used for a variety of purposes while still being able to fulfill their main purposes.


What Lessons Does the PT Boat Offer Today?  History is always willing to educate us if we’re willing to learn.  Here’s what WWII’s PT boat experience can teach us today.

  • The PT Boat was the distributed lethality of its day and, as far as sinkings of enemy ships, was a failure.  The failure was due mainly to the lack of sensor range.  PT boats were limited to visual sensing and, typically, night visual sensing.  Thus, their sensor range was on the order of hundreds of feet.  Unsurprisingly, then, they were unable to find targets even when they had pretty good intel on target movements and timing.  The PT boat’s weapons far outranged their sensors. 

We’ve noted the same problem today where we may have weapons with hundreds or thousands of miles range but our sensors are more on the order of tens of miles.  That distributed lethality LCS with an over the horizon anti-ship missile is going to be limited by a sensor with a radar horizon range.  The Navy hopes to solve this by using a vast, magical “system of systems”, all-encompassing sensor net of non-survivable platforms linked by a vast network that is assumed to be impervious to enemy electronic and cyber attack.  We’ll see how well that works.  If the sensor limitation can’t be solved, today’s distributed lethality platforms will be no more successful than yesterday’s PT boats.

We should also note that sensors work both ways.  If the LCS is going to use its radar to find targets then it is giving away its position and the enemy’s radar can find it.

We should also note that the islands that are hoped to provide concealment for the LCS by allowing it to blend into the radar clutter of the shoreline will also significantly degrade the performance of the LCS’ radar as the surrounding hills and elevations block large sectors of the radar picture.  The Navy seems to note all the advantages while ignoring the disadvantages.  I have yet to hear anyone elucidate how the LCS will find targets without itself being found.

In short, history and today’s parallels with that history, strongly suggest that the LCS will be every bit as ineffective in the distributed lethality role as were the PT-boats.

  • Size matters.  In the barge-busting role, the PT boat’s small size and disproportionately heavy weaponry proved advantageous.  The boats were able to blend in with the surrounding island shorelines and were difficult to detect.  Navy Admirals who are envisioning the LCS as today’s PT boat may be overlooking the discrepancy in size between the 80 ft PT boat and the 400 ft LCS!

  • Numbers matter.  PT boats were very successful as remote sensors and were able to extend the situational awareness of the fleet.  Of course, many boats were lost during the course of that performance.  That was an acceptable trade because the cheapness of the PT boat allowed us to deploy large numbers and accept the inevitable losses.  Can we afford to treat a $600M+ LCS, for example, as an expendable remote sensor?  What’s more, we certainly don’t have sufficient numbers of LCSs to deploy an effective network of ships as remote sensors.  We had hundreds of PT boats and we have only 20 or so deployable LCSs.

  • Support matters.  The PT-boats had very limited endurance at sea and depended on crude forward bases and motherships for resupply and maintenance.  Today’s LCS also has very limited endurance and, by design, cannot support itself with even basic maintenance.  Among the 50,000 islands that Adm. Gabrielson references, how many have forward operating bases?  None.  How many could support a forward base?  Few.  How many of the forward bases would be survivable given today’s thousand mile cruise and ballistic missiles?  None.  How many LCS motherships do we have?  None.  So, where is the support for the distributed, PT-boat-ish LCS going to come from?  I have yet to hear the Navy explain that.

One final thought about PT boats. In WWII, they were safe from attack from anything that they couldn't see and, given their heavy weaponry relative to their size, they at least had a chance of fighting back. WWII was basically a visual range war. Today, a "PT boat" is subject to attack from dozens/hundreds of miles away, far beyond its own sensors. They're not survivable in combat for long and will likely never know where the attack that sank them came from and will, therefore, be unable to fight back.

On a related note, a much better equivalent to the PT-boat is the Chinese Type 22 missile boat which is stealthy, 35% the size of the LCS, and heavily armed with 8 C-80x type anti-ship missiles.  It also suffers from the same weakness as the PT-boat – limited sensor range.

Type 022 Missile Boat




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(1)Breaking Defense website, “LCS In Pacific: Run Silent, Run Shallow”, Sydney J. Freedberg Jr., 23-Jan-2018,


50 comments:

  1. Hey, The US manufactures perfectly fine equivalents to the
    Type 022.
    The Ambassador MK III missile boat
    Oh, only they're for export for some reason USN does not order them, and BTW they are better armed than LCS :D

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    1. Oh man, how have I never seen that boat before? That seems like what the LCS was supposed to be all along. And $240 million a piece? That seems like a steal. With some upgraded radar and stuff it would still come in under $300, and if we committed to a bulk buy of 20 or more I bet that cost could come down quite a bit.

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    2. "That seems like what the LCS was supposed to be all along"

      If you want to see what the LCS was originally supposed to be, read the post below.

      LCS - Conceptual Origin

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    3. Yeah I read that. Small, stealthy(ish), fast, well armed, cheap. Its an LCS without a helo, which should have always been considered DOA in a medium threat environment anyway.

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    4. One of the key aspects - in my opinion, THE key aspect - of the original conceptual LCS design was the capability to engage in counterbattery artillery and counterbattery missile fire. That may or may not have been part of the rationale for the original NLOS weapon but, if it was, it was quickly dropped. The lack of counterfire capability has rendered the LCS unable to protect itself and unable to secure the near-shore area for larger units which, again, was one of the main functions, if not THE main function.

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  2. I know I keep harping on this, and I know you have too, but to me it sounds like for all Navies the emperor has no clothes. Brahmos, DF21, TASM, LRASM... everything.... we have super fast uber ranged weapons tied to short ranged sensors, hard to target satellite info, or networks vulnerable to disruption.

    From PT boats to the Pegasus class, I've heard the same refrain; weapons out ranging sensors sometimes by a factor of 10.

    The only outliers in sea warfare, at least for a brief time, sound like A) a Carrier that can loft an E2. Yes, they are vulnerable, but they can stay farther behind the lines and at least have a chance against longer ranged missiles if they shut down. Lose data now and hope to live and fight another day. Also, it might make more sense to build more and accept they might be an attrition unit. Barring that if they had something like an S3/E3 they could go back to more conventional scouting.

    the other outlier would be B) the sub; which can sneak in close enough to get good targeting data for its weapons.

    I'm not saying the weapons are bad. Or that we should just have short ranged weapons, or not try to have the 'system of systems'. That's fine, as far as it goes.

    But we should also have weapons matched to our sensors that are robust, easily fixed, and quickly usable; and we should train to fix them.

    Because once sensor degradation happens if we only know how to play with our fancy toys we'll pay a steep price.

    It wouldn't shock me to see a peer war, at least at sea, in the future fought with carrier strikes like WW2 and sub attacks.

    JFw

    JFW

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  3. Oh, and I have no bloody idea what role the LCS plays in any peer war. None at all. It's simply not well armed enough, or even robust and simple enough to be easily deployable like the PT boats.

    JFW

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  4. "The PT Boat was the distributed lethality of its day and, as far as sinkings of enemy ships, was a failure."

    Zee Germans might disagree. Wiki summarizes the S-boat record of sinkings thusly: "During World War II, E-boats sank 101 merchant ships totalling 214,728 tons.[10] In addition, they sank 12 destroyers, 11 minesweepers, eight landing ships, six MTBs, a torpedo boat, a minelayer, one submarine and a number of small merchant craft. They also damaged two cruisers, five destroyers, three landing ships, a repair ship, a naval tug and numerous merchant vessels. Sea mines laid by the E-boats were responsible for the loss of 37 merchant ships totalling 148,535 tons, a destroyer, two minesweepers and four landing ships." A different operating environment to be sure, but that's not too bad. If not for Japanese airpower, I'd wager that a small fleet of PT boats and tenders could have racked up an impressive list of sinkings, particularly of merchant vessels, in the Indonesian Archipelago early in the war.

    "If the sensor limitation can’t be solved, today’s distributed lethality platforms will be no more successful than yesterday’s PT boats."

    The size of the LCS, the independence class in particular, also has it's advantages. Unlike a PT boat, LCS can carry and support it's own remote sensors. Potentially those could be UAVs with their own radars, or just EM receivers to suck up the adversary's EM emissions.

    Two factors that you don't seem to take into account in many of your analyses are (i) the future use of directional transmitters and receivers (e.g. AESA datalinks like the F-35's MADL) and (ii) the counter-detection problem. Directional LOS signals are hard to detect, let alone jam, and will likely assure the availability of at least a limited LOS network in wartime, the range of which can be greatly extended by relays. Coupled with the fact that a target can usually detect a signal from distances on the order of 2 to 3 times further than the source can detect the target (the counter-detection problem, although LPI waveforms do make this more difficult), a network of passive sensors and linked by directional LOS datalinks with a LCS might facilitate the kind of guerrilla warfare strategy suggested by the Navy.

    Related to the recent ASW discussions, the counter-detection problem exists for sonar as well, but due to the potential for the formation of convergence zones, sonar counter-detection can occur at ranges on the order of 10 times the source's detection range when conditions are favorable.

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    1. "Germans might disagree"

      Not if they read the post since the post was about PT Boats not German S/E boats. If I write a post about German S/E boats, I'll be sure to include their record.

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    2. "future use of directional transmitters and receivers (e.g. AESA datalinks like the F-35's MADL"

      There are two reasons I don't generally account for AESA datalinks like MADL:

      1. They don't exist in any useful way. They may in the future and, if they do, I'll account for them. Currently, for example, the only platform that can "talk" to a F-35 via MADL is another F-35. That's not a particularly useful capability.

      2. I have little actual data about MADL performance. I hear the same kind of over-the-top claims that I do for all aspects of the F-35 (none of which have yet panned out) but no actual data. How resistant is it to interception based on testing? How resistant is it to jamming/disruption/ECM based on testing? What is the actual range of transmission? What is the bandwidth? What kind of signal error checking does it have? What impact does it have on radar functionality? And so on ...

      It might be the greatest invention in the history of warfare or it might be yet another overhyped flop or something in between. Give me some real data to look at.

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    3. "availability of at least a limited LOS network in wartime"

      What a great comment. I, too, believe that we'll have at least limited, sporadic data transmissions and networking. No enemy ECM can totally shut down all comms, all the time. The problem is that we design our weapons, tactics, and operators to assume that we DO have 100% comm functionality all the time. What will happen when we have only sporadic, limited capability? Will we still be able to coordinate all those distributed lethality platforms? Will we still be able to assemble a coherent situational awareness tactical picture? Will we still be able to retarget missiles mid-flight? Will our cooperative engagement capabiity and NIFC-CA work with only sporadic, incomplete networking? Who knows? I suspect the answer is we'll be rudely surprised and shocked by how dependent we've become on our networks and datalinks and how poorly they'll perform and, thus, how poorly our weapon systems that depend on them will perform.

      We need to be training against total ECM/cyber opposition and finding out what works and to what degree. We also need to be training our operators in degraded operations so that when they face data/network degradations they're not paralyzed by uncertainty and fear. Could a ship's Captain, today, fight his ship effectively with no datalinks, networking, or comms with higher authority? I doubt it, so we need to train for it.

      We can't even handle simple navigation so I'm pretty sure we can't handle the kind of combat challenges I'm describing. We need to begin training for war and we need to begin immediately.

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  5. "Not if they read the post since the post was about PT Boats not German S/E boats. If I write a post about German S/E boats, I'll be sure to include their record."

    They're effectively the same thing. The German record suggests that the PT boats could have been more effective if used differently or in a different operating environment.

    "I have little actual data about MADL performance."

    This is one of the better sources that I've found on LPI radars, detecting them, and jamming them.

    https://web.archive.org/web/20120914110145/http://edocs.nps.edu/npspubs/scholarly/theses/2006/Sep/06Sep_Denk.pdf

    Essentially, MADL is just a collection of small Ku-band AESA radars mounted on various portions of the F-35 to provide spherical coverage. It is resistant to detection because AESA beams are exceptionally narrow and AESA radars are able to effectively control their side lobes. This means that for all intents and purposes only what you're looking at has a good chance of detecting you, and LPI radars have various means of reducing this likelihood of detection as well. A jammer would most likely have to accurately know the position of the data-link receiver, to effectively jam the receiver if the receiver is also be directional (i.e., another AESA datalink). Bandwidth is high. The satellite internet on airliners, for example, generally utilizes the Ku or Ka-band. These bands, however, are more susceptible to adsorption by atmospheric moisture than longer wavelengths. MADL doesn't use the X or S-band because the TRMs would be prohibitively large to provide spherical coverage on a fighter. A ship or ground installation could use the X-band on a trainable mount to provide sufficient coverage and better tolerate atmospheric moisture.

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    1. "The German record suggests that the PT boats could have been more effective if used differently or in a different operating environment."

      I've addressed their actual results which were poor as regards ship sinking. One interesting aspect of the E/S-boat is that if you take away the merchant shipping, the results are similar. They sank 12 destroyers and a handful of auxiliaries - a record comparable to the PT boats.

      I note that the PT boats never encountered merchant shipping to any appreciable extent. You can't sink what you don't encounter!

      Against warships, the results are actually similar.

      It would also be interesting to compare loss rates for the boats. At a quick glance, I don't see any data. Maybe you have some?

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    2. "One interesting aspect of the E/S-boat is that if you take away the merchant shipping, the results are similar."

      I agree, but I think that the comparison illustrates the value of fast attack craft in conducting interdiction missions in the littorals. As the USNI blog post cited below says, “They were not designed to patrol hundreds of miles to sea, but to deliver sudden punches close to shore and relatively near their bases.” The post covers some of what you do but goes into more detail with respect to the Solomons Campaign. I think it's worth a read.

      https://blog.usni.org/posts/2009/09/22/the-solomons-campaign-torpedo-boats-and-littoral-warfare

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    3. The PT boat and the S-boat were nearly equally ineffective against warships. Yes, the S-boat was effective against merchant ships but any platform is. Subs, aircraft, patrol boats, anything can be effective in that role. The S-boat's success in that role was simply opportunity. Japanese merchant shipping never sailed in the PT boat's area of operations which points out the limited range of the boats. That merchant shipping sailed within range of the German S-boats was an artifact of the geography rather than a testament to any particular characteristic of the S-boat (other than decent seakeeping, by all accounts).

      This does suggest that a "PT-like" force could be effective amidst the peripheral merchant shipping lanes around China but the forward basing need would have to be solved.

      To return to the original post premise, nothing we've discussed even remotely suggests that the Navy's vision of "PT-LCS-boats" and distributed lethality can be successful.

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    4. The Schnellboots, were, and arguably remain, the best small combatant of their size, but I agree with CNO’s assessment on the overall utility and limitations of this type of platform.

      The LCS tragedy speaks for itself.

      I would venture other roles where a modern PT/Schnell-Boote/MTB etc. could prove useful: 1) support for Visit Board Search and Seizure (VBSS), or offensive ship boarding, and harbor security(really harbor approach patrols).

      Of course a larger vessel, e.g. the Norwegian Skjold class, could perform these roles better (range, payload, sensors), and expose fewer crew to danger. O&M costs, as well as the total cost of ownership issues remain serious questions affecting our *value* observations of how this class of vessel fits into the Navy, or not.

      GAB

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  6. Seems like we should have kept working on the Sea Shadow concept.

    Also, I think a perfect pairing for a small boat like this would be something along the lines of a jumbo RIM-116 configured for anti-ship. Or maybe a short-range Harpoon although the speed of the RIM-116 is a big plus. Something supersonic with a big warhead, and a ~15-20 mile range sounds ideal.

    That paired with a small, fast, and (ideally) stealthy ship which could sneak in close, unleash a barrage, and then dash out and you are really rolling.

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    1. "a small, fast, and (ideally) stealthy ship which could sneak in close, unleash a barrage, and then dash out and you are really rolling."

      Sneak in close to what? What's there and how do you know it? You're overlooking the same thing the Navy is - sensors! You can't sneak in close to anything unless you can see it. How are you going to detect a target without giving yourself away?

      Passive EO would work but that takes you back to short range.

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    2. Hence the stealth? Maybe you want to be lurking around a port, or known shipping lanes, or you have other intel that suggests a potential position for enemy ships. I am talking about being able to be within 20 miles of an enemy ship or shore without being detected while having sensors cable of detecting other ships. You are saying that in all likelihood future naval battles will be conducted in that 20 mile envelope, right? I am talking about a potential ship with sensors and weapons all optimized to fight at that range.

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    3. "talking about being able to be within 20 miles of an enemy ship or shore without being detected"

      If there were only ships, that might be true. But, within 20 miles of ships and shore there will be people, fishing boats, helos, aircraft, etc., all with simple eyes, if nothing else. The odds on remaining undetected under those conditions is zero.

      The only platform with a chance in that scenario is a submarine.

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    4. After spending many years on oil platforms, I can say that being able to spot anything out past 15 miles is borderline impossible, and I am talking about big hulking things like other oil platforms. A ship like the Sea Shadow would be very very difficult to see.

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    5. "A ship like the Sea Shadow would be very very difficult to see."

      On radar, possibly. But not for EO, IR, or eyeball when vessels, subs, boats, helos, and aircraft are regularly coming and going. Someone is going to notice!

      Also, where are these sneaky ships going to be based since your concept has them operating within 20 miles of enemy bases and shores?

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    6. Uhhh it definitely would be just as hard if not harder to see, and in this situation since its mission would be attack, all of those things would be targets too. They would be the mission, not get in the way of the mission.

      Subs are always gonna be the wildcard, but I would imagine you would make these boats small enough to where you could have a separate hull dedicated to sub hunting, or large enough where one hull could do both. They should be cheap enough so that they can outnumber any littoral DE sub presence, or expensive enough to not be threatened by them.

      As for basing? That isnt really a problem. They could get resupply from the main fleet. They could use forward bases. Whatever. In a hot war, the fleet will always be around (or its time to pack it in anyway). In a cold war, they would have more than enough range and endurance to operate out of a friendly forward base somewhere close.

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    7. I get the impression you haven't really thought through the specifics of this. What would be a specific example mission? Not a generic, "they could sneak up on an enemy" but something specific. What Chinese target, for example, might such a vessel be useful for attacking?

      One of the problems with a China war is that all the worthwhile targets are on the Chinese mainland which is protected by a thousand miles of A2/AD zone. How would these vessels penetrate a thousand miles to get within 20 miles of the Chinese mainland?

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    8. I think that a Very Low Observable surface vessel would be useful as a sort of tomahawk missile arsenal launcher, but just that.

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    9. So you are asking me to present a hypothetical situation inside a hypothetical situation that exists inside your mind? I feel like you are trying to heap as many ridiculous constraints on my comments as possible in order make them seem invalid.

      I am talking about generic close quarters ship v ship combat, potentially but not necessarily inside littoral waters. Do you not think combat like is likely?

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    10. SS, Tomahawks have enough range that I dont think VLO would be necessary for a launcher. And once you launch them everyone is gonna know right where you are anyway.

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    11. No, you can program the course on those missiles anyway you like, its not a straight shot, and yes a vessel with a VLO signature launching cruise missiles 2000km away from target locations is a big asset

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    12. "So you are asking me to present a hypothetical situation inside"

      No, the exact opposite. I'm asking you to consider actual enemies (China being the most likely) and offer a specific scenario and specific target that your conceptual vessel would be appropriate for.

      Too many people get caught up with generic capabilities without ever stopping to consider actual use. For example, the entire LCS was developed as a collection of technology with all kinds of theoretical, generic uses but no one asked whether it offered any real world capabilities that would be of use - and the answer, thus far, has been no. The Zumwalt is another example of a ship built with generic technological capabilities but no useful, real world purpose. And so on.

      So, what would be a specific Chinese target in a war that your concept vessel might be useful for. How would it get there undetected? How would it find its target(s)? What weapons would it use? How would it survive under realistic enemy search conditions? Are there better existing alternatives such as Tomahawks? And so on. Answer those and you might have a useful concept. Failing to answer those, you just have a generic technology with no real world purpose.

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    13. Any Chinese warship or group of warships anywhere in the South China Sea, Sea of Japan, etc? A resupply convoy to Taiwan or one of their island bases? Something acting as a long range patrol and forward sensor platform for the carrier group? Assuming open, or semi open conflict, aerial recon would be spotty. So enemy ship positions would be hazy at best. These ships would be operating out of Japan or the Philippines, or even AUS (remember I have never been talking about something as small as an old PT boat). Unless a Chinese sub got very very lucky, how is China gonna know where they are? Their aerial recon would be even spottier. Even a non-VLO ship would stand a good chance of making it inside Harpoon range before being detected. These VLO ships should be able to make it inside of the horizon to ID the Chinese ships and then either from that distance or back over the horizon they would unleash a barrage of short-range, supersonic, anti-ship missiles. They would have a few ESSMs to counter enemy aerial patrols that might pop up, and because of their VLO design they would be able to spot them first, or at least not get spotted first.

      Tomahawks and Harpoons are fine, but something supersonic would stand a better chance of making it to target. The closer you are when you launch the less time the enemy has to react also. Limiting the range also means no need for large and expensive ramjets to power it past supersonic. You just need a two-stage rocket motor. Something like a sea-launched version (non-nuclear) of the AGM-131 would have the warhead size, range, and speed like I am thinking.

      A sub is always going to be the ideal stealth launch platform, but these should be no more than 1/3 the cost. Without knowing how the Sea Shadow program turned out its tough to know if something like this is at all possible. And its hard to know how much additional cost the fancy gun, and fancy powertrain heaped on the Zumwalt. But, building something 1/3 the size, without the helo capability, and radar in the range of SPY-1K or 1F, aught to be significantly cheaper.

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    14. Well, all I can say is that you have an incredible faith in naval stealth that goes far beyond anything I've ever heard. There is no publicly available naval stealth data so I can't dispute your assumption. Of course, neither can you support it! I'll only say that, logically, if naval stealth were as good as you say, the world's navies wouldn't be concerned about anti-ship missiles and we wouldn't be building more Burkes with ever more powerful radars. So, logically, your assumption would appear hugely overoptimistic.

      That aside, it would be an interesting exercise to try to build a pure stealth, corvette sized vessel and see what could be achieved. Of course, every gun, sensor, boat, mast, bit, stack, light, antenna, etc. that you add negatively impacts the stealth. By the time you add all the necessary equipment, what has happened to the stealth? The most extreme example is the Zumwalt which has the bare minimum of external equipment and I've never heard anyone describe it as stealthy to the point that it could approach an enemy within 20 miles, undetected.

      You're welcome to your vision of stealth and if you ever find any concrete data on naval stealth beyond the "small as a fishing boat" type descriptions, be sure to let me know! It would be fascinating to read.

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    15. Here you go, the basis for a stealth PT boat,

      http://www.hisutton.com/images/Sealion_cutaway_big.jpg

      Space for a 2-4 NSMs in the rear, or a similar number of ESSMs.

      A lighter missile would be nice.

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    16. Here is a quote from one of Sea Shadow's project managers:

      "Gupta described one night exercise where Sea Shadow was able to sneak up on an aircraft carrier, pop one of its flush-fitting deck hatches, and fire three flares at the heavily defended carrier. Until the hatch opened, Sea Shadow went undetected. “They could barely see where the flares came from, but by the time we had closed the hatch, we disappeared again,” he said. In another test, engineers placed a common aluminum soda can atop Sea Shadow’s narrow black deck. The “enemy” radar in the exercise could pick up the soda can, but not Sea Shadow, Gupta said."

      Sounds like they were able to get inside of 20 miles! Building more Burkes has nothing to do with this. They are concerned with protecting a carrier (which we cant seem to build a non-stealth version for under 10 billion) from enemy planes, subs, ASMs, and BMs. To put all that into something looking like the Shadow, well, could we afford to build any? And they dont care to hide from those threats anyway, all the money is going into knocking them out. They are confident in their ability to do that so the added hassle and expense of stealth is not needed. And since we are gonna be sailing non-stealthy carriers for.....ever? They damn well better be good at knocking down ASMs. All the stealth destroyers in the world wouldnt help with that.

      But anyway, back to the Shadow. Supposedly it cost $170 million to build, and it was basically the size of a corvette. So seems like $500 million for something similar today with an ASM punch isnt totally unrealistic.

      Delete
    17. "one night exercise where Sea Shadow was able to sneak up on an aircraft carrier"

      This is identical to the stories about a SSK "sinking" a carrier in an exercise. The SSK supporters loudly trumpet the event. What they don't tell you about is the other 35 tries where the SSK was sunk or the fact that the exercise was designed to give the sub's crew attack training and the scenario was designed to give them a shot and so on.

      Who was looking for SS? What sensors were they using? Were escort ships patrolling around the carrier? How many times was the exercise performed and what were all the results?

      Without those answers, all you've got is one interesting, unverified, anecdotal story. Hey, have you heard the one about the LCS that passed shock trials with flying colors (until the real story came out about reduced explosive loads, terminated tests, removed equipment to prevent shock damage, and millions in actual shock damage)? Amazing stories are common - reality is much more mundane.

      Don't get me wrong, I'm intrigued by Sea Shadow but I have come across no actual performance data so I withhold judgement.

      Delete
    18. "Sealion"

      I've never heard of that boat and the picture seems to completely lack any purpose. It has no weapons and no useful transport volume.

      Fitting 2-4 NSM's (13 ft long and 900 lbs without any launch mechanism or exhaust handling) would be a challenge.

      Delete
    19. http://www.hisutton.com/SEALION%20and%20Alligator%20stealth%20boats.html

      The aft payload area is long enough to carry a 15ft CRRC and 4.4m wide.

      Delete
    20. Hey, discount it all you want, but you said you hadn't heard anyone make claims like that.... So I found someone who did. Everything else is classified still about that boat, so that's all you're gonna get.

      Delete
  7. I'm a little surprised anyone would seriously think of the current LCS as a PT boat (unless it is just for PR purposes). While fast (which was not a good requirement for a large ship), it has little else in common with a PT boat. Some of the early concepts for the LCS had them as missile boat or corvette size ships, but that was dropped pretty early on.

    That said, I would suggest that in the modern naval environment the PT boat has been replaced by helicopters. Multi-role and attack helicopters can perform most of the roles you discussed as PT boat missions at a much more effective cost in dollars and manpower. Although you could argue that helicopters don't have the endurance of a PT boat and that you still need small vessels for identification and boarding functions in some areas.

    One thing to note too is that the Chinese seem to think the PT boat idea might not be worth the investment. They originally planned to build a couple hundred of the Type 022 missile boats, but production stopped before reaching 100.

    While your post is only about American PT boats and not motor torpedo boats in general, I do think you overlook the radar capability that was added to the boats later in the war. This capability helped create an effective Allied convoy-busting team in the Mediterranean, where American PT boats acted as spotters and guides for British LCGs and Fairmile D MGBs. It still makes the PT mainly a sensor platform, but does show how a little imagination and cooperation made them more effective.

    It could be interesting to look at how motor torpedo boats from all navies influenced post-war designs and missile boats.

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  8. I've always wondered, one simple way to increase radar range on smaller boats is to mount the radar on some kinda telescopeic pole that can be raised and lowered.

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  9. "Oh man, how have I never seen that boat before? That seems like what the LCS was supposed to be all along. And $240 million a piece? "


    If you think the Ambassador is well, check out the Sa'ar 5 corvette for the Israeli navy and compare to LCS

    Yes, another vessel that is superior to LCS and being build in the US for a foreign customer, notice a pattern here.

    https://www.naval-technology.com/projects/saar5/

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  10. Everyone is now aware:

    Every now and then, a definite success, as with the submarine I-3 or, a couple of days later the destroyer Terutsuki hit by a PT torpedo and sunk.

    https://blog.usni.org/posts/2009/09/22/the-solomons-campaign-torpedo-boats-and-littoral-warfare

    The article notes that many PT boat hits were with defective torpedoes that did not explode.

    The key change is that we now have self-guided torpedoes, and small radar. So PT like boats can fire from miles away rather than closing within 500 yards.

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    Replies
    1. "The key change is that we now have self-guided torpedoes, and small radar. So PT like boats can fire from miles away rather than closing within 500 yards."

      Where would these PT-like boats operate from? Given their short range, their base would have to be very near their targets. Do you see China allowing a PT-like base to exist very near any worthwhile targets?

      Delete
  11. As a counter-proposal;

    Why not create a large fleet of small single purpose, torpedo armed diesel submarines, and convert some of the nuclear submarines we're retiring into tanker submarines? Would that not fulfill the same theoretical purpose of both the pt boats and lcs, Ie sinking ships in locations not suitable for a battlefleet?

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    Replies
    1. "in locations not suitable for a battlefleet? "

      By "not suitable", I assume you mean not survivable. If that's the case, how would the PT-ish vessel survive?

      Remember, in WWII, the sensors were eyeballs and a tiny boat COULD HIDE against the shore of an island. Today, with radar, IR, EO, and DF, the ability of a boat to hide against an island is hugely reduced (not possible?). And, if the searching sensors can be degraded by the island features enough to hide the boat then the boat's own sensors would also be badly degraded and it wouldn't be able to find targets unless it came out to look and then it would be quickly found.

      You're on the right track with submarines (SSKs) but I think the fantasy of PT-LCS-boats is just that, fantasy.

      Delete
    2. My apologies for the wording and brevity of my post, I'm replying via flipphone.

      I agree with your notion that this pt style usage of the lcs is fantasy, but that said we need warships that can contest constricted areas if the need arises (which I feel the lcs is inadequate for, currently).

      I was stating if they wish to carry out pt style, ssk with submarine motherships is probably more effective, both economically and combat wise.

      Sorry for any miscommunication on my part.

      Delete
    3. Okay, I'm with you on SSKs. Now, regarding the use of an SSN as a tanker to an SSK, have you ever heard of such a thing? I know the Germans used large tanker subs in WWII but the drawback was that they had to be surfaced to refuel. Would you envision having to surface a SSN-tanker and SSK to refuel or are you aware of some means to refuel underwater?

      The concern, of course, being that if the subs have to surface then they're subject to all the detection issues that would plague a PT-LCS.

      Have you seen something along this line or do you have an idea for it?

      Delete
    4. I haven't heard or read of this being down in a long time. To my knowledge the last recorded use of a submarine refueling another submarine, was ww2. I have a few ideas of it could be done, on of which is the ww2 method of withdrawing for the frontlines to do surface refueling. You've already pointed out the drawbacks of the simple method. A modern approach could be similar to how aircraft refuel, via catching booms. One of your readers with engineering experience could point out the flaws, but I personally don't see why it couldn't be done. The conversion itself of the ssn is straightforward, with the missile tubes being replace with fuel tanks or an I being naive on that?

      Delete
    5. The problem with withdrawing from the front lines is that if you're a thousand miles inside an enemy's A2/AD zone, there's nowhere to withdraw!

      Regarding a aviation style refueling, that's interesting. One obvious drawback is that pilots can clearly see the refueling plane and the refueling mechanism. This wouldn't be possible underwater. Still, worth thinking about!

      Delete
    6. Sub surface refueling should be doable with current ROV technology. Hatch opens on SSN, ROV with fuel line attached goes out, connects to open hatch on SSK, inserts fuel like into fuel port.

      Primary downside would be the slow speed limitations during refueling.

      Delete
  12. CNO, good post and great comments.

    It makes perfect sense to upgun PT's for coastal defense or to use them as the Navy does, in the gulf. For the Navy they will always be Special ops/harbor defense-escort/EOD/mine niche boats.

    The only massive buying of PT boats should be the Coast Guard as they are in charge of our coastal defense. But due to geography they would be better suited to CNO's idea of an ASW corvette which means something larger to handle towed arrays and VDS.

    Once we go along the lines of where we operate, how we get there, how we protect ourselves and where we are based(as CNO rightly said) then we start to modify the PT boat. It has a tendency to turn into a large corvette/small frigate.

    ReplyDelete

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