AiryW
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Posts: 183
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Post by AiryW on Nov 29, 2018 12:53:53 GMT -6
Surcouf travelled quickly underwater. Surcouf only surfaced a little. You are objecting to what I have not described.
I said submersible cruiser. You have turned that into cruiser submarine.
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Post by mycophobia on Nov 29, 2018 13:44:46 GMT -6
Surcouf travelled quickly underwater. Surcouf only surfaced a little. You are objecting to what I have not described. I said submersible cruiser. You have turned that into cruiser submarine. Seems like I misread the chain of conversation earlier. In any case, the large amount of machinery to achieve any reasonable cruiser-like speed on the surface is going to be very heavy compared to what’s usually mounted on a submarine. Many of the very large( for their era) submarines had sea-keeping and depth keeping issue. It is likely an enormous engineering challenge to build a “cruiser that can dive” compared to a crushing submarine. As many have mentioned earlier as well, 8’ gun are not the most effective weapon for sinking merchants, and at night with early war surface search radar it’s only going to be worse. Granted with the generally atrocious japanese anti-sub capability you are probably safe if you can hide, it probably won’t have the same impact as conventional submarines. Putting any more guns than what’s needed to sink merchants are not necessary and probably counter productive. The idea of a heavy surface raider is that it can probably engage either convoy of merchants ships, or outfight what it cannot out run. In this case, a cruiser that can submerge are almost going to certainly be outclassed by any normal cruisers and likely will not risk engaging in any gun battle where the opponent have the range to fire back. Being a submarine, it will also be more sensitive to any damage it receives , which will already be an issue with even larger surface raiders like Graf Spee. Therefor it really should just play to the advantage of its guns letting it attack enemy merchants from a safer range than torpedos. Giving it more firepower only complicate the already difficult engineering challenge and will not add to its mission.
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Post by jwsmith26 on Nov 29, 2018 15:30:22 GMT -6
The Japanese designed, but did not build an interesting class of submarine tenders that would combine the functions of submarine tender, aerial scout and flotilla flagship. They were surface ships that would also carry a fair number of floatplanes to provide aerial reconnaissance for their charges. As flagship it would coordinate the operations of the submarine flotilla and as a tender would provide replenishment and minor repairs. I think that is an interesting idea in that it's like a surface raider with tentacles that could cover a very large area while the surface component would never be expected to engage in combat if it could avoid doing so.
The Japanese also deployed the 1-400 class of subs that carried 3 floatplanes and a single 5.5 inch gun, as well as several AA guns. Their 6,500 ton displacement put them solidly in the cruiser weight class. They had a ridiculously long range of 37,500 nmi with the aim of being able to reach any point on Earth and return to base without refueling. However, they were not very good sea boats. Their large superstructure with a hangar for 3 planes made them almost un-navigable when surfaced with any kind of wind and even underwater their offset superstructure caused steering issues. The large superstructure also made them much easier to detect both visually and via radar. Their slow submerging speed (it took almost a minute) made them vulnerable to any type of surprise attack and their shallow maximum dive depth didn't help when under attack. I believe they were originally suggested by Yamamoto with the objective of striking targets along the North American western seaboard and to possibly attack the Panama Canal.
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AiryW
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Posts: 183
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Post by AiryW on Nov 29, 2018 15:58:24 GMT -6
As many have mentioned earlier as well, 8’ gun are not the most effective weapon for sinking merchants, and at night with early war surface search radar it’s only going to be worse. Granted with the generally atrocious japanese anti-sub capability you are probably safe if you can hide, it probably won’t have the same impact as conventional submarines. Why do you think that the Japanese would divert more sea traffic and devote more heavy cruisers to a submarine making attacks in the East China Sea then a heavy cruiser covering ten times as much ground and probably firing shells into the harbors at Shanghai, Port Arthur, etc? Because disrupting sea traffic and diverting warships are the point, not sinking merchant ships. Hence the 8 inch guns instead of 6 inch guns. 6 inch says a light cruiser slipped through. 8 inch says a heavy cruiser slipped through.
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Post by aeson on Nov 29, 2018 16:05:23 GMT -6
I am putting together a list of armed merchant ships that the Kriegsmarine deployed in WW2 with their total tonnage. The armed merchant ship had the best chance of succeeding in its mission for one reason. It looked like any other merchant ship on the seas, even the warships looking for raiders could not tell the difference. These ships would reconfigure themselves on a regular basis using Lloyd's of London's ship register which gave details on the merchant ships of the world. Captain Rogge speaks of it all the time. Warships, sent out as raiders, into the Atlantic stick out like a sore thumb. The Kriegsmarine picked the fastest merchant ships they had for this duty, then rebuilt them adding 6 in. guns in disguised cover's which could be lifted automatically to fire. They were very effective. Note: Numbers are from Wikipedia, and I haven't checked them for accuracy. Also, I know that I listed gross register tonnage instead of displacement for Kormoran; Wikipedia didn't list a displacement, unless I overlooked it. At a guess, its displacement might be about twice its gross register tonnage since that seems to have been about what relationship between displacement and gross register tonnage was for the other eight auxiliary cruisers.
If Japan's freedom of movement was not restricted by the USN's submarine fleet, then replacing the USN's submarine fleet with a significantly smaller number of far more expensive submarines of a design of questionable practicality within the period is very unlikely to improve things, especially since a very large submarine is probably more vulnerable than a normal diesel-electric patrol submarine such as a Gato, seeing as it'll almost certainly dive significantly slower and is at the very least pushing the boundaries of what was possible and practical at the time.
Surface cruisers are far, far easier to detect than a surfaced submarine, even if they have the ability to detect aircraft much further out and take action to evade aerial detection. They're significantly larger targets - whether for visual or radio detection - and sit much higher in the water unless something's gone badly wrong. I also have serious doubts about the claim that they can detect aircraft far enough out to evade detection by aircraft; ships are significantly slower than aircraft, and even the better WWII radars don't have effective detection ranges much better than that of the Mk.I Eyeball at 5000 feet above sea level in good weather; depending on which suite of radars a ship happens to have, how experienced its radar operators are, whether or not the aircraft itself has radars or radar detectors, and how good the aircrew are at spotting ships the old-fashioned way and using any high-tech toys that they may have been provided to aid in that effort the search aircraft might be able to spot a surface combatant well before the surface combatant can spot it.
Also, sure, a ~1,500t patrol submarine might hunt for a month and never hit anything, but the same is true of a ~10,000t submarine cruiser - especially one that blunders around almost blind in the dark and then goes turtle come daylight. The big vessel might cover more territory than any given smaller vessel, but that's at least partly offset by the fact that I can have more of the smaller vessels than I can of the larger vessel. If I can afford six fairly normal ~1,500t American diesel-electric patrol submarines which can each sweep a path ten miles wide at 10 knots overnight and then hide out for the day, or one ~10,000t diesel-electric submersible cruiser that can sweep a path 50 miles wide at 15 knots overnight, there's not actually that much of a difference in terms of total area searched, that's roughly 600 square miles per hour of night searched by the six ~1,500t diesel-electric patrol submarines, or about 750 square miles per hour of night searched by the submarine cruiser - and I rather suspect that calling the submarine cruiser's average overnight speed 15 knots is rather generous and its nocturnal detection radius 25 miles is rather generous (of course, that latter in particular is probably also true to some extent of the normal diesel-electric patrol submarines, but at least sea-search radars picking surface targets up at five miles isn't that unlikely, whereas picking up a surface target on radar at 25 miles is much more unlikely, especially considering that some of the early radars were only rated to pick up surface targets out to about 15 miles and could be confused by such things as islands, slightly-rough surface conditions, and resting flocks of seabirds, especially when served by inexperienced operators who have to figure out what the return signal meant without the aid of modern signal processing reducing noise and clutter, or even in many cases the now-familiar radial plots commonly used in media). Sinking merchants in large numbers - as USN submarines did in the latter half of the Pacific War, or as German submarines did in the various "happy times" - is at least as disruptive as merely causing delays, and an occasional pinprick from a rare surface raider is far, far more ignorable than almost-constant losses to an intensive submarine assault on merchant shipping. German submarines sunk about 14 million tons of Allied and neutral shipping, German auxiliary cruisers about another 800,000 tons, and German heavy surface combatants about another 300,000 tons. Relatively speaking, the heavy surface combatants, and even the auxiliary cruisers, only inflicted a pinprick. That holds even if you restrict the comparison to only those years where German submarines, auxiliary cruisers, and heavy surface combatants all engaged in commerce raiding activities.
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Post by oldpop2000 on Nov 29, 2018 17:28:48 GMT -6
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Post by aeson on Nov 29, 2018 19:38:47 GMT -6
oldpop2000 , the numbers you put up for the armed merchant cruisers sum up to about three quarters of a million tons, not half a million tons, and the site you link suggests an aggregate tonnage sunk by the auxiliary cruisers of over 870,000 tons.
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Post by oldpop2000 on Nov 29, 2018 19:48:30 GMT -6
oldpop2000 , the numbers you put up for the armed merchant cruisers sum up to about three quarters of a million tons, not half a million tons, and the site you link suggests an aggregate tonnage sunk by the auxiliary cruisers of over 870,000 tons. My apologies, I deleted the data and just left the website. Thanks again, I don't like to make stupid errors.
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AiryW
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Posts: 183
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Post by AiryW on Nov 29, 2018 20:50:02 GMT -6
far more expensive submarines Once again, not a submarine.
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Post by aeson on Nov 29, 2018 22:40:13 GMT -6
far more expensive submarines Once again, not a submarine. Historical submarines played submersible gunboat quite a bit in both world wars, until doing so became too dangerous to be worth the risk. What does your submersible cruiser bring to the table that historical submarines don't already have? High surfaced speed? Something like a Gato or Surcouf can hit 18-20 knots and cruise 10,000-11,000nmi at 10 knots on the surface. That's already plenty for attacking most merchant shipping or undertaking harassing shore bombardment missions and then running a decent way off to avoid whatever comes out in response. More firepower? It's a raider. Its primary missions are attacking merchant shipping, attacking more merchant shipping, compelling the enemy to use some of its limited supply of appropriate escorts on trade protection instead of fleet screen duty, and maybe some occasional harassing shore bombardment, with the odd bit of spec ops and intelligence gathering thrown in. It needs neither big nor many guns for that. Stealth, supposedly? Color me completely unconvinced that a 10,000t (surfaced displacement) submersible cruiser would actually be more capable of evading detection than something more like a historical diesel-electric patrol submarine
What are you gaining? It's not armed well enough and probably isn't a good enough gunnery platform for picking a fight with real cruisers to make sense or for it to really have all that much stand-off potential against an AMC or - worse - a destroyer, its size means it's unlikely to be able to hide all that well or all that quickly from ASW forces and patrolling aircraft and could very well be problematic close to shore, it probably won't make for a convincing phantom cruiser because its armament of four 8" and no secondary guns is completely unlike any cruiser I've ever heard of and its nondetection by air search should naturally suggest a submarine (especially if it's not careful about its timing for bombardment missions or if someone's able to give a decent description of it, allowing a presumably-not-completely-incompetent intelligence service to go "that sounds like that enormous weird submarine that X was building a few years ago"), and I really don't see how four of them in the East or South China Seas would throw any more of a wrench into Japanese operations and plans than five or six times as many Gatos operating in the same area would. What real advantage does your submersible cruiser offer over a Surcouf-type cruiser submarine or a Gato-type diesel-electric patrol submarine to justify its much higher unit cost?
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AiryW
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Posts: 183
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Post by AiryW on Nov 30, 2018 8:21:33 GMT -6
What does your "submersible cruiser" which apparently isn't a submarine bring to the table that historical submarines don't already have? I have already explained what I view as their proper deployment and strategic benefits. I am not particularly inclined to explain this again to someone who uses scare quotes and misnaming to delegitimize the idea from the get go. I do not see a productive conversation coming from that.
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Post by williammiller on Nov 30, 2018 11:48:52 GMT -6
I am mostly out of pocket for the next couple of days, and have granted several NWS Team members Moderator privileges.
Let us leave out *all* personal attacks, from all sides of our discussions; such attacks not only directly violate our TOS, they are also just plain unprofessional and unpleasant to see on a forum.
Thanks for your attention gents.
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Post by mycophobia on Nov 30, 2018 12:16:26 GMT -6
As many have mentioned earlier as well, 8’ gun are not the most effective weapon for sinking merchants, and at night with early war surface search radar it’s only going to be worse. Granted with the generally atrocious japanese anti-sub capability you are probably safe if you can hide, it probably won’t have the same impact as conventional submarines. Why do you think that the Japanese would divert more sea traffic and devote more heavy cruisers to a submarine making attacks in the East China Sea then a heavy cruiser covering ten times as much ground and probably firing shells into the harbors at Shanghai, Port Arthur, etc? Because disrupting sea traffic and diverting warships are the point, not sinking merchant ships. Hence the 8 inch guns instead of 6 inch guns. 6 inch says a light cruiser slipped through. 8 inch says a heavy cruiser slipped through. you are only going to divert significant amount of warship if there is significant risk to leave you alone. As others have said, heavy surface raiders are not sinking much to begin with. Given the comparative little effort japan did to asw despite the losses they take, I am not sure they’d necessarily divert anything. If this submersible cruiser can behave as effectively a heavy cruiser that can submerge, as you envisioned, then leaving it alone can have drastic consequences. E.g German heavy surface raiders have sunk convoys early in the war until air and naval pressure forced them more or less stock in port. However I don’t see it to be technically feasible to build something that have both great speed to cover large area, hunt down many merchant ships( speed does matter even if you just hide in water in day, merchants will scatter and run, and since you are likely firing from close to max range, you will need good speed to catch a good number of ships), and enough heavy fire power to effectively sink many merchants. (Guns really aren’t good at sinking merchants, using radar that’s unreliable early war, at night time does not help.) For example convoy HX84 was quite disastrous but in the end only 5 ships are lost. The fact that the submersible cruiser can’t get close( or risk being seriously compromised by luck hits), and that it is likely slow means it is probably going to seriously compromise it’s ability to deter shipping. The engineering difficulty will also mean this will be a very ineffective weapon. Will this work? I think if the ship can be build to your requirements and given japan’s poor asw. Probably yes.Will it be better to simply invest in more conventional subs? Honestly, seeing how it’s highly unlikely for this ship to move with any speed underwater, it can be hunted down by extensive search with small surface vessel with sonar in conjunction with landbased aircraft( granted japan don’t build nearly as enough asw escort ships like British or UK, but this is something that they can, and probably will do as opposed to diverting capitalships)
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Post by oldpop2000 on Nov 30, 2018 13:14:00 GMT -6
Why do you think that the Japanese would divert more sea traffic and devote more heavy cruisers to a submarine making attacks in the East China Sea then a heavy cruiser covering ten times as much ground and probably firing shells into the harbors at Shanghai, Port Arthur, etc? Because disrupting sea traffic and diverting warships are the point, not sinking merchant ships. Hence the 8 inch guns instead of 6 inch guns. 6 inch says a light cruiser slipped through. 8 inch says a heavy cruiser slipped through. you are only going to divert significant amount of warship if there is significant risk to leave you alone. As others have said, heavy surface raiders are not sinking much to begin with. Given the comparative little effort japan did to asw despite the losses they take, I am not sure they’d necessarily divert anything. If this submersible cruiser can behave as effectively a heavy cruiser that can submerge, as you envisioned, then leaving it alone can have drastic consequences. E.g German heavy surface raiders have sunk convoys early in the war until air and naval pressure forced them more or less stock in port. However I don’t see it to be technically feasible to build something that have both great speed to cover large area, hunt down many merchant ships( speed does matter even if you just hide in water in day, merchants will scatter and run, and since you are likely firing from close to max range, you will need good speed to catch a good number of ships), and enough heavy fire power to effectively sink many merchants. (Guns really aren’t good at sinking merchants, using radar that’s unreliable early war, at night time does not help.) For example convoy HX84 was quite disastrous but in the end only 5 ships are lost. The fact that the submersible cruiser can’t get close( or risk being seriously compromised by luck hits), and that it is likely slow means it is probably going to seriously compromise it’s ability to deter shipping. The engineering difficulty will also mean this will be a very ineffective weapon. Will this work? I think if the ship can be build to your requirements and given japan’s poor asw. Probably yes.Will it be better to simply invest in more conventional subs? Honestly, seeing how it’s highly unlikely for this ship to move with any speed underwater, it can be hunted down by extensive search with small surface vessel with sonar in conjunction with landbased aircraft( granted japan don’t build nearly as enough asw escort ships like British or UK, but this is something that they can, and probably will do as opposed to diverting capitalships) I am in complete agreement. Almost all the data and historical article I have read have agree with our conclusions.
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Post by rob06waves2018 on Nov 30, 2018 14:03:02 GMT -6
Perhaps the best idea for a raider would be as it was historically. The Graf Spree could outrun anything heavier and beat anything lighter. However, she was hindered by lack of knowledge about enemy task groups. The best raider might be a hybrid carrier-heavy cruiser with large guns and the latest possible radar and fire control.
In RTW 1, I experimented with small (20,000t) battlecruisers (30knts) with 2 or 4 16 inch guns. These were cheap and could out-range any large light task groups and out-run heavier vessels. Their weaknesses lay in not knowing where the enemy was and sailing head-first into a battle division. When put on raider status, they were practically invincible.
A heavy-cruiser of similar design, albeit with smaller guns (maybe 4 12"), a formidable AA battery and a carrier wing of perhaps 6 planes (4 fighters, 2 torpedos) might be able to see anything before it's too late.
On the subject of submersible cruisers, they were never terribly efficient and, in practice, leaked. They were large, clumsy and failed to have a great impact compared to faster and better armed surface raiders.
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