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Post by Avatar on Jun 3, 2024 14:16:37 GMT
Okay, a subject near and dear to me! 1. It is not just the torpedoes that have to be fixed. It is the users. If the Japanese have trouble with freighter killing, then forget not that the USN has a lot of submariners who have to unlearn the pure warship-hunter doctrine, too. Fleet problems have also taught American submariners to fear the airplane too much. They dive at the first alarm of enemy aircraft, when they are in the middle of an attack. 2. It should be noted, that other companies were interested in torpedoes besides Bliss. I would like to see Bliss have some competitors like General Electric and Westinghouse. And I would like to see the dratted EL1 (The electric torpedo brainchild of the luckless Ralph Christie.), actually make it into operation and evaluation, op-eval, so that the Germans are not the only ones with electric torpedoes. You might also want to look at the NAVOL torpedo. If that was true for freighter convoys, then imagine how tough it was/will be to work inside the Japanese warship fleet screens in the later war years.
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Post by Avatar on Jun 3, 2024 14:18:44 GMT
Is it feasible to have sound homing and wire guided torpedoes with pre-WWII war technology? ========================================================================== Not until 1935: The proper Pz crystal transducers don't exist in the US tech tree yet. ========================================================================== Goat Island and congressional interference? ========================================================================== Someone from the machine tool industry (preferably Chicago Tool and Die or FORD) had better be contracted to take over Goat Island and run it, because those watchmakers and civil service types of the RTL are not going to automate the assembly line. =========================================================================== You better hope your development program can eliminate the "sine wave" depth keeping typical of the Bliss-Leavitt/USN designs; if Howells could run at a constant depth in the 1870s... =========================================================================== Howell torpedoes used a massive flywheel and the gyro's angular conservation principle. The best depth control for a torpedo of that WWII era is nose or midbody spin control by Bernouli effect, not tail steer vanes set by hydrostatic valve and pendulum limiter. It will be a weird looking US fish.
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Post by Avatar on Jun 3, 2024 15:00:27 GMT
The historical changes I expect. ======================================================================= Oddly enough, I believe the first year of the war, runs according to script, more or less, as the Japanese intend, with only the Battle of Midway being significantly different. It is possible that Shokaku could go down at Coral Sea if the bombs work better and the Philippine defense put up by the US subs at Lingayen Gulf might actually amount to something, but there are a lot of other critically wrong things that need fixing in the evil time of 1942-1944 from pre-war faulty doctrine to such basic mechanical factors as getting decent small arms and basic personal items to the troops. These things will take a couple of years. Some things may never get fixed as they were not in the RTL; such as a decent machine gun or decent uniforms for the sailors and soldiers that can take the beating of the climates. How about malaria for example? The Japanese had a solution. The Americans were still stuck in the 19th century with such tropical diseases. US ordnance needs a lot of work from things like the basic bayonet and grenade all the way to artillery shells. Ye-old-helmet was a problem. Or how about incompetent army officers who do not understand that you cannot waste time in planning set piece assault fighting against the Japanese. The sooner you attack off the beach, the sooner the Japanese artillery stops killing your men. There are bullheaded admirals who have not figured out that sometimes it is better not to charge into a carrier battle against the Japanese without proper recon. (Halsey does this constantly and it costs the US Navy. And while it is bad enough to be clobbered by the Japanese but clobbered by typhoons, too?). Subs can bring a naval siege on sooner, and whittle the naval odds down in the middle period, but it will still take at least three years of island hopping to get within bombing range. That is not going to change much. ========================================================================== In the real history, the British and the Germans had gone through their torpedo crises by 1941 and were either court-martialing people or fixing their fish by 7 December 1941. The US may have been aware of these foreign problems or not (accounts conflict) that early, but the British sure as heck were and did not warn the Americans to check their own fish for mechanical and quality control faults. And this should have been the case because the British would have received defective US torpedoes (Mark VIIIs used on the Clemsons and the Wickes) that came with the Lend Leased four stackers in the base swap deal. ========================================================================== USN submarine tactics were outmoded. The submarine doctrine (both strategic and tactical) at the start of the war (IOTL), well... sucked. That is absolutely correct. Having a torpedo that works won't change that. Crappy doctrine and tactics were the result of pre-war exercises that emphasized caution above all else, and that were skewed to preserve the concept of the battleship being the center of the fleet. The old-timer "Gun Club" admirals were smart enough to realize the potential of the submarine to make their magnificent battleships obsolete. Exercise rules were sometimes intentionally manipulated to demonstrate the vulnerability of the submarine and the invulnerability of the battle line, sometimes to a ridiculous extent. Violating the rules during the exercise was cause for a career ending reprimand. In addition, a series of accidents during the 1920's (S-5, S-51, S-4, O-5, S-48, etc.) and the bad press they gathered gave the Navy a severe PR headache and safety and caution became official policies. All of this created an artificial environment that squelched initiative, creative thinking, and daring, all qualities that were later shown to be vital to a successful war patrol. ========================================================================== The realities of war hit many American sub skippers. Psychologically they could not adapt. many folded under the pressure of the reality. Many captains were relieved. There was no time to retrain the leadership. On the job training, OJT, results were what mattered to those who were at the top. Unfair as it was and is, that is just how democracies operate; om demonstrated merit in crisis connditions. ========================================================================== Overconfident Germans were the victims of the opposite effect. The morale crunch for them comes in 1943. That is how totalitarians operate and why they fail. ========================================================================== The Mark 13 torpedo fails to deliver. Once again, the US became instantly aware that something funny was going on with this iteration. This will happen at Pearl Harbor when Japanese aerial torpedoes are dropped higher and from planes operating at faster speeds than a Devastator. The Type 95 torpedoes ran shallower than US ones. Somebody noticed but did not either want to find out why or did not follow up. As late as Coral Sea the "crappy" Mark 13 seemed to do its work well (Shoho ate a bunch of them that exploded nicely. All of those fish were made by Bliss, by the way, who designed the fish.). Even at Midway, where the torprons were slaughtered enough fish hit, that Japanese sailors fished out of the water afterwards reported to their American interrogators that torpedoes did hit carriers (Kaga), but they failed to function. "Our torpedoes work good; but yours don't." I believe one survivor bragged. =========================================================================== How will the Japanese react to alternative conditions when they discover US torpedoes work in an alternate history? Not much differently than they did in the real history, will they react. They could not devote rersources, prewar, to build both a battlefleet and an antisubmarine warfare defense to defend their merchant marine. So, they will allot too little, too late as they historically did. =========================================================================== TechnologicaL variations on the themes, that lie outside historical patterns and limits of what was known, can be stretched a little bit. Electric torpedoes and the dratted hydrogen peroxide torpedo did enter service, after all! Some comments about the noise flow problem with acoustic torpedoes is interesting. The USN developed FIDO to kill U-boats in one of those WW II "wonder programs" that keeps me scratching my head and wondering why we cannot do that now? Nine months from concept November 1941 to opeval and then 17 months to first U-boat kill (May 1943). FIDO was modified into a submarine swim out weapon (CUTIE) to engage charging Japanese destroyers. As to whether wire-guidance is possible, that is a good question. Probably not in WW II though the US tried. As to an acoustic seeking heavyweight torpedo, the answer is definitely yes. There was nothing in the G7e/T4 Falke or the G7es Zaunkonig's seekers that was unique or difficult for HUSL or General Electric to master, duplicate or frankly surpass. This will culminate in the Mark 35 torpedo and later the Mark 37. Both of those fish started their lives in the war emergency programs the USN started to rectify the torpedo disaster they had on their hands. How large was that crisis program? Mods to the Mark 13, 14, and 15 were rolling out almost monthly after January 1943. King was personally involved by then; which meant Leavenworth and careers ended for non-performer people who did not hustle to fix things. Lockwood was at the operational end applying pressure. Even E. W. Bliss, the company, was called in to look at the Navy built Mark 13s after the Midway and Solomon Islands disasters. The Naval Torpedo Station monopoly of Goat Island was forever ended as Westinghouse, General Electric and others got into the torpedo business. At one time, there were a dozen different torpedoes under panic development: five of them acoustic seekers, seven electric, one using a seawater battery, and one with a kind of primitive binary kerosene/oxidizer precursor to Otto fuel. This activity of the RTL actually makes it hard to ASB the American torpedo effort, because even wire guidance (Mark 39 a failed first effort) comes out of these WW II program.
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Post by Avatar on Jun 3, 2024 17:44:00 GMT
Getting the hydrostatic valve depth control wrong. US torpedoes had not only placement issues with their hydrostatic depth keeper, (The Uhlan device.), but it carried from WWI torpedoes forward. Why was that so? Best guess? The hydrostatic flow valve that operated as the pressure sensor for depth setting was placed in the wrong position along the torpedo shell-body. Thus, the pressure dropped in the diaphragm unexpectedly due to flow turbulence, especially in the Marks 13, 14 and 15. If the fish had been tank tested into nets or allowed to sandshark into a known beach shelf slope, this problem would have been instantly recognized. War is the wrong time to find this stuff out. As for the Mark III exploder; there seems to have been a defect with the safing mechanism. Anyway, it still worked far better than the firing pin and guide cage on the Mark VI. A case of keep-it-simple-Simon, KISS, sure would have helped here. =========================================================================== Circular runs were a fault, especially in the Mark 14 submarine torpedo. I really do not know why, unless the 20 foot 6 inch size constriction limit meant that the anti-circular run feature had to go to make way for other “more important” items inside the shell? US submarine torpedoes were the smallest among the great powers. I do not understand this self-imposed size limit, either. =========================================================================== Was it just the Mark 14 torpedo which had the defects to be corrected before WWII? The Mark 15 had the horrible Mark 6 exploder/Mark 5 magnetic influence assembly, which failed in the Mark 14. It, also, ran deep. The Mark 13, in its case, was a fragile fat fish that either broke up if it hit the water too hard or twisted off bearing as its gyro tumbled on water impact. Somebody forgot to design it like a retarded fall bomb. The quick, dirty fix essentially duplicates what modifications the Japanese did to the Type 91 used at Pearl Harbor to make their torpedoes work there. The Americans added a wooden drogue nose ring shock absorber to the Mark 13 torpedo to act as a cushion to mitigate impact and to prevent the fish from broaching sideways upon water entry. The tail assembly was essentially the other half of the breakaway kit. It aimed the fish for proper nose first entry at water impact, slowed its fall as a volute, and guided its water entry into a shallow plunge so it could be used to hit ships in sheltered anchorages. It was successfully demonstrated at Truk. I suspect that this “dirty fix”, would be more important than anything else one could do to the Mark 13 pre-war to make it effective. The Mark 13 torpedo used a contact version of the Mark VI exploder assembly (Mark 5?) without the influence feature, and at least in the Mark 13 torpedo made by Bliss it worked. The Goat Island versions, of course, clanged on metal. So… two minor departure points; make the drogue kits immediately after the US conveniently “captures” a Type 91 that sandsharks intact at Pearl Harbor, and make sure that Bliss makes all the Mark 13 torpedoes. That alone guarantees Kaga is Waldron and or Lindsay killed and allows McClusky to allocate those dive bombers who got her to clobber Hiryu instead. So much went wrong at Midway… =========================================================================== Torpedo manual for the Mark 14 and Mark 23 torpedoes as revised March 1945. =========================================================================== Circular runs were an issue. a. The Mark 18 ( manual) has a known design fault. b. Anecdotes about circular runs. That one about USS Grunion is rather startling. I suppose the best cure for a circular run torpedo is a subordinated 2-d bang/bang guidance logic that kicks in after a clock limited caged mechanical governor unlocks the tail control. This is a relatively “modern” safety feature that became necessary once subs started using CUTIES. It is essentially a steering safety that is a little more complicated than the run arming safeties used in American fish to make sure the fish did not run hot until clear of the tube. Needless to say, both the Americans and the Russians have had hot fish in the tube incidents with catastrophic results (Kursk). ============================================================================. Erratic runs were more common than circular runs. HMAS Canberra may have been a recipient of such an erratic run Mark 15 torpedo, the USS Bagley intended for the IJNS Chokai. ============================================================================ How common were circular runs? The only evidence we have that I find convincing is testimony from survivor (Japanese), eyewitnesses about American torpedoes cutting circles in the water as seen from their ships. I have seen nothing in the test and revalidation programs where the USN experimentally verified that the circular run was a problem for the Mark 14 torpedo. However, such gyro compartment flooding and electrical shorts were known to be a Mark 18 torpedo defect when that fish was issued. The Mark 18 steer control design was based in the main off the Mark 14. Make of that what you will. In any event, if we are going to alternate timeline, ATL, fix this issue, then the USN, when it captures a U-boat, will have access to FaT T1 or T3 torpedoes to reverse engineer the feature. The trouble is, that event happens for real in 1944. So, the gyro guidance difficulty will remain unless the USN goes all acoustic seeker and uses 2-d bang/bang command steer in every fish it uses. And THAT means the circular run issue for the electric motor driven fish remains until the Mark 28 in 1944. I am not happy about that fact for this ATL. The Mark 28 was a roller with a huge nose wander problem, as an added issue, for that torpedo. ============================================================================== How many boats were hit by their own fish? Four boats or possibly five boats sunk by own weapon? Why in Murphy's name was that torpedo (N0. 24210), not beached, sent to a machine shop and torn apart by ordnance to find out what caused the erratic run? If the fish was erratic in an exercise shot, with the crew who prepped the fish not being responsible for the fish's malfunction (To be determined, TBD, by the ordnance people and USS Tench's officers.), and recovered, it is evidence of a mechanical fault that needs investigation. It would be a verified sample of a batch run that would need to be further pulled and inspected. From Blair Silent Victory; the Mark 18 torpedo's problem with it is less serious, than with the Mark 14 torpedo, not more--but that may be on sheer numbers. Note the Mark 14 3As and the Mark 23s? Add to the cases, the known troublesome Mark 18s and that leaky inspection and access plate to the gyro compartment, it becomes a rather damning indictment, in my estimation. (See below.). If 5 US boats were killed as a result of erratic or “circular runs” of their own weapons, that is a ~ 10% kill factor and 440 trained, skilled submariners lost to the imbecility of the people at Goat Island. This is the stuff of court-martials and review boards to fix blame. Was it Blandy who ultimately failed here? I would not be surprised. It should be mentioned that this erratic run problem was only one of about a dozen problems with the torpedoes. Perhaps, spending the US navy's athletics budget of the 1930s on weapon testing might or could have saved a lot of grief, but I still suspect that somehow the same difficulties or similar ones would have confounded the operational forces. The leadership of the 1930s USN was not all the perfection that the popular histories of WW II make it out to be. There were a host of dud officers in that service. In the end, if the torpedo scandal is to be avoided, there has to be a drastic culture shift in the United States Navy to go with the mechanical fixes we enumerated above.
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Post by Avatar on Jun 4, 2024 22:19:26 GMT
I used to make a villain out of the luckless Ralph Christie. I was very much guilty of such 20/20 hubris. He had a hard time with the magnetic influence feature (Mark 5 component of the Mark 6 exploder.). And it is not as if the USN did not try to anticipate some issues with their new magnetic influenced exploder. That same man who would stubbornly insist on his sub crews using the magnetic influence feature when he commanded Southwest Pacific submarines had the foresight (In 1933?) to insist the USN conduct live testing of the feature aboard the USS Indianapolis. These were 100 exercise torpedo shots he supervised to calibrate the magnetic influence feature, with about 7000 readings taken. It is roughly akin to attempting to compile a ballistics table for a new gun. Conducted at the equator between 10 degrees north and south latitude, it was probably the most comprehensive testing of such a feature conducted by any navy in that era. Christie came away from the tests with the firm hunch that a tuner (rheostat) needed to be incorporated into the Mark 5 magnetic influence exploder to set to local conditions. He was overruled by his superiors, who looked at the same results (Mostly successful along the equatorial route with little variation in the influence feature's function.). They were convinced, that the discovered variations in the Earth's magnetic field in the area tested, were too insignificant to merit such a costly and time delaying modification. I do not know what made Christie so stubborn and different in opinion about what he suspected at the time, later during the war. Maybe there was the war on, and he knew he did not have the time or resources to map the Earth's magnetic field, or install a rheostat circuit as was done postwar. The navy finally had the time, admiralty wisdom (bloody price paid), and incentive to fix their last mistake. Whatever his inexplicable reason was, this was the main folly that damns him in some quarters. I do not criticize him now, because I knew he at least tried. Blair, Clay, Jr. (1975), Silent Victory, Philadelphia: Lippincott, ISBN 0-553-01050-6 pp 61-62. =============================================================================== The hubris of the Goat Island torpedo developers; their failure to test… If you qualify that statement with the proviso, that in their arrogance they thought they had already tested for everything (see above.); sure. The height of folly is to ignore persistent complaints that cover the same basic points. If over forty submarine captains complain that their torpedoes do strange things when the fish leave the tubes during the first two months of the war, then someone had better take a look at: a. prepping procedures. b. crew training across the force. c. the torpedoes. The last thing a supremely confident man (and you have to be one to stand watch or command at sea), wants to admit, is that he goofed. And the last one a skilled craftsman or engineer wants to admit, is that the machine he built or designed is a piece of junk. This is what the Mark XIV and its brethren are to the people responsible for its make, validation, and issue. An indictment that THEY are no good. It might have been a beautiful Swiss watch on the bench when it is tested at Goat Island. When it reached the fleet and the end users, it is like most GM cars that I've ever test driven for real use. Junk. And what makes it embarrassing historically is that by May 1942, the USN knew how frighteningly effective Japanese torpedoes were. (I may have something to contribute about how this was an intelligence bolo for the USN in the Solomon Islands, as several of our admirals seemed to forget that the Japanese had those long runner Type 93s). So, double the embarrassment; the Japanese could plainly do what Americans could not; make an effective, deadly and clearly technologically superior weapon. Postwar, the dud history, the guidance (nose wander issues), and other (explosive) problems the Japanese had with their oxygen-boosted Type 93 and Type 95 torpedoes would become known. During the war, however, all the USN recipients of these weapons saw was sunk US cruisers from a weapon that had twice the range of a Mark 15 and which seemed to always work. That hubris that leads to such errors, is not simple to overcome, because frankly that kind of humility and caution in combat leaders which would catch and correct mistakes such as the torpedo crisis entails, does not win wars. Not everyone can find the proper balance to be a Fletcher, Spruance or a Nimitz or a Lockwood. You wind up with Merritt, Connelly, and the Bull. You certainly need these guys because they can lead, but they come with their blind spots, and their built-in disasters that have to be borne as the price of their admiralty. It turns out that Christie was one of those kinds of officers. But not Admiral Blandy; that gentleman knew better. He did nothing when it mattered. He should have been held accountable for it at the time. =========================================================================== The 16th Naval District was a dumping ground for dud naval officers in the USN. That unfortunately was also the Philippine Islands, which would be the first theater of war, where the USN and the IJN would meet in battle. While the history of the 16th Naval District as a dumping ground for dud naval staff officers is accurate, I remark that these same duds actually present in and around Manila at the time of 7 December. They stepped up and performed rather better than their army compatriots (Remember, MacArthur, Brereton and Sutherland and the disaster of Clark air base?) once the shooting started. And it must be remarked, that Pearl Harbor, the 14th Naval District, also left a great deal to be desired as to leadership, projects undertaken and general naval efficiency at about that same time. One can only go so far in isolating the human factors present. Goofballs there were aplenty everywhere. Ghormley and Pye are not at Manila in the weeks that follow. Guess where they were screwing up? They had some negative effects during the confusing weeks while the US Pacific command dislocation was repaired. Thomas Hart and his crew actually come off rather well, given what they had to work with and with whom they had to cooperate. ABDA and the Dutch, Arthur Percival and his lot, Sir Tom Phillips and the RN in its entirety, Sir Conway Pulford, and after he died of malaria, Sir Paul Copeland Maltby (a real winner for the RAF Far East) were further goofs. The British colonial administration in general in Malaysia, etc., make the American Pacific Command shambles look brilliant by comparison. Furthermore, if we want to discuss infuriating, incomprehensible, bollixed-up, inefficient, misbegotten almost Japanese like American snafus, can I recommend the inter-service shenanigans of the Alaska Defense Command? That amorphous nightmare, was jointly shared by the irascible Admiral Robert A. Theobald and the equally does-not-play-well-with-others and somewhat inept General Simon Bolivar Buckner. Theobald's reporting HQ was the 14th Naval District at Pearl, while Buckner's immediate higher HQ was located at the Western Defense Command at the Presidio in San Francisco. During the Battle of Midway, the combination was so deleterious that the only reason the Japanese did not take all the Aleutians was because they fielded an opposing team of commanders (Hosagaya, Kakuta, Akiyama, and Yamasaki) who were even more inept. What I am trying to illustrate is how complex the jigsaw puzzle is, how vast, in time and space, the distribution of military actions is. And how befuddling little things like malaria (Maybe MacArthur?), mental illness (Pye) and dental disease (Ghormley) can affect outcomes in war. And let us not forget the politicians. They did not help matters on either side. And by politicians I include Admiral O'Richardson and his Japanese counterpart Isoruku Yamamoto. There is no easy hardware fix, or administrative remedial action when fallible human beings become involved. ========================================================================= Own subs sunk by own torpedoes, again. I used five (5) because that is the number that can be probably confirmed by the Japanese or American survivors. To show how good American reporting on this can be, I cite the USS Dorado, lost off Panama to mines about October 1943, laid by U-214. That is incredibly precise reportage by the silent service of a navy that didn't even know where a whole desron was during the Battle of Leyte Gulf. (Surigao Strait was confusing.) ========================================================================= Why wasn't torpedo 24210 (USS Tench mentioned earlier.) pulled and inspected? That fish was sabotaged! There IS an actual paper trail that he, Blair, found to prove it, (Silent Victory cited previously.), there should have been a prosecution, even at that late date, when he discovered it. Sabotage is hard to prove. Falsification of documentation, though, after the fact, is not. ========================================================================= Torpedoes defective versus torpedoes fired as total: what data? Someone did that work for us.========================================================================= Prosecuting Blandy? Blandy sat on his duff as a rear area Washington admiral, during the torpedo crisis, not really under combat pressure until 1943, (took command of an amphibious force and managed it reasonably well.) and was in a sinecure [BuOrd 1941-1943] where he could afford to take a cautious risk to check things here and there. It was not just torpedoes he screwed up during the war-time operational emergency while he was BuOrd: there were problems with naval artillery that can be laid at his feet. Yet, even he can get a pass for some of the good things he did while he sat there, (proximity fuse). This game-player was involved in Operation Crossroads and demonstrated to the public, the same careless attitude toward concerns about what he was doing with atomic bombs that probably shows the character defect underlayment for the Mark 14 and Mark 18 debacles he aggravated, during his watch. He was not called "the Atomic Playboy" for nothing. Of course he was right on the physics, he cited, but he was wrong about the concerns (FALLOUT) expressed about the tests he supervised. In other words he was incompetent to notice the problem's nature in front of him and would not brook criticism or advice from people who did . ============================================================== I've made my current opinion clear about Christie. He made mistakes not involving the Mark XIV, while he was Southwest Pacific Submarines for which he can be second guessed, like the awarding of medals to crews that could have tipped off Magic and Ultra to the Japanese, and his failure to play well with Thomas Kinkaid and Uncle Chuck (Lockwood) which is incredible considering that those guys were rather easy-going. And then there is the Dealey affair, (Kinkaid's nephew went down with the USS Harder, too) with the medals again, the damned telegram about Kinkaid and his chummy relationship with MacArthur that did not sit well with the USN. He had to go. Not because he was a poor operational commander, but because he did not understand how to play the game within the war that is service politics. Basically he torqued off the wrong people. Fife, his replacement, was an utter disaster as an operator. Postwar, when Sublant came up, guess who got that flag? Fife could play the politics game. =========================================================================== Fixing these problems, both human and mechanical? Tough to do. Admiral Blandy and Admiral Fife are prime examples of why that would be so.
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Post by Avatar on Jun 4, 2024 23:03:15 GMT
=========================================================================== Why did it not occur to USN strategists to go after oil tankers immediately? JANAC.Despite the subsequent revisionist historians attempts to 'adjust" the Joint Army Navy Assessment Commission reports, the findings have remarkably held up. One can track the losses, month by month. The tanker targets stand out from the data sets early. Doenitz. Here is the need for revision: especially his post morte bellum assessments and his glossing over of the KMs problems of which he was a major cause, and the stubborn refractious facts he ignores is evident. He was a man who did not play well with others. He was a delegator to be sure, but was he an efficient one? He liked to micromanage.
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Post by Avatar on Jun 4, 2024 23:15:38 GMT
"When you detect a U-boat signal near a convoy, you need not be Alan Turing to guess what it is about. You do not really need to read a message's content to know you should reroute the convoy away from it. Why was the radio intelligence available so poorly used? ========================================================================== This happened late real timeline, RTL, but the flying weather into the North Atlantic was and is horrible at the medium and low altitudes where the Long range maritime patrol, LRMP, aircraft then and now operate. The North Atlantic flying weather is horrible in northern latitudes anyway, but off Newfoundland and Southern Greenland it can be exceptionally terrible. Losses in the mid-Atlantic were RTL high due to flying accidents in that weather. It also futzed the radio spectrum. =========================================================================== Think big in the timeline as the Butterflies Flap? For example: Go beyond the USS Nautilus hitting IJNS Kaga. Almost 90% of that account was honest wishful thinking. ========================================================================== Settle for IJNS Kaga and be happy. That result alone saves Hammann and Yorktown. IJNS Hiryu only acts because she was not one of the carriers dedecked in the massed dive bomber bounce that got Kaga, Soryu, and Akagi. If one wants to be greedy, alien space bat, ASB, the Mark 14 torpedoes as acoustic seekers homing in on prop noise and have Akagi and Kaga have their propellers blown off and rudders mangled. That is how FIDO worked against subs and how CUTIE was supposed to hit destroyers. Rudder chasers homing in on prop noise. ========================================================================== Bring Iceland into the war earlier? Close the mid-Atlantic air gap? Oh, yes. That is a doable (ASB, maybe, but far more doable than some of the nutty ideas that rattle around in my overactive imagination (See what I wrote about screw noise chasing homing anti-ship torpedoes above?), and or such ideas as the Mark 1e (Mark 20) electric torpedoes being ready by 1935.); for it is an executable idea that would relieve Atlantic convoy escort forces pressure in the Western Approaches and could release (British?) resources for Pacific or Mediterranean action. Is a reverse Norway possible? It RTL happened to Iceland. The Icelanders were not exactly originally happy to receive British or American occupation or be thrust so prominently into the Battle of the Atlantic. I imagine the Irish Republic would be equally un-thrilled; but somewhat acquiescent as long as it was Americans and not the Black and Tans. =========================================================================== As nutty as Ireland becomes, as a sidebar, in the discussion about better American torpedoes: Ireland does bear on the question of US aircraft delivered antisubmarine torpedo weapons in the North Atlantic antisubmarine war, AST/ASW, efforts the Americans will launch from the Western Approaches, later when the British screw up the Second Battle of the Atlantic. America's failure to secure host nation basing rights in the Irish Free State, can be seen as bearing directly on the Germans' ability to operate in the Eastern Atlantic approaches to Europe. =========================================================================== The Americans will get no Guiness? I guess there will be no Guiness for Americans after all. =========================================================================== If by some alien apece bat, ASB, miracle de Valera could get over his personal hatred of Franklin Delano Roosevelt, FDR, then it might be possible to get more cooperation out of the Irish Free State. If that could be managed, then there is a further hurdle. Might I suggest the New York and Massachusetts National Guard units?Here. and here. I would be cautious about regular army and Marine units of the WW II era until leavened with drafted conscripts and volunteers.
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Post by Avatar on Jun 5, 2024 13:06:42 GMT
Technical features involving aircraft versus submarine interactions? The feature here; is weather effects and naval shoreline geography where aircraft and submarines fought each other. RAF pilots / crews grew up, and trained, in relatively benign metropolitan / European weather, whereas Canadians were more from the frontier / crappy weather, therefore didn't have as much trouble with the North Atlantic weather, as it's similar to the northern latitudes of the Canadian Tundra.========================================================================= I think exposure might be part of it, tho I doubt most RCAF fliers had much. (There would not generally have been bush pilots prewar; there simply were not enough of those to account for it.) In my opinion, IMO, it is more a matter of attitude: Canadians, like Americans and Australians (to varying degrees), were "wilder" than the British, less inclined to obey strict discipline and more willing to accept risks.
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I include Australia, (Oz), as frontiersmen based solely on remarks I have come across which put their infantry in a "wilder" class than the British, also occupied by U.S. and Oz.--but it fits: our ancestors all were pioneers, unafraid of the hazard of leaving home (or getting sent away as lawless yobbos. Not to cast aspersions, mind). It carried on.
How, exactly, that gets translated into a national culture, I do not know, IDK; but it makes sense to me.
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Post by Avatar on Jun 5, 2024 13:26:42 GMT
The subject of Thomas Hart and the US submarines in the Philippine Islands? One of the key features of US submarine performance in the Philippine Islands context is that a combination of Admiral Thomas Hart, navy-army politics, the bollixed command structure, pre-war military doctrine, all combined to produce poor results. =========================================================================== A comparison with Dutch doctrine in the Netherlands Dutch East Indies, DEI, or Indonesia, is instructive. The RNLN submarine arm was supposed to save the Dutch East Indies by ambushing and destroying a Japanese invasion fleet, and accordingly developed wolf pack tactics in the '20s and '30s. Is it possible for the US to see the submarine arm as a way to buy time for the Philippines when war plan Orange is abandoned? I cannot see the Americans using their subs in the same suicidal attack runs the Dutch submarines were supposed to make in the inter-bellum period. But they could be tasked to aggressively attack Japanese supply convoys to the Philippine Islands after the initial invasion, trying to help the defense to buy as much time as possible. The problem is that Admiral Thomas C. Hart had to answer to General Douglas MacArthur. Another issue with the situation was that the commander of the American submarines in the Philippine Islands, was incompetent and unfit to lead a manure shoveling detail. Idiots, like Commander, later admiral, John E. Wilkes, did not help matters at all. Looking at how the Dutch would have handled it? It seems to me that the theory in place was the use of submarines in a few lines to act as 'smart minefields' to take a few shots at the invasion fleet passing by if they were lucky enough. Even with preparations being adequate instead of neglected, that might not be the best approach, especially as it seems that it doesn't yield the right effect on doctrine and training as per OTL. For that to happen, you need the same geographical advantages as the DEI has. Furthermore, the Philippine Islands will never make the USN go all kamikaze like the DEI made the RNLN.
What I am proposing is that the US submarine force focuses on attacking Japanese resupply convoys in groups after the invasion force has made its landing. Those convoys will be less well protected. Powerful attacks might draw more escorts, but that weakens the Japanese fleet that is supposed to fight the USN.
This gives the US submarine arm a reason to change its doctrine and might get support for it from the Gun-lobby.==================================================== There are problems with the Dutch approach as laid out above: 1. Geography. See Maps. --the main points to see; are that the Japanese come at the Philippine Islands for one main objective, to neutralize American presence and control. Luzon. Their p[position in Taiwan and in Southeast Asia has already ceded air superiority in the South China Sea. The north to south Japanese attack vectors cannot be flanked by any submarine blocking force, with the era's technical limitations on those ;launch platforms and their support systems. The shoreline conformations allow no establishment of patrol lines such as the North Atlantic shorelines offer the Germans. 2. Command limitations. -- The theory in place was to use submarines for coastal defense. That was the assigned task after Japan attacked. The problem was, Com Asiatic Fleet (Hart) and Commander Submarines Asiatic fleet (Wilkes) misallocated dispositions. There were no boats off Japanese ports in Formosa, one lousy Sugar boat was assigned off Lingayen Gulf, where the invasion was allegedly expected. No-one had a real plan for sea defense. Nobody had laid defensive minefields to plug approach routes. Asiatic Fleet subs were then screwed further by the loss of Brereton's B-17s in the Clark Airfield disaster, which had been intended to provide air reconnaissance cooperation.Like it or not, in addition, Hart was under the orders of MacArthur, who wanted no aggressive moves by U, S. Forces to give the Japanese an excuse. This included minimal United States Army Air Corps, USAAC, and USN reconnaissance, over Taiwan. Defensive coastal mining was 100% under the control of the Army, who almost exclusively focused on Manila Bay, excluding other possible invasion beaches, especially Subic Bay which controlled the left flank of Bataan. Furthermore, Hart had no naval minelayers attached to the Asiatic Fleet.— 3. Material results caused by Wilkes failure to disperse and safeguard his inventory of weapons? Thomas Hart knew the surface forces of the Asiatic Fleet had to move south, but hoped to use his submarine forces to fight a delaying action. Hart had been assured by MacArthur that the USAAC could protect the facilities at Cavite, something that came to bite him. On the third day of the war, with the total devastation of Cavite, and the loss of over half the fleet's stock of torpedoes. One thing, I have never found; was a breakdown of torpedo types which survived the air raid.Of the torpedo stocks lost at Cavite, about 230 submarine torpedoes were erased from the national war reserve. How many of these were Mark 9, and Mark 10 torpedoes is not documented. It is presumed by most American historians, that the torpedoes destroyed, were Mark 14 torpedoes. If that presumption was the case, then the war reserve for the Asiatic Fleet modern submarines (Not S-boats which could only handle the Mark 9 and Mark 10 torpedoes.), was 2/3 gone. See photo. There are approximately 5 rows of roughly 20 torpedoes indicated in the photo above. These are the 100+ surviving torpedoes on-hand at the torpedo dump after the air raid of the 11 December 1941. If you run the numbers, then it appears that of the 23 fleet boats and 6 smaller S-boats, that we can generate the total torpedoes on hand as follows: 23 fleet boats x 24 war-shots aboard = 552 Mark 14 torpedoes. 06 S-boats…. X 12 war-shots aboard = 072 Mark 9 and Mark 10 torpedoes.Torpedoes stockpiled at Cavite* .......= 330? (230 destroyed in the air raid on Cavite of 11 December 1942 local time.)Totals in theater?................................824? 27% loss of local inventory. I have read that the loss was closer to 30% loss. Add the USS Sealion lost in that same Cavite raid. ========================================================================= 4. Think about the situation if mining had been able to keep the Subic Bay mostly clear of Japanese during the siege.
--Submarines could function as minelayers, but Washington has to send the mines for them to lay those mines. Since mining was the Army's job, "we" do not need to send Hart any mines. Hart was conditioned to being a gunnery expert, but he was also submarine qualified. I would need to do some rereading on the patrol limitations Hart had set pre-war for his submariners.
It would have been interesting to see what would happen if Hart's subs had laid mines in the first days of the war to defend the entrance to the Lingayan beaches, as well as the harbor entrances on Formosa.=========================================================================== In all of these calculations and situations, the center of gravity was Lingayan Gulf. =========================================================================== Coming back to Thomas Hart as related to the torpedoes: Thomas Hart has very little input to torpedo design and production actually. His chief contribution is in adopting and incorporating of lessons the Germans learned in WW I from surrendered U-boats into USN subs. Hallmarks such as the long and troubled development of the torpedo data computer for example and the Christmas tree system of dive control start with him. He also is one of the "sink freighters" iconoclasts in the US submarine community.
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Post by Avatar on Jun 8, 2024 0:26:57 GMT
Those Marvelous Tin Fish need a decent launch platform. ======================================================================== Those whacky Italians! (Note: Profound respect for the Italians.) Excellent technologists handicapped by some bum political leadership and unfortunate decisions by their professional industrial and political classes resulted in terrible misfortunes and outcomes. Anyway; the relations between Italy and America were fairly decent during the critical Hoover/Roosevelt period from 1928-1935. There is a point of departure there for GUPPY if anyone wants it. ======================================================================== Will the war be accelerated and shortened with better torpedoes? The US could possibly arrive in the Marianna Islands by March 1944 at the earliest. It takes time for the Americans to raise equip and train the divisions they need to wrest island strongholds from Japan. The only way to speed the collapse of Japan is to get into bombing range and until May 1944, there are not enough B-29s to even start the Lemay treatment. ======================================================================== By the way… just to give an idea of what these submariners were trying to do; The Germans The Americans The things you noticed immediately? The German boat looks horrible from a human factors engineering point of view. They crammed 56 men into a volume about the size of a two-bedroom house. They had to share that volume with two diesel engines, two electric motors, an air plant, and assorted accoutrements, including up to 15 metric tons of food and the means to cook it. The USS Silversides has about twice the useable volume for a crew of 60 men. Of course there was also twice everything to move a larger boat, that submerged, was about 3x the mass of a Type VII. And twice the torpedo load and almost twice the food, and much better living accommodations. Also: notice the care with which control systems are laid out? The Germans crammed controls anywhere and everywhere haphazardly. Their engine rooms were mechanical horrors that could maim a man who did not watch where he put an arm or foot. The Americans (just as cramped you'll notice), went out of their way to ensure that there were safety features built in, including encased diesel engines and safety caging for the electrical systems which you do not see on the German boat. The German boat interestingly has a better sonar (the famous GsG sheaved array.); but no radar and rather lousy radios. The arrangements for torpedoes aboard the German boat are actually a bit better than aboard the Silversides, with the German boat actually having craning arrangements and mechanical assist in the forward torpedo room. The Silversides relied on rack traying, a belay line pulley and heave come-along manual system to move the fish in to the tubes. The Germans could therefore reload their tubes much faster than the Americans with fewer men. They also, until 1944, had better methods to set guidance controls for their fish electrically, once the fish was in the tube. The Germans often complain that they were up against better ASW forces than the Americans ever faced. But a careful examination of the German's campaigns shows that the Allies did not really get tough on the Germans until the middle of 1943. Once that happened, it was the last two years of the war where it was suicide to be a U-boater and where German efforts fell to naught. Compare that to the Americans. The first eighteen months of the Pacific War see the Japanese ASW effort as being almost zilch. It is not until late 1943 that the Japanese really try to mount an ASW effort with convoys. By then the Americans have a halfway reliable torpedo and are about to have their banner year. Roughly speaking, the Japanese and Americans fight on a par with about the Germans and British of 1940-1941. The Japanese have superior Magnetic Anomaly Detectors, about the same quality of sonars and ASW weapons as the British; and the Americans have better code breaking, radar and a much better set of submarines and much worse torpedoes than the Germans. The results are interesting. More US submarine combat takes place in the shallow seas of East Asia around the Philippine Islands, Indonesia, and Japan. Japanese air cover is a more formidable threat and their escort vessels are not so present; much, as opposed to the Anglo-Canadian surface forces and paucity of air cover in the North Atlantic comparison period. German subs tended to have deep water in which to hide and could frolic more on the surface. Also, convoys were large fat targets. The Americans did have another advantage, the Germans did not. There was a blue water navy that applied ceaseless pressure on the Japanese Combined Fleet that disallowed diversion of needed resources to commerce defense. It could have well happened that if the USN was not able to apply such pressure, that the Japanese could have made the necessary investment in ASW. This would have kept pace with the USN submarines in the critical slaughter year of 1944 when the American submarine fleet went wild. For statistics on the WW II submarine war, may I recommend this?Never forget that like the Russians, who are the real cause of the German defeat in WW II, the German U-boat campaign was three times the size of the American submarine campaign. It lasted twice as long, and was in the end fought against a tougher ASW enemy than the IJN. But also never forget that the Americans started from the same deficits, fought an enemy who improved and in oceans where the defense was more geographically favored than the Germans ever did. =========================================================================== What are the metrics of the US World War II submarine campaign that we use as a baseline or “mean” in this alternate history? It is claimed that the American submarine force only sank 1392 ships in WWII. The Joint Army Navy Assessment Committee, JANAC. In this otherwise hilarious thread, there is a claim that 15,000 Japanese vessels of all types were sunk. My reasonable guess is that: is perhaps based on everything from a punt up to and including IJN vessels bombed or scuttled at pier-side just before the surrender, someone magically arrived at those numbers. That 15,000 would have to include every rowboat, fishing sampan and even dinghies the Japanese lost to whatever cause attributed. No way could the US submarine fleet have sunk that much shipping. Summary: That number of ships sunk (1392), includes Japanese warships; ~1200 freighters and ~200 IJN combatants. ============================================================================ Circular runs among American torpedoes? In case one is wondering about Mark XIV circular runs? Look at Page 79. Follow the linkages from the gyro/depth setter assembly to the rudder/planes pivot assemblies. There is a built-in jam feature right where the semicircular annul half ring crosses the upper rudder pivot point. What mechanically happens is that as the torpedo sine waves through the water and as the torpedo depth control joggles the tail planes up and down to keep the torpedo at proper depth, the annul bridge (that half circle metal ring) joggles back and forth. If the torpedo attempts to broach, that ring bangs forward into the upper rudder pivot, and if the upper rudder pivot (see the flanged edge?), is actuated left or right more than 30 degrees (hard to tell from the photo) it gets knocked hard over and it locks. An attempted gyro recovery is impossible because the gyro will waste its air charge trying to recover and then tumbles. So in addition to the hydraulic or electrical fails at the gyro compartment, we can now add mechanical rudder jam. The collars, added to the Mark XV torpedo, separated the two control assemblies with bang barrier ring assemblies that prevented this mechanical jamming from occurring. As far as I can tell, AFAICT, the reason the Mark 14 did not get the feature could be because it would make the torpedo too long to fit the submarine torpedo tube. If that reason is the case, (The urge to keep as much commonality between the Mark 14 torpedo and Mark 15 torpedo, but still keep the Mark 15 “short”: the designers knew this problem in 1930. They persisted with that fault clear into the postwar fixes.), then somebody really was potentially criminally negligent in the engineering sense. That tail control linkage setup is just awful. My opinion. ============================================================================ So… The Mark 15 torpedo received a rudder throw limiter. The Mark 14 torpedo did not receive an anti-circular run device. Why? I speculate that the Mark 15 torpedo may have been originally designed without the feature? When the torpedo launcher was designed to match, somebody could have said "Whoops!" and "fixed" the torpedo. It is easier to modify a surface ship launcher than a submarine torpedo tube; which is a complete pressure lock system. In any case, the torpedo air flask section could have been modified. It was for the Mark 16 obviously. The Mark 15 torpedo tail control was adopted in the Mark 16 afterbody. Something else may be going on, here. I just have not found it yet.
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Post by Avatar on Jun 8, 2024 14:06:49 GMT
Three methods, we see, for submarine launched torpedoes. The US method, for the WW II era, was to use compressed air to shove an inert torpedo out the torpedo tube. This air impulse, drove a steel piston, that drove forward, forcing a water ram, from an impulse tank, into the rear of the inert torpedo. The torpedo had a two position lever latch that, as the torpedo was forced forward into the tube, was first pushed down to press on an internal start switch. Once the torpedo cleared the tube, that lever latch released tension on the start switch to initiate a “hot run”. The danger in that supposed idiot-proofed setup, was that the lever latch could fail, or the idiot, it was designed to proof against, would somehow operate the lever. You could get a hot run torpedo on the stowage rack or inside the tube. An explosion, as the end of timed-run safety feature engaged, was the result. In this alternate timeline, the Americans, mid-war, develop an electrical power-up and motor-start cable connection from the submarine to the torpedo (swim-out), for their electric battery powered torpedoes. Their alcohol-fueled-combustion turbine engine torpedoes retain the “water-column-ram” method. The Germans used the water-ram method as well. The British and other nations used a compressed air ram method, as was practiced on most surface ships' torpedo tube launch systems. This sometimes necessitated, either a jettisoned button or ram-plug as a push plate for the torpedo (Italians and French liked this method.), or a tight-fitted torpedo that allowed for little gas flow-by. It, the compressed air ram method, could vary by submarines' classes, or national preference, but it inevitably meant a bubble of air that rose from the torpedo tube muzzle to reach the surface. This announced to anyone, who saw or listened for the bubble “pop”, that torpedoes were on the way. If your surface ship sound-man was any good, he could even give the targeted ship the bearing of the “pop”; so the target could maneuver to avoid the inbound torpedoes. That might explain why the water ram method was developed? ============================================================================ Baseline metrics on US submarine performance as compared to other causes for enemy ships sunk. The source is JANAC. Hyperwar is an awesome online resource for WW II minutiae. It is a bit (More than a bit.), Anglo-American biased, but even Dutch and Polish military history in that conflict is covered there in monographs. Glaring holes in the resource base are for Russia and China. These nation's archivists have not participated in the hoped for extent with first source articles and documents. The Americans and British try to fill in, but as I mentioned, they are a bit biased. Another resource for baseline metrics is the Submarine Operations Resource Group, SORG. ============================================================================ My function check, between JANAC and SORG is USS Nautilus as to what type torpedoes she used, and what her sinking credits were. Until 43 it was the Mark 15 torpedo, then Mark 14 3A torpedoes and finally Mark 18 torpedoes at the war's end. Her JANAC numbers. It is a rather large difference between SORG and JANAC. USS Nautilus patrol reports. This is primary source data. ============================================================================ What makes for a deadly Mark 14?Now here follows a layman's description of how to guide a torpedo. The torpedo is a tail control missile that relies on a screw or propeller to push it along. It uses a pair of tail-planes to control its nose point in the vertical or Y axis, and a pair of rudders to control its yaw in the X-axis. This is called 2 direction or 2-d control. To steer the torpedo, a mechanical system that dates back to 1898 in the Whitehead torpedo was the norm up until the second world war. This was the compass and pendulum system. The “compass” was a gyroscope that could control the yaw/rudder control. Different nations had different linkage setups, but basically the gyroscope because of its spin could gate or lock the rudder to a set bearing, either along a straight run, or a log curve to steer the path of the torpedo. Straight, left or right. Or in accordance with an accordion roll pattern, running tape that would weave or curl the fish along a baseline track. To maintain running depth, the pendulum control, regulated by a pressure sensor, would keep the fish running at a pressure level zone below the surface waves often confused with “depth”. This zone was subject to such vagaries as current flow, and sunlight heating the ocean surface, so it could vary as much as two meters in the torpedo depending on the type of sensor employed! The Whitehead type torpedo could sine wave vertically and nose wander horizontally with this setup. Needless to say, this made for some erratic running fish. Obviously, a better means of guidance would be desirable? The Germans and the Americans, coming at it from opposite directions and for opposite purposes, tried acoustic seekers or signal chasing to provide torpedo steer guidance. Since the Germans were interested in killing surface ships, their first attempts were to create a left-right signal chase based on noise striation. This meant rudder control and a set of hydrophones tied into an electrical resistance setup that would actuate rudder control to try to point the torpedo's nose at a balanced or centered “signal” between the left and right hydrophone sensors. It was effective. That torpedo had a tendency to sine wave horizontally now as well as vertically, but it would chase the clanking reciprocating engine of a liberty ship or the standard British tramp steamer. Note that the Germans would improve sensitivity to listen for a destroyer's mechanical… But essentially it was mostly restricted to killing surface ships. It could be foxed off by a noisemaker trailed astern that mimics the noise of a target ship and decoys the torpedo off on a false target tangent track. This causes the fish to lose the signal, or acquisition. Maybe in their naïveté, the Germans never expected what the Americans did. This was full 2-d torpedo control using acoustics and what is called 4 sensor shadow body striction. It is simplicity itself. The signal chase is set up so that the torpedo nose point is bang/bang tail-plane and rudder signal simultaneous chaser steer so that the nose is pointed at a screw noise both vertically and horizontally. The hydrophones are placed midbody so that the torpedo creates a noise shadow if it steers the wrong way and loses the signal on one side. A “corrector” shoves the torpedo opposite way until the hydrophone that signal drops receives the signal again, thus centering the torpedo in a sort of corkscrew fashion. Obviously, the thing is meant to chase submarines. In an experiment, the Americans modified an S-boat with caged propellers and used it to test out “inert” Mark 24 Fidos. The test boat would confirm it had been “killed” when the inert warheaded torpedo “clanged” into it. DEADLY, because the Americans tried to figure out countermeasures and the only one that worked was to stop the engines and surface. But that does not give the Americans a surface ship killer, although by disabling the vertical signal striction a kind of “German” type acoustic “destroyer killer” could be made. Still a clumsy solution. Now, remember what I said about sunlight and current affecting ocean pressure? So does a ship moving through water when it creates a wake. That nice trail of bubbles makes a dandy sound reflector. Guess what you can do with that information? Put a small sonar set up in a torpedo that points up either side of the torpedo mid-body and pings off that bubble curtain. Couple that with a “corrector” as was used in Fido and couple that with German style 1-d noise striction rudder steer, and you have a WAKE HOMER. Doable but difficult with US technology in 1939-1941. ============================================================================ I mentioned FIDO, which was the first American acoustic or sound signal chase guided torpedo. From where did it come? The Harvard Underwater Sound Lab, HUSL, and Bell Laboratories, did some fine guidance logic research into signal chase, to make FIDO work. A lot of things and people had to come together at exactly the right moment. ============================================================================= Why were gun cameras, (Periscope cameras?), not installed to record sinkings and torpedo attacks? You would need a reliable movie camera, triggered by a gate limiter switch, when the periscope rises from its well. 1. The camera only runs when the periscope is raised. That is why I wrote there had to be an automatic switch. 2. Gun cameras took lousy pictures. They were movie cameras. And yet, any picture is better than no picture for confirmation. What about leaving the periscope up for the enemy to spot it, while you film the torpedo run to target? That torpedo could run for minutes. That is a long time for a lookout to spot a periscope wake? There is a man with a stop watch. He is part of the target tracking party and therfe is a sound man on the hydrophones to hear the bang.. All those people and groups should have a good idea of the torpedo's time of run to meet the target. If not, they, collectively, have no business to be aboard a sub.
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Post by Avatar on Jun 8, 2024 15:24:11 GMT
Here is some more information about periscope cameras. That is USS Growler (577). Currently moored at the USS Intrepid Museum, NYC. She was ordered a decade after the end of WW II. She was of the Grayback class. What do you not see attached to the periscope? That one is a Foxtrot moored in Great Britain. She was built in Russia in 1967. What fittings do you see on this periscope? Hint: you can mount a camera to it. This is what one looks like inside: That is a Foxtrot moored at the San Diego Maritime Museum in California. I do not know exactly when she was built. I believe she was 26 years old at the time of the tour, which means she was built around 1983? Not only that, but I have only one comment. Russian submarines, at least the postwar ones, were and are not as "primitive" as some people like to believe. ================================================== How about magnetic exploders? A dubious claim has been made that the British and Germans fixed their magnetic exploders during World War II. The Americans mostly abandoned work on the Mark 6 influence device in the Mark 5 exploder when it failed them. What was that magnetic influence feature? The Mark 6 exploder assembly (magnetic influence section Mark 5 and firing mechanism.). Note the direction of the firing pin. And (later version). Different (front) view. And yet a later version, designed to overcome a mechanical acceleration fault. (Ball electrical contact switch instead of firing pin.) And some idea of how the arming safety feature worked and where the Mark 6 assembly sat in the warhead section. It was Rube Goldberg, extremely complex with at least three "fail paths" built in. The mods are progressive workarounds that appear to cure the symptoms and not the basic problem. A quick look at the British contact pistol in use at the same time. And here is what the Germans developed. The interesting thing is that the engineering in the British design is straightforward. The German design is more Rube Goldberg than the American design, but neither has the built-in fail paths of the Goat Island device. =============================================================== By the way...I had thought about that possibility before I posted the Mark 5 assembly/Mark 6 influence (I got that one backwards ^^^^), but it seemed a ridiculous idea at the time. ======================================================================== Why not go for a Japanese solution? Why not build a big warhead into the torpedo? Physics.Quick layman's explanation. Take 30,000 tonnes of metal that is (250 m) long and (30 m) skinny and is unable to support its own weight if suspended on a fulcrum, teeter totter fashion in the middle as a bridge load (either live or dead weight, it does not matter). It floats in a condition of equilibrium pressure floatation. Now supply the fulcrum in the form of an underwater under the keel midbody explosion. Snap. Instant hog and sag actions. I like blowing the propulsion shaft seals myself. Guaranteed dead in all cases, even if the hulk floats because the hull is permanently pranged through the keel and longerons. And you can write off the propulsion train, too. That seems to be a "Russian" thing by the way. ======================================================================= Physical size limitations, ballasting and balance issues, and costs dictated the limits of the warhead volume available. That is the only conclusion I can offer, for the USN preference for an under the keel torpedo detonation method, unless this is a case of the C-130^1 problem which constrains the possible systems that could be formulated. ^1 The barrel diameter of the aircraft limits what can be shoved into it. In the case of a torpedo tube it is the exact same problem. Now there is another solution path: look for a better explosive. I know that the US conducted some experimental work in the late 1930s with explosives. It was parallel to British work and that some of the experimental explosives, produced by both nations, was about 1.5 times the explosive force of TNT. Thus: the explosives, RDX and HMX, are available from `1933 on in the US tech tree if someone builds the production plants. That is RE value of 1.6 and 1.7 respectively. ================================================== Funny thing about HMX...Closely related to it, is a precursor solid rocket fuel. Rocket torpedoes? Not to throw a monkey wrench in the proceedings, but you know the Whitehead/Brotherhood engine system setup, contempoary with the American Civil War Hunt torpedo, operated off cold gas pressure, right? It has always struck me as idiotic that no major world power has ever until recently thought of a low grade self-combusting solid rocket candle to supply the gas for either a cold piston or turbine motor to drive a LONG RANGE steerable torpedo. I know current US torpedoes use a liquid triune glycol/nitrate/butylene base fuel that can be ignited and self generate such a gas that drives a swash plate ICE piston engine. The slow burning solid fuel motor would be a more exotic, but doable attempt at a self oxidizing gas generator. It does have the ballast problem in that you cannot admit seawater into the fuel tank to maintain the correct density weight. The torpedo would rise unless there was a piston diaphragm that allows seawater displacement and pushes the candle back along the fuel case as the wicking burns the fuel off. It is doable. The chemistry is not that exotic. ============================================================================ Well, if you cannot get a longer torpedo, how about a fatter torpedo? Make it as fat as a Mark 13 but 22.5 inches in diameter and 24 feet long? 57.15 cm x 731.52 cm? Good grief, that is a 2000+ kg torpedo. The Mark 14 was probably already a beast at 1500 kg to handle manually with block and tackle. There was little or no power assist on US boats. Look, I think the Mark 6 exploder was too large, complex, and mis-oriented in the warhead block. Make the detonator linear with a nose spinner clock safety with cam lugs instead of that impeller setup (^^^^). That probably gets you another 100 kg in the primary charge without fumbling with the rest of the fish because the cast warhead block can use and fill all of the void space of what looks like a cake pan fore-body more efficiently. I like a four or six whisker trigger switch inertia hammer initiated contact exploder with the apple core shaped initiator center buried dead center in a plasticized hexanite aluminum oxide warhead... just in case the torpedo decides to roll as well as yaw and pitch. This probably could be coupled with a top secret magnetic influence feature that the US Army was familiar with using for other applications by 1936. In other words, a US version of the Pi-2 (^^^^), only one that actually works.
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Post by Avatar on Jun 8, 2024 18:49:40 GMT
Torpedo tubes, again. And now some history. The international standard for torpedo tubes, (and oddly enough for railroad gauges) was established by the British. Initially this was the 45 cm (17.72 inch) torpedo because that was the standard Whitehead diameter of the 1880s and 1890s. This Whitehead gauge standard was British and American (Bliss Leavitt), but increased to 21 inches (53.34 cm) in the decade just before WW I because with the appearance of bigger battleships and more powerful guns. The need for a bigger long range fish to sink them was necessary. Since most torpedo launchers in the era were destroyer, cruiser and battleship mounted, swapping out of above deck launchers was less onerous than designing new submarine front ends. The swap-over was not complete until the end of the first world war. Even at that, many nations; Italy, UK, Germany, Russia, Japan used 17.7 barrel diameter torpedoes for the new air-dropped version of the weapon. And the new submarine standard for the torpedo became the 21-inch (53.3 cm) diameter bore tube. Even Japan adopted and did not change this submarine standard. The one oddball nation that refused the standard was France. France being France decided on a 55 cm (21.65 inch) standard. Note how long and relatively lightweight for overall size the WW II French submarine fish are? Anyway, for US purposes, the new torpedo tubes (longs from 1925 on) set the size limit for US fish at 21 inches (53.34 cm) in barrel diameter and 20 feet (6.1 m) 6 inches (15.24 cm) in length. This standard is the smallest in volume of all the submarine torpedo tubes used by the great powers of the interwar era. Should it have been extended by two to four feet? It could be doable, but the problem is that now the existing sub's bow section has to be completely rebuilt and extended forward (See “Italian” GUPPY above.) It would be cheaper to design a new torpedo than change the gauge limits. There are economic boundaries and rather stringent ones to what the USN can afford in the 1930s. So… any point of departure, PoD, that is not alien space bat, ASB, has to find the cheapest practical possible alternative to the RTL Goat Island fiascos. The best alternatives technically possible are electrics, some kind of (dangerous) NAVOL fish, or something off the wall like the solid propellant catalytic gas generator fueled torpedo that I proposed. Not likely. So we are stuck with the Mark 14 propulsion setup. Whatever happens in this proposed timeline, the actual alcohol fuelled wet-heater technology and the volume limitations are going to restrict torpedo performance to a run time of 500 seconds at 24 m/s. This will give a maximum reach of 12,000 meters and an effective chase reach of about 4,000 meters before the angle solutions become impossible. Warheads are limited to no more than 300 kg on a 1500 kg very heavy and dense fish. To tweak for effect, we need guidance alternatives to compass and pendulum and different fusing options. More bang through better chemistry (^^^^) is possible, but some way to cure nose wander and to chase screws is my preferred solution. Someone (espionage) needs to look at a German G-7 and realize the whiskers could serve as passive fore-body fin (nose canards) stabilizers as well as contact actuator levers to set off an initiator charge. As for some kind of keel-breaker, has no one considered how a land-mine detector works? ============================================================================ How about a modular torpedo? Not likely. There was no working room for such a solution. Six in the tubes, six spares plus another four in the racks, and up to twenty men bunked in the compartment. That makes for no space for any dial-a-yield warhead or for packing a war-shot to target size with explosive fill specifically tailored to the intended victim as a dismountable nose section. My thing is missiles, but can you imagine trying to pull maintenance on a Mark 14 or doing battery checks on a Mark 18 torpedo under weigh? Then pack a warhead cavity with blocks of Hexanite and attach said warhead to a power unit and propulsion body? The British tried that trick with some of their early ship borne surface-to-air missiles. It was a NIGHTMARE, fraught with peril and dangerous to the firing unit. The British were crazy. I would rather have the one size fits all targets, low-maintenance weapons, than a high maintenance lead acid battery powered torpedo with a warhead that had to be packed before ready as a warshot. Yikes, their situation with the Mark 14 torpedo with its leaky battery power cells, lube oil everywhere, flammable alcohol fuel and finicky trigger mechanisms that needed constant checking was horrible enough. Those men were brave. =========================================================================== Buoyancy and balance matters in a ship, but in a submarine it is critical for the boat and the torpedo. Too big a torpedo may compromise the weight forward more than design tolerances for a sub allow. There is a Spanish submarine class that an engineer recently screwed up when he put the decimal point in the wrong place for a critical displacement volume value. The sub is the S-80. The displacement error was about 80 tonnes. Tolerances for a submarine are so tight that a few dozen tonnes error in mass can balloon the volume displacement size by 15% or more. =========================================================================== Rocket candle gas generators for a turbine propelled torpedo. The thing that worries me besides the buoyancy issues is the bursting pressure the combustion would put on the torpedo casing or fuel container. Sure, solid propellant can be packed dense and its burn geometry jigged to give a constant volume gas flow, but the secret about solid propellant burn is that the candle burns in a fashion so that the length of the candle is involved without a single constriction point in the burn developing. This it to prevent burn through, local gas pressure build up at the wrong spot and cause melting from the blow torch effect. Needless to say, with the Goat Island crowd and their RTL reputation for quality control? Having them cast such a candle is not my first choice. Better off with a precursor OTTO fuel if it can be devised. It should be remarked that the problems I noted (see previous) are the problems encountered with the US 12.75" (32.4 cm) Mark 40 torpedo. (1955) These problems have apparently been solved in a later US torpedo (in current inventory). Those problems were finally solved post 1995. Do not expect such solutions in World War II. Til then... I still dislike the Mark 6 exploder's inherent design fault paths, but short of ASB solutions, it is the standard that the US is stuck with. And the fixes worked. ========================================================================== Dead in the tube is a problem we have not addressed.So what can be done about that problem? How about a water ram, previously mentioned? Post-war, the Americans switch from air to a turbine generated expulsion setup, but the tech is not that hard to develop pre-war. Your hot run is by hydraulic action expelled, and you clear datum (noise) to try again later? ============================================================================ In case you think that the Americans borrowed or stole most of their submarine technology from Europe? John Phillip Holland invented most of it in New York and New Jersey. ============================================================================ More about torpedo tubes:=========================================================================== How to set the speed, depth, and gyro angle setting on the ever defective Mark 14 torpedo. See above. =========================================================================== Regarding those magnetic exploders they were an excellent idea if they could have been made to work. Detonating the torpedoes under the hull of major warships or large freighters therefore bypassing the armour and torpedo blisters and likely breaking the ships' back.
Fixing the depth keeping ability and ensuring the reliability of the contact exploder is good and necessary. But do you think it was possible with the technology of the day for the Americans to have built an effective and reliable magnetic exploder?So those torpedo exploders?
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Post by Avatar on Jun 20, 2024 1:10:25 GMT
Physics. Quick layman's explanation. Take 30,000 tonnes of metal that is (250 m) long and (30 m) skinny and is unable to support its own weight if suspended on a fulcrum, teeter totter fashion in the middle as a bridge load (either live or dead weight, it does not matter). It floats in a condition of equilibrium pressure flotation. Now supply the fulcrum in the form of an underwater under the keel midbody explosion. Snap. Instant hog and sag actions. I like blowing the propulsion shaft seals myself. Guaranteed dead in all cases, even if the hulk floats because the hull is permanently pranged through the keel and longerons. And you can write off the propulsion train, too. That seems to be a “Russian” thing, by the way. There are physical size limitations, ballasting and balance issues, and costs, which dictate the limits of the warhead volume available to a torpedo. Making the most efficient use of the warhead volume and yield is so critical to the constrained American torpedoes, that it is not a problem solved by just a simple contact pistol and more explosives. Keel-breakers are what you need for a Yamato class battleship hull. That is the only conclusion I can offer. This is a World War II case of the C-130^1 difficulty, which constrains the possible systems that could be formulated to fit inside it. ^1 The barrel diameter of the aircraft limits what can be shoved into it. In the case of a torpedo tube, it is the exact same issue. ============================================================================= Why not pack in more explosives? There is another way to get more bang. I know that some US experimental work in the late 1930s, with explosives, was parallel to British work and that some explosives produced were about 1.5 the explosive force of TNT. RDX and HMX are available from `1933 onward, in the US tech tree; if someone builds the production plants. That is RE value of 1.6 and 1.7 per pound of TNT respectively. ============================================================================= What about the propulsion setup? Historically, you know the Whitehead/Brotherhood engine system setup operated off cold gas pressure, right? It has always struck me as idiotic that no major world power has ever until recently thought of a low grade self combusting solid rocket candle. It would supply the gas for either a cold piston or turbine motor to drive a torpedo. I know US torpedoes use a liquid triune glycol/nitrate/butylene base fuel that can be ignited and self generate such a gas that drives a swash plate ICE piston engine. The slow burning solid fuel motor would be a more exotic, but doable attempt at a self-oxidizing gas generator. It does have the ballast problem in that you cannot admit seawater into the fuel tank to maintain the correct density weight. The torpedo would rise unless there was a piston diaphragm that allows seawater displacement and pushes the candle back along the fuel case as the wicking burns the fuel off. It is doable. The chemistry is not that exotic. ============================================================================= Looking at the Mark 13 torpedo specification, as a baseline, it would not have been a terrible choice had it been as long as the Mark 14 torpedo. The Mk15 was forty-two inches longer, not an outrageous increase in a boat three hundred and eight feet long. So what about a 22.5 × 288 inch (732 centimeter) submarine torpedo? Make the destroyer fish the same size? Given half the extra length is the warhead, that puts the warhead at about seven hundred fifty pounds. If other systems are changed, can it reach one thousand pounds? Make it TORPEX, for an equivalent of one and a half tons TNT?A torpedo that is 57.15 cm x 731.52 cm? Good grief, that is a 2000 kg torpedo by weight. The Mark 14 was probably already a beast at 1500 kg to handle manually with block and tackle. There was little or no power assist to move such fish on US boats. Look, I think the Mark 6 exploder was too large, complex, and misoriented in the warhead block. Make the detonator linear with a nose spinner clock safety with cam lugs instead of that impeller setup (^^^^). That probably gets you another 100 kg in the primary charge without fumbling with the rest of the fish. The cast warhead block can use and fill all the void space of what looks like a cake pan fore-body more efficiently. I like a four or six whisker trigger switch inertia hammer initiated contact exploder. The apple core shaped initiator center is buried dead center in a plasticized hexanite aluminum oxide warhead… just in case the torpedo decides to roll as well as yaw and pitch. This probably could be coupled with a top secret magnetic influence feature that the US Army was familiar with using for other applications by 1936. In other words, a US version of the Pi-2 (^^^), the only one that actually works. Torpedo tubes one more time (AGAIN?):. And now some history. The international standard for torpedo tubes, (and oddly enough for railroad gauges) was established by the British. Initially this was the 45 cm (17.7 inch) torpedo because that was the standard Whitehead diameter of the 1880s and 1890s. This Whitehead gauge standard was British and American (Bliss Leavitt), but increased to 21 inches in the decade just before WW I because with the appearance of bigger battleships and more powerful guns, the need for a bigger long range fish to sink them was necessary. Since most torpedo launchers in the era were destroyer, cruiser, and battleship mounted, the swapping out of above deck launchers was less onerous than designing new submarine front ends. The swap-over was not complete until the end of the first world war. Even at that, many nations; Italy, UK, Germany, Russia, Japan used 17.7 barrel diameter torpedoes for the new air-dropped version of the weapon. And the new submarine standard for the torpedo became the 53.3 cm diameter bore tube. Even Japan adopted and did not change this submarine standard. The one oddball nation that refused the standard was France. France being France decided on a 55 cm standard. Note how long and relatively light weight for overall size the WW II French submarine fish are? Anyway for US purposes, the new torpedo tubes (longs from 1925 on) set the size limit for US fish at 21 inches (53.3 cm) in barrel diameter and 20 feet 6 inches (625 cm) in length. This standard is the smallest in volume of all the submarine torpedo tubes used by the great powers of the interwar era. Should it have been extended by two feet? It could be doable, but the problem is that now the existing sub's bow section has to be completely rebuilt and extended forward (See "Italian" GUPPY above.) It would be cheaper to design a new torpedo than change the gauge limits. There are economic boundaries and rather stringent ones to what the USN can afford in the 1930s. So... any PoD that is not ASB has to find the cheapest practical possible alternative to the RTL Goat Island fiascos. The best alternatives technically possible are electrics, some kind of (dangerous) NAVOL fish, or something off the wall like a solid propellant catalytic gas generator fueled torpedo. Not likely. So we are stuck with the Mark XIV propulsion setup. Whatever happens in this proposed timeline, the actual alcohol fuelled wet-heater technology and the volume limitations are going to restrict torpedo performance to a run time of 500 seconds at 24 m/s and give a maximum reach of 12,000 meters and an effective chase reach of about 4,000 meters before angle solutions become impossible. Warheads are limited to no more than 300 kg on a 1500 kg very heavy and dense fish. To tweak for effect, we need guidance alternatives to compass and pendulum and different fusing options. More bang through better chemistry (^^^^) is possible but some way to cure nose wander and to chase screws is my preferred solution. Someone (espionage) needs to look at a German G-7 and realize the whiskers could serve as passive fore-body fin (nose canards) stabilizers as well as contact actuator levers to set off an initiator charge. As for some kind of keel-breaker, has no one considered how a land-mine detector works? ========================================================================== Modular Warhead systems? Again as seen above? Not likely. There was no working room for such a solution. Six in the tubes, six + four in the racks and up to 20 men bunked in the compartment. That makes for no space for dial a yield warheads or for packing a war-shot to target size with explosive fill tailored to the intended victim. My thing is missiles, but can you imagine trying to pull maintenance on a Mark XiV or doing battery checks on a Mark XVIII under weigh? Then pack a warhead cavity with blocks of Hexanite and attach said warhead to a power unit and propulsion body? The British tried that trick with some of their early ship borne surface to air missiles. It was a NIGHTMARE fraught with peril and dangerous to the firing unit. The British were crazy. I would rather have one size fits all low-maintenance weapons than a high maintenance lead acid battery powered torpedo with a warhead that had to be packed before ready as a warshot. Yikes, their situation with the Mark XIV with its leaky battery power cells, lube oil everywhere, flammable alcohol fuel and finicky trigger mechanisms that needed constant checking was horrible enough. Those men were brave. ============================================================================ Suppose we went for that larger torpedo anyway? It may compromise the weight forward more than design tolerances for a sub allow. There is a Spanish submarine class that an engineer recently screwed up when he put the decimal point in the wrong place for a critical displacement volume value. The sub is the S-80. The displacement error was about 80 tonnes. See above. (^^^). Tolerances for a submarine are so tight that a few dozen tonnes error in mass can balloon the volume displacement size by 15% or more. ============================================================================ The rocket candle. The thing that worries me besides the buoyancy issues is the bursting pressure the combustion would put on the torpedo casing or fuel container. Sure solid propellant can be packed dense and its burn geometry jigged to give a constant volume gas flow, but the secret about solid propellant burn is that the candle burns in a fashion so that the length of the candle is involved without a single constriction point in the burn developing. This it to prevent burnthrough, local gas pressure build up at the wrong spot and case melting from the blow torch effect. Needless to say, with the Goat Island crowd and their RTL reputation for quality control? Having them cast such a candle is not my first choice. Better off with a precursor OTTO fuel if it can be devised. It should be remarked that the problems I noted (see previous) are the problems encountered with the US 12.75" (32.4 cm) Mark 40 torpedo. (1955) These problems have apparently been solved in a later US torpedo (in current inventory). Those problems were solved post 1995. ============================================================================= We are still stuck in World War II. I still dislike the Mark 6 exploder's inherent design fault paths, but short of ASB solutions, it is the standard that the US is stuck with. The fixes eventually worked. ============================================================================= Dead in the tube is a problem we have not addressed. How about a water ram? Post-war, but the tech is not that hard to develop pre-war. Your hot-run is by hydraulic action expelled and you clear datum (noise) to try again later? Clearing the tube was the problem, so much as the hazard of it happening in the first place. I guess a water ram, if fitted, would be faster than the wartime standard system, which appeared to need the tube to flood, first. (Unable to overcome the friction, otherwise?) (Actually, the tube flood was necessary to create a neutral buoyancy condition.)[/i] Dumping a hot-run torpedo with the attendant bubble was a sure way to attract attention. At least with a water column doing the shoving, you can save time on the trim out during the ejection, it should be slightly less noisy. The tube can be cleared faster. The down side is that one bets that hot-fish will become a circle jerker wanting to come back home to mother, so there might be some fancy plane and rudder work with a nose heavy boat? Not too good even with a hydraulic ejector, was that situation. There was that other problem: the circular run torpedo. Yup. The best cure for such a wet heater, hot-run-in-the-tube, was/is to install a kill gate in the same air leads that set the gyro spend in the tubed torpedo (1944) that can disconnect, a valve close command, to the fuel line to the engine. Now you have a dead fish. Eject that torpedo at slow hover, turn away, then let the torpedo sink. ========================================================================== The Mark 18 Maintenance Manual is here. After reading that horror novel, I sure wish someone had investigated aluminum seawater batteries in the 1930s instead of waiting until the 1990s. ========================================================================== Dumping a hot-run torpedo with the attendant bubble was a sure way to attract attention. At least with a water column doing the shoving, you can save time on the trim out during the ejection, it should be slightly less noisy and the tube can be cleared faster. The down side is that one bets that hot-fish will be a circle jerker wanting to come back home to mother, so there might be some fancy plane and rudder work with a nose heavy boat? Not too good even with a hydraulic ejector. ========================================================================== The Mark 13 torpedo. Are clamps that hard? Obviously, the air dropped torpedo could be applied to small fast attack boats. Dump them over the side. at Timestamp 20:00. That Hollyweird docufiction still showqs the danger of a gunpowder (impulsep-fired) torpedo launch method. The dump launch is mechanically a lot safer than the gunpowder tube launch method described (^^^) above. ==========================================================================
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Post by Avatar on Jun 20, 2024 12:23:03 GMT
As long as we are in “the school of the torpedo” I thought we could look at these. More on the Mark 6 magnetic influence feature in the Mark 5 exploder assembly. This will clarify the generated electricity function of the impeller/generator and clarifies why Goat Island adopted the peculiar design of the original Mark 5 exploder. It also explains the CYA ball switch feature added late war and highlights how even after the Mark 6 influence feature/Mark 5 exploder assembly was discredited and/or field modified to sort of work. The Rube Goldberg crowd found new ways to infuriate and bedevil navy armorers. Briefly, I will add my own “opinion” of this debacle. It does not matter where the impeller is set or how it operates with respect to torpedo motion as long as the generator produces current load to a discharge capacitor to operate the pickup coil and/or the solenoid ( see Pi-2 pictures and compare to the American unit here. Manual on the Pi-1 and 2 torpedo exploders for the German G-7 torpedo family, described here as the USN understood the device.). HOWEVER… the Germans used a battery. And they used a linear action in the direction of acceleration arming path. The Whitehead torpedo originally used a set screw impeller mounted on the nose that spun a set of revolutions that operated a spindle cam assembly that unlocked the safety gate on a contact pistol. This was an arming safety. Virtually idiot-proof, it relies/relied on the torpedo to swim a period of time away from the launch unit before it armed. The same impeller setup could do double duty as an electric generator. The spinning screw provides the armature rotation. Or the Goat Island “geniuses” could have put the generator in the power unit attached to one of the turbines. (More on that PU in a moment.) Since the Mark 37 torpedo has been mentioned, here is some information on those fish. Mark 37C torpedo (Otto fuel). Mark 37 electric. Complex does not begin to describe their design and use. Some info on the WW II tools of the submarine trade. But back to the design of the American torpedo. Here are a few things to note. Pi_2_exploder_2.png1. Given the technology of the day (or even today) a piston driven internal combustion engine will give more “run time” per given amount of fuel/watts generated than a turbine. This means that the turbine is lighter and in many cases easier to miniaturize and manufacture. If a three cylinder or four cylinder 150 kilowatt engine can be fitted into a torpedo after body power unit in the same volume as the two turbine Goat Island setup. That probably will give more run time on the same fuel. If the engineers can swash plate the engine so that it dispenses with the crank and instead roller coasters the torpedo screw armature, that is even better as far as space savings and seawater cooling jacket flow is concerned. BUT then someone needs to design a contra-rotator gearbox and opposite spin flywheel weight to counteract swashplate torque loads. I actually like that as an engineering solution because active angular momentum cancellation through gyroscope effect cures a huge torpedo problem as a good side effect; nose wander. That torpedo will point. 2. A linear fuse in the direction of acceleration with an inertia hammer ball switch saves space in the warhead. An external armature impeller/screw arming safety feature also saves volumetric space better used for hexanite. As for the prong vanes, levers, “whiskers” in keeping with my mania for double duty purpose and features, these “fins” can serve as fore control as well as contact levers/horns to set off the torpedo at oblique strike angles. Note above how the German sailor carries the Pi-2 assembly like a baby? NOW after reading the Mark XVIIII service manual and what bad things happen when you have to dismount the warhead to get at the exploder to service it, does it not make sense to have a SCREW IN MODULE that just slides into the torpedo nose as a complete assembly? 3. Which brings me to the problem about the earth's magnetic field and compasses and how to detect land mines and photo-electric eyes and other goo-gaws. I find it interesting in reading about Christie's little boat ride off Ecuador when he made those tests using a destroyer to fire practice torpedoes at the USS Indianapolis, that to prove the influence feature tripped at the proper time he used an electric eye put into the exercise fish to time the shadow of the cruiser as the torpedo passed under the Indianapolis to compare that to the trip time of the Mark 6 influence feature circuit. NOW THINK ABOUT WHAT I JUST WROTE.... One Mississippi, Two Mississippi, Three Mississippi... What the bloody hell was wrong with Christie? He used an electric eye as a trip feature in the cockamamie torpedo to check another trip feature in the same torpedo! Uhm. He apparently knew the photoelectric eye would work as an under the keel influence device to measure how the magnetic influence feature was working. Why didn't he use the photoelectric eye setup as a fusing feature? 4. John Q. Landmine. Once upon a time, the British army was worried that the Germans would do something cute like apply naval mine warfare to tanks. The British army, being who they were, decided it would be a good idea if they could devise a way to find these mines by not rolling tanks over them. Since the mines expected would be buried in the dirt and should be cheap, plentiful, and made out of steel, a magnetic means to find aforesaid mines would be a bit better than Private Fumbles poking the dirt with his bayonet. The British army guys came up with a contraption that used a magnetically sensitive switch hooked to a tone emitting circuit that would detect the presence of a mass of metal that distorted the magnetic field. They did not use the Earth's magnetic field to do this. Great minds hunting for German land mines think alike. The American army had a slightly different approach that did exactly the same thing. (1936). Someone should have talked to these “army” guys. Both the RN and USN were guilty of the same exact hubris. Anyway... Goat Island sure could have used a manufacturing process analyst and a systems logic engineer. ================================================= The photoelectric eye would not work? There are issues with sensitivity and false shadow, for the daylight only under the keel sensor. Suppose there are clouds or opaque wave conditions? About that photoelectric eye, if it had been used as a keel-breaker; there are lots of good arguments against the device, but one thing is certain... at Lingayan Gulf six transports would have been sunk in deep water, if it had been an option.. And if you do have to have a proximity fuse, daylight at 40% is better than 24 hours magnetic pistol success at 15%. And there is always the metal detector approach. Just make sure your arming safety lock disengages well away from the sub or destroyer.
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