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High Tech German military

Discussion in 'Armor and Armored Fighting Vehicles' started by JCFalkenbergIII, May 24, 2008.

  1. Proeliator

    Proeliator Member

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    Regarding the Type XXI boat:

    Anyone trying to argue that this boat wasn't way ahead of time must be in complete denial, as it was the Type XXI was a huge improvement over any previous subs used by any nation, a quatumn leap, featuring some very dramatic improvement over older type subs;

    1. Sonar targeting system for torpedo firing solution (A vast stealth & precision improvement, esp. at night and in tight haze)
    2. Automatic torpedo reloading system (Six could be loaded and fired in the time it took to reload just one in any previous Uboat)
    3. Hydrodynamically optimized hull making it much harder to detect with sonar and improving running speed. (Sonar of the time, scanning or not, simply couldn't detect it before it was well within effective firing range)
    4. Advanced dedicated silent running motors providing higher speed & increased silence in this condition. (Another vast stealth improvement)
    5. Unrivalled submerged speed (So fast that anti sub equipment on destroyers would've been ineffective against it, only aircraft remaining a threat)
    6. New generation passive accoustic homing torpedoes with greater range and less sensitivity to decoys.
    7. Excellent crew facilities, with large freezers for provisions, air conditioning system, ultraviolet lighting for prolonged submergence, showers & washbasins for the crew. (Vastly improved onboard health, hygiene & odour)
    8. Unmatched maximum safe diving depth of 280m, most Allied boats couldn't even reach half that.
    9. Unmatched dive speed, esp. the crash dive was much faster than on any previous types.
    10. Unmatched fully submerged time period between necessary surfacing.
    11. Snorkel system

    In short the Type XXI was none other than revolutionary for its time.
     
  2. ickysdad

    ickysdad Member

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    and when armies aren't involved in active operations their vehicles don't eat nothing whereas horses still have to be fed besides horses can eat up local grazing faster then you think.
     
  3. ickysdad

    ickysdad Member

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    Oh on diving depths USN subs could reach much farther half the 280m figure you mentioned just read Friedman's book on USN subs.
     
  4. Proeliator

    Proeliator Member

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    Really, 80m seems to be the maximum. It could be that some were taken down lower and survived, but then the odds were against it. The Germans also sometimes went deeper than the maximum design specs, but doing so was very risky business.
     
  5. T. A. Gardner

    T. A. Gardner Genuine Chief

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    While the GHG (GruppenHorchGerät) was an improvement on previous U-boat sonar systems it was hardly some amazing new system. It simply grouped 24 hydrophones in a semi-circular array under the bow of the boat. This was a passive system and on its own incapable of resolving a target sufficently to allow blind fire.
    The active set was the newly developed S-Gerät Nibelung. This was a typical magnetostrictive type sonar. This set was capable of active sonar pinging and could resolve target range, bearing and, course. Of course, in using an active pinging system the submarine would be potentially telegraphing its presence to surface ships with sonar systems aboard. The S-Gerät had a maximum range of about 10,000 yds in optimal conditions.
    There was in the works (but never fitted to a boat) an improved SP-Gerät system that would have given a rought three dimensional fix on a target allowing true blind submerged fire. But, this never got beyond the development stage before the war ended.

    This system did allow for a faster reload time of 15 minutes versus the previous 34 for hand loading of all tubes. But, it took up more space so reloads were limited to just 14 torpedoes meaning fewer carried and potentially forcing a boat to curtail operations sooner.

    Originally, the Type XXI was designed for a very fast submergance time. The way this was accomplished was through the use of free flooding slots in the outer hull equalling 100 sq m in area. This gave the boat a dive time of 20 seconds. The problem with this was the slots were found to increase hydrodynamic resistance by 28% reducing underwater speed to 15.8 knots.
    To improve underwater speed two-thirds of the slots were plated over to give 31 sq m of flooding surface. This increased dive time to 25 seconds but improved speed by 1.7 knots to 16.5 knots.

    There is little evidence that major sound reductions over previous boats were made in the Type XXI. Most machinery was still rigidly mounted... This can be seen in photographs of the various subsections of these boats during assembly. The flooding slots on the hull represent a major source of noise as does the screws. The later were not designed with any real attempt to reduce potential cavitation at speed.
    While there was a creeping motor running on a belt drive, this was no more capable of moving the boat beyond a couple of knots than it was on previous boats.

    Hedgehog, trainable hedgehog, and Squid would all still have been effective weapons against a Type XXI. The then in development Weapon Alpha would also have been. The Allies were also in the early stages of developing active homing and wire guided torpedoes as well.
    As for sonars, US sets like QGB and QHB and British ones like Type 147 were three dimensional scanning sonars that could detect a target over the entire area of the sonar beam rather than the previous 'flashlight" types that had a (typically) 11 degree beam and were manually trained. These sets carried the Allies into the immediate postwar period and were capable of dealing with a Type XXI-like threat.
    Allied ASW aircraft by late war were carrying sonobouys and equipped with MAD sets. They also carried small explosive charges for active 'pinging' in conjunction with their sonobouys. This was in addition to various radar and ESM equipment they carried for greater detection ranges. And, yes, snorkel heads were prone to be detected by late war centimetric radars up to as much as 5 NM or more.


    The T5 and T11 were the two available sound homing torpedoes. However, the T5 was easily fooled by noise decoys. The T11 was an improvement but there is little evidence of its operational use to determine its true effectiveness.
    The Type XXI could also carry LUT (Lagenunabhängiger) or course independent torpedoes that could be programmed for up to a 180 degree turn and the pattern running FAT (Flächenabsuchender torpedo in addition to the electric G7e.

    Okay, they caught up with US fleet boats that had that stuff in 1939.

    Allied boats manufactured late war were matching that diving depth and beyond.

    As mentioned 25 seconds. The problem here was this was so fast that there was a real danger of submerging so fast that all the necessary valves, hatches, etc., were in the proper position to prevent flooding. It also made the two AA gun positions death traps for their crew.

    This was only due to the snorkel system. Running on batteries the Type XXI could only achieve higher underwater speeds at the cost of a greatly shortened battery time.

    This was nothing new. The Type XXI could make about 10.5 knots on diesels while snorkelling. Of course, this also made for a noisy boat and could not be done in close contact to a potential ASW craft.

    The Type XXI was no "miracle boat" nor was it particularly revolutionary. Instead, it was a logical evolutionary step born from experiance with Allied ASW. In fact, one might want to look up the Japanese Sensuikan Taka submarines of the late war I 200 class. These were very similar in design to the German Type XXI. So, the Germans were hardly unique in coming up with such a submarine.
     
  6. Proeliator

    Proeliator Member

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    I am really struggling to see your point here knowing how big a country Russia is and how much of it is covered by wide open grassy plains. To be honest you must have never visited Russia, and regarding how quickly horses can eat up local grazing, well let me put it like this: I've lived on a farm my whole life and plenty of horses as-well cows can graze for a loong time on just a 200x200m grassy field.

    Or maybe you're under the impression that the Germans were on some kind of camping trip in the USSR and therefore parked their horses on a single strip of land for several weeks?

    Come on now..
     
  7. T. A. Gardner

    T. A. Gardner Genuine Chief

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    You cannot just graze working military animals and use them for daily heavy work as armies do. The US Quartermaster and vetenary corps recommended 20 to 24 lbs of provisions per horse per day in normal use. For heavy work, such as hauling artillery or in poor conditions 24 to 32 lbs per horse of food was recommended. In addition, 5 to 15 gallons of water per animal would have to be provided per day depending on temperature and use. The typical feed was 50 - 50 forage and grain. Barley, oats, or other grains could be used along with sutiable grasses. If grain feeds were not available, the amount of feed required would more than double to 45 to 70 lbs per day as the nutritional value per pound is lower.
    One cannot simply have a military unit with say, hundreds of horses let them roam free on a potentially unfenced pasture to graze either. Just having to later round up the animals and then resaddle / mount etc., them would require far too much valuable time. The only really effective way a military unit can feed horses is if they are staked or bridled and using bulk food placed before the animal.

    Of course, this food and water had to be provided at intervals over the day, not all at once. Animals also require regular rest periods. This meant that a horse team would have to stop every 30 minutes to an hour depending on work and rest the animals. Cavalry would typically walk, trot, and lead their horses to vary the work load and not wear the animal out through constant use.
     
  8. Proeliator

    Proeliator Member

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    TA,

    The Type XXI could run for 3 days on battery power alone at 5 knots, this was longer than any other Uboat in service during the war.

    And regarding the automatic reloading system, it took 10min to load and fire six torpedoes with it, which was exactly the same time it took to load just ONE torpedo in older boats. And the Type XXI actually also carried more torpedoes than previous boats, so no curtailing of operations either.

    And regarding the silence of the the boat, it was a lot more silent than previous types, not only because it featured dedicated silent running motors, but also because of the hydrodynamically much cleaner hull. The clean design produced less noise on the run, so effectively infact that at 7.8 knots submerged the Type XXI generated less noise than a Type VIIIC running at 3 knots on silent running, and at 15 knots it generated the same amount of noise as a USN Balao class submarine doing just 8 knots. (How is this not a major improvement??)

    And your point regarding the flooding slots is equally absurd as every single US & German Uboat featured these as-well.

    Fact is that the more streamlined design of the Type XXI made it much less noisy underwater and less susceptible to sonar than any other boat during the war, something most mariners will realize by just looking at the thing and comparing it to older types. And it was infact a tried & tested fact that the Type XXI gave a smaller sonar signature than previous boats, and it was proven in action as-well when a certain Cpt. Schnee of U-2511 managed run straight through a tight screen of British ASW vessels completely undetected only to carry out a dummy attack on the Cruiser HMS Suffolk in 1945.

    Finally I'd really like to know which US submarine could even approach the 280m (919 ft) diving depth of the Type XXI. So far the deepest I've seen is 120m (400 ft), which is a good deal short of even what the German Type VIIC & IX were capable of (250-295m [820-970 ft]).
     
  9. ickysdad

    ickysdad Member

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    Check pages 208-209 of Norman Friedman's "U.S. Submarines Through 1945,An Illustrated Design History" . The 27.5 lb or 9/16" hulled vessels had a test depth of 300' or a crush depth of 550'. The 35lb. or 7/8" hulled vessels raised this to 400' test depth or 675' crush depth. The later models with 35 lb or /7/8" HTS were good to a 600' test depth or 909' crush depth. Me thinks your comparing Kriegsmarine crush depths to USN test depths and you also need to update your sources..

    On diving times the USN tested a IX to a USN fleet sub & found that the German sonar was superior though the US sub dived faster. The smaller US M class subs which were about the same size as a Type VII dived to a depth of 35' in 41 seconds compared to the German's 30' in 50 seconds.
     
  10. ickysdad

    ickysdad Member

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    Doesn't matter how big the country is since you need the animals close to where your combat units are. It does no good to have good to excellent grazing pastures 200 miles behind the front. If horses are being used to move artillery they need to be close to the field pieces or ammo depots.
     
  11. T. A. Gardner

    T. A. Gardner Genuine Chief

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    But, could the boat stay submerged on the available air for that long? CO2 scrubbers weren't invented yet....

    Well, in the article The Type XXI Submarine in Warship Quarterly by Erwin F. Sieche he says it took 15 minutes during the initial trials and testing to accomplish this. Maybe 10 minutes was the design spec. 15 minutes isn't bad but it also is an eternity to make a second attack. A slow target could move several miles in that time.
    Yes, the sub could to but if its initial attack was detected it could also be busy avoiding detection and attack itself....

    All German subs had creeping motors. These were used not only for silent running submerged but for maneuvering in harbor, among other things.
    Machinery and prop cavitation (at high speed) are major sources of noise. I don't see anything to indicate that the Germans did a better job of isolating machinery or prop design than anyone else did. A clean hull helps but those free flooding slots are a major source of hull noise. This is why the US eliminated them in the late going to ones that closed flush with the hull followed by the Soviets about a decade later. Now everyone uses these.



    No, it isn't flooding slots are a major source of hull noise when running at higher speeds submerged. In addition, the fast submerging time was a danger. Two Type XXIII boats, the U2331 and U2326 both sank due to this exact reason. Postwar the now West German Hai (ex Type XXIII) sank in 1966 again for the same reason. In all three cases the entire crew was lost with the boat.

    It was on HMS Norfolk by U-2511 Korvettenkapitän Adalbert Schnee commanding. It was one of two surviving boats (the other was U3008 of the first group of 10 to go operational. The other 8 had been sunk enroute to Norway by Allied ASW aircraft. Of 121 boats completed 9 were sunk in transit to Norway, 2 mined in the Baltic, 12 bombed in harbor and sunk or damaged beyond economical repair, and 86 scuttled by their crews at the end of the war. 12 boats ended up in Allied hands.
    As for its sonar signature on active sonar, I couldn't say for sure. But, it is likely that it would have given just as good a return being a steel hulled, slab sided vessel like its predicessors. While the hull might have been more hydrodynamic, it was still a slab sided design much like many boats that followed it in many navies.
     
  12. lwd

    lwd Ace

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    I'm also not sure just how much grazing could be found in say Febuary in Russia.
     
  13. bigfun

    bigfun Ace

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    ok......back on track......


    This has been posted in here before, but this is my all time favorite!

    [​IMG]
     
  14. Triple C

    Triple C Ace

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    Horses have poor sustained mobility over prolonged distance or time. For horses to sustain themselves naturally by grazing, they had to remain stationary and only move when the pack run out of pasture in the area. Natural horse populations don't migrate with the speed of armies; John Keegan asserted in A History of Warfare that a Roman Legion was as mobile as any all-cavalry force, because the latter need longer and more frequent pauses. The Mongols didn't carry five horses for every warrior for no reason.
     
  15. Spaniard

    Spaniard New Member

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    Well I read that many horses were used as food, You would have to carry in Battle so much hay just for the Horses for the winter months.

    HORSES & MULES DURING WW II

    [​IMG]
    The Waffen-SS cavalry brigade which served in Russian in 1941 was an elite unit, and like other Waffen-SS outfits had special clothing and equipment.



    [​IMG]



    German High Tech Guns THE SCHWERER GUSTAV - FATHER OF ALL GUNS
    YouTube - THE SCHWERER GUSTAV - FATHER OF ALL GUNS

    http://www.youtube.com/watch?v=nAxySDG_jjs&feature=related

    [​IMG]

    [​IMG]
     
  16. Proeliator

    Proeliator Member

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    German figures are test depths as-well, crush depth for the Type XXI was 330 meters (1082 ft). Now which WW2 US submarines are you claiming to have a test depth of 400 or 600 ft?

    A Type IX is not a Type XXI Icky.
     
  17. Proeliator

    Proeliator Member

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    And yet still the Type XXI generated less noise at 7.8 knots than a Type VIIIC running at 3 knots on silent running, and at 15 knots it generated the same amount of noise as a USN Balao class submarine doing just 8 knots. This is based on German & US trials.

    The Type XXI was a revoluionary Uboat for its' time, something most maritime historians seem to agree upon.
     
  18. ickysdad

    ickysdad Member

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    COMMENT: No it isn't a Type XX1 but the type IX is a contemporary of the Gato's/Balao's which the Type XXI isn't.
     
  19. ickysdad

    ickysdad Member

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    According to Friedman's "U.S. Submarines Since 1945: An Illustrated Design History" the Type XXI U-2513 was a fast diver and very quiet BUT though it was believed she had went down to 600' in service her designed operating depth was 120m(394') ,BuShips listed her maximum operating depth at 440'. In his footnotes Friedman quotes from SubLant report on 2/18/1946 & from W. E. Schevill & A. C. Vine "Submerged Performance Tests of Type XXI,Wood Hole,17 March 1947{Submarine Warfare Division Papers,Operational Archives} )that it would have been "devastaing" but for the fact "as they have so often done before" the Germans committed the fatal error of overcomplicating it's hydraulic system.
    USN tests also showed that the lack of bow planes on the Type XXI might have been a far bigger problem then the Germans had thought. The Germans also evidently hadn't solved the fundamental hydronamic & control issues that a high speed sub raised.
     
  20. Proeliator

    Proeliator Member

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    Icky,

    I strongly suggest you read German U-boat Type XXI by Siegfried Breyer and Anatomy of the ship: Type XXI U-boat by Fritz Kohl & Ebeerhard Rossler. And throw Friedman's book away, because Friedman makes so many mistakes it's a real wonder the book even got published. First of all the Type XXI never lacked bow planes, it infact had a very advanced retractable bow plane system which was directly copied by the Allies in all their subsequent postwar designs, and the boat was reported to be very manueverable. Furthermore the tested depth of the Type XXI was 280 meters, crush depth was estimated as 330 meters. (Type IX boats were tested all the way down to 295 meters btw)

    The words of Siegfried Breyer himself:
    "The German U-boat Type XXI was a revolutionary marvel at the time of its development, close to the end of World War II"
     

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