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Italian Subs in op Drumbeat

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  • Carl Schwamberg
    replied
    Originally posted by The Exorcist View Post
    I was thinking more of the general fragility of Italian boats, the ineptitude of their skippers and their inability to coordinate with the KM.


    No argument about it. Taken as a whole, it was much worse than Pearl Harbor... and yet somehow or other, Adm King kept his job.
    Crazy, eh?
    The USN problems that created the conditions for the sucess of Drumbeat went far beyond Adm King. Note that King did not take the CoS job until January 1942, when Op DB was starting. Aside from a severe shortage of suitable escorts the ships commanders and fleet staffs lacked training for ASW. That had a lot to do with the huge mobilization & expansion of the previous 20 months. Also King was not the only Anglophobe in the USN several of his predecessors wasted some the few and small opportunities they had to train in ASW to British experience because they could not accept that Brit. experience.

    Once King grasped the situation he did push effective remedial action through. The decline in cargo ships sunk in the US zone of responsibility declined as fast as it rose & from mid 1942 the proportion of submarines not returning from patrol went up dramatically from a average of ten per quarter to between 30-40 per quarter. There were a lot of reasons for that, but the change in USN tactics/doctrines had a significant contribution.

    Donetizs eventual decision to move operations back to the mid Atlantic had everything to do with the unacceptable losses of his submarines in US waters from mid 1942.

    Hughes & Costellos 'The Battle of the Atlantic' has detailed quarterly information on numbers and locations of German subs lost during the war.

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  • Roadkiller
    replied
    Originally posted by The Exorcist View Post
    ... and yet somehow or other, Adm King kept his job.
    Crazy, eh?
    Agreed! Yet every time I mention it, within moments someone will cough up that King was an Anglophobe and therefore loathe to take the advice of the RN to start a convoy system, as if this were a valid excuse

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  • The Exorcist
    replied
    Originally posted by Carl Schwamberg View Post
    Made it back?
    I was thinking more of the general fragility of Italian boats, the ineptitude of their skippers and their inability to coordinate with the KM.

    Originally posted by Roadkiller View Post
    The effects of the initial Drumbeat boats and follow on waves of U-boats to shipping on the US east and gulf coasts and in the Caribbean was dramatic. In the first 6 months of 1942, 397 ships totaling over 2 million tons of shipping went down. The Germans lost just 7 U-boats in arguably the single greatest defeat in the history of the USN.
    No argument about it. Taken as a whole, it was much worse than Pearl Harbor... and yet somehow or other, Adm King kept his job.
    Crazy, eh?

    Leave a comment:


  • Roadkiller
    replied
    The KM had 12 type IX's. However, 6 of them were earmarked for an operation off Gibraltar. We need to look up name/purpose and whether the Italian boats were involved. That left 6 type IX's for Drumbeat. One was temporarily unfit sea, so the operation went ahead with 5 boats.

    The effects of the initial Drumbeat boats and follow on waves of U-boats to shipping on the US east and gulf coasts and in the Caribbean was dramatic. In the first 6 months of 1942, 397 ships totaling over 2 million tons of shipping went down. The Germans lost just 7 U-boats in arguably the single greatest defeat in the history of the USN.

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  • Carl Schwamberg
    replied
    Made it back? It needs to be confirmed but IIRC post war examination of German records show the USN failed to sink any German subs involved in op Drumbeat until April. Note that these were primarily the Type IX, which were designed back circa 1930 & completed by 1935. They were large & considered slow diving & slow manuvering. The Cagni class boats, completed in 1941 were the four subs originally suggested in the OP. I wonder what the actual performance differences between them & the Type IX were?

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  • The Exorcist
    replied
    Well, with 36 torpedoes they would have to have hit something...

    If they could have been there before April, yeah, they would have done some damage.
    However, they would have had to stay clear of the German subs. Put one on either side of Florida and they couldn't have helped but do well.

    Would they have made it back?
    Well, that's a whole 'nother question, ain't it?

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  • Carl Schwamberg
    replied
    Originally posted by Roadkiller View Post
    Germany and Italy declared war on the USA on the 11th of December, '41.
    The first 'Drumbeat' boat, U-125 sailed on the 18th, which is a pretty quick response. The last two sailed on the 27th, with all boats planned to be on station by the 13th of January.

    Where were the big Italian subs? Could they have been made ready in two weeks?

    It would appear that several Italian boats (LUIGI TORELLI, ENRICO TAZZOLI, GIUSEPPE FINZI, PIETRO CALVI) were used in the rescue of crewmen from the German supply ship ATLANTIS. It had been sunk in late November in the South Atlantic, so it would seem a large number of Italian boats were operting in that area at the time 'Drumbeat' was stood up.

    Further, some Italian submarines such as the LUIGI TORELLI were operating in the Caribbean by Febuary '42 http://www.regiamarina.net/detail_te...&lid=1&cid=44/ )

    The ENRICO TAZZOLI was off florida by March: http://www.regiamarina.net/detail_te...4&lid=1&cid=42 )

    It would seem that those Italian boats that were fully operational were sent as quickly as they could, but perhaps there were no assets on hand to take part in Drumbeat?
    The German patrols along the US east coast ran on to April. It appears three relays were sent for somewhere between 18 & 24 sorties. That the high point in the losses did not peak until March supports this. If the Italian subs cant make it there in January then February will do.

    Originally the question was soly about the four largest Italian subs. I'm getting the idea perhaps a dozen others could have been used as well. If so that might have made a bit of difference.

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  • Roadkiller
    replied
    It would also appear that you will need to find 5 Italian boats to expect the same return as a single German boat, and this number comes from the Italians themselves!
    " ... It is obvious that a single cause of inferiority could by itself be very serious, while the concurrency of all of the factors [cited], and [those also] omitted for the sake of brevity, becomes extremely serious.

    Thus defining as 1 the war performance of a German submarine, and estimating only slightly lower the one of an Italian submarine for instance 0.8 the performance of an Italian submarine due to the combination of the seven more complex causes of inferiority which have been [previously] listed (if all of the causes are globally considered) reduces the performance to .8 to the 7 factor, or .21..."

    And that's just to get hits, not necessarily sinkings:

    "... This calculation, which serves as guidance, refers more than anything else to the chance one of our submarines has to perform its duties to the end: bring the torpedo to explode upon contact with the enemy hull. But if the weapon is instead, due to built-in defects, incapable of sinking or even seriously damaging the target, then due to this main deficiency, there is no longer any ratio which is worth computing. This one [deficiency] alone is enough to destroy the fruits of all labor, all fervor, and sacrifices of the entire submarine fleet..."

    http://www.regiamarina.net/detail_te...53&lid=1&cid=4

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  • Roadkiller
    replied
    Germany and Italy declared war on the USA on the 11th of December, '41.
    The first 'Drumbeat' boat, U-125 sailed on the 18th, which is a pretty quick response. The last two sailed on the 27th, with all boats planned to be on station by the 13th of January.

    Where were the big Italian subs? Could they have been made ready in two weeks?

    It would appear that several Italian boats (LUIGI TORELLI, ENRICO TAZZOLI, GIUSEPPE FINZI, PIETRO CALVI) were used in the rescue of crewmen from the German supply ship ATLANTIS. It had been sunk in late November in the South Atlantic, so it would seem a large number of Italian boats were operting in that area at the time 'Drumbeat' was stood up.

    Further, some Italian submarines such as the LUIGI TORELLI were operating in the Caribbean by Febuary '42 http://www.regiamarina.net/detail_te...&lid=1&cid=44/ )

    The ENRICO TAZZOLI was off florida by March: http://www.regiamarina.net/detail_te...4&lid=1&cid=42 )

    It would seem that those Italian boats that were fully operational were sent as quickly as they could, but perhaps there were no assets on hand to take part in Drumbeat?

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  • Carl Schwamberg
    replied
    Hmm... the plot thickens. Five Type IX subs were in the first wave in January. The type IX were the only boats imeadiately available for realistic operations in those waters. I wonder what the technical differences between those & the Italian long range cruiser subs were?

    The second & third groups dispatched were also primarily Type IX, with some Type VII. Since Germany had only built some twenty Type IX the gross fleet that could be deployed was severely limited. I also notice the claim on one German sub was confirmed as sunk by the USN from 1 January through 31 April.

    In that context adding in one or two Italian subs on station makes some sense, even if inferior to the Germans. Even if inflicting far fewer losses they can add conservatively another 10% sunk at a time the Allies were in a bad way with cargo ship operations. A more optimistic 20% adds to the burden.

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  • Roadkiller
    replied
    You are correct, there were only 5 boats in Op Drumbeat and they did not work as a group. Not that they needed to in the environment they were in.

    I just got carried away and forgot the original question

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  • Carl Schwamberg
    replied
    Originally posted by Roadkiller View Post
    ...

    These issues, as well as an inadequate communications fit (by German standards) made it difficult to blend Italian boats into wolf packs, and indeed they were employed as "lone hunters".
    Most of that reflects against the low sucess of the USN/USAAF locating German submarines during Op Drumbeat.

    In the last observation I dont recall the Germans using pack tactics in Op Drumbeat. The number of actual subs on station off the US coast was very low. IIRC they were distributed across the entire east coast traffic lanes so as to spread the US ASW effort out. I could be wrong there, but dont have time to dig any deeper for information.

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  • Carl Schwamberg
    replied
    I was wrong about 1939 being a low year in tonnage per submarine. Ellis estimates it at approaching 50,000 tons per, with a avergae of 14 submarines at sea during the last quarter of 1939.

    In 1940 that rockets up to between 70 & 75 thousand tons per in the third quarter of 1940, with a average of 13-14 subs at sea each quarter. However the average drops off to under 10,000 tons per in the third qtr 1941, with the average at sea number rising to 33. A quick check against Huges & Costello 'The Battle of the Atlantic' confirms this trend & general numbers. It also confirms the complete institution of the convoy system from mid 1940.

    In the first quarter of 1942 the overall average per boat sunk rises a estimated 25,000 tons, with the average number at sea rising through 47, 56, 85, 99 subs at sea for each 1942 quarter. For the submarines involved in Operation Drumbeat during the first quarter the number hyperventilates to nearly 90,000 tons per sub (Ellis estimate).

    From the last quarter of 1942 there is a clear decline in tons per sub sunk. Dropping to under 5,000 tons avg. each.

    The original question concerned Operation Drumbeat - adding four Italian subs to it. If they average half that of the German per sub score in that campaign then 45k x 4 = 180,000 extra tons of US cargo sunk. It is possible they would do better against the unescourted cargo ships, and the USN handicap at that point was not in sinking the subs, but in getting a positive location.

    Overall the Germans sunk some 2,000,000 tons of cargo (not ship tonnage) destined for the UK in 1942. Adding a few percentage points to that does not change much. Conversely this period was the nadir in Allied cargo ship losses and a few percentage points addition ships sunk badly complicates the Allied cargo delivery problem in 1942. Concentrated on US shipping in early 1942 & the effect is even larger for the moment.

    I supose it is possible the Italian subs could perform so abysmally the difference would not show, but we need to better identify their actual sucess in terms of hard numbers.

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  • Roadkiller
    replied
    Although the Italian subs did not live up to the paper specs, there were also other technical and doctrinal issues. Italian subs were designed as fleet scouts and lone hunters which effected doctrine and design.

    Italian subs made a significant amount of diesel smoke on the surface and dived slower than German boats. Neither were problems to the Italians who expected their subs to patrol submerged most of the time, surfacing only at night to recharge their batteries.

    But if the boats were required to search on the surface as per German practice, crash diving only when threatened, both these issues became great weaknesses. They were especially problems when working within the range of land based ASW patrols.

    Italian subs were also expected to make all their torpedo attacks submerged, surfacing if necessary to finish off targets with their deck gun. Thus a very large periscope was fitted which increased the size of the conning tower in relation to other types of boats. This made their submarines easier to spot on the surface (especially by radar) than their German counterparts.

    These issues, as well as an inadequate communications fit (by German standards) made it difficult to blend Italian boats into wolf packs, and indeed they were employed as "lone hunters".

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  • johnbryan
    replied
    Originally posted by Carl Schwamberg View Post
    Four submarines dont look like a big difference anyway. Only one would be on a active combat patrol on any given day.

    Dont usually cite other discussion threads for information, but this has some numbers and sources.

    http://forum.axishistory.com/viewtopic.php?t=105324

    I've no time to pick over the numbers or check sources, but this remark caught my eye. Perhaps I can check it later.

    From the linked discussion.
    "by Jon G. on 10 Dec 2006, 11:51 Further to the numbers posted by Andy, above, the 32 Italian submarines operating in the Atlantic sank an average of about 17,750 tons of shipping each, a slightly better average than the German boats operating in the Atlantic.The top scoring Italian boat in the Atlantic was the Da Vinci, which sank 116,686 GRT worth of merchant ships. In addition, Italian submarines sank 74,000 tons of merchant shipping in the Indian Ocean.

    Numbers from Sadkovich."

    The average may be 'valid' over the long haul, but I'd want to take German averages from circumstances similar to when & where the Italian submarines were operating in the Atlantic. The German numbers from 1939 or 1943-45 tend to drag down the average
    Were those Allied ship losses in GRT actually verified? The Italians also had a problem with inflating the size and type of their ship kills. One boat skipper claimed to have sunk the US Battleship California with a spread of torpedoes.

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