Italian Submarines

Discussions on all aspects of Italy under Fascism from the March on Rome to the end of the war.
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Pips
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Italian Submarines

Post by Pips » 28 Jul 2006 09:13

It's probably safe to say that the Detroyers, Destroyer escorts and minesweepers were the most active of all the vessels in the Regia Marina. And performed outstandingly well. Even the larger vessels eg Cruiser and battleships, did well given the limits imposed by lack of fuel, radar and especially poor air reconn support.

But the submarines for some reason which I haven't been able to determine failed badly. It certainly wasn't due to lack of numbers, with more than 70 operational in the Med at the start of the War in 1940. And it wasn't to do with skill and courage, that old chestnut has long been proved no more than propaganda. So what was it? Tactics? Strategy? Planning? Lack of skill at implementing a submarine campaign? Poor intelligence?

The British and Germans achieved far more with much less numbers. And it wasn't due to not employing the 'wolf pack' concept - no Submarine force of any nationality utilised that tactic in the Mediterranean. So what were the factors that affected submarine performance?

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Davide Pastore
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Post by Davide Pastore » 28 Jul 2006 15:09

In the Mediterranean the Allied targets were very scarce, just a major convoy to Malta every two-three months or so, and this means they were heavily escorted as an added disavantage. Note that the UBoote operating there suffered a very high loss ratio too.

On the contrary the Allied subs had much more targets, and much easier ones.

Davide

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Christian W.
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Post by Christian W. » 28 Jul 2006 20:30

I might be wrong, but I belive that Italian submarines sank some 900000 tons during the war in total.

zmija
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Post by zmija » 28 Jul 2006 21:22

If you can read german try 'Krieg unter Wasser' by Franz Kurowski.

red admiral
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Post by red admiral » 28 Jul 2006 22:37

http://www.comandosupremo.com/italian_subs.xls

Is a spreadsheet giving details on Italian submarine victories by Submarine and Commander.

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Davide Pastore
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Post by Davide Pastore » 29 Jul 2006 13:53

Christian W. wrote:I might be wrong, but I belive that Italian submarines sank some 900000 tons during the war in total.


Many were in the Atlantic (where a sub could meet a lone easy merchant).

Davide

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Pips
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Post by Pips » 30 Jul 2006 11:43

During the course of the war (1940 -1944) in the Mediteranean the Royal Navy Submarine Force performed in the following manner:
a) It operated (at various times) a total of 87 submarines.
b) It lost 46 submarines.
c) It sank 324 merchant vessels totalling just over 1,000,000 tons.
d) In addition RN subs sank (Italian) 3 cruisers, 12 Destroyers/escorts and 17 submarines. And a further 9 U-Boats.

The Kriegsmarine, between 1941 and 1944, committed 81 U-Boats to the Mediteranean. Nine were sunk on passage, 10 damaged and failed to make it through the Gibraltor Straights (returning the France). 62 operated in the Med. The U-Boats sank:
a) 95 merchant vessels totalling 449,206 tons of shipping
b) 2 Aircraft carriers, 1 Battleship, 4 Cruisers, 12 Destroyers, 3 Subs and 6 small naval vessels
c) All 62 U-Boats were lost

The only information I've been able to find on the Italian Sommergibili is:
a) Italy started the war with 117 submarines
b) 88 were sunk int he Mediteranean, 40 elsewhere
c) They sank 129 merchant vessels totalling 668,311 (all oceans)
d) They sank 13 warships (all oceans)

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Davide Pastore
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Post by Davide Pastore » 30 Jul 2006 15:00

Pips wrote:The only information I've been able to find on the Italian Sommergibili is:
c) They sank 129 merchant vessels totalling 668,311 (all oceans)
d) They sank 13 warships (all oceans)


According to my sources, actual total is 132+18.
Of these, 111+5 were sunk by just 25 boats operating in the Atlantic. As you can see, giving equal opportunities, Italian subs can sink target as well as anyone else.

Davide

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Post by Wargames » 14 Nov 2006 09:27

Italian submarines were not as boldly commanded as German U-boats, as U-boat losses confirm. The principal problem with being "bold" was the water was shallow for depthcharging a submarine so most British and Italian comanders looked for targets that wouldn't shoot back.

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Post by TRose » 28 Nov 2006 17:44

A big question I would have is of the 117 Subs Italy started with is how many where long range and how many where small coastal subs. The war showed that except for training, small coastal subs where of not much use as they did not have range to attack merchants ships and attacking heavy defended invasio fleets and the like was a messy form of suicide

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Post by Wargames » 29 Nov 2006 06:08

TRose wrote:
A big question I would have is of the 117 Subs Italy started with is how many where long range and how many where small coastal subs. The war showed that except for training, small coastal subs where of not much use as they did not have range to attack merchants ships and attacking heavy defended invasio fleets and the like was a messy form of suicide


As I recall, Italy had about 30 ocean going (Atlantic) submarines, leaving 87 coastal subs (The figure also posted by another). They were small, energy efficient boats easily able to stay at sea for 30-40 days. They were well suited to the Mediteranean and represented a modern, effective weapon. As was true of all submarines of the period, they ran on the surface to get to station and this posed a problem as they neared Alexandria in the eastern Mediterranen as they became subject to land based air attack. The British also engaged in "anti-submarine sweeps" in the Eastern Mediterranean using a squadron of four destroyers to hunt one submarine. If the DD's detected an Italian submarine, there wasn't much chance of it getting away. Finally, British subs also hunted Italian subs which leads to the next factor. The Eastern Mediterranean was a long ways away from Italy even if it doesn't look like it on a map. I think it took about 10 days to reach station and then another 10 days to return, so the actual net days on station was about 20. In order to maintain a constant patrol of such a sector, another submarine had to leave Italy 10 days after the first reached its station. That way, when the second left, the first would then arrive to take over the patrol duty. Thus, it took two submarines to maintain a constant patrol in what was a very unfriendly area. Making it even more unfriendly, British subs stationed themselves in the central Mediterranean where the Italian subs passed, on the surface, either going to, or coming from, the eastern Mediterranean. Between planes, destroyers, and British submarines, an Italian submarine patrol was very dangerous to perform in the east.

Further, when one considered refit times, it actually took about three submarines to maintain a patrol. If we accept this math, Italy could field about 29 subs in the eastern Mediterranean, the most likely place for British targets. However, since Gibralter also offered a hunting ground, usually about 10 of these subs were in the western Mediterranean, leaving the max for the east being about 19 boats. As stated, it was very dangerous to operate here and, if more boats were lost than replaced, the number would (and did) drop below 19.

While 19 boats represented an effective number, the Eastern Mediterranean is a big sea and the boats may miss a task force altogether and, even if sighted, may not get close enough for an attack or, if night, may not even see the target go by. The odds were fairly good that a British task force leaving Alexandria could get by the screen without being attacked. When the British did leave Alexandria they knew the Italian subs were out there and provided a heavy DD escort. Italian submarine captains declined to try and penetrate this escort (British sub captains did the same) and so had to be satisfied with "long shots". The required "spread" at this range seldom resulted in more than one torpedo hitting its target. The result was that, unless the target was a transport, another submarine, or a destroyer, it seldom sank. It was, however, usually out of the war for six months.

The result was that establishing and maintaining a screen of submarines produced more losses than sinkings. The Italians later changed tactics and pulled out all but a few recon boats from these dangerous waters and, instead, began to vector them towards known convoys, particularly in the Sicilian channel. Although they had to make night attacks here, sinkings now exceeeded losses and this became known as the "Victory of the Light Forces". Had the tactic been employed earlier, such as against the "Tiger" convoy, Italy probably would have had a higher sinking score as well as more surviving boats by the end of the war.

German U-boats were commanded differently. They would penetrate a DD screen and then launch torpedoes at closer range and with a tighter spread. The target didn't just get hit by one torpedo, but several. Compare the warship scores for both the Germans and the Italians posted above:

Italians (87 boats): sank 3 cruisers and 12 destroyers
Germans (62 boats): sank 2 aircraft carriers, 1 battleship, 4 cruisers, 12 destroyers

So the Germans, by their daring, accomplished more with less. However, this is deceiving in two ways. First, it was more dangerous to do (all 62 U-boats being lost). Second, it fails to take into consideration the Italian PIG attack on Alexandria which was actually a submarine launched attack. When this is considered, the score changes:

Italians (87 boats): sank 2 battleships, 3 cruisers, and 12 destroyers
Germans (62 boats): sank 2 aircraft carriers, 1 battleship, 4 cruisers, and 12 destroyers

The edge still goes to the Germans but not by much and that was achieved at a greater price. All in all, I found nothing to criticise about Italian coastal submarines. Properly used they're a very powerul, yet fuel economical, force.

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Bronsky
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Post by Bronsky » 29 Nov 2006 18:01

Another problem with Italian submarines was their high conning towers and long diving times. This meant that they were vulnerable when on surface - easier to spot, longer to disappear - and, like all WWII submarines, largely powerless when submerged unless already in position.

U.S. submarines had the same problem, and those few that operated in European waters were quickly withdrawn. On the other hand, the Italian submarines had better seakeeping qualities than U-boats. Davide may correct me here but I don't believe that Italy lost subs from non-combat causes whereas Germany lost several (including at least one of the captured ones).

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Andy H
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Post by Andy H » 01 Dec 2006 06:52

Off the 115 commisioned units, 39 were ocean-going, 69 were Mediterranean going, whilst 7 were old boats of no value.

On June 10th 1940, the Italians had 84 operational boats, 2 completing trials and 29 undergoing repairs.

From June 1940 to September 1943, Italian submarines in the Med:-
Completed 1553 patrols
made 173 attacks
fired 427 torpedo's
fought 33 gun actions
sank 23,960GRT of warships (4CL's 2 DD's 1SS, 3 minor vessels and 1 auxillary vessel
sank 69,690GRT of merchant shipping.
BUT
Lost 68 boats (59 were sunk in action, 2 were captured (before the Armistace) and 7 lost in accidents or bombed in port

Of the 32 boats which operated in the Atlantic:-
16 were lost
189 patrols were made
101 merchant ships were sunk and X warships
totalling 568,573GRT plus a further 200,000 damaged

Source:Bagnasco

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Andy H

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Andy H
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Post by Andy H » 01 Dec 2006 07:18

Germans (62 boats): sank 2 aircraft carriers, 1 battleship, 4 cruisers, 12 destroyers


Is this figure upto the war ends, or upto when Italy surrendered?

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Andy H

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Xª Mas
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Post by Xª Mas » 01 Dec 2006 22:43

As said before, I believe that the reason for the lack of success with Italian subs, is the fact that they didn't travel in Wolfpacks like the germans. The Italians did a hit and run maneuver and take out 1 ship at a time. The German wolfpacks could take out an entire convoy, which is much more effective than the Italian "solo" attempts.

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