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Italian Submarine Doctrine


Staff member
by Mr.Bluenote » Sun Dec 11, 2005 7:48 pm

I've been reading up on some of the stuff regarding the Italian submarines and (proposed) carriers - mostly webbased sources as literatur on the matter is quite scare in Denmark - before and during WW2. One thing that I can't seem to figure out is who led these endavours (I'm lacking a better word)? Who was the Italian equivalent of Dönitz? And who exactly did argue for a carrier or two?

Speaking of submarines! What exactly was their intended use? It seems like the Italians - or the Supermarina (high naval command, yes?) hadn't really given doctrine and deployment a lot of thought or I'm I again showing my ignorance for all to see?

Oh, I hope this is the right forum?

I hope you guys can shed some light on these matters!

Best regards!

- Mr.Bluenote.


by SUPERMARINA » Mon Dec 12, 2005 6:05 am

The Regia Marina's doctrines about the conventional (Diesel and electric) submarine warfare between the two world wars was not different fron the British, French, USA, Japanese or Soviet one: a simply replay of World War one.
The Germans only had been able to conceive something new (the Wolfpacks tactic).
Italy, had least, had the merit not to follow, like France, USA, Japan and the same Britain (with the three Thames boats) the phoney path of the Fleet submarine.

The main responsable and theoricians of the Italian submarine fleet were, during the Thirties, Adm. Falangola and Legnani. They were the leaders of the submarine branch too during the war.
The brainchildren of this period were the oceanic boats ordered since 1935 (with the big submarine cruisers of the Caracciolo class as the most important result of that doctrine) and the CM mass production 100 t boats conceived in 1943.

Prototypes of snorkels had been tested successfully in the Tweinties and Thirties, but were considered simply fancies then.
Little true single engine diesel closed circuit submarines were tried in the Thirties too, but the system worked only for very small (15 t) attack craft boats.
Elektroboot were studied too, since 20 to 100 t, but again it was a technological dead end for the Italian batteries industry of the Thirties.
The same for acoustic torpedoes, while magnetic pistols were available in 1942 only, after five years of reseaches according a different system than the German one that the Kriegsmarine did not spare with the Italians.

The only way was, so, the classic boat doctrine.

About the carriers the Italian navy tried since 1919, but both for money and for Mussolini absolute and absurd love in aeronautics nothing was achieved. Adm. Cavagnari, chief of staff since 1934 to 1940, tried any system, direct and subtle included, but nith no result.




by Mr.Bluenote » Wed Dec 14, 2005 4:46 am

Thank you for your as always very informnative answer, Supermarina! It was kind of you to reply and shed some light upon the matter!

Again I might be very igorant, but I'm not afraid to show it!
How did the Italians used their submariens exactly? Did they work in unison with the surface fleet ala the Japanese? Or as a branch apart ala the Germans? Did they focus on keeping watch stations - acting like glorifed sentries -, raiding convoys, attacking warships or other?

I'm actually a bit confused in regards to the Italians submarine force and its use. The force was quite big, but seemed to have little or no impact on the war in the Med, or I'm I again wrong? It seemed the few German boats deployed there had some spetacular sucesses, but the Italians had little to show (and please don't take this the wrong way, I'm only asking bacuase I'm truly curious)!
I know, or seem to recollect to have read, that the Mediterranean is not very well suited for submarine warfare in the first place, but why then go to all the trouble of building up a huge submarien fleet?

On the note of carriers. What was Cavagnari and Co's idea of their use? Simple air cover? Reconaisance? Independant attack force? Convoy protection?

Best regards!

- Bluenote.


by SUPERMARINA » Wed Dec 14, 2005 5:28 am
Take it easy Bluenote, your answers are sound ones.
The 1940-1941 doctrine was to patrol in ambush zones.
Since 1942 the rule was: only some boats on patrol and most of the ones ready to sail if an eneny force was sighted (and was, of course, within the range of those slow boats).

The hard truth was that in the Med. there was not a traffic like the Atlantic ones, but only less then two dozens of convoys for Malta and a very reduced activity with Greece (57 freighters during all 1940) and coastal (usually MFVs) along the Palestine coast or boud for Tobruk.

The game with men-of-war was a very diccicoult one. You could be so lucky to score a torpedo, but the retailation was, usually, a fatal one.

The German U boats were used in 1941 and 1942 with the best daring attitude gaining goos results but paying an awful percentage of losses. If the Italian Navy had suffered the same % of boats lost like the German one with the huge numerical production of new boats, since the beginning of 1942 not a single Italian boat would be afloat.

When the North African Mediterranean traffic begun, results were quite better as there was, at least, a target to attack. The conventional Italian boats (and the German ones) in the Med., anyway, faced, in Spring 1943, the same defeat by the Allied ASW systems the Kriegsmarine faced in the Atlantic ocean in April and May 1943.

Since that time they were a necessary sea denial tool, but no more a war winning instrument.

The real contribute of the Italian submarine in the Med. (not to mention the boats on the oceans, which had, at least, in the 1940-1943 run, a pro unit result better than the U boats, accordign statistics) was to drain forn the Atlantic routes about 40 modern DDs and sloops since June 1940 until 1942. This condition helped very much the Germans to achieve their results during the same time.

The warm Med. waters are hell for Sonar, but they were very clear too, then, and the air menace was quite helped by this factor.

The idea of an indipendent carrier force like the USN or IJN ones
was dropped in 1934 as the balance did not allow to built and man more than two carriers.
The doctrine was, so, until Sept. 1943, like the British one: a companion of BBs.




Italians had many too big submarines for Mediterranea and their 600t ones for Med had no reloads until the last version already build in war, beasides most Italian submarines had only 4 bow torpedo tubes.


Italy's plans for submarine warfare were aimed almost entirely at France. Italy planned to mine the Sicilian Channel from Sicily to Pantelleria and cover the remaining distance south with MTB's, MAS, and submarines. The effectiveness of this was demonstrated with the Pedestal convoy. When Britain moved its naval base from Malta to Alexandria, the move did not fit with Italian naval thinking, and Italian naval strategy went from offensive (the Sicilian Channel) to defensive (recon submarines and aircraft south of Crete) as the area was way too big to maintain offensive patrols. Italy did send some long range attack patrols to the Eastern Mediterranean (likely searching for oil tankers off Haifa) but with virtually zero success. Such long range patrols were unwelcomed by Italian submarine crews who were granted extensive shore leave to prevent desertions. The extended leave reduced the amount of time Italian submarines were at sea.

Another factor effecting Italian patrol times was refit times. Italian submarines could only travel so many miles before requiring a 45-60 day refit or even longer. So a boat would suddenly disappear off the active duty rolls for two months. Italy started the war with one boat just hours away from refit and four others only three patrols away from refit. Other boats were designed for just 10 day patrols (in a month) in which two days were used reaching their station and another two days to get back, meaning they were only on station for six days a month.

Italian submarines lacked onboard computers to calculate firing solutions. The skipper was expected to calculate it in his head. However, my research shows they simply memorized a 2,000 yard solution and then closed to that range. Although the solution was effective, submerged Italian submarines had difficulty closing the range on a moving target. Further, Italian skippers preferred a three torpedo spread to four, with the middle one expected to hit. It was effective but Italian torpedoes used a 595 pound warhead expected to sink a 3,000 ton transport. Yet the British didn't play fair, sending 10,000-12,000 ton transports through the Mediterranean that could survive a single such hit.

It is true that German U-boats performed better than Italian boats. Most Italian coastal submarines were designed with 260 foot diving depths while the British were equipped with 300 foot depth charges. A German U-boat could dive well below British depth charges while an Italian one was a sitting duck in such clear waters. This made Italian submarine commanders very wary of being pinged by sonar/ASDIC as the British claimed a 50% probability of a sinking. It wasn't until 1942 that the Germans shared with the Italians how to avoid such detection.

German boats were also faster than Italian boats which allowed them to take up intercept positions.

The Italians also went through a period of an imaginary torpedo shortage. How they got this idea isn't known as Italy had enough torpedoes for the entire war from the first day. As a result of this delusion, Italian skippers were limited to spreads of 1-2 torpedoes.

Finally, Italian periscopes were unsuitable for night attacks. The Germans showed the Italians how to solve this in October 1940 but they took little interest.