"Pugliese Water-Line?" Topic

I posted this question on another site yesterday, but it looks like nobody over there can help me with this one, so I'll put it up on TMP to see what happens.

I happened to Google Umberto Pugliese during my morning break yesterday, and got one rather puzzling hit. The Jewish Virtual Library has a short article about the Regia Marina's chief naval architect, and says, "His most remarkable invention was a device known as the Pugliese Water-Line capable of enabling bombed battleships to float and, in many instances, to resume service."

Apart from me having always thought his most famous invention was the anti-torpedo system which bore his name, I have to admit I've never heard of this "Water-Line". I tried Googling the term but got nowhere with that search. However there are many people on this site who are much more knowledgeable than me on naval history, so I was wondering if anyone here can fill in some of the blanks?

"The Italians made the next, much more negative leap in 1934, with the Pugliese System introduced in the Vittorio Veneto Class and the reconstructions of the Conte di Cavour Class and Andrea Doria Class ships. The Pugliese design filled the volume of the TDS with a large cylinder, which was in turn filled with closed tubes reminiscent of those in HMS Ramillies. Pugiese's theory was that the torpedo would expend its energy crushing the cylinder. In practice the design failed miserably. Following the path of least resistance, the blast traveled around the cylinder and concentrated itself against the weakest point of the complex structure supporting the cylinder: the concave holding bulkhead."

From an article called "Torpedo Defense Systems of WWII" by Joseph Czarnecki, written in 2001 on the Navweaps.com website.

Hope that helps.

Eric

My guess is that the "Pugliese Water-Line" is a badly translated reference to his underwater protection system. That would be likely if the original text was not English, and if the translator wasn't knowledgeable, or if the translator was a computer program.

Mark

I think you guys are right, it is a very poorly worded reference to his torpedo defence system.

To add a bit of perspective on the Pugliese system, the following is taken from:Bagnasco & de Toro's fine book on Littorio class battleships –

quote -

The proposed structure of the entire (Pugliese anti-torpedo) system was reexamined under the most realistic conditions during the early months of 1935, analyzing the effects on a purpose-built test structure of contact explosions against the two underwater surfaces by charges of up to 640kg of trinitrotoluene (TNT), which was much greater than the 320kg in the warheads of contemporary 533mm torpedoes, on the assumption that in the near future a rapid increase in the power of both torpedo warheads and mines was possible. Overall the results of the numerous tests were judged to be satisfactory with respect to the system's ability to absorb the energy of the explosions. Further prrof was provided by analysis of the torpedo damage sustained by the Littorios during the war.

Generally speaking, the Pugliese system was fairly effective against contact-fused weapons that hit the ships on the sides in the area of the citadel; however, as was predictable, its performance was more limited when faced with torpedoes that exploded at the extremes of the citadel area, where the system's dimensions were reduced. This, however, was true for all other underwater protection systems as well.

- unquote

Criticism of the Pugliese system appears to stem from the experience of Littorio at Taranto, where she was hit by three 18in aerial torpedoes with 176kg warheads. However, the evidence seems rather insufficient to justify such a harsh judgment. Hit No. 1 struck between the forward main battery turrets, within the scope of the protective system, and was absorbed. The other two hits struck well beyond the protective coverage of the anti-torpedo system – Hit No. 2 at the extreme stern by the rudder, and Hit No. 3 in the bow well forward of No. 1 main battery turret.

In 1943 Littorio took a near miss from a Fritz X off her starboard side in exactly the same locale as the No. 1 Taranto torpedo hit. The bomb's 320kg warhead exploded about 15-20 feet from the ship's side and its effects were absorbed by the anti-torpedo system.

B

Criticism of the Pugliese system appears to stem from the experience of Littorio at Taranto

IIRC, the British 18" torpedoes used at Taranto were using their magnetic exploders. Such torpedoes would allow hits close to the turn of the bilge, or even under the ships, thus partially or totally circumventing any conventional WWII-era torpedo defence system, and vastly increasing potential damage due to whipping, etc. In the case of Cavour and Duilio, at least, the "Warship 2010" article shows the damage as being of this sort. The same article contains an image showing what happened to Littorio's float plane (at the extreme stern), which suggests to me that the ship was subjected to some degree of whipping,

Some interesting information on whipping damage can be found in the "Wartime Damage" chapter of DK Brown's book "Nelson to Vanguard". For example, on around page 161, he discusses what happened to HMS Belfast.

Mark

Hi Mark,
FWIW – re torpedo fuzes, Lowry and Wellham ["The Attack on Taranto"] say that the torpedoes employed were all Mk XII's with contact exploders, although they do not provide any reference citation. The Italians appear to have been of the opinion that the degree of damage suffered by their ships was related to explosion energy reflecting off the very shallow harbor bottom.

Do you recall where you read about British use of magnetic exploders? If correct, that would be really interesting to me.

B

Hi Blutarski,

See the "Warship 2010" O'Hara article referenced above, page 81, etc. Not a primary source of course. Also, note that he shows a cross-section of Duilo's damage, showing a large hole *under* the forward magazine group.

Another source is the "Sea Battles in Close Up" series from the 1970s, These were republished in the 1980s with updated content. In the first volume (with the Wilkinson River Plate painting on the cover), in the "The Attack on Taranto" chapter, there is the following on page 38: "The torpedoes were to be armed with the Duplex pistol, which could explode either on impact or under a vessel's hull, being activated by magnetic influence. The Duplex pistol performed badly in anything approaching a heavy sea, and in the relatively shallow waters of Taranto there was a danger that the torpedoes would hit mud and not metal, but the advantages of the dual strike capacity and the damage that could be inflicted by an explosion under the hull, plus the calm waters of Taranto, seemed to justify the risk."

The British probably also used Duplex pistols when they attacked Richelieu in Dakar harbor on July 8 1940, but I haven't found a reference stating that yet. The Richelieu suffered very extensive shock damage from that single 18" torpedo hit, per the new "French Battleships" book.

They of course used them on the intial attempt to stop the Bismarck in 1941, where they exploded prematurely in the rough seas (fortunately for HMS Sheffield).

Mark

Thanks, Mark.
Very interesting. Vince O'Hara is pretty scrupulous about his work.

B