Italian Sonar/Asdic

[red admiral]

I wonder if someone could comment on the Italian sonar of the interwar period?

"The first (experimental, and primitive) Italian sonar device was tested in 1931 of the Langhiria-Florison type.
The first satisfactory Italian device was mounted onboard the sub-chaser Albatros, completed in 1934.
An upgraded version (2,000m range, +/- 1° accuracy(0.3%)) was mounted onboard the four Avviso Scorta of the Pegaso class, completed in 1938."

Any idea on the sweep range of these sonars? I ask because if they use a 5° sweep like RN versions then the 1° margin of error is huge. The accuracy figure quoted of 0.3% indicates a 360° sweep. (1/360x100% = c.0.3%)

Thanks

[Davide Pastore]

I wonder if someone could comment on the Italian sonar of the interwar period?

"The first (experimental, and primitive) Italian sonar device was tested in 1931 of the Langhiria-Florison type.
The first satisfactory Italian device was mounted onboard the sub-chaser Albatros, completed in 1934.
An upgraded version (2,000m range, +/- 1° accuracy(0.3%)) was mounted onboard the four Avviso Scorta of the Pegaso class, completed in 1938."

Any idea on the sweep range of these sonars? I ask because if they use a 5° sweep like RN versions then the 1° margin of error is huge. The accuracy figure quoted of 0.3% indicates a 360° sweep. (1/360x100% = c.0.3%)

Thanks

I wrote on 14 May 10:28 this passage:

Actually the first (experimental, and primitive) Italian sonar device was tested in 1931.
The first satisfactory Italian device was mounted onboard the sub-chaser Albatros, completed in 1934.
An upgraded version (2,000m range, +/- 1 degree accuracy) was mounted onboard the four Avviso Scorta of the Pegaso class, completed in 1938.

I did NOT wrote "(0.3%)" and I have not the slightest idea about its meaning.

I suppose someone quoted my words (without saying it, I suppose ) and added a percentage of his own making for good measure. He added as well the words "of the Langhiria-Florison type" above (BTW the correct spelling is Florisson with two "S").

Where did you find that text? Who wrote it?

BTW are you sure that +/- 1 degree accuracy at 2,000m is a "huge margin of error"? It means +/- 35 meters (2,000 x 2 x 3.14 / 360 ). If RM ships had had a 2Km-range standoff ASW weapon fired on that data alone, it would have been very close to a one-shot-one-kill.

Davide

[red admiral]

Combination of text found on another forum, comandosupremo IIRC and some other information from RegiaMarina.net with regards to the type and that percentage figure for accuracy.

The 0.3% accuracy is equivalent to +- 1° in 360° which is why I thought of a sweep of 360°.

The RN sets used a 5° wide beam to illuminate the target submarine. The +-1° error in this is very large.

The 1° error at 2000m gives an error of +-35m so need to drop the weapon within an area of 70m diameter. At 500m range this reduces to area of 16m diameter, much greater chance of a hit.

I'm wondering what sort of weapon would be best for firing ahead and trying to get a hit within the technology of the time. I'm thinking about a small torpedo, say 325-350mm diameter. Something similar to W 120/500 but launched into the target area and taking a spiralling path downwards until it hits the submarine.

Also, any idea what this is on the stern of Gabbiano?


Original from Marina.Difesa.it

[Marcus]

Welcome to the forum.

/Marcus

[Davide Pastore]

Combination of text found on another forum, comandosupremo IIRC

Well, now I must be happy because, as the poet said, plagiarism is the most sincere form of adulation, or something like that...

Also, any idea what this is on the stern of Gabbiano?

It is a Scaricabombe Gatteschi. Corvettes had two, each loaded with 24 B.G.S. (Bomba da Getto Simultaneo, a 50kg depth charge) in group of 4. Inside each group the B.G.S. were set to explode at a different depth (30, 60, 90 and 120 meters) to create a vertical pattern. Each corvette salvo included a minimum of 8 bombs (one group per rail) [#1] but all 48 on board could be launched with short delay. By far the most effective Italian ASW weapon.

[#1] plus 8x 100kg bombs fired from the eight conventional throwers, 4 to port and 4 to starboard. These launchers had 16 ready reserve DCs.

Davide

[red admiral]

Thank you.

Along similar lines I was searching for photos of Gatteschi discharger and found this mounted on one of the Gabbiano corvettes, Sibilla. The caption says "catapulta per il lancio di bersagli aerei radiocomandati". Is this post-war and basically what is it as I'm never seen nor heard mention of such a thing before.


http://www.marina.difesa.it/storia/Alma ... 2-57ag.jpg

[Davide Pastore]

Three pictures of the Gatteschi. For some reason I could not find any image of a loaded discharger. The top image shows the way the bomb were loaded.

Inside each group the B.G.S. were set to explode at a different depth (30, 60, 90 and 120 meters) to create a vertical pattern.

A thing I didn't say: these were four different types of B.G.S. (not the same bomb with four variable settings) each one with a different descent speed, so that all four of them exploded at the same time, each one at its own depth. The effect was a giant vertical shock wave.

The caption says "catapulta per il lancio di bersagli aerei radiocomandati". Is this post-war and basically what is it as I'm never seen nor heard mention of such a thing before.

Launcher for remote-controlled target drones (for AA training, I suppose). Drone model unknown. The modification is definitely postwar, date unknown: note that Sibilla has a NATO hull number. During WW2 his hull would have instead shown two letters of his name (probably SB) as per standard Italian policy.

Davide