The SteelNavy.Com Message Board: Re: Thank you. N/T

i have never heard of a wire being used at Taranto, but the aerodynamic tail WAS USED and used by the Japanese at Pearl Harbour, to hold the torpedo horizontal when dropped from low altitude, this combined reduced the "depth of dive".the tail was designed to break away on surface contact!
the tail was also used by Coastal Command strike wings torpedo droppers! again from low altitude!
i would have thought the problem with a wire being involved would be it getting caught in the proppelors???

Previous Message

Just like to say, that was a great reply.

Previous Message

Quote:
"What actually was the desired initial dive for Taranto and how low the aircraft flew ?"

Two sources list the following:

"All torpedoes were to run at twenty-seven knots
and at a depth of thirty-three feet, and all were armed with duplex pistols.40"

"At Taranto the torpedoes were set to run at 27 knots at a pre-set depth of 33 feet. This was calculated to enable the torpedoes to pass under anti-torpedo netting while still allowing the new Duplex magnetic warheads to ‘sense’ a warship above and explode while passing beneath, or detonate on contact. Taranto's battleship harbour had an average depth of 49 feet." (Other sources list 39 or 40 feet.)

As to "desired initial dive," I found that the British knew this much from their exploratory efforts:

"What the Italians did not know was that the British had found a solution. The nose of the torpedo was hooked to a wire wound on a drum beneath the aircraft. Upon launch, the wire pulled the nose of the torpedo up so that after falling from low level, it hit the water in a belly flop instead of a dive. Attack was possible in water as shallow as 22 feet."
(From this source:
https://www.airandspaceforces.com/article/the-air-raid-at-taranto/ )

As to how low they flew, AI reports "as low as 50 feet." This account from the lead plane's observer indicates they were a good deal lower:

"The flight leader of the first attack wave, Lieutenant Commander Williamson, dropped his 1,600 pound torpedo before turning away sharply. Williamson flew so low when dropping the torpedo that the wing tip of his Swordfish hit the water surface during the turn. "I fell out of the plane. We were six feet above the water, so it wasn't a long fall." "
(From this source: https://www.tracesofwar.com/articles/5425/British-attack-on-Taranto.htm )

There's a photo here of a Swordfish dropping with his wheels nearly touching the water. Look for the section titled, "Shallow-Water Torpedoes":

https://www.armouredcarriers.com/operation-judgement-swordfish-attack-taranto-from-hms-illustrious

Previous Message

Since the 80th anniversary of Taranto raid a Youtube channel has been demonstrating the method used in which a tension wire connects Swordfish and its torpedo in order to ensure a belly flop and thus a shallow initial dive, the tension wire running from torpedo nose to a reel in Swordfish. There was also a wooden aerodynamic tail as both splinters of wood and tension wires are said to have been later floating around. I wonder what is the background of this because the concept involves a wire holding a long and heavy object (CofG close to 50 %) under the aircraft with the other end unsupported. Maybe this matter has already been discussed elsewhere but here are my thoughts.

A wire should not be necessary at extremely low altitude. The torpedo possibly stays near horizontal and in calm conditions skims shortly on the surface. Aircraft's speed is still high compared to any surface craft so bouncing could also happen. Then tail planes and control rods could get damaged. On the other hand unwinding wire should produce no pull upwards at all. The reel should also be above torpedo's nose where Swordfish has its engine. What would detach the wire from both ends and would it not whirl around ?

The wooden tail was to prevent rolling and give the right angle of entry, hardly needed at a very low level. In general, usual means to control depth (in short) was done by adjusting hydroplanes, depth gear and engine. Torpedoes could also be made to run light without fuel and water ("cold") as CMBs did in Kronstadt in 1919. Depth control was critical on coastal waters and improvements were tested in the 1930's. Perhaps RN had developed its own system.

Both initial dive and depth keeping varied greatly. For comparison one 45 cm 800 kg torpedo dived down to 5-6 m before reaching 3 m depth setting (static tube, 1,5 m height). A margin was accepted. I do not know Taranto waters but battleships (9-10 m) could move there and Conte di Cavour was immersed by the barrels of C turret. The height from the ship's bottom (17 m) suggests a fair depth even if embedded in mud. With magnetic exploder a depth setting of 9-10 m plus something plus margin was obviously needed. These torpedoes must have run this deep all the way. To my knowledge in 1940 no device could gradually guide a torpedo deeper.

In developing its Avio torpedo, Whitehead of Fiume conducted shallow water (20 m) trials with an aerodynamic tail. An initial dive of 11,2 m was achieved (angle 32 deg, weight 880 kg, speed 312 km/h, altitude 85 m, 4 m depth setting). What actually was the desired initial dive for Taranto and how low the aircraft flew ?

Olli