Operation Principle December 42-January 43

[Paul Nuttall]

Operation Principle December 42/January 43 involved three RN submarines - HMS P311, HMS Trooper and HMS Thunderbolt all carrying British versions of the Chariot, two, three and two respectively.

P311's Chariots were to attack the Italian cruisers Trieste and Gorizia at anchor off the Sardinian island of La Maddalena.

P311 never made it to La Maddalena and its wreck was found in 2016, probably lost due a a mine.

HMS Trooper and HMS Thunderbolt both went to Palermo, Thunderbolts target was originally Cagliari.

What was at Palermo and Cagliari at this time for other two submarines especially as Trooper carried three Chariots against the other two subs two.

[Nik_SpeakerToCats]

https://en.wikipedia.org/wiki/Chariot_manned_torpedo

[Paul Nuttall]

https://en.wikipedia.org/wiki/Chariot_manned_torpedo

Yeah, that's one of the sites I found looking, but it doesn't say what else was there at the time.

It also makes me wonder if the MkII Chariot warhead with 1,200lb Torpex could have been used from the start with the MkI with its 600lb of Torpex...1,200lb of Torpex is going to give you a lot of problems.

[Simon Darkshade]

Major units of the Regia Marina in December 1942/January 1943:

Littorio, Roma, Vittorio Veneto - La Spezia
Duilio, Andrea Doria - Laid up at Taranto
Giulio Cesare - Laid up at Pola
Conte di Cavour - Under repair at Trieste

Bolzano - Immobile at La Spezia
Gorizia - La Maddalena
Trieste - La Maddalena

Attilio Regolo - Under repair at Livorno
Giuseppe Garibaldi - Active, La Spezia
Luigi di Savoia Duca degli Abruzzi - Active, La Spezia
Eugenio di Savoia - Damaged by USAAF raid at Naples 4/12/42
Muzio Attendolo - Total constructive loss by above raid 4/12/42
Raimondo Montecuccoli - Damaged by USAAF raid at Naples 4/12/42
Luigi Cadorna - Active, Taranto


At most, there would have been destroyers at Cagliari and Palermo; the real remaining targets were Trieste and Gorizia, with everything else large enough out of reach.

[Paul Nuttall]

Thunderbolts and Trooper's Chariots sank a light cruiser at Palermo but the two cruisers at La Maddalena look to have been the better target for all three. Be interesting to know if their positioning would have allowed them to sit on the harbour floor as with QE and Valiant or whether they would have been write offs.