In a prior entry at this link I posted the arrival information for freight in North Africa by month, from the Italian navy’s official history. This entry will complete this information by adding monthly merchant and military (where used for freight transport, not escort – but see note on December) tonnage losses on the Libya route. I am presuming that German merchant vessels lost are included.
I am also presuming that the difference between ‘sent’ and ‘lost’ does not equal the tonnage that actually arrived, but instead includes the tonnage that abandoned the attempt. This is a particular important caveat in November, when the large convoy ‘C’ returned to port in Italy after it had been attacked from the air and by submarine, as well as the damaged Iseo and tanker Volturno. I have a separate post on successful voyages in November 41, which you can read at this link.
Numbers for returned tonnage are lower not just because of the losses, but also because vessels were held back for cabotage traffic along the Libyan coast, or because they were damaged.
As part of their very useful statistics, the USMM also provides success information by type of attack, even though this is not elaborated on further (e.g. how they counted joint attacks by air/surface, such as on Iridio Mantovani on 1 December). These numbers seem only to relate to actual attacks, not sorties:
Surface vessel – 10 attacks, 100% success rate*
Submarine – 33% success rate
Aerial – 32% success rate
Sent 161,043 tonnes
Lost 54,011 tonnes (33.5%)
Returned 35,042 tonnes
Lost 0 tonnes
Sent 79,930 tonnes
Lost 31,436 tonnes (39.3%)
Returned 30,266 tonnes
Lost 6,311 tonnes (20.9%)****
Sent 107,602 tonnes
Lost 13,098 tonnes (12.2%)*****
Returned 71,532 tonnes
Lost 5,741 tonnes (8.0%)
*I can identify four (five if attacks on Regia Marina vessels transporting goods are included) of these ten attacks to have taken place during the broader CRUSADER period:
Destruction of the Beta/Duisburg convoy
Sinking of Maritza/Procida
Sinking of Adriatico
Sinking of Mantovani (Adriatico and Mantovani were sunk on the same day, but in separate engagements)
Sinking of light cruisers da Barbiano/di Giussano (possibly included)
**Most of these losses fell on the Beta– or Duisburg convoy which was entirely destroyed. But other ships were lost as well, such as Capo Faro to air attack on 30 Nov.
***The numbers here could be inflated by the loss of two Italian light cruisers da Barbiano and di Giussano with between them over 13,000 tonnes on 13 December. On the other hand, just adding up the losses of Iridio Mantovani, Adriatico, Fabio Filzi and Carlo del Greco, gets us to 26,189 tons, so it appears that the cruisers were not in fact included.
****This was Sebastiano Venier, torpedoed by HM Submarine Porpoise and beached on the Greek coast on return from North Africa, with Prisoners of War on board. A lot of detail on her loss and the consequences can be found at this link. I can state with reasonable confidence that while the Royal Navy knew of her passengers before she left harbour (Naval Headlines 159 issued on 8 December 1100 hours states that she was to leave harbour on 8 December 1600 hours with 2,000 POW), it is exceedingly unlikely that the commander of HMS Porpoise could have known this, since he would have been at sea well before the naval headlines were circulated.
*****This was the large liner Vittoria, sunk by aerial torpedo attack as part of the T.18 convoy on 23 January.