This post received a major update on 9 July 2012 based on a discussion with Stefan Westermann.
A lot of discussion and research about the war in North Africa focuses on supply. This is quite right, since supply was the decisive factor in the battle. What is of interest in this discussion is that there are few hard, reliable numbers being used. This is surprising, given that the German and Italian documents are available, and provide a lot of the answers.
One question that has arisen to me is the validity of the often cited numbers by the historian Martin van Creveld, from his book ‘Supplying War’ (which I would highly recommend). The question is how, if the monthly capacity of Tripoli is 45,000 tons, much higher delivery rates could be achieved in some months. Another question is how, if Tripoli is supposed to be the major harbour in Libya, it’s daily capacity is considerably below Benghazi’s (1,500 daily tons to 2,700 daily tons, according to ‘Supplying War’)? For those who do not own the book, an article citing the numbers can be found at this link, and it is well worth reading too.
Based on the book, the port capacities of Tripoli and Benghazi are 1,500 tons/day and 2,700 tons/day, respectively, with RAF attacks downgrading Benghazi to 750 tons/day (while I presume this is for 1942, I should have thought that RAF bombing in 1941 also had significant impacts). No footnotes are given for these numbers, and it is quite strange, since many other things are very well footnoted, and van Creveld clearly had access to primary documents. In any case, this equates to a monthly capacity of 46,000 tons for Tripoli and 82,000 tons (ideal)/23,000 tons (effective) for Benghazi. Based on further discussion, I think it can safely be said that van Creveld is quite completely wrong on this. The situation in reality appears to be as follows:
On ideal days, 5,000 tons could be discharged in summer’41 (remark by Admiral Sansonetti during a staff discussion on supply in Rome in September 1941, to be found in Panzergruppe War Diary Appendices Chefsachen).
On ideal days, 1,700 tons had been discharged during summer 1941, and on average 1,000 tons had been discharged over the summer months, with a plan to move this up to 1,500 tons. The German view was that 2,000 tons was attainable, and the Italian navy did not dispute this in the meeting.
Constraints in getting additional supplies across the Med were multi-faceted, and direct port capacity was only one aspect, as the conference minute from 12 September 1941 makes clear. Even before the heavy losses of merchant vessels in the last quarter of 1941, there was a shortage of shipping space and convoy escorts for the North Africa route. At the Italian end, capacity of the railways made it difficult to load ships up to ideal weights. The sending across of motor vehicles led to ships ‘cubing out’ before they ‘weighed out’ – i.e. the trucks took up a lot of space compared to their weight, meaning that they restricted overall load. In assembling the convoys, restrictions in number of berthing space at the Libyan end had to be taken into account, limiting the number of ships, but then ships were sunk, leaving capacity in the receiving harbour idle. In those harbours, trucks were missing to handle transport of goods from the quays, Benghazi and probably Tripoli were missing storage, and there were not enough lighters and barges. RAF attacks restricted capacity further, both in Benghazi and Tripoli, with part of Benghazi blocked due to ships sunk in harbour. But this is all related actual capacity, rather than real capacity.
So one could maybe argue that van Creveld is talking about presumed capacity taking all this into account. But that doesn’t fly either. Below is an excerpt from a radio transmission from the DAK war diary, giving monthly figures unloaded for May to August 1941 in Tripoli and Benghazi. An issue in Tripoli’s capacity to me seems to be the transfer to coastal shipping. I would presume that in many cases this transfer would be done while the ships involved are not necessarily moored, but are somewhat offshore, and that it is done directly from ship to ship, or by barge from ship to ship, and therefore does not necessarily constitute a direct impact on the port facilities beyond requiring barges.
Nevertheless, as the table clearly shows, Tripoli easily attained above 1,500 tons/day in two months of 1941, Benghazi in one month, and presumably the ports would not have operated at capacity (even considering restrictions outlined above), with flow of goods related to convoy arrivals.
|Tripoli German Cargo||20,300||17,000||35,800||17,400|
|Tripoli Italian Cargo (includes civilian)||26,000||45,000||28,800||49,300|
|Tripoli Total Cargo||46,300||62,000||64,600||66,700|
|Tripoli Coastal Transfer||16,380||14,700||11,720||13,820|
|Tripoli Daily Cargo Discharge||981||1,551||1,734||1,734|
|Tripoli Daily Coastal Transfer||537||482||384||453|
|Tripoli Total Daily||1,518||2,033||2,118||2,187|
|Benghazi German Direct||1,420||–||4,570||3,470|
|Benghazi German Coastal||10,580||7,100||5,720||7,920|
|Benghazi Italian Direct||5,000||3,500||7,100||10,700|
|Benghazi Italian Coastal||5,800||7,600||6,000||5,900|
|Total North Africa||52,720||65,500||76,270||80,870|
The minute of the staff conference further does talk about a ‘calculated’ port capacity in Benghazi of 2,000 tons/day, which (see table above) it was recognized that it was unlikely to be reached. Constraints were the removal of unloaded goods from the quay, and the storage of goods that could not be removed from the port area immediately. Both of these of course directly related to the shortage of trucks in North Africa. Berthing space in Benghazi was given as two large (max. 3,500 GRT, 7 m draft), one small vessel, and one tanker. Only eight Italian and four German merchants fitted that bill. These merchants which fitted Benghazi were further restricted by being able to only take itemized cargo or vehicles, but not both. Maximum realizable capacity was therefore seen as 45,000 tons/month, or 1,500 tons/day, even though recently daily discharge had reached rates up to 1,700 tons – but of course this was dependent to some extent on the types of goods being discharged, and their specific weight. Realistic capacity was assumed to be 1,000 tons/day.
On 1 November 1941 a note is appended to the war diary of German Naval Command South that states that the situation has not changed since the memo of 11 August 1941, and that based on experience to date the capacity of the harbour was assumed to be 30,000 tons monthly, but that it was feared that weather conditions and expected damage from air attacks would reduce this over the next few months. It crucially does state however that the real discharge capacity is higher, and has not been reached due to a combination of adverse weather conditions, enemy action, and a lack of shipping.
The inescapable conclusion of this is that van Creveld’s numbers on port capacity are wrong. It is important to note that this does not affect his main argument however, which is rather concerned with port distance from the frontlines, and which I continue to believe stacks up.
Other items of note:
– in terms of the impact that distance had on the effectiveness of supply, a German claim in a document on submarine supplies to Bardia, namely that 100 tons of cargo discharged in Bardia were of equal value as 600 tons discharged in Benghazi!
– transport of troops by air is more fuel efficient than by sea, but restricted by a lack of available planes (100 required, 15-20 available with a capacity of 30 troops each (I presume Sm.82), and these need heavy maintenance after just two round-trips). Shortly after the conference, Mussolini prohibited transport by sea in passenger liners in any case, following the sinking of the Neptunia and Oceania (see here) in which 384 soldiers and sailors lost their lifes, and which had been preceded by the loss of MV Esperia in August (see here). There are good pictures of Neptunia, Oceania, and Victoria, which was lost to aerial torpedoes on 23 Jan 42 at this link.