I certainly appreciate your effort in sifting through thousands of pages of Italian history on this relatively (and undeservedly) obscure subject. My proficiency in Italian is close to zero, but I think I may have caught a mis-interpretation here:
I assume these German locomotives were steam engines?Bronsky wrote:...Then there are various mentions of a convoy arriving on August 4 in Tobruk with, among other things, the German locomotives that I mentioned in a previous post...
OK, I buy your notion that the line was never completed all the way up to Tobruk, which sheds more light on the Axis' logistical situation in Egypt in 1942. However, the term 'locomotor' usually denotes a shunting/light locomotive with an internal combustion engine ('motor'), which by extension should mean that the four Italian locomotors that you mention bear no relation to the German engines that were delivered to Tobruk on August 4th.This means: "At dawn on 7 November 1942, the last train from Mersa Matruh, pulled by a single locomotive, because the other three had run out along the way [the train had started out with 7 "War Department" captured rail cars, pulled by 4 small Italian locomotives, and rescued plenty of fugitives along the way] reaches Tobruk ... where the rail line ends 10 kilometers from the city".All'alba del 7 novembre 1942, l'ultimo treno da Marsa Matruh trainato da un solo locomotore, perché gli altri tre sono andati fuori uso lungo il viaggio, giunge a Tobruk dove la linea ferroviaria finisce a dieci cholometri dalla città
So it seems that the junction was never fully completed after all, and that the 7 miles gap identified in late July was in fact permanent. I have no idea how the locomotives unloaded in Tobruk reached the "Tobruk to El Daba" rail line, as this looks like a heavy load to carry and I'm positive that the convoy unloaded in Tobruk.
There's a fairly famous picture of a captured Marmon-Herrington armoured car converted to rail use and used by the Axis. Maybe the locomotors (called 'Italian' by your source) were captured British engines?
It could also be that the locomotives were delivered by coastal shipping after the convoy had arrived at Tobruk.
From the other side of the fence, here is another scan comparing the British desert engine I posted before with a standard NZ steam engine. Note, BTW, that New Zealand railroads are narrow-gauged!
This scan also very kindly provided by JonS