All of this information was gratefully recieved from Oliver Lörscher, who found all of this information out for me free of charge, and had to translate the German UB-59's Commander's (Erwin Waßner) war diary which is naturally all in German, it could not have been easy, many thanks!!
Below you will find out takes from the war diary, on the night S.S South Western was sunk, from what i can make out from reading this the first time, the South Western did not at any point, open fire on UB-59, she spent her last hour afloat trying to to out run and out wit the german u-boat by zigg-zagging, a technique used to make it hard for a submarine to stike.

Summary of patrol.

Around midnight torpedo shot missed against a 3000t steamer with a course to Cherbourg. Had to fire from behind (firing from behind in this case means, that UB-59 carried on with her attack, despite a "zagg" from South Western). Torpedo detonated after two minutes after hitting the sea bed.
After midnight hit the same steamer with torpedo (Mk. K111) fired from the surface, 5 miles south of St.Catherines point. The whole forepart of the ship flew in the air. The staemer sunk after 20 minutes.

Taken from the war diary (handwritten).

Surface attack against a steamer 3000t- with course to Cherbourg. Had to fire from behind, obviously the steamer changed course for her regular zig-zag course. Torpedo detonated after two minutes, on the seabed.


17/03/1918 12.45am


Surface attack against the same steamer, Torpedo Mk k111, distance 450m, hit in the front section. the whole forepart including the hatch was blown in the air. The steamer floated for another 20 minutes and then sunk.


The reason for the hour difference between attacks, is that another hour was needed to overtake the South Western again to gain an good firing position for the second attack.