Complex sentence: In the port, a German ship the "Ehrenfels" had been providing information to 3 German U-boats, on the movement of Allied shipping with the result that some 250,000 tons of British shipping had been sunk over a period of 45 days.
Split into simpler sentences: In the port, a German ship the "Ehrenfels" had been providing information to 3 German U-boats, on the movement of Allied shipping. As result, some 250,000 tons of British shipping had been sunk over a period of 45 days.