Complex sentence: While the attack on Kaafjord was being conducted, the commander of the German submarines in the Norwegian sea ordered Group Trutz to take up new positions to the south-east of Jan Mayen and intercept the British ships as they returned to Scapa Flow.
Split into simpler sentences: While the attack on Kaafjord was being conducted, the commander of German submarines in the Norwegian sea ordered Group Trutz to take up new positions to the south-east of Jan Mayen. It was hoped that this redeployment would allow the submarines to intercept the British ships as they returned to Scapa Flow.