the submarine had a maximum surface speed of and a maximum submerged speed of . when submerged, the boat could operate for at ; when surfaced, she could travel at . "u-847" was fitted with six torpedo tubes (four fitted at the bow and two at the stern), 24 torpedoes, one sk c/32 naval gun, 150 rounds, and a sk c/30 with 2575 rounds as well as two c/30 anti-aircraft guns with 8100 rounds. the boat had a complement of fifty-five.