Type 81 U-boats carried 12 torpedoes and had various arrangements of deck guns. U 81 to U 83 had one deck gun with 140-240 rounds. U 84 - U 86 were constructed with two deck guns. In 1917, U 84 - U 86 were converted to a carry one 10.5 cm and one 8.8 cm deck gun and carried 240 rounds.
