SM UB-43

SM UB-43

SM UB-43 was a Type UB II submarine or U-boat for the German Imperial Navy (German: Kaiserliche Marine) during World War I. UB-43 was sold to the Austro-Hungarian Navy (German: Kaiserliche und Königliche Kriegsmarine or K.u.K. Kriegsmarine) during the war. In Austro-Hungarian service the B was dropped from her name and she was known as SM U-43 or U-XLIII as the lead boat of the Austro-Hungarian U-43 class.

UB-43 was ordered in July 1915 and was laid down at the AG Weser shipyard in Bremen in September. UB-43 was a little more than 121 feet (37 m) in length and displaced between 270 and 305 metric tons (300 and 336 short tons), depending on whether surfaced or submerged. She was equipped to carry a complement of four torpedoes for her two bow torpedo tubes and had an 88-millimeter (3.5 in) deck gun. As part of a group of six submarines selected for Mediterranean service, UB-43 was broken into railcar sized components and shipped to Pola where she was assembled and launched in early April 1916, and commissioned later in the month. Over the next year the U-boat sank twenty-two ships, which included the Peninsular and Oriental liner Arabia. UB-43 also damaged the British cruiser Grafton.

The German Imperial Navy was having difficulties filling submarine crews with trained men and offered to sell UB-43 and a sister boat, UB-47, to the Austro-Hungarian Navy. After the terms were agreed to in June 1917, both boats were handed over at Pola. When commissioned into the Austro-Hungarian Navy, the B in her designation was dropped so that she became U-43 or U-XLIII. She damaged one Italian steamer in limited Austro-Hungarian service through the end of the war. U-43 was ceded to France as a war reparation in 1920 and broken at Bizerta that same year.