At 22.56 hours on 30 April 1943 U-515 fired two stern torpedoes at convoy TS-37 about 130 miles southwest of Freetown and observed hits after 58 and 59 seconds. The first ship was seen sinking fast and another broke in two after being hit under the bridge. At 22.57 hours, one torpedo was fired that struck a freighter amidships after 52 seconds. A fourth torpedo fired one minute later struck another freighter amidships, which exploded. At 22.59 hours, a fifth torpedo was fired and struck after 1 minute a ship, which immediately sank. A sixth torpedo fired at 23.01 hours hit a freighter after 1 minute 30 seconds, but the sinking could not be observed. Henke claimed five ships of 31,000 grt sunk and another of 6000 grt probably sunk. However, only four ships were hit and sunk, the Corabella, Bandar Shahpour, Kota Tjandi and Nagina.

The Kota Tjandi (Master Master Karel Simon Joseph Tendijck) in station #14 was hit by one torpedo on port side in #2 hold and sank by the bow within six minutes, leaving no time to send distress signals or rockets. Five Lascar crewmen trapped in the forecastle were lost. The master, 66 crew members and seven gunners (the ship was armed with one 4in, two 20mm and seven machine guns) abandoned ship in the lifeboats in a moderate sea, but the third officer was washed out by a wave from one of them and drowned. Less than two hours later the survivors were picked up by HMS Birdlip (T 218) (Lt. E.N. Groom, RNR) and landed at Freetown the next day.