SS Arkansas which was berthed at Eagle Beach next to the Arend/Eagle Refinery. Just one of the torpedoes struck Arkansas and partially sank her but the damage was moderate and caused no casualties. Commander Hartenstein then steamed further around Aruba and directed his men to take to the deck guns and prepare for a naval bombardment of the large oil tank of the Lago Oil and Transport Company The crew of the 10.5 cm SK L/45 naval gun forgot to remove the tampion from the barrel, so when Hartenstein ordered them to fire, the gun blew up. Gunnery Officer Dietrich von dem Borne was wounded badly, one foot having been severed. His comrade and trigger man Heinrich Büssinger was badly wounded as well and died several hours after the attack. Hartenstein ordered the 3.7 cm flak gun to continue the attack, causing only superficial damage. Third patrol On Hartenstein's third patrol (22 April 1942 – 7 July 1942), U-156 sank 12 ships and damaged a further two, including the on 25 May 1942. This achievement earned Hartenstein a reference on 6 June 1942 in the Wehrmachtbericht, a propaganda bulletin issued by the headquarters of the Wehrmacht, the OKW. The mention was entered in the orders and decorations' section of a soldier's Service Record Book. U-156 along with U-502 again departed from Lorient under the protection of a pathfinder on 22 April 1942 destined for the Caribbean Sea. Prior to the departure Dietrich von dem Borne, who had been severely wounded on the second patrol, was replaced by Oberleutnant zur See of the Reserve Gert Mannesmann. Chief engineer Wilhelm Polchau reported to Hartenstein on 6 May that the diesel compressor had malfunctioned. Hartenstein radioed under the command of Robert-Richard Zapp to assist. On 10 May U-156 and U-66 rendezvoused and exchanged of fuel oil for the necessary spare parts, and the fuel compressor was repaired. U-156 sighted the first steamer in the early afternoon on 12 May, the first of twelve ships—eleven merchantmen and one warship—attacked on this patrol, ten of which were sunk. U-156, positioned near Fort-de-France, was ordered to observe the traffic to and from Martinique. At roughly offshore, the hydrophones detected a ship. Hartenstein attacked from a submerged position firing two torpedoes. One torpedo struck the bow of the Blakeley after a 25-second run-time. Hartenstein observed that the bow was completely blown away, but its engines kept running.