Robert Bartels joined the Reichsmarine in 1934. From 1937 to June 1940, he served as a Watch Officer on U-21. He went through U-boat familiarization in July 1940 in preparation for his own command.
On 24 July 1940 Bartels commissioned the new Type IID U-139.
He left the boat on 20 December 1940. From there he went to the 1st U-boat Flotilla and another U-boat familiarization, this time in order to prepare for his command of the larger Type VIIC boat, U-561 on 13 March 1941.
With this vessel Bartels went out on his first war patrol on 25 May 1941, a 69-day-long patrol where he sank one small ship. When he left the boat on 5 September 1942 after eight patrols he had sunk or destroyed five ships for over 21,000 tons and damaged another - the last three ships fell to mines laid by U-561.
Bartels went through his third U-boat familiarization in September and October 1942 in order to prepare for the much larger Type IXD2 boats.
These vessels were very long range and were later converted for transport use. Bartels commissioned the new U-197 on 10 October 1942. The day before its loss, U-197 had met with Wolfgang Lüth"s U-181 where Bartels told Lüth he intended to stay in this area and hunt the traffic Lüth had told him about.
Their radio chatter had allowed the Allies to pinpoint the location, finding Bartel"s boat the next day.
On 20 August 1943 U-197 was attacked south of Madagascar, in position 28°40′South 42°36′East, by a British PBY Catalina aircraft of Number. 259 Squadron Royal Air Force with six depth charges and slightly damaged.
As the aircraft had no more bombs, it attempted to strafe with her machine guns, but the U-boat responded with ferocious Associate of Arts fire. The aircraft then circled the U-boat at a safe distance and radioed for assistance.
The U-boat remained on the surface, perhaps assuming that any support was unlikely, and that the aircraft would eventually have to abandon her vigil.
Unfortunately for the German submarine, another Catalina, FP 313 of 265 Squadron and piloted by captain Ernest Robin, (receiving the Distinguished Flying Cross for the sinking of the vessel), arrived. U-197 promptly crash-dived, and the aircraft dropped three depth charges, two of which detonated to port of the U-boat, but the third hit her squarely, killing all 67 hands. Eitel-Friedrich Kentrat, commander of U-196, was severely criticised by the Befehlshaber der U-Boote (BdU) for his lack of support for U-197.
Bartels of U-197 had radioed a distress signal.
The correct response by any boat in the vicinity, according to orders, would have been to assist at top speed. The BdU twice ordered U-196 to aid U-197 before Kentrat responded, and by that time U-197 and the entire crew were lost.
Patzwall, Klaus Doctorate. Scherzer, Veit (2001). Das Deutsche Kreuz 1941 – 1945 Geschichte und Inhaber Band II (in German).
Norderstedt, Germany: Verlag Klaus Doctorate. Patzwall.