The R

The RO-501 Story

    On 13 May 1944 the USS Francis M. Robinson was a member of a the task group CTG 22.2 with Captain A. B. Vosseller as the new commander of the USS Bogue. The task group consisted of five DEs supporting the USS Bogue (CVE-9). The five ships were:

    1. USS Francis M. Robinson (DE-220), Lt. J. E. Johansen, Commanding
    2. USS Haverfield (DE-393), Cdr T.S. Lank, TF 51 Commander.
    3. USS Swenning (DE-394), Lt. R. E. Peek, Commanding
    4. USS Willis (DE-395), Lt. Cdr. G. R. Atterbury, Commanding
    5. USS Jannsen (DE-396), Lt. Cdr. H. E. Cross, Commanding

    At 1900 hours, traveling at 17 knots on a heading of 200 degrees, the asdic (sonar) operator detected a target at a range of 825 yards. The sonar operator and sound officer classified the target as a submarine. Lt. (jg) R. L. Rather, an ASW specialist officer on temporary duty on the USS Robinson, confirmed the target. The asdic indicated the target was on a heading of 130 degrees changing to a heading of 110 degrees. (Note: These headings are from the official report in the ship log. Assuming they are accurate, the submarine was turning onto a perpendicular course to the convoy while diving deeper. At this point I believe the log incorrectly says the target bearing was moving right. A magnetic heading moving from 130 degrees to 110 degrees would be turning left. This would be consistent with a fresh captain, crew and boat avoiding a convoy of five submarine killers and an aircraft carrier. If the 130 degree heading and 110 degree heading were transposed in the log, the submarine would have been turning right to parallel the task force. I do not believe this makes sense. First: This would have been very aggressive behavior for a submarine, especially one that had been detected as this one had. Second: The submarine commander was lieutenant-commander Norita Sadatoshi, an experienced U-Boat officer, unlikely to risk his crew and boat on such long odds. The log error is confirmed when the log states the Robinson turned right 40 degrees to increase the range and gain an more favorable attack position (attack from the rear).)

This is the sequence of events.

19:00:00

Target detected at 825 yards. USS Bogue turns away. Sonar contact quality was excellent, clear and indicated submarine with a slight down Doppler.

19:04:00

Robinson's speed decreased to 15 knots

19:06:00

Turned to attack course of 302 degrees.

19:08:00

Foxer streamed to decoy acoustic torpedoes

19:08:08

Hedgehog fired at the submarine.

19:09:04

Two rapid and distinct hedgehog detonations heard and recorded. Target indicated depth was approximately 170 feet.

"When we got the two hedgehog hits, I grabbed the TBS ship-to-ship radio instead of the interior communications phone in the excitement and yelled, 'We got the sonofabitch, we got him!' Thus went out the report to the Task Group Commander! I only wanted the crew below to know. After we secured and were going over the whole thing in the wardroom, Paul Campbell, executive officer and our next captain, wanted to know who it was on the TBS. Captain Johansen was sitting in his place at the head of the table. He said, "What was that?" I blushed and admitted I got too excited and grabbed the TBS by mistake. The skipper said, 'I want that in the log'. He thought it was great."
Malcomb B. Fraser

19:09:40

Fired first volley of Mk 8 Depth Charges set to magnetic triggering.

19:09:44

Second volley of depth charges fired.

19:09:48

Third volley of depth charges fired.

19:09:52

Fourth volley of depth charges fired.

19:09:58

Fifth volley of depth charges fired.

19:10:04

First depth charge explosion seen and recorded. Sonar contact lost.

19:10:18

Second depth charge explosion seen and recorded. Thought to be stern-rolled charges detonating at 550 feet. Submarine had descended 380 feet in 1 minute and 9 seconds.

19:11:21

A heavy underwater explosion is heard and recorded. Approximate depth of charges was 1200 feet. Submarine had descended 820 feet in 1 minute and 3 seconds.

19:11:45

A second, larger underwater explosion is heard and recorded. Approximate depth of explosion was 1850 feet. Submarine had descended 650 feet in 24 seconds.

19:12:20

A third underwater explosion is heard and recorded. Approximate depth of explosion was 2275 feet. Submarine had descended 425 feet in 35 seconds.

19:13:11

Final underwater explosion is heard and recorded. Approximate depth of explosion was 2900 feet. Submarine had descended 625 feet in 51 seconds.

The USS Robinson and USS Haverhill continued searching the area visually and with sonar for 3 hours and 30 minutes without finding a trace of the submarine. That night, aircraft from the USS Bogue searched the area with radar but did not detect the submarine. Based on the quality of the sound traces on the chemical recorder, the USS Robinson was awarded the "kill" for RO-501 (ex-U-1224), a Japanese submarine. RO-501 rests in 2,900 feet of water at 18.08 N / 33.13 W (see map below). The USS Robinson received a Presidential Unit Citation for the sinking of RO-501. Details of RO-501 were provided in a letter from Dr. Rohwer, a German authority on submarine activity in WW II and author of several books on the subject. On the 50th Anniversary of the sinking of RO-501, congress issued a citation to the crew and entered it into the Congressional Record.

DE220's Log entry

Cruise Report, page 1

Cruise Report, page 2

Cruise Report, page 3

Cruise Report, page 4

DE220-RO501-ASW-Report-1.jpg (96858 bytes)

DE220-RO501-ASW-Report-2.jpg (79495 bytes)

DE220-RO501-ASW-Report-3.jpg (86122 bytes)

Anti-Sub Action Rpt, page 1

Anti-Sub Action Rpt, page 2

Anti-Sub Action Rpt, page 3

RO-501 (ex-U-1224)

Type IXC

Type	IXC/40
Laid down	30 Nov, 1942	Deutsche Werft AG, Hamburg
Commissioned	20 Oct, 1943	Kptlt. Georg Preuss
Commanders	10.43 - 02.44 02.44 - 05.44	Kptlt. Georg Preuss Kptlt. Norita (Japanese captain)
Career	1 patrol	20 Oct, 1943 - 15 Feb, 1944 31. Flottille (training)
Successes	No successes
Fate	Served as RO 501 in Japanese service from 15 Feb, 1944. Sunk 13 May, 1944 in the mid-Atlantic north-west of Cape Verde Islands, in position 18.08N, 33.13W, by depth charges from the US destroyer escort USS Francis M Robinson.

Here is how the action narrated in Chapter Five is described by the U.S. Naval Institute in the book “U.S. Destroyer Actions in World War II." This report was furnished to me by Lieutenant Joel T. Loeb, probably the finest watch officer on the ship.

Francis M. Robinson Kills RO-501 (Thereby Downing a U-Boat)
     German Vice Admiral Paul H. Weneker arranged the deal in Tokyo. Weneker was in charge of blockade running by submarines between Japan and Germany. A number of U-boats reached the Java Sea and Singapore late in the war, and several made Japan. One or two Japanese submarines managed to run from Japan to Germany. Weneker did not think much of Japanese submarines. “They were too big for easy handling when under attack," he asserted, "and consequently they were easily destroyed. Then the Asdic and sonic and radar equipment was very far behind in development."
     However, Weneker cooperated fully with Admiral Miwa, and the Nazi U-boaters did their best to aid and abet the Nipponese submariners. Weneker arranged for a Japanese submarine crew to be sent Germany for training. "They had, I think, very good training in German boats and German attack methods. But unfortunately they got caught in the North Atlantic in early 1944 while returning to Japan.
    Evidence indicates that Admiral Weneker’s information was essentially correct, but his date was slightly off. His account, therefore, was not quite as accurate as the report submitted by Lieutenant Commander J. E. Johansen, U.S.N.R., captain of the destroyer-escort FRANCIS M. ROBINSON.
    The DE was a screening unit for BOGUE in Task Group 22.2, the hunter-killers who had relieved the BLOCK ISLAND team in the Cape Verdes area where BUCKLEY had won her memorable battle. Not to outdone by their predecessors, on the very day they took over from the BLOCK ISLANDERs the Bogue team stirred up a submarine.
    The date was May 13. The enemy was 1ocated northwest of the Cape Verdes, only a few miles the spot where BUCKLEY downed U-66. The play fell to the FRANCIS M. ROBINSON.
    The seascape was painted with sunset (time: 1900) when the ROBINSON made sound contact at 825 yards In a flash the hedgehogs fired. As the scattered projectiles splashed the water, a salvo of depth charges went lobbing over the side-Mark 8 magnetics set to the moment they were "influenced."
    Seven seconds after the projectiles were fired, two distinct explosions indicated a couple of hedgehog hits. Then came the deep throated thundering of three depth-charge explosions, booming with a rumpus of up thrown water. Two or three minutes after the last depth charge explosion there was a roar that sounded like a bursting pressure hull. This was followed by a deep-sea blast that must have killed fish a quarter of a league away.
    The destroyermen presumed they had polished off a U-boat. As indeed they had---the U-1224. It was not until after the war that they learned this was the same U-boat was also the RO-501. There in the Atlantic the FRANCIS M. ROBINSON had sunk a Japanese submarine!
    The records in Doenitz's German Navy Headquarters and the testimony of Admiral Wenekar is Tokyo explained the paradox. The U-1224 had been turned over to a Japanese crew in Germany, and renamed the RO-501, and entered into the service of the Emperor. Then, en route to Japan, she was removed from the Emperor’s service by the handiwork of Destroyer-Escort FRANCIS M. ROBINSON.
    The DE's skipper summed up the matter tersely:

“HEARD SUB SANK SAME”

Although not a USS Robinson kill, another USS Bogue hunter-killer element destroyed another submarine on the night of 23 June. Avenger pilot Lt. Commander Jesse Taylor detected the Japanese submarine I-52 on his malfunctioning radar (only the right half of its sweep was working). The Bordeux-bound I-52 had departed Singapore on 23 April carrying molybdenum (9.8 tons), tungsten (11 tons), tin (120 tons), Caoutchouc (rubber)(55 tons), quinine (3 tons), caffeine (0.537 tons), and 14 Japanese industrial experts. She had met U-530 only hours earlier to pick up a German liaison officer, wireless operators and a radar warning device (details of the encounter with U-530 below). Lt. Taylor dropped flares to illuminate the submarine, and followed these with two 500-pound depth bombs which forced I-52 to submerge. Guided by sonobuoys, Taylor attacked again with a Mk 24 Fido acoustic torpedo and heard an explosion and what he thought were noises of the submarine breaking up. However, Bogue's war diary states that, more than one hour after Lt. Taylor's attacks, two additional Avengers both heard the propeller beats of I-52. Lt. (jg) William Gordon dropped a Fido and,18 minutes later, heard a long rolling explosion, break-up noises, and further propeller beats which quickly faded. There were no survivors. Debris, including some of the cargo, found by the destroyer escorts confirmed the kill. Displacing 3,644 tons submerged, I-52 was the largest Axis submarine sunk in the Atlantic during the Second World War.

USS Bogue (CVE-9)

USS Corregidor (CVE-58) to show a different angle.
Courtesy of Robert E. Taylor, Email: taylor794@msn.com

USS Corregidor (CVE-58) to show a rear view w/full flight deck.
Courtesy of Robert E. Taylor, Email: taylor794@msn.com

U-530

Type	IXC/40
Laid down	8 Dec, 1941	Deutsche Werft AG, Hamburg
Commissioned	14 Oct, 1942	Kptlt. Kurt Lange
Commanders	10.42 - 01.45 01.45 - 05.45	Kptlt. Kurt Lange Oblt. Otto Wermuth
Career	8 patrols	14 Oct, 1942 - 28 Feb, 1943 4. Flottille (training) 1 Mar, 1943 - 30 Sep, 1944 10. Flottille (front boat) 1 Oct, 1944 - 8 May, 1945 33. Flottille (front boat)
Successes	2 ships sunk for a total of 12.063 tons 1 ship damaged for a total of 10.195 tons
Fate	Surrendered in the Rio de la Plata, Argentina on 10 July, 1945. Transferred to USA and used for tests. Scuttled during tests on 28 Nov, 1947 north-east of Cape Cod, by a torpedo.

Encounter with the Japanese I-52

On 22 May, 1944 the boat left Lorient, France for operations in the Trinidad area. Outbound she was to rendezvous with the incoming Japanese submarine I-52 (huge boat, 356 feet and roughly 2600 tons) and supply the larger boat with a Naxos radar detector, Naxos operator and a German navigator to help navigate the end-leg of the journey.
    The three German men, Pilot Lieutenant Schafer and Radiomen Petty Officers Schulze and Behrendt, all perished with the boat along with its Japanese crew.
    The boats met on 23 June in the middle of the Atlantic, some 850 miles west of the Cape Verde Islands, and the exchange went well except the Naxos radar detector fell into the Atlantic, being retrieved by a Japanese who jumped in after it. U-530 immediately headed for Trinidad, finally returning to base after 133 days at sea. The Allies knew of the encounter and had the escort carrier USS Bogue at the scene and its aircraft managed to sink the I-52 with Fido torpedoes with the help of sonobuoys.
    The I-52 seems to have been found in 3.2 mile deep water in 1995. The interest in this boat, especially at this depth, is simple: She contains 2 tons of gold in 146 bars plus an assortment of other valuable industrial metals. Recovery was planned but according to an article in National Geographic (Oct 99) it was not possible to reach the gold and further attempts have been called off.