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Captain John Cromwell

U.S. Navy

Medal of Honor

Caroline Islands

Nov. 19, 1943

In November 1943, U.S. Navy Captain John Philip Cromwell fought a deadly game with the Japanese and lost. But with his noble sacrifice, he became the highest-ranking submariner awarded the Medal of Honor in World War II. Cromwell willingly died to keep a secret.

Born Sept. 11, 1901, in Illinois, Cromwell graduated from the U.S. Naval Academy in 1924. He served on the battleship USS Maryland and on several submarines, became engineer officer for the Pacific Fleet submarine force and, by the start of World War II, was on the staff of Commander, Submarines Pacific. In 1942 and 1943, he commanded Submarine Divisions 203, 44, and 43.

By the middle of 1943, the tide had turned in the Pacific, and the Navy had solved many of the tactical and torpedo problems that had plagued it earlier in the war. Navy ships were moving west across the Pacific, sinking Japanese vessels as they went. Much of their success was based on the breaking of Japan’s JN-25 code. Intercepts had already contributed to the U.S. victories at Midway and the Coral Sea in 1942 and were now pinpointing convoys in the Pacific. Such intercepts and the very fact cryptographers had broken JN-25 were highly classified. Cromwell was among the few high-ranking officers aware of the secret.

In fall 1943, following the Solomons campaign, the United States prepared to invade the Gilbert Islands (Operation Galvanic). The Navy sent a dozen submarines to patrol off the major enemy bases at Truk and Kwajalein, west and north of the Gilberts. Among the boats stationed around Truk was USS Sculpin, under Lt. Cmdr. Fred Connaway. Cromwell was aboard to take command of a wolf pack if conditions warranted.

Sculpin arrived on station November 16, made radar contact with a Japanese convoy on the night of the 18th and prepared to attack at dawn. On the sub’s final approach, however, an enemy sailor spotted its periscope, and Connaway was obliged to take Sculpin deep and allow the convoy to pass overhead. Sculpin then surfaced behind the convoy to attempt an attack from the rear. But the trailing destroyer Yamagumo forced Sculpin to dive. Yamagumo dropped a pattern of depth charges that, unknown to the crew, damaged the submarine’s depth gauge. Sculpin went deep and laid low for several hours.

Around noon Connaway attempted to take the sub to periscope depth for another attack on the convoy. But Sculpin’s broken depth gauge stuck at 125 feet, confusing the diving officer and causing the boat to broach in view of Yamagumo. Sculpin again dove, and the Japanese destroyer dropped more depth charges, damaging Sculpin’s hull.

Connaway concluded Sculpin’s only hope was to surface and fight it out. With the sub’s decks awash, its crew manned the guns. But Yamagumo’s opening salvo killed Sculpin’s entire bridge watch team, including Connaway. The ship’s senior surviving officer, a reserve lieutenant, ordered the boat scuttled and the crew to abandon ship.

Given his personal knowledge of JN-25 intercepts and Operation Galvanic, Cromwell realized if he was interrogated by the Japanese, he might compromise those secrets under the influence of drugs or torture. Instead, he rode Sculpin on its final plunge to the bottom, taking those secrets with him.

The Japanese pulled 41 Sculpin crewmen from the sea. Many later died when another U.S. sub sank the Japanese transport on which they were being held. Due in part to Cromwell’s courageous act, U.S. forces captured the Gilberts in late November, and the JN-25 intercepts remained secret through war’s end.

In 1954 the Navy honored the Sculpin hero, naming a Dealey-class destroyer escort USS Cromwell.


Originally published in the September 2010 issue of Military History. To subscribe, click here