A Most Curious Assignment

The Tucson did not have much time to make her mark in the war.  Commissioned on 3 February 1945, the light cruiser set out for the western Pacific in May with Captain Arthur D. Ayrault in command.

Arriving at Leyte on 16 June, she joined the screen for Task Force 38.  The powerful striking force of the Third Fleet, TF 38 then included 14 aircraft carriers, 6 light carriers, and 8 battleships and, under the command of Admiral Halsey in the flagship USS Missouri (BB 63), was preparing to undertake a series of raids on the Japanese home islands.

Soon after the Tucson’s arrival, Captain Ayrault was summoned to the flag offices of Admiral Carney where he was surprised to learn the details of a planned deception: His cruiser would impersonate the Missouri.  Specifically, Booth’s Dirty Tricks Department would convince the Japanese that the transmissions it would send from the Tucson were emanating from TF 38.  “At first Captain Ayrault was a bit perplexed at this assignment,” remembered Booth, “but we could not have carried it out from a better ship.  Tucson was bristling with anti-aircraft guns and well equipped to defend itself from air attack.”

The goal of the complex deception was for the Japanese to believe that after TF 38 made a heavy air strike on Tokyo, scheduled for 10 July, it turned south to support a possible invasion of southern Japan.  The task force, meanwhile, would actually be heading north under strict radio silence to strike Hokkaido and northern Honshu islands, areas outside the range of B-29 bombers.  A planned 11 July strike by U.S. carrier-type, but Okinawa-based, aircraft against Kyushu, southernmost of the four main home islands, would be an additional facet of the hoax that added to the complexity of Booth’s assignment.  In addition to executing deceptive Morse code communications, his unit was also to broadcast voice communications to make it seem like Task Force 38 was coordinating the attack on Kyushu from its carriers.  In theory, this added ruse would help convince the Japanese that a southern invasion of their homeland might be under way.

Late on 30 June 1945, the two officers and six radiomen of Halsey’s Dirty Tracks Department along with Radiomen Second Class Richard Wethy reported aboard the Tucson, which was still at anchor in Leyte Gulf.  A late but key addition to Booth’s team, Wethy was a Missouri radioman whose Morse code “fist” was familiar to Japanese signals intelligence analysts.  Four officers from the Tucson’s wardroom were also recruited to help with the deception.

On 1 July, Task Force 38, including the Tucson, stood out of Leyte and headed northward.  Recalling the subsequent voyage toward Japan, Booth said:

We did not get much sleep, and spent days studying all aspects of the deception plan, preparing deceptive dispatches and deceptive voice scripts for combat air operations, and trained our operators to simulate the “fist” and transmission characteristics of the actual operators identified with our Fleet and carrier type commands.  All circuits we planned to use for deceptive transmission were monitored for days prior to commencement of the deception so that we could acquaint our operators with current circuit conditions and traffic loads.

During the morning of 10 July 1945, more than 1,000 TF 38 planes launched strikes against Tokyo and its surrounding airfields.  At 1400, after the attacking planes had been recovered, the task force headed northward, as a lone ship, the Tucson, steamed south at high speed.  Task Force 38 and the cruiser commenced total radio silence, which was highly significant from the Japanese intelligence standpoint.  Enemy analysts had learned that radio silence – a total communications blackout – indicated a U.S. attack was imminent.

Ensign Edward Behm, a 1944 graduate of the U.S. Naval Academy, was serving on board the Tucson as she set off on her mysterious solo voyage.  He recalled that

[T]he Pacific was very calm during our mission, and the days were clear and bright.  We would have been in big trouble if kamikazes had come out after us.  I also remember that it was our navigation officer that had brief the wardroom in advance of our mission and told us how we would soon be turning away from the Fleet and heading south, but not why.  But the captain informed the crew over the 1MC, and well after we had already pulled away from the Fleet that we were on a top-secret mission and that we would be without an escort.

Source: Master Chief Thomas H. Helvig, U.S. Navy (Retired)

Featured Image: Soon after Munda Point, New Georgia, was captured by U.S. forces, Unit #41 Communications Security (COMSEC) arrived and set up shop in an abandoned Japanese cave strongpoint where temperatures reached 115 degrees.  Commenting on this photograph, Booth later, “These men were all sailors, and we never could have imagined the navy ever living like cave rats… but here we were.”