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Navy's Role in Finding USS Indianapolis

Aug. 19, 2017 | By Dr. Richard Hulver, Ph.D., historian and Robert Neyland, Ph.D., Underwater Archaeology Branch Head, Naval History and Heritage Command
Editor's Note: It was announced today that the wreckage of the World War II cruiser USS Indianapolis (CA 35) was located by a team of civilian researchers led by entrepreneur and philanthropist Paul G. Allen. The search was aided by historical and archaeological support from the Naval History and Heritage Command. Just last year, NHHC uncovered information about the ship's loss which shed new light on where the ship might have gone down. We asked the author of that research, Richard Hulver, Ph.D., and NHHC's branch head for underwater archaeology, Robert Neyland, Ph.D., to share their thoughts and experiences related to the search for the final resting place of the ship and several hundred of her Sailors and Marines.

Over the past seventy years, the USS Indianapolis sinking has often been a misunderstood, and overly sensationalized episode in the U.S. Navy's World War II history. Instead of focusing on the commendable service of a decorated combat ship, and on the ordeal faced by her final crew, emphasis is placed on shark attacks and the treatment of the ship's commanding officer, Captain Charles B. McVay, III.

Last year, Director of Naval History and Heritage Command, Samuel Cox (RADM, retired) stood up a team consisting of historians and underwater archaeologists, to revisit the sinking. Our job was to ensure an accurate history was readily available to the public and the Navy, and to see if any new light might be shed on the final resting place of one of the Navy's most storied ships.? The revisit came with exciting new conclusions.

Why was Indianapolis so hard to find? Here's what we determined:
First, all of the ship's mission records and logs went down with Indianapolis in the frantic 15 minutes it took her to sink after suffering two torpedo hits from Japanese submarine I-58. Secondly, it took the Navy four days to realize that Indianapolis was missing; that discovery was made when she failed to show up for her port visit.

To make matters more difficult, the precise coordinates keyed out in an S.O.S. signal (that never left the ship) were forgotten by the surviving radiomen and were not received by USN ships or shore establishments. The coordinates reported by Japanese submarine I-58 as the location of the sinking were not recovered in the U.S. intercept of the message. Upon being rescued on 3 August 1945, Captain McVay reported to his rescuers that Indianapolis was exactly on the course where it was supposed to be when hit. All of these led to the Navy selecting the position where Indianapolis should have been along her route at 0015 20 July if following her routing instructions exactly as the point where she went down.

Several reports filed shortly after the Indianapolis rescue concluded mention that the ship passed an unspecified LST approximately 11 hours before Indianapolis was attacked. This LST was reported by Captain McVay to have been on the same track as Indianapolis, but maneuvering northward at the time of the passing to conduct anti-aircraft gunnery practice. Authors of Indianapolis books recalled this passing, but never endeavored to identify the LST. Because all U.S. Navy combatant ships were supposed to record their positions at 0800, 1200, and 2000 each day in their deck logs, NHHC historian Richard Hulver determined that identifying the LST passed by Indianapolis could provide a critical piece of unknown information from Indianapolis's final day. Finding the LST and then finding it's coordinates would provide researchers a new data point along the route of Indianapolis and possibly help determine a more precise position for where she was attacked.
"In terms of what's next? There remains a lot we can learn. From the sinking to the battle damage and site formation processes, we hope to gain a better understanding about the wreck site and how we can better protect USS Indianapolis to honor the service of the ship and crew."
A Memorial Day blogpost post written by the son of a passenger on the LST reportedly passed by Indianapolis, coupled with historic research in U.S. Navy muster rolls and deck logs, finally revealed the identity of the mysterious ship as LST-779. 779 followed the same route across the Philippine Sea as Indianapolis during the same time. She did not specifically mention being passed by Indianapolis in her deck logs, but did recount in detail the gunnery practice at 1300 on 29 July recounted by Captain McVay in his post-rescue interview.

The 1200 coordinate of LST-779, her set and drift recording, and the timing of her gunnery practice all gave indications that Indianapolis was most likely not exactly on the routing track as historically believed - something not surprising because the captain of a combatant ship could deviate from the track up to 40 miles, or 3 hours without having to report it to the port of arrival.

This new information renewed public and scholarly interest in the Indianapolis story and helped spark a surge of explorers eager to locate the sacred resting place of the heavy cruiser, one of which was the team of civilian researchers led by entrepreneur and philanthropist Paul G. Allen.

What's Next for USS Indianapolis? Connecting History with Underwater Archeaology
USS Indianapolis is a fit and final resting place and serves as a war grave. As U.S. Navy shipwreck it is protected from disturbance under the Sunken Military Craft Act. Now that the wreck site has been discovered, our Underwater Archaeology Branch will carefully review and assess the data associated with the discovery. Doing so will enable the U.S. Navy to better understand its sinking and the present condition of the site. There are presently no plans to engage in any form of recovery from USS Indianapolis. In terms of what's next? There remains a lot we can learn. From the sinking to the battle damage and site formation processes, we hope to gain a better understanding about the wreck site and how we can better protect USS Indianapolis to honor the service of the ship and crew.

USS Indianapolis Timeline of Events
  • 16 July 1945: Departs San Francisco for high speed transit to Tinian with A-bomb components for uranium bomb "Little Boy" crew, including Captain McVay unaware of what they carry
  • 19 July 1945: Reaches Pearl Harbor(sets speed record), unloads passengers, sails for Tinian
  • 26 July: Arrives in Tinian, unloads secret cargo, given routing instructions to return to Philippines and the forward area of the war
  • 0900 28 July: Departs Guam for Leyte, direct route, unescorted, orders to report to Vice Admiral Oldendorf upon arrival for much needed training prior to planned invasion of Japanese mainland
    • Follows "Convoy Route Peddie," travels at 15.7 knots, planned arrival 1100 Tuesday 7/31
    • Supposed to cross the 130? chop line between Philippines Sea Frontier and Marianas Monday 30 July
Sinking
  • Approximately 2230 Sunday 29 July: McVay orders ship to stop zig-zagging due to weather conditions
    • Ships speeds up to 17 knots
  • 2335-I-58 surfaced, shortly after under an east moon, saw a silhouette using binoculars set on power of 10. Dove to 19m, target on bow was 0° bearing range 10,000 meters. Thinks it is a surfaced submarine because it is high in the middle. Following dive, target visible through periscope.
  • 2338: Hashimoto orders crew to battle stations, turns left and toward target setting attack course. Target is below the moon and approaching him. Still does not know what it is.
  • 2339: Orders shooting method six, will fire a spread of 6 torpedoes. Kaiten number six on standby. He estimates a target speed of 11-12 knots (likely assumes that target was would be zigzagging).
  • 2348: Kaiten number 5 put on standby. Target still approaching under the course at 0° on bow. Hashimoto determines it has no hostile intention. Continues to approach, at about 3000 meters he knows it is coming towards the right, he now sees that it has fore and aft mast.
  • 2356: He begins shooting all are on their way by 0002 on 30 July.
  • 0003: Watches one torpedo hit, sees flames rise at No. 1 turret, followed by thee water columns.
  • 0004: Hears four torpedo hit sounds and propellers cease, ship reportedly stops (this is not the same as the Indianapolis's report).
  • 0005: Indianapolis survivors report violent explosion [around frame 7 starboard], then shortly after -2-5 seconds] another [frame 50 starboard at ICC room]. Initial list is gradual to about 3°-5°. Entire forward portion of ship engulfed in a blaze, bow nearly torn off, rapid flooding ensues.
  • 0008: McVay orders Navigator to go to Radio I and deliver SOS w/coordinates.
  • 0010: List is at 12°, McVay orders further investigation before issuing "Abandon Ship." From bridge, he feels it can be saved
  • 0015: Executive Officer reports "The bow is down, I think we are finished", "Abandon Ship" issued. McVay tries to get to radio room to ensure the distress call went out. While going from navigation to signal bridge, the ship lurched to 25° and steadied. The ship circled to port slowly.
  • 0016: List to 30°, 45° by time McVay reached communication platform, only stays at 45° a few seconds.
  • 0017-0018: List to 65°, then 90° (reportedly stays at 90° about 2 minutes). McVay climbed over the rail and walked on the shell to frame 110.
  • 0020: Ship plunges by the head, rolling completely over, assuming an "up and down" as she sinks. Stern completely vertical before going under. Port screws visible to McVay and not turning.
  • 0021: There are flickers of light at the center of the ship, he hears 10 secondary explosions, 4 or five are louder than torpedo hits would be. He fears counter attack, so puts target at his stern and makes distance between them, prepares for a second attack.
  • Ship continues moving throughout. The two torpedo hits forward and starboard likely lifted the ship and placed it on a trajectory toward port. The crew lost the power to steer almost immediately. Power was lost to the engines in the forward engine room, which controlled the outboard screws. Power was lost to one of the engines in the after engine room, which controlled the inboard screws. The functioning inboard engine maintained 160rpms. So, within minutes all screws except one inboard would have slowed. The bow was ripped off and rapidly taking on water. The ship would have slowed considerably from the 17 knots it was making when hit. The crew recollects the ship losing way and circling to port. So, most likely, the ship slowed down to a few knots, going down by the bow with a gradual, then, extreme starboard list, while veering off to port.
  • 0030: There are no more sounds; he can't see any ship on the surface through his periscope. Hashimoto returns to the scene submerged running.
  • 0020: Ship sinks [10 knot wind from SW, slight swell from west, drift slightly under 1 knot]
    • Ship traveled an estimated 2 miles before slowing to 3 knots and sinking
    • Approximately 700-900 sailors go into water out of a crew of 1,199 (approximately 400 go down with ship)
    • Nature of the sinking prevents all 35 rafts being deployed (approximately 12 are)
    • Torpedoing coincided with midnight watch change and likely reduced casualties
  • 0100: I-58 surfaces in good moonlight at the position the ship would have sank, determines that they sank their target.
  • (U.S. Navy intercepts this report/coordinates not recovered, estimated to be an attempt by Japanese to lure in targets)
Survival/Rescue
  • Losses
    • 316 out of 1,198 crew members survived the torpedoing and ordeal at sea
    • 67 out of 81 officers lost, 808 enlisted crew perished
    • Estimated that 200 were victims of shark attacks (approximately 50 men per day)
Want more history about USS Indianapolis? Check out our website for photos, archival documents, story map, and more!