IJN Submarine I-172: Tabular Record of
© 2001-2016 Bob Hackett & Sander Kingsepp
16 December 1933:
Laid down at Mitsubishi's Kobe Yard.
6 April 1935:
Launched and numbered I-72.
7 January 1937:
I-72 is completed, registered in the IJN and attached to Kure Naval District. Assigned to SubDiv 20. LtCdr (later Captain)
Nanri Katsuji (48)(former Chief Equipping Officer) is the CO.
1 December 1937:
LtCdr (Rear Admiral, posthumously) Kayabara Yasuchika (49)(former CO of I-68) is appointed CO.
5 May 1938:
W of Kurahashi Jima, Inland Sea. Around 1000, while proceeding surfaced on a northerly course in limited visibility, I-72 collides
with the 60-ton motor vessel HACHIYO MARU. The submarine receives minor damage; HACHIYO MARU sinks at 1002.
15 November 1938:
LtCdr Kayabara is promoted Cdr.
10 October 1939:
LtCdr (later Captain) Hori Takeo (50)(current CO of I-71) is appointed CO of I-72 as an additional duty.
20 November 1939:
Cdr (later Captain) Koizumi Kiichi (49)(former CO of I-71) is appointed CO.
20 August 1941:
LtCdr (Rear Admiral, posthumously) Togami Ichiro (51)(former CO of I-65) is appointed CO.
15 October 1941:
LtCdr Togami is promoted Cdr.
11 November 1941:
I-72 is in SubRon 3's SubDiv 20. Cdr Togami is the Commanding Officer. Departs Saeki with I-68, I-69, I-70, I-71 and
20 November 1941:
Arrives at Kwajalein.
23 November 1941: Operation "Z":
Departs Kwajalein for Hawaii on her first war patrol.
2 December 1941:
The coded signal "Niitakayama nobore (Climb Mt.
Niitaka) 1208" is received from the Combined Fleet. It signifies that hostilities will commence on 8 December (Japan time). 
5 December 1941:
Hawaiian Islands. I-72 first reconnoiters the Kaholi Channel between Molokai and Lanai, then heads to reconnoiter Lahaina Roads.
6 December 1941:
Cdr Togami reports to Carrier Striking Force that Lahaina anchorage is empty.
7 December 1941: The Attack on Pearl Harbor:
I-72 is stationed at the entrance to Pearl Harbor between I-73 and I-70.
16 December 1941:
After sundown I-72 surfaces off Hilo Bay, Hawaii, and shells the port from her 4.7-in deck gun.
19 December 1941:
150 miles S of Oahu, Hawaiian Islands. At 0530 (LZT), I-72 torpedoes 5,113 ton American cargo steamer PRUSA, en route from
Honolulu to Baltimore. A torpedo wrecks PRUSA's engines and she sinks within nine minutes at 16-45N, 156-00W. Five minutes later I-72 surfaces to establish
the identity of her victim, illuminates the lifeboats with a searchlight and submerges shortly thereafter. Eight days later, Coast Guard cutter TIGER (WSC-152) rescues 13 men
from one lifeboat. The master of PRUSA and ten others reach Nonouti atoll in the South Gilbert Islands with the second lifeboat after 31 days.
28 December 1941:
I-72 returns to Kwajalein.
12 January 1942:
Departs Kwajalein on her second war patrol with I-71 and I-73 to relieve I-18, I-22 and I-24 that form a picket line in the Hawaii area.
21 January 1942:
Arrives at her assigned patrol sector.
23 January 1942:
135 miles W of Honolulu. 7,383-ton oiler USS NECHES (AO-5) is proceeding unescorted to a refueling rendezvous with Vice
Admiral Wilson Brown Jr's (later President Roosevelt's Naval Aide) Task Force 11's USS LEXINGTON (CV-2) that is steaming to conduct an air raid on Wake
At 0310, Cdr Togami fires a torpedo that hits NECHES amidships, but fails to detonate. At 0319, a second torpedo hits the oiler starboard aft and
destroys her engine room. Togami maneuvers and hits NECHES portside with a third torpedo. I-72 surfaces to finish the job with her deck gun. She fires
three rounds at the oiler, but the NECHES' gun crew returns fire from her 5-in and 3-in guns. Togami submerges. At 0437, NECHES, listing to starboard, sinks by
the bow at 21-01N, 160-06W.
Without the oiler's fuel, Task Force 11 cannot execute the planned strike on Wake and is ordered back to Pearl Harbor.
16 February 1942:
I-72 returns to Kwajalein.
18 February 1942:
Departs Kwajalein with I-71.
20 February 1942 - Aborted Raid on Rabaul:
Task Force 11, en route to attack Rabaul, is spotted by a Kawanishi H6K "Mavis" flying boat of the Yokohama
Kokutai. Since surprise is lost, the American attack is canceled. TF 11 is attacked off Bougainville by the 4th Kokutai's naval land-based bombers, but the
Japanese are beaten off with heavy losses.
After the aborted raid on Rabaul, I-72 and I-71 are diverted to an area E of Wake Island.
5 March 1942:
Returns to Kure for repairs.
16 March 1942:
Vice Admiral, the Marquis, Komatsu Teruhisa (former CO of CA NACHI) assumes command of the Sixth Fleet (Submarines).
20 March 1942:
SubDiv 20 is disbanded. I-72 is reassigned to SubDiv 12.
15 April 1942:
3 May 1942:
Arrives at Yokosuka.
10 May 1942:
12 May 1942:
Arrives at Kure for upkeep and repairs.
20 May 1942:
I-72 is redesignated I-172. Cdr (Rear Admiral, posthumously) Emi Tetsushiro (50)(current CO of I-8) is appointed CO of I-172 as
an additional duty.
30 June 1942:
LtCdr (Cdr, posthumously) Ota Takeshi (55)(former CO of RO-34) is appointed CO.
7 August 1942 - 9 February 1943: American Operation "Watchtower" - The Invasion of Guadalcanal, Solomons:
Rear Admiral (later Admiral) Richmond K.
Turner's Amphibious Task Force 62, covered by Vice Admiral (later Admiral) Frank J. Fletcher's Task Force 61 and Rear Admiral (later Admiral) John S. McCain's
Task Force 63's land-based aircraft, lands Maj Gen (later Gen/MOH/Commandant) Alexander A. Vandegrift's 1st Marine Division on Guadalcanal opening a
seven-month campaign to take the island.
22 August 1942:
Departs Kure for Truk.
28 August 1942:
Arrives at Truk.
30 August 1942:
Departs Truk on her third war patrol for a
reconnaissance mission to the Guadalcanal area.
30 September 1942:
Returns to Truk.
12 October 1942:
Departs Truk with Captain Yoshisuke Okamoto (47),
ComSubDiv 12 embarked, on her fourth patrol to support a "Type A" midget
submarine attack on shipping off Lunga Point, Guadalcanal.
14 October 1942:
Diverted to proceed to an area S of San Cristobal with I-26 to recharge the batteries of Type A midgets from the tender CHIYODA.
15 October 1942:
I-172 is diverted to take station on a picket line SE of Guadalcanal (the "A" group comprising I-1, I-2, I-3, I-4, I-5, I-7, I-17, I-22 and
26 October 1942: The Battle of Santa Cruz:
Rear Admiral (later Admiral) Thomas C. Kinkaid's Task Force 16 and Rear Admiral (later Vice Admiral)
George D. Murray's Task Force 17 engage Vice Admiral (Admiral, posthumously) Nagumo Chuichi's (former CO of KIRISHIMA) carrier force. ENTERPRISE (CV-6)
is damaged by planes from the carriers JUNYO and SHOKAKU. Planes from JUNYO, SHOKAKU and ZUIKAKU also damage HORNET (CV-8), scuttled later. JUNYO's
planes damage battleship SOUTH DAKOTA (BB-57) and SAN JUAN (CL-54). USS PORTER (DD-356) is scuttled by USS SHAW (DD-373).
Douglas SBD dive-bombers (VS-10) from USS ENTERPRISE damage carrier ZUIHO. SBD's (VB-8, VS-8) from HORNET also damage carrier SHOKAKU and
the destroyer TERUTSUKI. Grumman TBF torpedo-bombers (VT-6) from HORNET damage heavy cruiser CHIKUMA.
28 October 1942:
Group "A" is disbanded. I-172 is diverted to the area SW of San Cristobal to interdict the US replenishment missions to Guadalcanal.
3 November 1942:
SW of San Cristobal Island, Solomons. LtCdr Ota sights a convoy of American transports, heading for Lunga Point. At 0410 (local)
he transmits a sighting report about seven enemy transports on course 300,
steaming at 12 kts. This is the last signal received from I-172.
USS HELENA (CL-50), steaming with Task Group 65.4 providing escort for a supply echelon to Guadalcanal, makes radar contact with a surface target on
bearing 046 (T), distance 16,000 yds. At 0520, USS MCCALLA (DD-488) is dispatched to investigate the contact.
An almost stationary submarine is sighted on bearing 090 (T), about 2000 yds distant. The guns are trained on the target and the destroyer develops flank
speed in an attempt to ram it. At 0532 the submarine dives, turning sharply towards MCCALLA. A periscope is briefly sighted off her port bow, 100-200 yds away.
At 0537 MCCALLA commences an attack with depth charges, set to the depth of 50/100 ft. Six 600-lb and five 300-lb depth charges are expended. Thirty seconds
after the last charge of the pattern has exploded, another underwater explosion is heard. Thirty seconds after this there is a second explosion, and three minutes
later a third explosion. The sonar contact is lost; a heavy oil smell is noticed near 10-53S, 161-50E. 
27 November 1942:
I-172 is presumed lost with all 91 hands off Guadalcanal.
15 December 1942:
Removed from the Navy List.
Authors' Notes:  Mt. Niitaka, located in Formosa (now Taiwan), was then the highest point in the Japanese Empire.
 Although USS SOUTHARD (DMS-10) is often credited with I-172's sinking, her target was more likely I-15.
On 29 October 1942, Lt F. Joe Hill's PBY-5 "Catalina" of VP-11 claimed a submarine - thought by some to be I-172 - at 13-15S, 162-45E, but I-172's last report was made six days later.
Thanks go to Dr. Higuchi Tatsuhiro of Japan and to James C. Sawruk of USA for sharing his research on MCCALLA's attack and other anti-submarine actions in that area.
– Bob Hackett and Sander Kingsepp.
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