YUSOSEN!
SAN RAMON MARU prewar as a Mitsubishi Shoji tanker
IJN SAN RAMON MARU:
Tabular Record of Movement
© 2008-2020 Bob Hackett and Peter Cundall.
Revision 8
4 February 1935:
Nagasaki. Laid down at Mitsubishi Jukogyo K.K Nagasaki Zosensho as a 7,309-ton for Mitsubishi Shoji K.K.
15 September 1935:
Launched and named SAN RAMON MARU.
20 November 1935:
Completed and registered at Tokyo. Her gross registered (GRT) tonnage and net registered tonnage (NRT) respectively are 7,309-tons and 5,439-tons. Her call sign is JWWJ. [1]
1935-1941:
In Mitsubishi’s service. Engages in transportation of oil between California and Japan.
23 December 1941:
Chartered by the IJN as a general transport (oil supply) under the Kure Naval Jurisdiction and assigned to the Naval Department.
26 December 1941:
Departs Kure.
29 December 1941:
Arrives at Mako.
1 January 1942:
Departs Mako.
4 January 1942:
Arrives at Mako.
14 January 1942:
Departs Kure.
15 January 1942:
Arrives at Moji.
16 January 1942:
Departs Moji.
21 January 1942:
Arrives at Saipan, Marianas.
13 February 1942:
Departs Kure.
23 February 1942:
Arrives at the Anambas Islands, Netherlands East Indies (now Indonesia).
22 March 1942:
Departs Kure.
24 March 1942:
Arrives at Yokkaichi.
28 March 1942:
Departs Yokkaichi.
2 April 1942:
Arrives at Mako.
5 April 1942:
Departs Mako, Pescadores (now Magong, Penghu Islands, Taiwan).
9 April 1942:
Arrives at Kure.
16 April 1942:
Departs Kure.
21 April 1942:
Arrives at Mako.
23 April 1942:
Departs Mako.
E 27 April 1942:
Arrives at Tarakan, Borneo, Netherlands East Indies (now Kalimantan, Indonesia).
10 May 1942:
Arrives at Yokohama.
15 May 1942:
Departs Yokohama.
22 June 1942:
Arrives at Takao, Formosa (now Kaoshiung, Taiwan).
23 June 1942:
Departs Takao.
26 July 1942:
Arrives at Mako.
28 July 1942:
Departs Mako.
3 August 1942:
Arrives at Yokosuka.
4 September 1942:
Departs Yokosuka.
17 September 1942:
At 140 degrees and 30 nautical miles of the Danjo Islands attacked by an enemy submarine with a torpedo but isn’t damaged
18 September 1942:
While sailing with TANGO MARU an enemy submarine is sighted near Danjo Gunto and avoided.
20 September 1942:
Arrives at Mako.
23 September 1942:
Departs Mako.
29 October 1942:
Arrives at Mako.
30 October 1942:
Departs Mako.
6 November 1942:
Arrives at Shimotsu.
9 November 1942:
Departs Shimotsu.
10 November 1942:
Arrives at Tokuyama Naval Fuel Depot.
12 November 1942:
Departs Tokuyama.
15 November 1942:
Arrives at Yokosuka.
28 November 1942:
Departs Yokosuka.
29 November 1942:
Arrives at Yokkaichi.
1 December 1942:
Departs Yokkaichi.
3 December 1942:
Arrives at Moji.
5 December 1942:
Departs Moji.
10 December 1942:
Arrives at Mako.
12 December 1942:
Departs Mako.
9 January 1943:
Arrives at Mako.
13 January 1943:
Departs Mako.
19 January 1943:
Arrives at Tokuyama.
22 January 1943:
Departs Tokuyama.
24 January 1943:
Arrives at Sasebo.
26 January 1943:
Departs Sasebo.
2 March 1943:
Arrives at Mako.
5 March 1943:
Departs Mako.
15 March 1943:
Arrives at Yokohama.
26 March 1943:
Departs Yokohama in convoy with NITTATSU MARU.
28 March 1943:
Arrives at Tokuyama.
1 April 1943:
Departs Tokuyama.
4 April 1943:
Departs Ominato, Honshu.
9 April 1943:
Arrives at Paramushiro (now Paramushir, Russia), Kuriles.
3 May 1943:
Light cruiser KISO comes alongside and is refueled.
4 May 1943:
Departs Paramushiro.
8 May 1943:
Arrives at Ominato.
13 May 1943:
Departs Ominato.
16 May 1943:
Arrives at Kure.
19 May 1943:
Departs Kure.
26 May 1943:
Arrives at Paramushiro.
27 May 1943:
Transfers 3,280 tons of L1 fuel oil to auxiliary oiler TEIYO MARU. [2]
4 June 1943:
At Kataoka Bay, Shimushu Island, Kuriles (now Zaliv Kozyrevskogo, Ostrov Shumushu, Russia). Transfers 961 tons of L1 fuel oil to auxiliary oiler TEIYO MARU. At 1200 departs Paramushiro.
10 June 1943:
At 1900 arrives at Sasebo.
17 June 1943:
Departs Sasebo.
21 June 1943:
Her ownership changes to Mitsubishi Kisen K.K.
23 July 1943:
SAN RAMON MARU departs St Jacques in unescorted convoy No. 412 also consisting of tankers ATAGO, NICHIRIN and KIYO MARUs and cargo ships JUNGEN GO and KAIJUN GO, GYOKO MARU and seven unescorted merchant ships. The convoy later splits into three parts.
29 July 1943:
Arrives at Takao.
27 July 1943:
At 1200, arrives at Mako.
30 July 1943:
Departs Mako.
3 August 1943:
Arrives at Tokuyama.
7 August 1943:
Departs Tokuyama
10 August 1943:
At 1400, SAN RAMON MARU departs Moji in convoy No. 185 also consisting of tankers CHIYODA, TACHIBANA, MATSUMOTO, TONAN, YAMAMIZU and NICHIRIN MARUs passenger-cargo ships TEIBI (ex French BERNARDIN de ST PIERRE), KACHIDOKI (ex-PRESIDENT HARRISON) and GINYO MARUs, cargo ship ASUKA MARU and one unidentified ship escorted by kaibokan SADO.
11 August 1943:
Off Nagasaki convoy No. 184 consisting of IJA shared tanker (A/C-AO) FUSHIMI MARU No. 3 and IJN converted merchant tanker SHUNTEN MARU and one unidentified merchant ship without escort merges with the convoy.
15 August 1943:
Arrives at Mako, Pescadores.
18 August 1943:
Departs Mako for Singapore to load 12,300 kilolitres of crude oil in convoy No. 316 also consisting of tankers TACHIBANA, NICHIRIN, YAMAMIZU and TONAN MARUs, passenger-cargo ships KACHIDOKI (ex-PRESIDENT HARRISON) and GINYO MARUs, cargo ship ASUKA MARU and three unidentified ships.
21 August 1943:
The convoy now consists of eight ships, the three unidentified ships likely having detached for either Hong Kong or Hainan. At 1340 in position 15.24N 115-32E the convoy is attacked and three torpedoes narrowly miss GINYO MARU.
26 August 1943:
Arrives at Saigon, French Indochina (now Ho Chi Minh City, Vietnam).
1 September 1943:
Requisitioned by the IJN and registered as an auxilairy transport (fuel supply) in the Kure Naval District. Assigned to the Naval Department as an auxiliary transport Otsu category belonging to the Kure Naval District. SAN RAMON MARU is manned by an IJN crew. [3] [4]
21 September 1943:
Arrives at Mako.
24 September 1943:
Departs Mako.
30 September 1943:
Arrives at Kudamatsu.
5 October 1943:
Departs Kudamatsu.
10 October 1943:
At 1505, SAN RAMON MARU departs Moji in convoy No. 105 consisting of TEIKAI (ex-German FULDA) , CHICAGO, AMERICA, GYOKUREI, MIKASA, HEIAN, NICHIEI and GYOTEN MARUs and tanker MITSU MARU escorted by destroyer SHIOKAZE. CHICAGO MARU is carrying 1365 men from 1st Battalion, 37th Infantry, 4th Division, the 37th Infantry rapid fire artillery unit (antitank), the transporatation regiments headquarters and one company of trucks, and 1st Field Hospital, 4th Division; GYOTEN MARU carries the 3rd Battalion, 8th Infantry Regiment, 4th Division and AMERICA MARU carries the regimental headquarters, 8th Infantry, and 1st Battalion, 8th Infantry, both 4th Division.
15 October 1943:
At 0110, LtCdr (later KIA) Charles F. Brindupke's (USNA ’32) USS TULLIBEE (SS-284) torpedoes and sinks CHICAGO MARU at 24-30N, 120-26E. 42 troops, one gunner and 8 crewmen are KIA. Over the next five hours, SAN RAMON MARU, NICHIEI and GYOKUREI MARUs rescue survivors. Later that day arrives at Takao.
At 2122, USN codebreakers intercept and decrypt a message that says CHICAGO MARU had aboard 1,304 men, elements of a field antiaircraft artillery battalion. [5]
4 November 1943:
Departs Miri, Sarawak, British Borneo (now Malaysia) carrying 10,600 tons of crude oil, bound for St.Jacques, French Indochina (now Vung Tau, Vietnam).
November 1943:
Arrives at St. Jacques (now Vung Tau, near Saigon), French Indochina.
November 1943:
Arrives at Mako.
November 1943:
Arrives at Takao.
21 November 1943:
Departs Mako. At 1450, joins convoy No. 221 consisting of auxiliary shared emergency tanker (B/C-AO) TAKETOYO MARU, IJA shared tanker (A/C-AO) FUSHIMI MARU No. 3, IJA transports CHILE, SHOYU and SEIWA MARUs and one unidentified merchant ship escorted by patrol boat PB-36.
27 November 1943:
East China Sea, off Uki Jima, Goto Retto. At 0005, at 33-36N, 128-57E , in a surface attack, LtCdr (later Captain) Slade D. Cutter’s (USNA ’35) USS SEAHORSE (SS-304) fires three bow torpedoes and gets one hit on SAN RAMON MARU carrying a full load of 10,600-tons of crude oil. The torpedo hits between the first and second oil tanks. At 0128, Cutter again attacks and hits SAN RAMON MARU with two of four stern torpedoes he fires. At 0133, patrol boat PB-36 drops for depth charges. At 0138 PB-36 drops another 4 depth charges. At 0213 SAN RAMON MARU sinks by the stern at 33-35N, 128-45E. At 0234 PB-36 drops 5 depth charges. At 0254 PB-36 drops another 5 depth charges. At 0800, PB-36 searches for victims and rescues 25 survivors. 28 crewmen and 28 crewmen and three gunners are KIA. [6]
5 January 1944:
Removed from the Navy List:
Author's Notes:
[1] NRT is a ship's cargo volume capacity expressed in "register tons", one of which equals to a volume of 100 cubic feet (2.83 m3). It is calculated by subtracting non-revenue-earning spaces i.e. spaces not available for carrying cargo, for example engine rooms, fuel tanks and crew quarters, from the ship's gross register tonnage (GRT). Net register tonnage (NRT) is not a measure of the weight of the ship or its cargo, and should not be confused with terms such as deadweight tonnage or displacement.
[2] Fuel oil was of four grades:
L0: Heavy oil for boilers.
L1: No. 1 heavy oil for diesel. 90% light oil ingredient.
L2: No. 2 heavy oil for diesel. 50% light oil ingredient.
L3: No. 3 heavy oil for boilers. Less than 10% light oil ingredient.
[3] As distinct from a Navy requisitioned merchant tanker.
[4] There were two categories of Yusosen. (Ko) category with an IJN Captain as supervisor aboard and (Otsu) category without.
[5] A Japanese magazine news story says that seven torpedoes were fired, five evaded, two hit but did not explode.
[6] Japanese and American accounts of the sinking differ. USS SEAHORSE’s patrol report indicates Cutter attacked at 2302 and got two hits that broke SAN RAMON MARU in two. Witnesses on USS SEAHORSE’s bridge claimed the bow sank immediately, followed shortly by the stern. USS SEAHORSE’s patrol report further indicates that, at 0027, Cutter attacked and sank another tanker; however, postwar, this second sinking could not be substantiated.
Thanks go to John Whitman of the USA for info on CNO intercepts of Japanese messages, and Japanese units and to Mr. Gilbert Casse of France and Mr. Berend van der Wal of Netherlands for general assistance. Thanks also to go to Yutaka Iwasaki of Japan for his help in decoding IJN fuel grades in JACAR and Gengoro S. Toda of Japan.
- Bob Hackett and Peter Cundall.
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