Research: Japanese Wartime Transportation Convoy History

[Donner]

I posted this last June in the SH4 Forum and it seems that it is very appropriate here as work is being done in modifying the Campaign files and such.

I have a translated copy of S. Komamiya's Wartime Transportation Convoys History on a CD. A fellow submarine researcher gave me this in 2005. It is an indespensable document (nearly 500 pages total in 3 files of MS Word) if you are interested in the subject. I am unsure who holds the copyright (if any) on this translation.

Komimaya's work contains the following (where available): depature/arrival times, merchant ship names, escorting warship names, and a brief and sometimes detailed account of the convoys journey...including which particular Allied submarine (or ship) inflicted the losses. There also on index to locate US submarines involved in attacks. The index isn't that great though...

You may PM me if you are interested in obtaining these files. All three files combined are about 3 megs.

A few sample listings:

About dawn.
17th. March, 1942.
From: Hakata Bay, northern Kyushu.
21st. March, 1942.
To: Bako, Pescadores Islands.
Yubae Maru, Montreal Maru, Samaran Maru, Hanan Maru (4).
Auxiliary minelayer Kahoku Maru, destroyer Minekaze (2).
After safe arrival at Bako, Yubae Maru left bound for the Philippine Islands with an independent garrison force onboard. The other three headed for Singapore with replacement soldiers for the 18th. Infantry Division

1200.
7th. May, 1942.
From: Mutsure, northern Kyushu.
To: Singapore.
No. 109
Taiyo Maru, Mikage Maru, Dover Maru, Ryusei Maru, Yoshino Maru (5).
Auxiliary gunboat Peking Maru (1).
At about 1945 on the 8th. May while at position 30.45N 127.40E off south‑west Kyushu Taiyo Maru was torpedoed by the U.S.S. Grenadier.
The submarine found convoy No. 109 and decided it consisted of six freighters and with her distinctive silhouette, the Taiyo Maru. Four torpedoes were fired for two claimed hits.

At the time lookouts on Taiyo Maru reported sighting a twinkling blue object astern to starboard, possibly this was from one of two magnetic torpedoes set to run under the ship, at the same time another torpedo exploded on her port side stern. The impact instantly destroyed Taiyo maru's communication facilities, it also caused her compass to be blown off.
The second missile struck home in No. 2 hold on the same side, about 150 tons of calcium carbide there caught fire and a cargo of hand‑grenades erupted in a series of explosions.
A few seconds later a third torpedo hit in the front part of No. 2 sealed the ship's fate for huge fires took hold. However as the submarine claimed only two hits possibly this so‑called third hit was actually an onboard explosion.
Meanwhile Peking Maru replied with a string of depth‑charges, close but Grenadier remained undamaged. The submarine later reported that she was attacked by "destroyers" afterwards, a total of thirty‑six were dropped over a period of four hours.
After the torpedoing there was chaos inside the maru, quickly the eighteen lifeboats carried were prepared for launching, some if not all of these crowded craft by 2020 were starting to leave the ship. By now water was up to C deck and a list of about 36 degrees had developed, consequently all hands were ordered off.
By 2035 Taiyo Maru's list because of the amount of water taken in had corrected itself but her bow had been thrust into the sea, finally the maru's stern rose vertically into the sky and by 2040 she was gone.
The weather was poor that evening and many of the evacuees were left struggling in the sea, consequently fatigue and the icy waters took their toll. Also some of the lifeboats capsized in the rough conditions adding to the casualties.
This large 14,457 ton ship owned by the Nippon Yusen Kaisha line was carrying 1044 passengers, 263 crew and four gunners, a total of 1311, 770 lost their lives.
However another report states that of the 1044 passengers, 660 lost their lives, of her crew of 263, 157 died representing a total of 817 casualties!
Her cargo consisted of the above‑mentioned calcium carbide, some shells, hand‑grenades and other ammunition plus baggage representing a total of 2300 tons.
Amongst the passengers were a large number of technicians, and people charged with the economic development of the newly captured territories in the southern area, many lost their lives.
The Japanese at the time were well aware that Taiyo Maru was a prime target for enemy submarines, afterwards they fully recognized the mistake of spending this 14 knot ship with a 9.5 knot convoy. Also because of the rough conditions the convoy was traveling a few knots less than the designated speed.
The rest of convoy No. 109 went onward and after making calls at Mako and Cape St. Jacques, arrived at Singapore on the 7th. of June, 1942.

0700.
18th. August, 1943.
From: Palau.
0700.
28th. August, 1943.
To: Ujina, West Inland Sea (or possible Moji, northern Kyushu.)
FU‑806.
Taifuku Maru, Hozugawa Maru, Mexico Maru, Toyokawa Maru, Toun Maru, Kayo Maru (6).
Minesweeper No. 17, Minelayer Yurishima, auxiliary minesweepers No. 7, Tama Maru, No. 6 Tama Maru (4).
Late on the night of the 22nd. at position 21.50N 137.52E, Toun Maru was hit aft on the port side by a torpedo. Four missiles were seen approaching, one struck her coal bunker on the port side, luckily as it was a dud damage was slight.
The culprit was the U.S.S. Pike, the submarine fired two torpedoes each at two targets for one claimed hit and damage, no depth‑charge counter‑attack is recorded.
On the 23rd. at 1805 position 24.08N 137.37E Toun Maru was attacked again, the maru avoided the missiles. Again the attacker was the Pike,
the submarine fired four torpedoes for one claimed hit and damage. The submarine counted five depth‑charges but remained undamaged.
At 0530 on the 26th. Mexico Maru reported torpedo tracks approaching from forward, the escorts immediately opened fire, then four deep running torpedoes passed underneath one of the escorts.
The submarine was the U.S.S. Whale, she fired at both the escorts, three torpedoes at one and one at the other for no claimed hits. The escorts dropped five depth‑charges, Whale incurred slight damage.

At 0258 on the 27th. Taifuku Maru was torpedoed from 60 degrees off the port side by the U.S.S. Pollack. An attempt was made to turn her rudder, then a torpedo passed across her bow, then two passed under the No. 2 hold and her bridge, the remaining pair hit No. 3 and No. 4 holds. A terrible tremor ran through the ship, inside all the lights went out, rudder troubles occurred and all facilities on deck were destroyed. As the ship was obviously sinking it was quickly abandoned. A few minutes later her stern sank into the sea and at 0311 Taifuku Maru's bow rose into the air and she sank at position 32.28N 132.23E, 30 kilometers south‑west of Tosa, Okinoshima.
This ship was a victim of the U.S.S. Pollack, the submarine fired four torpedoes at a cargo ship and two at a "destroyer" for just one claimed hit on the former for damage. The escorts dropped seven depth‑charges but Pollack remained undamaged.
Taifuku Maru was a 3520 ton ship owned by the Nippon Yusen Kaisha Line, at the time she was carrying 160 passengers and the ashes of 137 dead, about fourteen men lost their lives.

[Sailor Steve]

Thanks for bringing that up again, Donner. I copied those a long time ago and was busy working on a simple list far in advance of SH4, when I got displaced.

If someone else can use those to make the convoys more realistic it would be great. On the other hand, I can't play at all right now, so I have no idea how realistic they are! :rotfl:

[iambecomelife]

Thanks Donner - I'd love to take a look at this. Very interesting blow-by-blow descriptions, and thanks to ONI-208J it's possible to research almost all the ships involved.

[iambecomelife]

Donner check your PM

Thanks again

[Donner]

castorp345 & iambecomelife...

You've got mail!

Cheers!

[castorp345]

w00t!

many thanks again!!

[PeriscopeDepth]

Do you have access to a digital copy of ONI-208J, iambecomelife?

PD

[iambecomelife]

Originally Posted by PeriscopeDepth

Do you have access to a digital copy of ONI-208J, iambecomelife?

PD

Yes. You can buy it here: http://www.history-on-cdrom.com/

There are also several other very useful ID manuals for armored vehicles, merchantmen, and military aircraft. A large proportion of the manuals deal with vehicles that would have been encountered in the Pacific Theatre.

I noticed that one of the sample images at the site is of a merchantman that I'd like to include in my mod (modern, long bridge deck). The actual size of the scans is much larger than the pic below, and they are in PDF format.

[tater]

It's interesting to look at how many ships were convoyed in a given period compared to the total number of ships they had---all sailing back and forth as quickly as they could turn around. Basically 250 japanese merchant ships must have been at sea any given day.

[tater]

The ONI stuff rocks. Buy it now!

[iambecomelife]

Originally Posted by tater

It's interesting to look at how many ships were convoyed in a given period compared to the total number of ships they had---all sailing back and forth as quickly as they could turn around. Basically 250 japanese merchant ships must have been at sea any given day.

That's probably because their merchant marine was stretched to the breaking point. Even at the beginning of the war the Japanese didn't have enough ships, and that's counting the vast amount of Allied tonnage that was captured from European colonies. Although the Japanese military had been tied up in China since the 30's and knew that they would need much more new tonnage to take on the U.S. and U.K., they still had not produced enough new tonnage by December of 1941. Anyone who has read "Samurai!" by Saburo Sakai remembers how Sakai and his group of elite pilots were crammed into an aging, slow freighter that could have easily been sunk at any time; the US and Britain, OTOH, had enough fast liners to give most soldiers a reasonably safe passage, to say nothing of irreplaceable aircrews. There are lots of similar situations that demonstrate the poor state of their merchant fleet: island garrisons starving because it was impossible to transport supplies to them, loaded fleet oilers being used as troopships (!),carriers and destroyers used regularly to ship fuel & food, and so on.

[tater]

Oh yeah. You're preaching to the choir.

The decisive battle the IJN sought was fought... December 7th, 1941. Their war plan (if you can even say they had one) required a quick, negotiated peace. Pissing off the US by the PH attack (even had the war declaration arrived on time moments before the attack) guaranteed a protracted war—a war they knew they could not win.

BTW, another must-have book for the PTO enthusiast would be Combined Fleet: Decoded. Oh, and Kaigun, too.

tater

[PeriscopeDepth]

Thank you, sir.

PD

[Sailor Steve]

Those convoy documents are wonderful. Sometimes the "escort" is an empty merchant equipped with depth charges. I found one instance of a merchant sinking after a dud torpedo made a small hole that just couldn't be fixed. On the other hand there was the merchant that didn't sink after taking 8 torpedoes over a 10-hour period! (This is also recorded in United States Submarine Operations In World War Two).

If you like research at all, get a copy of that document from Donner; it's priceless.

[tater]

Yeah, really, that is an awesome find.