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Donner
03-28-07, 01:10 PM
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
03-28-07, 04:54 PM
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!:damn: :rotfl:

iambecomelife
03-28-07, 08:04 PM
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
03-28-07, 08:48 PM
Donner check your PM

Thanks again

Donner
03-28-07, 08:58 PM
castorp345 & iambecomelife...

You've got mail! :ping:

Cheers!

castorp345
03-28-07, 09:04 PM
w00t!

many thanks again!!

:rock:

PeriscopeDepth
03-28-07, 09:08 PM
Do you have access to a digital copy of ONI-208J, iambecomelife?

PD

iambecomelife
03-28-07, 10:22 PM
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.

http://www.history-on-cdrom.com/228c2440.jpg
http://i33.photobucket.com/albums/d54/iambecomelife/Yamo-1.jpg

tater
03-28-07, 10:24 PM
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
03-28-07, 10:27 PM
The ONI stuff rocks. Buy it now!

http://silenthunter4.us.ubi.com/images/ships/ship_850_tyoheimaru.jpg

http://members.spinn.net/~merrick/Stuff/tyohei_maru.jpg


http://silenthunter4.us.ubi.com/images/ships/ship_850_taihosanmaru.jpg

http://members.spinn.net/~merrick/Stuff/taihosan_maru.jpg

iambecomelife
03-28-07, 10:43 PM
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
03-28-07, 11:20 PM
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
03-29-07, 12:26 AM
Thank you, sir. :)

PD

Sailor Steve
03-29-07, 10:53 AM
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
03-29-07, 11:33 AM
Yeah, really, that is an awesome find. :up:

Forlorn
03-29-07, 12:02 PM
As far as the amount of merchants is concerned there is also the cut between military and civil merchants. Military merchants were controlled by the Japanese Navy for oil, weapon, food and other stuff only for the garrisons. Civil merchants were controlled by civil ministries on the Main Japanese Islands. They never shared experience, ships and escorts.

Example: 3 civil merchants load stuff for the industry on port A. They sailed to port B and unloaded their stuff there. Without loading new stuff they went back to port A. The military garrison on the island of port A however was resupplied by military merchants from port B. Fully loaded they sailed to port A, maybe with an escort. Unloading all their stuff on port A they went back to port B without loading anything at all. Cause the goods on port A that were needed in port B were civil. Even the civil merchants were not allowed to join another escorted military merchant. Even when attacked the military merchant would rather inform their superiors than the civil merchant 5 miles away and vise versa.

tater
03-29-07, 12:34 PM
Good points, forlorn, but you missed another complication: The military transport problem was doubly complicated because the IJ ARMY had its own shipping, totally separate from the IJ NAVY. They even had their own aircraft carrier for aircraft ferry duty. The IJN was even less likely to provide escort of IJA shipping than they were for civilian traffic. Pathological axis interservice rivalry strikes again.

I think the reality until '44 was that the vast supermajority of civilian traffic sailed as they saw fit with no escort. About 41% of shipping tonnage was pure civie. Around 25% was IJN, and the remaining 33% was IJA.

There was a dev post (I think) at ubi where he said that ~55% of shipping was escorted. I'd think that early in the war, 55% of the IJN traffic might be escorted, lol. A far far lower % of IJA traffic aside from invasions (where it would be a combined operation) would get escort from any IJN forces. Same with civies. As a boundary value, assume all IJN escorted, and none of the others. 74% unescorted.

tater
10-26-07, 04:31 PM
A useful tidbit:

There were several types of convoy nomenclature that can be summarised briefly as follows:

1/ Naval Convoys W Pacific theatre 4 numbers eg 4731
2/ Army Convoys W Pacific theatre used alpha prefix eg O, Fu, So.and then 3 numbers.
3/ Early SW Pacific and Kuriles convoys used letters A, B, C, D, E etc
4/ Later Kurile Convoys used 4 digits 1 northbound, 2 southbound
5/ Ordinary slow convoys to SE Asia used 3 of 4 numbers eg Moji-Takao 101-199, Singapore-Manila 3401-3499
6/ Philippine based Army convoys used letters H, M, C, D Z and number, and from 1944 3 numbers.
7/ Special convoys to specific end location used two letters to signify destination and then number. The most well known of these is the MI (Miri) convoys. MO, NA, TA, SHI were others.
8/ 4 letter convoys and number with first two letters signifying departure port and last two letters signifying destination port- see list below. Number followed.
9/ HI series fast convoys to Singapore as noted. HI and number as noted.
10/ Special convoys usually Army reinforcement convoys. Example include Take, Higashi-Matsu, Oki etc. The first was a one off, the latter a numbered series.
11/ Specialist location convoys like Wewak, Hollandia Convoys name of place followed by number eg Wewak No.2
12/ Unnumbered convoys that were common particularly in the early stages of the war.

Also evacauation convoys like Taihi and Shima Rinji and convoys named after lead ships eg Tsurumi deserve a mention.

There are several other types but these are the main types.

4 letter convoy prefiixes included the following:

BASU Bandjermasin - Sourabaya
HOMO Hong Kong - Moji
KANA Kagoshima - Naha
KATA Kagoshima - Takao
KITA Kirun - Takao
MASA Manila-Saigon
MATA Manila- Takao
MOSHI Moji -Shanghai
MOTA Moji - Takao
MUTA Mutsure-Takao
NAKA Naha - Kagoshima
NAMO Naha- Moji
PATA Palau - Takao
SAMA Saigon-Manila
SASI Saigon - Singapore
SATA Saigon-Takao
SEDA Cebu-Davao
SEPA Cebu-Palau
SHIMO Shanghai - Moji
SISA Singapore-Saigon
TAKA Takao - Kagoshima
TAMA Takao-Manila
TAMO Takao - Moji
TAPA Takao - Palau
TASA Takao-Saigon
YUTA Yulin - Takao

tater
10-27-07, 03:59 PM
Interesting article:

http://www.ibiblio.org/hyperwar/AAF/USSBS/IJO/IJO-45.html

Useful bits:

http://www.ibiblio.org/hyperwar/AAF/USSBS/IJO/img/plate_45-4.jpg
Q. Sketch a diagram of what you considered to be the best protective formation?
A. At this time the Number One Coastal Convoy Unit issued a book of instructions called "Number One Coastal Escort Unit Operating Plans". There are a great many formations, more then ten formations according to the number of ships. When looking out for submarine torpedoes, the normal formation was a block protected by ring formation -- the escort vessels standing off, one thousand or two thousand meters. If there were plenty of escort vessels a screen was sent forward but this situation seldom obtained. This screen was placed about 10,000 meters forward but always within visibility. Well before dawn it was advised that one escort vessel drop back to the limit of visibility and the same procedure at dusk. There was not any settled formation policy as defense against air attacks, but with regard to my own performance during air attacks I ordered the convoy to close formation in order to consolidate anti-aircraft fire.

Q. Under what conditions did convoys zig-zag?
A. Wherever there was room zig-zagging was normal procedure.


Airstrike.cfg issue for reality:
Q. Did the convoy commander have direct communications with the planes?
A. Only twice in my experience has any communications succeeded. We had radio sets especially intended for that communication but they never worked.

More aircraft stuff:
http://www.ibiblio.org/hyperwar/AAF/USSBS/IJO/IJO-56.html

A useful quote about air based ASW:
Q. Did you not have twin-engine bombers specially equipped for anti-submarine work?
A. We had at the most 36, Type 96 bombers, divided between FORMOSA, LUZON and HAINAN. Half with radar and half with the magnetic device, which was very effective in detecting submarines.

Need to make a MAD...

Southern area ASW:
http://www.ibiblio.org/hyperwar/AAF/USSBS/IJO/IJO-49.html

Q. What was the organization of your escort vessels?
A. Our escort vessels at AMBON consisted of one torpedo boat, the KIJI, and 15 converted trawlers of less than 500 tons and a maximum of 10 knots speed. No regular convoy routines were possible owing to the scarcity of escort vessels and their slowness. During the bad months of May and June 1944, my unit borrowed seven or eight small ships from SOERABAJA. At no time were any large naval ships, such as DD's or DE's, used for escorting in my area. The ships escorted were carrying provisions and personnel belonging to both the Army and the Navy. The escorting duty was the Navy responsibility. The only craft going without escort in my area were sailing boats; vessels of 1,000 tons and up received escorts. The area of escort responsibility for the Fourth Advanced Southern Fleet was between the eastern limit of 140ƒ East longitude and a line from PALAU to TALIABO Island in the NETHERLAND EAST INDIES and from that island a line running 160ƒ True.
(note that this is in 1944 when convoys became standard practice).

Different interview:
Q. Did you have air cover over your convoys?
A. Yes we had anti-submarine search planes, some times four or five of them equipped with magnetic detecting devices and searching in a special manner.

More interesting air based ASW:
http://www.ibiblio.org/hyperwar/AAF/USSBS/IJO/IJO-63.html

http://www.ibiblio.org/hyperwar/AAF/USSBS/IJO/IJO-48.html

swdw
10-29-07, 10:25 AM
Need to make a MAD...

Anyway to simulate the effect of a MAD on specific aircraft using Ducimus' visual zone idea (clone an aircraft, change the visual zone and rename, reinsert, it into the game?)

Wouldn't really be a MAD, but if the plane could spot a sub at the same depth a MAD could . . .

tater
10-29-07, 11:11 AM
Yeah, I've suggested a few MAD ideas in other threads. Could be radar as well, or even sonar if the ping noise could be done away with.

We'll get it figured out I'm sure. The trick will be that it should be VERY short ranged. Like 250m deep from the plane, tops (according to IJN interviews, probably less in RL). That includes the plane's altitude. So 250m, where the plane flies at 100+m most of the time. The lateral range should be less than 250m. Literally the plane needs to fly almost directly over the sub.

Then use "scripted" planes (really random groups set to spawn when I want them to) flying patterns in front of convoys... I have some tests already built of the convoys with planes ahead, actually :)

tater

john whitman
04-09-10, 08:11 AM
Hello Donner:

I noticed your old post and the fact that you have a CD with a translated Komamiya. I am studying Japanese logistics in WWII and have always needed that document. How might I obtain a copy? I tried the instant messaging, but my computer, or maybe my computer illiteracy, prevented me from contacting you.

John

Sailor Steve
04-09-10, 09:52 AM
WELCOME ABOARD, john whitman!:sunny:

Donner hasn't been around for quite some time, but I have a copy. PM me with your email address and I'll send it to you today.

SteveUK
04-09-10, 11:57 AM
Is there any way yo get hold of this still? I've always been interested to read this but have never been able to find a copy. Avid reader of the original war patrol logs and would be kken to see this.

Thanks

Sailor Steve
04-09-10, 12:57 PM
Um...read my post above yours?:sunny: