On the Japanese "gunboats" in SH4:

[akdavis]

I believe the devs confused these gunboats with accounts of US sub encountering "converted gunboats." While I can't find an view of a specific wartime Japanese example, here is a US converted gunboat from between the world wars:



Her upper decks had been removed to increase open water stability. A variety of different ships were converted to gunboat status during the war. Steamships were common.

The gunboats in the game should probably be excised entirely. Both the Atami and the Hira were not part of the Combined Fleet, but rather assigned to the Japanese naval forces in China, as can be seen in this document:

http://www.ibiblio.org/pha/pha/misc/45-41.html

They and their sisters (Atami class: Atami, Futami; Seta class: Seta, Katata, Hira, Hozu) were Yangtze River patrol boats. To show where they where later in the war, references indicate that the Atami was damaged by Chinese aircraft near Tung Ting Lake in China on June 10, 1943, while the Hira was damaged in an air attack at Kiukiang, China in August of 1944.

At the most, they might appear occasionally in Shanghai harbor.

Here are some examples of converted gunboats sunk by US submarines:

SHOSEI MARU

Japanese Navy; 1929; Amagasaki Zosensho; 998 tons; 210 x
30-5x18-7; triple-expansion engines.
The steamship Shosei Maru was taken over by the Japanese Navy
for use as an auxiliary gunboat. On May 20th, 1944, she was torpedoed
and sunk by a U.S. submarine [U.S.S. Silversides] about 50 miles S.W. of

Guam.

NIKKAI MARU
Nissan Kisen K.K.; 1938; Uraga Dock Co.; 2,562 tons; 297-9 x
45x23-8; 201 n.h.p.; compound engines & L.P. turbine. The

steamship Nikkai Maru was taken over by the Japanese Navy and
converted into an auxiliary gunboat. On November 26th, 1943, she

was torpedoed and sunk by the U.S. submarine Ray 350 miles N. of
the Admiralty Islands.

KEIKO MARU
Osaka Shosen K.K.; 1938; Uraga Dock Co.; 2,929 tons;
297 -9x45x23-8; 255 n.h.p.; compound engines & L.P. turbine.

The steamship Keiko Maru was taken over by the Japanese Navy
and converted into an auxiliary gunboat. On November 8th, 1942,
she was torpedoed and sunk by the U.S. submarine Seawolf off Mindanao Island, Philippines.

[nattydread]

I read an account (I cant remember if it was O'Kane or somebody else) of a freighter that dodge a torp spread from a US sub at PD and ran down the wakes to the now diving sub.

The skipper felt it was the smart thing to do since he lost the advantage of surprise and it seemed the freighter was going on the offense. During the dive the sub was rocked by several close depth charges. Since he hadnt seen any other ships is determined the frieghter was an old US Q-ship that was purchased by Japan between wars. I think he IDed it as an old Hog Islander.

[nematode]

Good post Akdavis.

You're absolutely right, the Japanese gunboats in game are river patrol craft and don't belong in the open ocean. As a campaign builder, I'm planning to remove them from open water patrol routes and restrict them to Chinese harbors and rivers, but they would also be reasonably appropriate in Korean ports, as well as southeast Asian places like Manila Bay, Singapore, and Java, to represent small captured Allied vessels used by the Japanese as riverine/harbor patrol boats, like USS Wake http://en.wikipedia.org/wiki/USS_Wake_(PR-3)

You are also spot on with the information about the converted gunboats. Before the war began, the Japanese military requisitioned about half of their nation's merchant fleet (one figure I have seen is 3.9 million tons requisitioned out of a total of 6.4 million tons in civilian ownership). From the pool of requisitioned merchant ships in the 1000 to 4000 ton range, the military converted about 90 of them into auxiliary gunboats.

About a hundred other small merchant ships were converted into minelayers or netlayers, as well as hundreds - maybe 600 total - fishing boats converted into very small naval auxiliary warships. More about the fishing boats down post....

Back to the auxiliary gunboats, they were open ocean capable, and were used for patrol, convoy escort, military cargo transport, and also as assault transports during the early war period when the Japanese were invading places. It appears to be the case that when the converted gunboats were used in convoy work or beach landings, that they were typically also loaded up with cargo.

Information on the auxiliary gunboats is hard to come by, especially in English language. But it's accurate to say that no two of them were exactly alike. Here are some links to a Japanese model builder's webpage showing his vision of what some of them looked like:

http://ww6.enjoy.ne.jp/~iwashige/chojusanmaru.htm
http://ww6.enjoy.ne.jp/~iwashige/kazanmaru.htm
http://ww6.enjoy.ne.jp/~iwashige/pekingmaru.htm
http://ww6.enjoy.ne.jp/~iwashige/shinkomarunigo.htm

Armament would vary from 2 to 4 small guns, like 3-inchers, and some light AA. It's possible that they were equipped with sub detection devices. I've read that the Japanese produced a hydrophone that was designed for installation into a merchant ship hull. Some of them appear to have carried depth charges, but whether that capability was any more advanced than a provision for dumping them over the stern, I have no idea. I don't know if any of them were ever equipped with radar, but my assumption is that they never carried any more sophisticated electronics - apart from sub detection gear - than a radio.

In SH4 terms, they shouldn't be terribly dangerous to an alert skipper, just enough to keep him on his toes. But, it would be really nice to have a converted gunboat for SH4. Any of the small merchant ships, like the Akita Maru, or the Taihosan Maru, could be kitbashed by a 3d modder into a sweet little auxiliary gunboat. I'd do it if I knew how, but I don't. However I would be tickled pink and do somersaults if someone made one

Altho it's a little off-topic, I wanted to mention the converted fishing boats before I signed off. SH3 players will remember the British ASW trawler, a tiny anti-sub vessel. The Japanese had their own rough equivalent to this, as they converted hundreds of fishing trawlers and whalecatcher boats - I've seen a figure of 265 units - into auxiliary subchasers. These would have been 100 to 400 ton boats armed with a small gun and perhaps an AA piece, some depth charges, probably a hydrophone and/or sonar.

As is the case with the converted gunboats, info on the auxiliary subchasers is really hard to come by. But, you can get an idea of what they looked like at http://ww6.enjoy.ne.jp/~iwashige/whalecatchers.htm

Although the auxiliary subchasers were marginally useful for combat, they were used as convoy escorts, and were very common as ASW patrol boats. I've read a wartime US sub patrol report where the skipper describes many trawlers seen in the area a couple hours after he had sunk a cargo ship right outside of a port, as if to suggest that the trawlers were sent out to "swamp" the area to screen off the sub. In any event, numerically at least, they were an important component of Japan's ASW effort.

The Japanese also converted hundreds of these type of boats into minesweepers and picket boats, like the ones encountered by the Doolittle raider force off the coast of mainland Japan in 1942, see http://www.aa.cyberhome.ne.jp/~museu...u/23nittou.htm I believe that's a pic of Nittou Maru No. 23, which was gunned under by USS Nashville.

There's no model of the Japanese fishing trawler/whalecatcher in SH4, and it would take a 3d modder to either scratchbuild one or maybe bash one out of the Allied trawler, but it would well and truly ROCK to have one of these, some day

[akdavis]

Great info! I'm going to crosspost this in the mod forum as a [REQ] thread. I also don't know how to "kit-bash," but it seems that with the addition of some guns, DCs and basic sensors, we could easily have this important gap in the game filled.

Regarding merchants with DCs, I've read a number of accounts of even regular merchants in convoy rolling DCs over the side at random or when they believe their under attack, perhaps with the hope that the explosions would confuse the submarine or deter it from approaching the convoy any closer.