IJN No.1 class Auxiliary Minesweeper

OK a question for the all things Naval experts here on the board. The Japanese No.1 Class Auxiliary Minesweeper, was it wooden or steel? I get differing answers from different sources. Some say it was wood hulled and the builders were selected from smaller yards with experience building wooden vessels. Elsewhere you find that it was steel hulled and vulnerable to magnetic mines.

While I may play a person knowledgeable in Naval subjects on television, I am not one in real life. Hopefully, someone here can give me a definative answer. If not I guess I'll have to go stay at a Holiday Inn Express to find the answer.

 

Hopefully this might be what you're looking for; Warships of the Imperial Japanese Navy by Jentschura et. al. describes the Wa 1 class minesweeper as "wooden-hulled trawler-type craft" 97 ft. long and 215 tons.

 

Beat me to the punch there, Carronade. Was looking at that the other day and got distracted. If indeed the Wa 1 is what you mean I will further confirm that, per the same source, they seem to have been built in generally smaller yards. Jentschura and Jung list five: Hitachi, Sakurajima; Mitsubishi, Shimonoseki; Naniwa, Osaka; Sanoyago, Osaka; and Namura, Osaka. Of these I can find three int he US Strategic Bombing survey. All are under a million square feet of floorspace with the largest being Hitachi with 826,000. By comparison the biggest five civilian yards were all over two million with MHI Nagasaki having over four million. (In fact Mitsubishi alone had four yards with over a million square feet, to give a little comparison.) I'd guess that MHI Nagasaki had more floor space than all the yards that built these little boats put together. Can't answer the wooden hull experience question, but it seems a reasonable guess.

 

Thank you gentlemen for your replies. Yes I was referring to the Wa 1 class. That is what I thought, but did not know definatively, because one site with pretty good information made the "steel hull" statement. It's a Russian site and from the verbage I assumed it was a translation error by someone to whom English is a second language, but I don't like to assume when I have access to the incredible "WW2F Rogue" database.

 

I had not responded yet, because I have not come across what I would call "definitive proof." While, Warships of the Imperial Japanese Navy by Jentschura et. al. is good, I have noticed some errors in the book. Having looked through the Fischer-Tropsch online archive of the US Naval Technical Mission to Japan had only brief mention of the class, and very little detail.(Although there is a plethora of detail on the Japanese minesweeping gear.

Also, it is not just the Russian website that you have found, but also Wikipedia, and that page uses Japanese sources: http://en.wikipedia.org/wiki/No.1-class_auxiliary_minesweeper

Still, it is worth noting that throughout their careers, none of the Wa-1 class were lost due to mines, magnetic or otherwise.

 

Looking at:
http://www.combinedfleet.com/W-1_t.htm
It mentions that there was both a W-1 and a Wa-1 could this be the source of the confusion? W-1 looks to be a steel hull to me from the illustration although it isn't mentioned on the page.
Here is their description of the class:
http://www.combinedfleet.com/W-1_c.htm
NOt finding much but perhaps these two pages point to the differences:
http://en.wikipedia.org/wiki/No.1-class_minesweeper_(1923)
vs
http://en.wikipedia.org/wiki/No.1-class_auxiliary_minesweeper
I'd ask over at the IJN page of j-aircraft for a more defintive answer. Although it mentions the auxilaries were steel hulled but as it is wiki that could be off.

 

Thanks for the reply, I had seen the Wikipedia mention also. I wasn't aware that none were lost to mines, good info!

 

Thanks for the help. I was referring to the Wa-1 class, auxiliary minesweeper, or the last link. I'm pretty much up on the (1923) No.1 class, and they are steel hulled, and were the progenitors of the No.13, then No.17, then No. 7 class. then culminating with No. 19 class. These were steel minesweepers in the 600 ton std. range. The Wa 1 class was an auxiliary minesweeper of around 215 ton std. Everything I've read said Japan based them upon wooden fishing trawlers and specifically went with smaller yards with experience in building wooden vessels. Some sources even identify them as 1-Go auxiliary wooden minesweepers. What threw me off is the comment that has crept into some sources, (Takao kindly provided another) that they were vulnerable to magnetic mines, "they were no match for the magnetic mine because their hull was made by steel".



Wa-2 (Wa 1 class auxiliary minesweeper)

 

I have nothing to go on but speculation and circumstantial evidence, but W 2 (W 1 class), W 9 (W 7 class), W 16 (W 13 class), W 22, and W 29 (W 19 class) seem to have been sunk by mines. (per Jentschura et al, as above) These appear to be a continuous line of related development, save for the late W 19 class, which were somewhat smaller and slower war-built ships, thus presumably subject to the usual exigencies of wartime pressures. They all look similar. I could easily understand someone mistaking them as a single class, given the similarity of size, appearance, general capability, and name. Neither the Jentschura nor Wikipedia lists any of the Wa 1 type as having been lost to mines. Further, the wikipedia article itself sources only secondary evidence, though to be fair I think they are well regarded publications: The Gakken History of the Pacific War, Kaijinsha Ships of the World, and Maru Special. I really wonder if the confusion arises from mistranslation of similar appearing names. None of the (few) photographs I have found appears conclusive, but the loss histories seem to be suggestive.

An aside: the Jentschura and Wikipedia loss lists do not appear to be drawn from identical sources. The details appear to generally match, but where the Wikipedia is often quite generic about causes (No. 4 . . . sunk by air raid off Timor Island on 19 July 1944) the Jentschura is more specific (sunk 19 July, 1944, by British aircraft in Dili Harbor, Timor) making me think that the Wikipedia article is working from exclusively Japanese sources and perhaps the Jentschura is cross referencing from both. This is, of course, speculative, but the case of Wa 3 is quite suggestive, since the Wiki entry gives it as MIA, which reads like a Japanese source doccument. Further, the Wiki uses more modern place names (Chuuk), while the Jentschura uses older ones common in wartime English language reference (Truk), again suggesting some Allied sources for the Jentschura and exclusively Japanese sources in modern translation for the Wiki. Given that the specific details from the Wiki are all present in the Jentschura, surely they both draw on some of the same Japanese sources. I wish the Jentschura had some better annotation and clearer sourcing, but the degree and type of conformity give me a fair amount of confidence in what I see, while the absences in the Wiki speak of rather narrower (though better documented) sourcing. It's something of a catch 22. I want the citations for a properly scholarly work, which Wiki has and the doorstopper doesn't, but the book just feels more accurate for a host of small and anecdotal reasons. (Having little to do with it's slightly musty smell.)

 

I was pretty sure you knew which class you were talking about but the combined fleet page mentions the possiblity of others confusing the two classes and it seems likely to me. I also note that some of these ships/boats seem to have had names as well as lettered-number designations. Makes it non trivial to follow. Again I'd ask over on the ijn board there are some real experts over there including a few who have access to Japanese records and can read them.

 

According to this response over on the IJN board:
http://www.j-aircraft.org/smf/index.php?topic=15166.0
They were steel hulled.

 

Interesting. He's talking about the correct class based upon his quoted displacement figure. The person that replied is an individual, since you visit the site, how reliable of a source is Dman, in your opinion? I don't mean to be insulting, for instance in this thread Carronade, Takao, Symphonic Poet, and you (Lwd) have replied, I have always found information from each and everyone of ya'll to be good as gold. I'd accept anything from ya'll at face value without a second thought. However, there are other posters here that give opinion as fact, inaccurate, partial or misleading information, we all know some of them and give information from them the appropriate weight. The site he provided about conversions is interesting and I have bookmarked it for further perusal.

 

I've found the data from that sight pretty good. I don't have a good fix on Dman right now but if he's wrong there's likely to be several people correcting him before long. I'd give it another day or two and check back.
Checking on the board he doesn't have a lot of posts but has been registered there since 2006. Here's a link to his posts there, looks pretty solid to me.
http://www.j-aircraft.org/smf/index.php?action=profile;u=938;sa=showPosts

 

Thanks for your feedback. I will check back as you suggested, but for now I'll assume he is correct.

 

unfortunately jane's dosen't mention the hulls on the sweepers.

 

Given that they're auxiliaries converted from merchant vessels, I wonder if they're not at last somewhat inconsistent as to materials. My thanks to LWD, as the site linked in the j-aircraft post is a fascinating one with some very interesting information and some rather obscure photography.

 

Some of the cooperative photo analysis I've seen on that site is fantastic. Not sure how recent any of those are though but an archive exists. The mine subs at PH thread in the archive is also interesting (if long) the way opinions changed over time in particular is worth noteing.