Hi all, Is there any way to determine/decide once and for all how many rudders the Aoba class has? There are several different people on this forum that have different sources and information on how many rudders are there. Does any have access to a copy of Conways or Janes? Those are usually good although Conways is better, from talking to the guys on the ship who do the intel gathering. J
AOBA is a single rudder. She had a very narrow stern. We knew the larger cruisers may have used dual rudders such as Mogami due to the broader stern beam. Stern is only large enough to acomodate a single rudder. If you put dual rudders on that cruiser your going to roll it over pretty hard in a turn. I'll research to try and get further info Jay.
Here are other images. Keep an eye on this guys build Jay. He will have the rudder location render soon. Uploaded with ImageShack.us
Thanks Curt, nice looking model. This definately looks like a single, but I think the build depends on the plans used, Crzyhawk has seen a book that says one but Rob C here in town has plans that show 2. Where did you find the 3D renderings? Those are awesome! J
The Japanese plans from Japan show 2 rudders. The MWC list has it with 2, but from what the history is, it can be built either way, it started with 1, and was later rebuilt with 2. Some of the MWC people researched it, had drawings and pictures from what I understand. Lou, who is on here at times was one of the fellows who researched it, he was doing a Cleveland build last year may still have some of the info on it. I have not seen any of the documentation myself. The Aoba and Kinugasa had different steering gear than all the rest of the Jap cruisers. All the rest used hydraulic rams turing the rudders, kind of like our linkage steering. The Aoba used electro-hydraulically driven gears spaced to each side of the rudder shaft. I have seen a picture years ago, but have not been able to find it again. The gear shafts went from the deck, to the bottom of the hull supporting the steering gears. I wonder if what they see as dual rudders from above, are really just the steering gear vertical shafts? I know the Mogami's went through 3 different shape of rudders during trials, but they were the only dual rudder Jap heavy cruisers that I could find information on.
Aoba was to be the 3rd of the Furataka/Kako class of Heavy cruiser. But they made so many improvements before they made the 3 unit of the Furutaka class, it was built as a new class of 2 cruisers, Aoba/Kinugasa. The Book Japanese cruisers of the Pacific war, states that they were built with just 1 rudder, but they did use the electro-gear drive for the rudder, instead of a hydraulic ram system that all the other Jap cruisers used.
Aoba and her sister ship Kinugasa were the only ships in the class. They were supposed to be the 3rd and 4th ships of the Furutaka-class. So the way I take what Rob said is that Aoba and Kinugasa had 2. Rob??? J
Dave, it's a big thick book; I can't even find the page where it says that any of that class had 2 rudders, can you point me in the right direction? On page 73 towards the bottom it looks like all 4 had a single rudder.
It talks about the electro-hy-draulically driven gears a little bit on page 73, under Aux machinery for the Aoba class. No where have I found anywhere that says 2 rudders.
So it looks like the class was built with one rudder which again makes sense looking at the amount of space for machinery available on such a very narrow hull at the stern.
Going to necro this thread...forgiveness is begged. According to Japanese Cruisers of the Pacific War by LaCroix and Wells, (p73) http://books.google.com/books?id=dP8Yuen6aPsC&pg=PA71&lpg=PA71&dq=Aoba+class+two+rudders&source=bl&ots=KTGTZLQEef&sig=1wEWpOS5aZhhx8l8uqCOhO428_Q&hl=en&sa=X&ei=vCUHUe-kHofa0QG_14DoDA&ved=0CGMQ6AEwBQ#v=onepage&q=Aoba%20class%20two%20rudders&f=false "The steering gear in the Furutaka class consisted of a two-cylinder vertical steam engine that drove the hydraulic rams actuating the balanced rudder" Singular. "In the Aoba class, electro hydraullicaly driven gears were adopted instead" The confusion tends to come from a photo from early 1943 or so, that /someone/ has identified as the Aoba, which shows two rudders. The Aoba's aft area was being repaired due to heavy damage sustained off Guadalcanal. At the the same time, the Mogami's aft area was also being rebuilt due to damage suffered at Midway. It's my belief that someone took a pic of the Mogami, and mis ID'd the ship as Aoba...which leads us to the confusion we have today. As Stokamoto pointed out, the hull is /very/ narrow aft, fitting in another rudder would not be easy...nor likely, given that the IJN had already deemed twin rudders were of no benefit, when they went back to single rudders for the Tone class after having twin rudders in the Mogami class.
