I am sorry Nuke mechanic but Ill go with the marine engineers who have desighned and build actual subs and even models they seem to be on the right track now for some time.
Tell me would the sub you are serving on would it go to sea with inactive bow plains,or be as effective in her mission overall?
The water current pressent at the bow area is the first to be used because the sub is moveing in that direction and therefore more preciese and "imediate response is achieved"than if only stern plains where used,the entire lenght of the sub of water flow would have to pass before a control response would take effect.That can be and is a problem with subs that need to run in preciese deepths and not "porpose"with poor control.
Small subs that run to scale not zipping around would benifit greatly from bow plains.Mark Green had to install bow plians on his Albacore for the above reasons see SCR thread.
Kind of like why are cars trucks excetra have the front wheels do the change in direction and not the rear,its more preciese ,can you imagine how difficult it would be if all cars steared like a boat/sub!Forward control verticle serfaces are more preciese no matter what vessel you are driving.
Yes cars are not the subject but stearing is in this case the verticle
The reason why PLo9 is having truble running his sub is that the sub is, one loseing forward speed as the stern props are cavitating the more the bow sinks .
Secoundly the bow has no operable dive plains so rapid change in attitude angle is not done to dive the sub and then maintain the desired water depth.
He has not finished out his sub in my opinion.Scale has nothing to do with it because we are dealing with the same rules and medium.
The transition from surface to underwater running is very important in that it is done properly for the sub to operate well.
This explians it pretty well
Figure 7 shows how the fore and aft dive planes are used during a dive. At the start of the dive the aft plane is rotated upwards so that the stern of the boat is forced upwards. The fore hydroplanes are rotated downwards thus forcing the bow of the boat down. During the dive the aft hydro planes are moved to the neutral position and the dive angle is controlled with the fore hydroplanes only. Close to the the required depth, the aft planes are rotated down and the fore planes up to level off the boat. At slow speeds the depth of the boat is maintained by the fore planes only. During the first dive, the water level in the main trim tanks is adjusted to obtain a neutral buoyancy so that the required depth can be maintained with a nearly horizontal position of the hydroplanes.
http://www.heiszwolf.com/subs/tech/tech01.html#Static
Dave Amur Sub Yard
