It's That Time Again!
If it's summer, it must be time for the 2nd Annual Summertime Beach Submarine Photoshop Contest over at The Sub Report. According to the contest rules, entries must be received by midnight EST on Thursday, 19 July; also, international submarines are allowed this year. Last year, I submitted a photo based on USS Asheville's unit crest; this year, I think I might take advantage of the option to use a foreign submarine -- maybe something like this:
Everyone should enter -- it's a cubic buttload of fun!
posted by Bubblehead at 6:59 AM
5 Comments:
Way, way OT, but I thought you'd be interrested.
http://instapundit.com/archives2/007176.php
7/16/2007 10:15 AM
Hey Bubblehead,
Since you're and engineering type maybe you can answer a question. In the TSR weekend edition there's a photo of a Greek submarine. The stern planes and rudder are configured as an X instead of a +.
I've been trying to figure out the advantages of an X configuration over the + design of almost all American and most other nation's submarines.
Unless there's some extra linkage that keeps it from happening, it seems that with the X plane design, every time you put on some right rudder, you also put on some up bubble, and visa versa for left rudder.
Do you think the X design allows for the merging of the helmsman and stern planesman into one position?
Your feedback as a most learned engineer on why this design would be employed would be appreciated.
Birdie
7/16/2007 10:37 AM
Good one - Made my "beddy bye" time special!@ lol
7/16/2007 7:41 PM
Birdie,
There are a couple advantages (and disadvantages) to the "X" Stern compared to the standard cruciform stern arrangement.
Advantages:
- It's possible to get a larger span for each of the surfaces while not exceeding the limits of the "box" defined by maximum beam & draft of the boat.
- When the boat is surfaced, you have two control surfaces still submerged, so there's better steering.
In regards to your comment about the combination vertical and horizontal, usually the planes are connected with a common stock, so that each pair moves in unison, although differently than the other pair. In turning, for example, the servo mechanisms are arranged so that the vertical forces cancel, and the horizontal forces add together.
You're correct in thinking this is a solo-helmsman arrangement, also, as the servomechanisms are designed so that the differential rotations of the planes are automatic, all the helmsman has to do is steer/dive.
There's a couple disadvantages, other than the more complex control arrangement, such as increased tendency to snap-roll due to the control surfaces all turning the same amount, therefore the range of control surface motion has to be limited.
The other large disadvantage is simply the more congested stern machinery, as the stocks would pass through the area normally occupied by the shaft.
All of this information is pretty much from "Concepts in Submarine Design" by Roy Burcher and Louis Rydell. Some of the stuff comes from a college design project of mine. As a bit of trivia, the USS Albacore AGSS-569 was fitted with an X stern in the 1960.
I hope that somewhere in there I answered your question, and I apologize to Bubblehead for taking up so much space. I'd like to hear his opinion anyway, as I'm just a NUB worthless Ensign.
7/16/2007 7:48 PM
Em1derful,
Your ability to clearly explain technical matters belies your rank, proving that the loss of at least some butterbars can't be compensated for by simply flooding 100 pounds each into forward and after trim.
BTW, if your command isn't using you to conduct training, tell your XO to get squared away (okay, ask your XO to get squared away--with all due respect, of course).
QSPN
7/17/2007 8:46 AM
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