Cosmetic? I don't recall ever having SEEN compressed air. How can it be cosmetic if you can't see it? Usually cosmetics come in colors. In fact, the color of a cosmetic is a big reason why it sells! What color is compressed air? No WONDER I can't find it in Walgreens! Lousy marketing.:88)

Of course it's cosmetic! What do you think makes the hair of top models "fly" all around the place in the ads? :yep:

:rotfl::rotfl::rotfl::rotfl:
I remember when it was cosmetic in a picture of Marilyn Monroe over a heater vent too!:cool:

Ok, wanted to comment on Marilyn's cooling system (god bless her) but I think we're trashing the thread!

Yes, compressed air was indeed used to launch the torpedoes. Wet-heater and battery describe the torpedo's propulsion system, but for those to operate the torpedo had to be ejected from the tube first. Compressed air was the preferred method.
http://www.maritime.org/fleetsub/air/chap2.htm#2A

Yeah, I ment compressed air to get the fish out the tube, after which it's own propulsion would take over, but I guess that was already cleared up. :lol:

Thanks guys, don't even need to clarify my own posts any more. :rotfl: :up:

How about waste disposal? Was compressed air used for the trash shute, or the toilets?

I beleive the trash was tossed over the side. Toilets.. dunno good question. How does one flush a toilet that is below the waterline?

There is a little story I found some time ago that sheds light on the toilet waste disposal. http://www.sid-hill.com/history/blatt/head.htm. Some more interesting stories on that site as well. :)

Been lurking here for a while ever since I got my SH4, finally decided to post to share this. :P

Welcome aboard, Slux, and thanks for sharing that:up:I wonder if that's where that expression came from?:hmm:

Good story Slux, and welcome aboard! :up:

Guess that confirms the use of compressed air for clearing sanitary tanks. AFAIK the trash disposal unit is similar to a torpedo tube, so I guess that implies it also utilizes compressed air. :hmm:

Wasn't compressed air modeled more accurately in SH3? IIRC I really had to keep a close eye on the reserves, because they were constantly decreasing as I was maneuvering the sub (depth changes). Not to spark another "this SH is better" discussion, but I wonder why it's limited to emergency blows in SH4. Kinda makes it pointless, unless you're using blows to control your depth after taking damage. Maybe a sacrifice for the benefit of playability? :hmm:

I don't think they used it much for routine depth changes. They may have had to vent a little for routine depth changes, but as long as they stayed as near to neutral bouyance as they could the dive planes did the work.

I think this is true for modern nuclear subs, they (I'm told) actually maintain an ever-so-slight positive bouyancy and let the planes do the work to hold them down. But, they move much faster and can sustain it.

For a diesel-electric, submerged speeds are slow and the planes don't get much "purchase". And consider that maintaining a true neutral bouyancy is a constantly moving target, dependent on temperature, salinity, and depth (even the slight compression or expansion of the hull resulting from a change in depth changes the volume and thus the whole bouyancy equation). So, maintaining a neutral bouyancy with a diesel-electric was critical to depth control...I'm not sure if they used trim pumps or compressed air to achieve this though. In any event, compressed air in SH4 appears to be largely cosmetic.

Depth is also a key factor in how much compressed air it took to accomplish something. Launching torpedoes in WW2 happened mostly on the surface or at periscope depth, but with modern subs launching a torpedo at deeper depths can consume a large portion of the boat's compressed air.

If I remember my scuba lessons correctly water pressure doubles every ten meters.

Every 33 1/2 feet is the figure I remember, which jibes pretty closely. 10 meters comes out to 32.8 feet, according to google. I've always been under the impression that Second World War era boats used compressed air to adjust buoyancy quite frequently, especially when in silent running. (Water over the dive planes won't do much at two knots.) Trim was handled via internal pumps. If memory serves though, the amount of air required for simple ballast adjustments was pretty trivial. I don't think it detracts too much from realism that this isn't simulated.

Where compressed air was particularly important was in torpedo firing---torpedoes were pushed out of the tubes by compressed air, and immediately upon firing the ballast tanks had to be partially blown to compensate for the mass of the torpedo. If a sub were stationary at periscope depth without a pretty reasonable amount of compressed air, even if it managed to fire a torpedo somehow, it would bob to the surface.

I suppose it might be possible to calculate a reasonable amount of compressed air to be consumed by a torpedo shot. The answer would be heavily depth dependent, though, since it takes a lot more air to 86 a ton or two of ballast at crush depth than at periscope depth. What mass of air is equal in volume to a ton of seawater at a given depth?

On the other hand, I have no idea whether that would be easy, or even possible to mod into the game---even if one assigned a static value to the use. (A static value wouldn't be too bad for realism, how often do you fire torpedoes from below periscope depth?)

It's an interesting question.

[EDIT: Noscript ate my paragraph breaks.]

Only for the first 10 meters! The weight of the atmosphere (that we're constantly under the pressure from) is pretty much equal to the weight of ten meters of water. So at 10 meters you have double the pressure of being at water level, at 20 meters you have three times the pressure, at 30 meters four times and so on.