Is "compressed air" cosmetic?

[Diopos]

Ok, I'l admit I never go below test depth (assuming that test depth is what a pointer is contlinuesly pointing at ~110 meters in my depth meter). I had some sudden sinkings with version 1.00 and I decided that fleet boats aren't u-boats and avoided 3 digit depths from thereon! (Of course the sudden sinkings could be due to a compromised hull but back then I didn't know if/when my hull was compromised in the 1st place!:) ). So not going beyond test depth maybe a reason for my next question which is:
Does "compressed air" ever get consumed by "normal operations"?
Remaining at 40 meters, for 10 hours, (stationary) doesn't affect it! [edit: Ok maybe to shallow...]
Surfacing, at 0 speed doesn't affect it!
Blowing tanks probably would, but haven't done that for a long time!
Or is it just a doomsday indicator such as "We lost our batteries, we lost our air... let's put something on the gramophone and wait for the grim ripper. It's harvest time!:cry: "
Playing: SH4 1.4 / no mods.

[Effigy]

Ok, I'l admit I never go below test depth (assuming that test depth is what a pointer is contlinuesly pointing at ~110 meters in my depth meter). I had some sudden sinkings with version 1.00 and I decided that fleet boats aren't u-boats and avoided 3 digit depths from thereon! (Of course the sudden sinkings could be due to a compromised hull but back then I didn't know if/when my hull was compromised in the 1st place!:) ). So not going beyond test depth maybe a reason for my next question which is:
Does "compressed air" ever get consumed by "normal operations"?
Remaining at 40 meters, for 10 hours, (stationary) doesn't affect it! [edit: Ok maybe to shallow...]
Surfacing, at 0 speed doesn't affect it!
Blowing tanks probably would, but haven't done that for a long time!
Or is it just a doomsday indicator such as "We lost our batteries, we lost our air... let's put something on the gramophone and wait for the grim ripper. It's harvest time!:cry: "
Playing: SH4 1.4 / no mods.

As I understand it, in the game, I think the compressed air is only affected by blowing ballast. (Not sure about RL) So that's probably why you aren't seeing it fluxuate any, as you said you haven't blown your tanks in a while.

[LeeVanSpliff]

I've only ever used compressed air to blow ballast. If it has any other function I'm too much of a n00b to have figured it out!

I think the CO2 doubles for oxygen for the sailors (the more CO2, the less oxygen)

[raymond6751]

Correct. Compressed air is used to blow water out of the tanks to surface. If you get damaged and are sinking, that might be the only way up. However, if you are badly damaged, you might have to blow and blow.

When the compressed is gone, you are in BIG trouble. The WW2 subs didn't have oxygen for the crew in containers. That is why you see in the movies so much sweat and angst if they are under too long.

Air for the crew came from surfacing, opening hatches, and running the fans and diesel blower.

[Arclight]

I think in RL compressed air was also used to launch torps out of the tubes and to force water out of the ballast tanks, maybe even more. AFAIK, as stated above, in SH4 it is only used for "emergency blow".

[Seminole]

I've never yet encountered a situation in SH4 where compressed air became a critical survial issue. So..from that limited point of view I guess you could say that it is pretty much cosmetic. There always is enough compressed air for daily operations it seems.

I recall ,way back in AOTD, where compressed air was often a very critical issue when trying to beat the clock, effecting repairs, before time ran out. When the air gave out... then down into the depths your boat went. :shifty:

It would have been nice to have that modeled in SH4. :yep:

[Diopos]

...
I recall ,way back in AOTD, where compressed air was often a very critical issue when trying to beat the clock, effecting repairs, before time ran out. When the air gave out... then down into the depths your boat went. :shifty:

It would have been nice to have that modeled in SH4. :yep:

That's exactly why I asked! :up:

So I gather the real question is was compressed air so important actually and were U-boats different from fleet boats in this aspect.

[Seminole]

I wouldn't think so....about there being a difference. Compressed air was vital for both in the real world.

It just that real world facts don't always get translated into the gaming world. Sometimes yes. sometimes no.

[Diopos]

Can't avoid commenting on how a DOSy gamlet (compared to modern monster sims) could give you more parameters to play around eh!

Anyway onwards with the patrol!
BTW I really enjoy the game and the excellent sunsets too!

[Orion2012]

I think in RL compressed air was also used to launch torps out of the tubes and to force water out of the ballast tanks, maybe even more. AFAIK, as stated above, in SH4 it is only used for "emergency blow".

I don't think it was ever used to launch torpedoes during WW2. Most of the WW2 Torpedos were the Wet-Heater. Injecting a flammable substance into the combustion chamber, and then cooling the combustion chamber with salt water. Some were Lead-Acid batteries which didn't leave a wake, but required constant maintenance and even some experiments with hydrogen-peroxide torpedoes.

Now if only someone had invented the supercavitation torpedo in 1940....the war may have ended totally different....

[Flamingboat]

Compressed air is something you never think about until you run out. Try to crash dvie and blow ballast a bunch of times and see if you can run out the air.

[Mush Martin]

I think in RL compressed air was also used to launch torps out of the tubes and to force water out of the ballast tanks, maybe even more. AFAIK, as stated above, in SH4 it is only used for "emergency blow".
I don't think it was ever used to launch torpedoes during WW2. Most of the WW2 Torpedos were the Wet-Heater. Injecting a flammable substance into the combustion chamber, and then cooling the combustion chamber with salt water. Some were Lead-Acid batteries which didn't leave a wake, but required constant maintenance and even some experiments with hydrogen-peroxide torpedoes.

Now if only someone had invented the supercavitation torpedo in 1940....the war may have ended totally different....
Pphhh anyone can do that

http://i43.photobucket.com/albums/e368/MartinPicfix/SH3Img18-2-2007_16.jpg

but theres always another mind on the other side working up
a hydrofoil freighter.

lifes like that

I think you maybe misunderstand he meant compressed air to
initially launch the torpedo from its tube not compresssed
air to power the torpedo that goes way way back to when
I was a rookie.

[edit] I think compressed air is poorly labled in shiv

[Digital_Trucker]

From http://www.bowfin.org/website/bowfin/bowfin_systems/torpedo_tubes/torpedo_tubes.htm

Torpedo tubes on U.S. submarines in World War II were basically large naval guns that used compressed air rather than explosives to eject their projectiles.


Edit:Mush beat me to it

[Orion2012]

Ohh, my mistake. I thought he was saying they were filled with compressed air.

Have you ever ridden a hydrofoil boat, the only one I ever have was a ferry from Portland, Maine to nova scotia, took a 4 hour trip down to about an hour and by far the smoothest sailing boat I've ever been on. Kinda made me feel wierd moving that fast through water, and not feeling the bow of the boat breaking waves....

[Mush Martin]

Ive seen a thirty minute video on that ferry very chic:up:

I havent but take a look at these.

http://www.youtube.com/watch?v=Nljxi4E4-4Y

http://www.youtube.com/watch?v=bQRtgEIs--k

[Rockin Robbins]

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)

[Diopos]

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:

[Rockin Robbins]

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:

[Diopos]

...
: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!

[Sailor Steve]

I think in RL compressed air was also used to launch torps out of the tubes and to force water out of the ballast tanks, maybe even more. AFAIK, as stated above, in SH4 it is only used for "emergency blow".

I don't think it was ever used to launch torpedoes during WW2. Most of the WW2 Torpedos were the Wet-Heater. Injecting a flammable substance into the combustion chamber, and then cooling the combustion chamber with salt water. Some were Lead-Acid batteries which didn't leave a wake, but required constant maintenance and even some experiments with hydrogen-peroxide torpedoes.

Now if only someone had invented the supercavitation torpedo in 1940....the war may have ended totally different....
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

[Arclight]

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?

[SteamWake]

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?

[slux]

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

[Digital_Trucker]

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

[Arclight]

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:

[Sailor Steve]

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.

[groomsie]

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.

[LobsterBoy]

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.

[swuboo]

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.]

[LeeVanSpliff]

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

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.

[swuboo]

You know, another thought occurs to me.

I can't check right now, since I'm on the Linux machine, but...

...does the amount of air used by blowing the ballast tanks vary with depth?

At periscope depth, pressure at the keel is right around three atmospheres. (One atmosphere from the actual atmosphere, and two more from depth.) At 330 feet, pressure should be around eleven atmospheres.

Does the simulation accurately reflect this?