Decks Awash toot (TEC)

[Sniper297]

A do it yourself tutorial for people who don't normally hack files, involves only two CFG files which can be opened and edited with notepad, no programming skills needed. Two items;

Not uploading this as a mod since Commands.cfg is altered with several existing mods, do it yourself means you can change any version of SH4 or any mod for it.

2, Decks Awash was an actual tactic used by actual WWII sub skippers, I'm not remotely interested in flawed theories using half understood science stated as gospel fact (a theory is not a fact until proven) by self appointed experts who think that a fleet sub could ever be unstable. A little knowledge is a dangerous thing, most college kids are educated beyond their intelligence and assume they know it all after reading a couple of science books. Don't take everything you read on the internet for gospel.

Difference when you're trying to sneak up on someone without submerging all the way:



Sargo class fully surfaced;



Flooded down to 25 foot depth, "decks awash".



Why the hack? The crew at the diving controls acknowledge an order to submerge to 25 feet if you set that on the depth dial, but then don't execute the order. Dive below 35 feet and then order them back up to 25 and they'll wobble up and down near 25 for awhile then say "20 feet, close enough - or maybe 19 is better" (scurvy dogs!). With the snorkel depth command activated they will hit and hold a 25 foot depth.

So, to start, those who don't know about file extensions:

http://www.trainsim.com/vbts/showthr...er-for-dummies


\Data\Cfg\Commands.cfg

Open that file with notepad.
CTRL F opens a search window, type

195

That will jump to this datablock;

[Cmd195]
Name=Snorkel_depth
Ctxt=1
Str=1033
;Key0=0xBA,C,"Comma"

In C code the apostrophe means "comment", with that at the beginning of the line it tells the program to ignore this line. So remove that, or just copy and paste this text to overwrite the 195 datablock;

[Cmd195]
Name=Snorkel_depth
Ctxt=1
Str=1033
Key0=0xBA,c,"CTRL semicolon"

Capital C replaced with lowercase makes it so the actual key is CTRL ; instead of just ; so you don't accidentally rise to decks awash when you meant to fire a torpedo or set rudder amidships. If you don't make k3yb0Rd m!$taK3$ you could leave the C alone and just press ; instead of CTRL ; . Save, exit.

Next file;

\Data\Submarine\NSS_Subtype\NSS_Subtype.cfg (for "Subtype" use the type of sub you want to mod, for example if you want to set the depth for a Gato don't use the s18 folder and .cfg)

Open that .cfg file in notepad, small file so just scroll down to;

[Properties]
PeriscopeDepth=16.7;meters
SnorkelDepth=8.5;meters
CrashDepth=40;meters
MaxDepth=100;meters
SurfaceDepth=5.061;meters
TorpLaunchMaxDepth=30;meters
StormConditions=9,0.1;max wind speed [m/s], max rain intensity [0,1]

Default for that is 15, since US subs didn't have snorkels until the war was over we don't need an actual snorkel depth (probably why it was disabled in the original command.cfg). Metric conversion is all off, possibly they used some weird French Fortnight conversion or subtracted the price of a Romanian postage stamp. But 8.5 will give you 25 foot depth, 9.4 a 29 foot depth. 30 feet or deeper will switch from diesel to battery power, so if you're trying to sneak into a harbor or something where you need to go a long way don't make it more than 9.4.

Save, exit, launch game and try it out. Use whatever sub you edited, if you changed NSS_Porpoise.cfg a Balao won't work, you'd have to edit NSS_Balao.cfg. Or edit all of them.

Known issues, in real life a sub running flooded down deeper than 25 ft in reasonably calm waters could shut the main induction and draw air through the conning tower hatch to keep the diesels supplied with air. This would also keep the crew supplied with air, but this game for some reason considers anything deeper than 22 feet to be "submerged" for the crew air supply (CO2 buildup). The battery draw doesn't start until 30 feet, so if you're at 29 feet the diesels run so no battery discharge, but no fresh air for the crew. Dunno how to fix that, so just be aware that if you set time compression on without fully surfacing the battery won't discharge but the crew will suffocate after 48 hours.

Yes, I did that yesterday, running at all ahead full through a convoy flooded down to decks awash, then headed for home forgetting to surface and killed TM2 Kublinsky. For some reason there's no court martial for that.

[TorpX]

Originally Posted by Sniper297

Why the hack? The crew at the diving controls acknowledge an order to submerge to 25 feet if you set that on the depth dial, but then don't execute the order. Dive below 35 feet and then order them back up to 25 and they'll wobble up and down near 25 for awhile then say "20 feet, close enough - or maybe 19 is better" (scurvy dogs!).

Yes, I've noticed the AI crew will stubbornly adhere to their programed routines. It can be very annoying. I hope the next generation of SH will permit some manual control of ballast tanks and dive planes.

... but this game for some reason considers anything deeper than 22 feet to be "submerged" for the crew air supply (CO2 buildup).

Hmmm.... didn't know that. Very odd.

[Sniper297]

A *%#&@$#! men. At the very least a way to blow safety or pump fore and aft trim tanks or blow selected ballast tanks or something. In real life even traveling all day and night on the surface they made a daily trim dive to get the boat balanced fore and aft, and as close to neutral buoyancy as they could. The actual sequence was flooding negative and bow buoyancy tanks on the surface (the safety was always flooded, they called it the safety because if the ballast tanks were holed blowing the safety would give positive buoyancy) after the low pressure blowers emptied the saddle tanks (main ballast), and when doing the trim they calculated the amount the negative needed to have for near neutral buoyancy. On diving they would open the vents for the main ballast tankS (plural, many, not just one!) starting with the forward tanks so the bow would go down first, then open the others in sequence fore to aft. Passing 40 feet the command is given "blow negative to the mark", whatever mark they decided on when they did the last trim dive. In case of flooding in compartments they could "put a bubble" in any of the main ballast tanks (those are NORMALLY either empty or full but you CAN blow air into different ones for more buoyancy, since the air is compressed the inner and outer pressure will match and the tank won't collapse) or pump from / blow compressed air into any of the internal tanks to compensate. They completely ignore the most important aspects of operating a submersible vessel, buoyancy and balance management, in every sub simulator I've ever played.

As for the CO2 buildup, like everything else I found that out the hard way. Once I discovered it I changed the numbers to various different values (which are way off if they're in meters, unless they're Martian meters or something, 25 feet should be 7.6 meters, not 8.5) and ran a bunch of tests to determine what the actual depths are - 21 feet or above will get the crew on deck, 22 feet you can operate the deck gun but the crew won't man it, 23 feet will pop you back inside if you're on the deck gun. You can man the AA guns at 38 feet but not 39, even though you're underwater at 38 feet. At 35 feet you can still be on the bridge but underwater. 29 feet no battery discharge, diesels running, 30 feet diesels quit and the battery starts going down. Dive and stay under for a day or so, see the CO2 level at about 50%. Then come up and rise gradually, the red instantly vanishes and you get the message "oxygen level 100%" at 21 feet, same depth that the crew comes up. The instant effect is realistic, but in actuality the conning tower hatch is opened as soon as it clears and the main induction is opened at about 25 to 27 feet, as soon as the deck is about level with the water. The boat is then ventilated through the main induction, so if needed you can pop up, ventilate the boat, and dive again with a complete air change in a minute or so. The 21 foot depth part is the only thing that's really wrong, if the diesels are running at 29 feet where do they think the air is coming from?

[TorpX]

Originally Posted by Sniper297

... unless they're Martian meters or something ...

Yeah, I've wondered about these things. How many of these flaws are due to simple mistakes?

... if the diesels are running at 29 feet where do they think the air is coming from?

Yes, why didn't they tie the oxygen to the diesel engine operation? Wouldn't that have been easier?

[Sniper297]

Occam's razor says the simplest explanation is that they hacked SH3 to "create" the "new" SH4, adding some files, eliminating some files, changing some files, and forgetting to eliminate - change some files. My guess is they edited the SH3 file for the diesels for more depth in SH4, but forgot to change the file with the crew air supply. Type VII u-boat had a smaller diameter (smaller in every dimension) than the US fleet boats, so had less freeboard and drew less water on the surface. Decks awash for Das Boot would probably be about 20 to 21 feet.

[BillBam]

Very nice, works perfect! Thanks.