Crush Depths!
 

Were you damaged in a previous attack, even slightly (enough to warrant the 'we're under attack!' message?) I believe (though the veterans can correct me if I am wrong) that all damage, even if it is repaired and no longer shows up on the damage screen, can affect ship integrity, which can reduce your crush depth. If in doubt, there is a program in the mods workshop called Damage Analyzer, I believe, that can analyze your save game files if you save after an attack, and tell you if this 'invisible' damage exists and is affecting your boat's ability to survive at what would otherwise be a certified depth.

LCdr Tally Ho
Currently Arranging Seating for Admiral's Wife's Gala
(Staff Attache to Adm. Dufuus)
NB Surubaya, Java

I was hit by a bomb from a zero on my way to the convoy area, but it was minimal damage, only deck damage. My deck crew was injured. I want to know why the hell it isn't announcing crush depth to me.

What was your water depth?? Maybe you ran aground or hit bottom. I've had that happen. Maybe a mine?? dunno.

Are you sure you're in feet and not meters?

Water depth? It was OVER TWO-THOUSAAAAAAAAAAAAAAAAAAAAAND!

I'm not sure how it announces crush depths, if it ever does, having never gone that deep. I know there is some problem with 'invisible', unrepairable damage. Because of that, I try to avoid going below 60 or 70 feet if I've taken any visible damage at all, just to be safe. The uncertainty is a bit annoying, but is probably realistic. It may be that the announcement of passing crush depths are set to the published crush depths, rather than the actual, reduced post-damage crush depth.

After all, if a sub is rated for 260 feet, the XO is going to announce (with a bit of a quaver in his voice, perhaps) when you pass 260 going down. But, if a bomb hit popped some rivets or warped a plate, that sub might actually crush at 150 now. BUT, the XO doesn't have perfect knowledge of what the new, reduced depth is going to be, or even if the depth was reduced at all, thus he cannot announce 'We are passing the ship's new crush depth which is only 61% of the prior depth due to hull stress'. I would say in such post-damage scenarios, it would be up to the CO to dive slowly, carefully, incrementally, and above all sparingly, to not press the limits of a bent boat too much.

My father worked for the Department of the Navy designing submarine hulls and bulkheads for almost 40 years. He got to design giant models, have them built, then stick them in huge pressure tanks and watch them go 'blooey!', or 'crunch', more accurately. Once, as a boy, I asked him if he was proud if he designed a hull or bulkhead that could go deeper than ever before, and he said 'No.' He said that far more important to the submarine fleet was not a hull that could dive deep, but a hull that crushed consistently at a specific depth in predicable ways, because then limits would be known, believed, and planned for. He mentioned Russian, titanium-hulled subs that COULD go twice as deep as US Subs, OR might crush at 80% of a US Subs' test depth, it really depended on the specific boat and circumstance, and such uncertainty bred either overcaution or unrealistic risk-taking. The U.S. boats, however, would always crush within a very narrow range of depths, which, while less-deep than the Russians; generally, gave the skippers a much more 'known' scenario and certainty that led to better operational procedures. One of his crowning moments was when his team designed a new type of bulkhead that would maintain similar crush integrity even when significantly compromised by stress.

Remembering that story reminded me of our situations in SH4, where it is not the damge per se that kills us, but that uncertainty of when and at what depth it might occur. Annoying, but apparently quite real.

LCdr Tally Ho
Picking Up Admiral's Dry Cleaning
Staff Attache
NB Surubaya, Java

There are two kinds of damage. Damaged systems that you can repair at sea, and damage to the hull that you can NOT repair at sea. The latter is "hitpoint" damage to the sub. It's not a problem, it's realistic. If you take a near miss from a bomb, say, you could have stressed wleds, etc that won't do the thing to the way the sub behaves, but it might well be a point of weakness if you try and dive deep.

Hitpoint damage raises the crush depth of the sub.

ANY damage you take, even a single 20mm hit hurts your ability to dive deep (though only a little in the case of a single 20mm hit).

If you take a near miss or certainly a direct hit from a bomb. Go home.

If you saw a hole in your boat in external view, go home.

If you see leaks inside the sub after damage has been repaired... go home.

In all the above cases, you can carefully execute test dives, and when you see wierd things like leaks, etc, that's farther than you can safely dive now.

tater

There shouldn't BE any uncertainty! In SH3 when you reached crush depth, gauges would start breaking, the sub would start creaking horribly, and the lights would blow out. NONE of that happens in SH4

One, there should be plenty of uncertainty. If there is a failure in a seal on the main induction due to a bomb blast, the first you may hear of it might be as you sink.

Two, the sub does leak. Lights blink, all kinds of wierdness happen near crush depth. If the crush depth is 150ft due to previous damage, it does it at 150ft.

If you get bombed. GO HOME.

Course you also should never have been bombed by a Zero since they didn't carry bombs, but that's another thread ;)

tater

There you go, man! There's no problem at all, just the real life situation that you don't know everything. Hidden damage plagued U-505 for almost a year between the time it was bombed by a single plane to when the boat was captured. The boat was never the same and they couldn't fix it or figure out just what was wrong.

So the game is annoying. Real life is annoying too. Wow, this must a really good simulation! And so it is. Please do not yell so.

There is a tool, Damage Analyser II http://www.subsim.com/radioroom/showthread.php?t=114405
This thing will ferret out all your hidden damage and tell you what it is. You have to save the game, start up Damage Analyser, which is a separate program, not a mod, and tell it to look at your save game file. That will solve your "problem" and give you superhuman ability to know EVERYTHING that is wrong with your sub. Now, if you could only use something like that on women...

"What's wrong, honey, you look upset."
"NOTHING!"
"OK, please stand quietly while I run this harmless program..."

Tater and rockin Robbins are right on. There is nothing wrong with the situation you described.

There is no "crush depth detector" that lets you know what's up, you just get crushed. Even if you are cruising at a set depth with damage and appear fine, by lingering deep with a compromised hull it could suddenly fail, as you described.

And it's silly for you to say otherwise, because no one from a submarine that passed crush depth ever was available for comment afterwards.

Warning Will Robinson (arms flailing wildly) approaching crush depth :p

Apparently SH3 had a magical hull integrity meter, perhaps some folks are just used to it.

Even the leaks, etc, are dead give away compared to a RL possibility of acute failure. Sure, I imagine that some failures could well be picked up by the crew before they were fatal, but I also think others would not be apparent until it was too late.

I treat my hull as having three states.

Fresh from overhaul/refit.

Possibly compromised.

Definitely compromised.

The 1st is in effect as long as I have taken ZERO damage, not so much as a 20mm hit from an aircraft.

The 2d is in effect from the moment I hear "We're taking damage!"

The 3d is any time I've taken flooding or more, or I see a hole in the hull externally.

If I reach "definitely compromised," I patrol towards home, or I at least minimize any chance I will have to dive below PD. If I decide to contine the patrol, I do test dives.

If I'm at the broad 2d state, it's partially feel based. If the damage was really light, I continue the patrol, but I'm wary of further damage.

It is my understanding that when a hull approaches crush deph, the hull moans, and grinds loudly, and some times violently. This was simulated in SH3 quite accurately withing the limits of the game. In SH4 you don't hear bolts blowing, glass breaking, or water spraying. Aside from your exec telling you damage upon damage, which actually slows down your inputs from your controller or keyboard, the death of a boat in SH4 is too silent.

This was a new thing from the recoding of SH3 to make SH4 as far as I can tell.