Deep!

[Bosje]

U 161 lost with all hands

Januari 10th, 1943.
200 km off the US east coast

U161 (edit: Type IXC on her 12th patrol) attacks a convoy in calm seas with clear weather, attack from periscope depth in the night.
spread of 4, each torpedo aimed at the bow of a big ship.
started evasive action while torpedoes were running (mistake)
Escort became aware of our presence and the convoy slowed down, turning away from us.
only 1 hit out of 4, a torpedo clipped the very front of the ship.

depth only 40 meters when the escorts came in for attack,

We increased speed while diving deep and turning away from the escort, depth charges all around us but we were still diving, only a lot of near misses, no damage to the boat.

as we passed 150 meters we slowed down to silent running with rudder 10 port or starboard as we crept down.

at 180 meters we were pinged but after many runs we weren't too concerned, trusting in the twisting and turning and diving to keep us safe.

suddenly, a big crash and water rushed into the boat everywhere, silent running aborted and engines revved up as the crew rushed to damage control.

almost immediately, our depth started to increase dramatically while damage reports came in.

heavy flooding in the rear torpedo room, diesel and electric engine rooms and rear crew quarters.

the LI left his station to take charge of damage control, the boat was tilting heavily: stern was deep down. depth increased rapidly.

passed 290 meters, the pressure hull was failing. crew worked hard on damage control, flooding was almost under control but the boat was dropping out of control.

all ahead flank with planes up for surfacing, blew ballast

depth went rapidly from 350, 360, 370, 380.
flooding under control in engine rooms, switched focus to stern torpedo room
in the control room, instruments are shattering everywhere, glass is breaking and the hull is audibly starting to collapse

compressed air at 50%, depth still increasing.
blew ballast again, speed measured no longer reverse knots, speed stopped and then very slowly increased. boat now moving forward at a severe angle, stern is pointing way down, water level in stern compartments is still critical

passed 400 meters, damage almost under control, 20% compressed air remaining

boat still heavily tilted rear down, speed increasing to 2 knots (ahead flank), lights and gauges all around us are shattered

hull is failing but boat has finally stopped at 407 meters, now very slowy getting back up, 406 now.

pressure hull failure,
game over.


**** i almost thought i made it! damage under control and boat is climbing up again! 407 meters and living to tell the tale...
that would have been something

ah well

a new career for Bosje
thankfully it's just a game

[u35_captain]

That is absolutely heartbreaking to have gotten so close to a miraculous escape and then to lose everything *wince*

[Tinman764]

Excellent read, so very close to saving the crew!

[flag4]

...the horrible thing is, this must have happened so many times in real life, they thought they'd made it, then BANG - finished.

its quite frighteneing visualizing it as i was reading.

and after 12 patrols, a good crew too.

[Harald_Lange]

hull is failing but boat has finally stopped at 407 meters, now very slowy getting back up, 406 now.

407 meters?????? That exceeds what I thought was possible by about a hundred meters


Hope you don't think I'm hijacking, but its relating to a similar experience I had last night west of the Canaries. I was in my VIIC and I'd already sunk 4 merchants. A Black Swan Class escort lit me up with his searchlight. (I was using the mantra of 'Be More Aggressive' after all.)
After a crash dive I thought I'd take it to 160m and follow the convoy along throwing caution to the wind, ahead standard, silent running off, whilst I reloaded my torps.

After a few 'wasserbomb' warnings and a lot of rocking about without damage, I thought I'd crank it up to flank speed and follow my course straight to cut underneath the convoy, and sit and wait for them to come to me whilst I reloaded. (Yes, too reckless I know, but I was 'being more aggressive'.)

Another 'wasserbomb' warning, then a long pause, then BANG, sub almost tipped 90 degrees over:
Deck gun destroyed, radio destroyed, hydrophone destroyed, fore batteries destroyed. Major flooding.

I started to sink and slammed it into back emergency, managing only 2kts, but still sinking slowly. I stopped at about 230m and managed to get the flooding under control. Once I'd stabilised the sub I ordered all stop, as I wasn't going to get any power from my electrics anymore, and went to silent running, hanging in the water whilst the Black Swan gave me hell.

Miraculously he never found his target again and after another four or five depth charge runs, and some bouncing around, I was left alone. I had to break silent running again to stop some flooding which reappeared in the bow torpedo room, but man I was lucky.

After my brush with oblivion, my only objectives now were getting some fresh air into the pressure hull, then getting to dry land.

With no hydrophone and no idea what was going on above my head, I gave it 24 hours sitting motionless right where I was, then bit the bullet and blew ballast.

Popped the hatch, nothing in sight, I breathed a sigh of relief and headed back to base, crippled but happy to be alive, and kind of smug that I'd put 20,000 tons at the bottom in any case.

[Luno]

It's the worst feeling in the world to watch that needle turn around without any power to stop it...

At that point, I'm just shouting to myself, apologizing for all the tankers I sunk, and just begging to be able to surrender alive.

I'm surprised that your hull caved in at such extreme depth, and only after you were already rising. I thought the damage model in silent hunter was simpler than that. I'm guessing extreme depth progressively damages the hull?

[Hinrich Schwab]

Originally Posted by Luno

I'm guessing extreme depth progressively damages the hull?

Yes, it does. Once you are below "true crush depth", the damage model begins applying DOT to the Hull Integrity (in stock. Supermods deal with this). The hull integrity is directly proportional to the calculation of true crush depth; specifically, the lower your hull integrity, the shallower true crush depth becomes. Once hull integrity is below 30%, one can no longer crash dive without risking death and anything below 20% is certain death unless you are already at or near periscope depth when you blow ballasts. This stock damage model is not realistic, but was apparently easy to program, hence its presence. I know GWX uses a completely different damage model that uses the percentage as an influence on pressure hull failure and compartment flooding. In that damage model, it is the flooding that gets you. Once your boat surpasses the randomly generated true crush depth, you implode. No false hopes of recovery. It is over.

[Kapt Z]

Yeah, that's a grim end. Still frankly amazed your boat went as deep as it did before imploding.

Kinda like the scene in 'Das Boot' where they dive out of control off Gibraltar and despite all their efforts they can't recover. The chief ends up just muttering, "We can't hold her...." They were just waiting for the end at that point.

[flag4]

Originally Posted by Harald_Lange

407 meters?????? That exceeds what I thought was possible by about a hundred meters


Hope you don't think I'm hijacking, but its relating to a similar experience I had last night west of the Canaries. I was in my VIIC and I'd already sunk 4 merchants. A Black Swan Class escort lit me up with his searchlight. (I was using the mantra of 'Be More Aggressive' after all.)
After a crash dive I thought I'd take it to 160m and follow the convoy along throwing caution to the wind, ahead standard, silent running off, whilst I reloaded my torps.

After a few 'wasserbomb' warnings and a lot of rocking about without damage, I thought I'd crank it up to flank speed and follow my course straight to cut underneath the convoy, and sit and wait for them to come to me whilst I reloaded. (Yes, too reckless I know, but I was 'being more aggressive'.)

Another 'wasserbomb' warning, then a long pause, then BANG, sub almost tipped 90 degrees over:
Deck gun destroyed, radio destroyed, hydrophone destroyed, fore batteries destroyed. Major flooding.

I started to sink and slammed it into back emergency, managing only 2kts, but still sinking slowly. I stopped at about 230m and managed to get the flooding under control. Once I'd stabilised the sub I ordered all stop, as I wasn't going to get any power from my electrics anymore, and went to silent running, hanging in the water whilst the Black Swan gave me hell.

Miraculously he never found his target again and after another four or five depth charge runs, and some bouncing around, I was left alone. I had to break silent running again to stop some flooding which reappeared in the bow torpedo room, but man I was lucky.

After my brush with oblivion, my only objectives now were getting some fresh air into the pressure hull, then getting to dry land.

With no hydrophone and no idea what was going on above my head, I gave it 24 hours sitting motionless right where I was, then bit the bullet and blew ballast.

Popped the hatch, nothing in sight, I breathed a sigh of relief and headed back to base, crippled but happy to be alive, and kind of smug that I'd put 20,000 tons at the bottom in any case.

...im wondering what lessons you might have learned from this knife edge close call. it doesnt get much closer than that!

[Andrewsdad]

It is interesting how the damage/flooding model works...
I am using GWX, OLC, and h.Sie's mods which include the Longer Repair Time.

My IXC was depth charged and damaged at 160 meters. Several compartments damaged, hydrophone destroyed, forward batteries damaged, main pump and compressor also damaged. Scrolling thru the individual compartments doing the assesment, there was no indication of flooding (no repair time for flooding indicated.)

I had to run at 2 knots to hold depth, which indicated a heavy boat, but I could not begin repairs until the DD's moved away which took about one hour.

When I went off of silent running I got flooding repair times!! The two compartments each estimated about two hours to stop the flooding, but no estimate until the compartment damage would be repaired.

The repair to the main pump was estimated to take 41 hours.

After surfacing I began the long voyage home. Repair was effected to several of the subsystems, but I kept getting a damage report on the left rudder which did not display on the crew/boat condition screen. I did have full directional control of the boat.

After some 20 hours on the surface, I got the "Boat Destroyed by Flooding."

I availed myself of the "Surrender" option, so at least we were alive !!!!

Since there was no indication of flooding repairs and the repair gang (Officer and about 8 repair petty officers placed in the "Repair" billets) were working the whole time, I was surprised at this turn of events.

I believe that the unavaliability of the Main Pump was the key as there was no way to remove the leaking water to the ballast tanks where it could be blown out.

sigh....

AD

[Luno]

Yeah, that's one of those annoying things in SHIII. At least you got to abandon ship and live to tell the story to your grandkids

[Bosje]

yup
this was with GWX but without the olc and longer repair times

the most suprising things were 407 meters and still alive, and getting back up and THEN death from pressure (game said i died from pressure)

i thought i knew how the damage model worked but now i'm not sure anymore

i remember a game where i could see the integrity and it was at around 65% after an air attack, i then dived to see how deep i could still go and at 180 meters i started to get damage warnings, blew immediately but integrity went to 64 and my crush depth was thus less, which meant my new safe depth was no longer safe,
i ended up at 60% integrity and a safe depth of 100 meters

i can only assume that in my adventure the hull integrity was already so low that i was being crushed inevitably even though we were on our way back up.

still, 407 meters was a new one for me

[Laufen zum Ziel]

Been there done that. Tis a lousy feeling to know you have done all you can to save your crew to no avail.