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-   -   [???] Would this DC have caused damage in reality? (pic inside) (https://www.subsim.com/radioroom/showthread.php?t=137873)

Quagmire 06-08-08 03:36 PM

[???] Would this DC have caused damage in reality? (pic inside)
 
Hey guys. I thought I would take a little argument I had with a friend of mine here for some expert analysis. In my recent tangle with Bungo Pete I had a depth charge dropped almost right on top of me. Fortunately I was at FLANK speed and full left rudder so I managed to get out from under it. However the DC detonated right behind my sub. Here is the action as it happened...


http://img503.imageshack.us/img503/117/bungo1xa3.jpg

When this charge went off it shook the sub violently. It seemed like I was on a roller coaster in the conning tower. However, the sub took no damage at all. My friend says that the screws or at least the rudder would have been blown off. I say it may be possible to take no damage from such a close hit since it happened behind the sub and not above or below.

So, what do you guys think? Should I have taken damage? And if so, can the damage model of the sub in SHIV be tweaked to reflect reality a little better?

Thanks in advance.
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Hylander_1314 06-08-08 03:37 PM

Knocked a few things loose, and maybe a couple small leaks, but not blowin' off the rudder or props.

Von Manteuffel 06-08-08 05:21 PM

I'm not overly sure of the physics used in the game; and scale from your excellent screenshot is difficult, but it looks as though the DC exploded at least 7 or 8 metres behind you, perhaps more If that's so, what you describe is perfectly accurate. You would have been shaken and perhaps sustained a few minor leaks ( mainly glands at the aft of the boat ) but no real damage. I have to say, though, that you were lucky. A few metres closer and you would have been in real trouble.

Depth-charges had to explode very close ( 4 to 5 metres, or less ) to cause real damage. The surrounding water carried the pressure wave, but also had a damping effect. Add to that the fact that subs were built very robustly. They had to handle heavy seas for days, or even weeks, on end - and that includes the screws and steering gear. It's easy to understand why DC's accounted for comparatively few "kills" Aircraft with bombs and armour-piercing cannon shells, rockets etc. were a bigger threat.

I believe that most subs which fell victim to DCs did so only after prolonged and sustained DC attacks, rather than a single "hit". They finally succumbed to that direct hit, or, more likely, were "battered to death" t so that all that "minor" damage accumulated to progressively weaken the boat. Then the water pressure which dampened the force of the explosions worked against the sub until the flooding became uncontrollable.

If Bungo Pete, for example, had managed to drop several more to exlode in the same position as your near-miss, the damage would have been cumulative, but again, mainly ever-worsening leaks and failed welds, or seams.

It's a sobering thought that for the majority of men lost in submarines - from all sides - death did not come quickly, or suddenly.

Count your blessings - and stay away from the Bungo Straits :yep:

Sailor Steve 06-08-08 05:41 PM

Actually a depth charge going off 8 meters (25 feet) away had a good chance of cracking the hull and sinking her almost immediately. But I don't think that one is really that close. More like twice that, easily. And, it's behind the boat, so the pressure hull is end-on. And, propellors and rudders are not really suceptible to that kind of thing; it would have to be right up next to them to have that kind of effect.

I think you're safe. Shaken, but not stirred.

Quote:

The British claimed this DC would split a 0.875 inch (22 mm) hull at 20 feet (6.1 m) and force a submarine to surface at about twice that distance. A minol charge introduced in 1942 increased these distances to 26 feet (7.9 m) and 52 feet (15.8 m), respectively.
http://www.navweaps.com/Weapons/WAMBR_ASW.htm
(Mk VII Heavy)

ATR-42 06-08-08 07:37 PM

in one of the books i had read about fleet boats, there was a part where the captain was recalling a story (non-fiction). it discussed the depth charge actually HITTING the aft foe deck, ROLLING aft (they were listening the entire time) then it rolled off the stern... they were at flank i believe. the DC blew up just behind the sub.

It was in the authors opinion that the only reason they survived the attack was because it blew up directly astern, the pointiest part of the sub, thereby 'deflecting' the shock wave subtly.



===Edit===
<<<<< yes! new avatar!

Quagmire 06-08-08 07:57 PM

HA! Thanks guys I knew I was right.

The only reason I was second guessing myself is that I have been rammed by a destroyer and not sustained a lot of damage. I know from reading these forums that the damage model is FUBAR in SHIV.

However in this case they got the experience right.
.

The Fishlord 06-08-08 07:59 PM

On her seventh patrol, USS Gato actually found a live depth charge sitting on the aft deck when they surfaced. They quickly put it in a rubber raft and shoved it off before the escorts could catch up (they were on the surface, in pursuit of a freighter with two destroyers chasing them).

ATR-42 06-08-08 08:20 PM

Quote:

Originally Posted by The Fishlord
On her seventh patrol, USS Gato actually found a live depth charge sitting on the aft deck when they surfaced. They quickly put it in a rubber raft and shoved it off before the escorts could catch up (they were on the surface, in pursuit of a freighter with two destroyers chasing them).

WOW! that is a great story!! holy crap!!! :o

Zero Niner 06-08-08 08:23 PM

Is the damage modeling in the game (whether sotck or modded) that sophisticated that it takes into account where in relation to the sub the DC goes off?

Just curious...

Fincuan 06-08-08 11:09 PM

I doubt that. As you know it does matter which compartments are near the explosion etc, but that's about it. No stern "deflecting" the explosion. With really bad luck you can actually have DCs explode inside your sub. They just fall right through the sub like it wasn't there and explode. Deflect that :D

LukeFF 06-09-08 12:11 AM

From U.S. Submarines Through 1945:

Quote:

Tests of the Tambor series began on 20 December 1940 off Portsmouth, with the submarine under way at periscope depth in 110-125 ft of water. A charge at 60 ft, 510 yd from the submarine, produced a sensation similiar to a slammed watertight door or the flapping of a Kingston valve - a sharp but not very intense jolt. The only damage was a dislocated microswitch on No.6 main ballast tank vent. A shot a 340 yd produced a sensation described as three times as intense. The boat was shoved sideways and noticeably shaken. One electric light bulb filament broke, and the 200-lb blow line (diver's connection) in the conning tower opened slightly and started to bleed air. A third shot at 275 yd, not quite doubling the intensity of the earlier ones, did real damage...the No. 4 battery ventilation blower developed a slight knock, apparently as the result of a loose stuffing box on the fan and no packing; the No. 3 main engine outboard exhaust valve began to leak...the main vent valve of a fuel-ballast tank leaked..six or seven bulb filaments broke; and a fuse burned out...

Depth charges were far less lethal than had been imagined; allowances on surface ships were increased and heavier (600 lb vice 300 lb) charges standardized. By the end of the war, it was assumed that a 300-lb depth charge had to explode within 14 ft to have a reasonable chance of breaking open the pressure hull. At twice that distance, it would probably disable the submarine. Within 60 ft, it would tend to demoralize the crew, but that could be minimized by training, discipline, and morale."


gimpy117 06-09-08 02:08 AM

yeah with all the subs my terrible captianing has lost:arrgh!:..none have been from a depth charge.

vanjast 06-09-08 06:36 AM

Quote:

Originally Posted by Fincuan
I doubt that. As you know it does matter which compartments are near the explosion etc, but that's about it. No stern "deflecting" the explosion. With really bad luck you can actually have DCs explode inside your sub. They just fall right through the sub like it wasn't there and explode. Deflect that :D

A sub hunters bearing to your sub certainly effects the asdics ability to pick you up, so I'd imagine it's not too difficult to include DC bearings to the damage calculations... one should test this :)


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