Can a WW2 sub survive a direct DC hit?

[geofflambert]

ORIGINAL: crsutton

My rule of thumb is that a solid "hit" on a smaller Japanese RO sub will sink it about 50% of the time.

Gorns don't have thumbs. What am I supposed to do?

[Alfred]

ORIGINAL: Dili

In game an "hit" just signals damage to the sub. It might mean that the DC exploded close or that hit 5 or 6m from the sub.

I don't think the ASW combat model include specifically direct weapons like Hedgehog that only exploded on contact but i might be wrong. If a hedgehog just damaged a sub might be rationalized that it just hit a control part, glanced on the sub or hit a extremity or the tower.

Not quite.[:)]

1. In AE, a hit is just a hit. It is neither an indicator that damage resulted from that specific "hit" nor the amount of damage inflicted by that specific "hit".

2. A "hit" of anything is always subject to FOW. This is particularly so if relying solely upon the Combat Report summary.

3. What a hit really means (accepting that it actually occurred) is that the combat algorithm first threshold has been passed. The second threshold is then determining how much damage actually results. Randoms play a significant role in the combat algorithms.

IOW no hit, zero damage ensues. If hit, then determine based on the weapon's characteristics, the damage (if any)inflicted. This is why the number of "hits" needed to sink something varies.

Alfred

[BBfanboy]

ORIGINAL: Anthropoid

Here is a good one. Not sure if this might be some kinda record:

German U-Boat commander claims some attacks lasted up to 8 hours and they counted 181 'water bombs' in one instance

My Dad's ship Fennel took part in the longest U-boat hunt of the war - they (with several other escorts) kept her down over 24 hours. I am not sure of the total number of attacks made but Fennel took part in four of them and fired on the sub when it surfaced.

There were times when contact with the sub was lost for several hours but the standard box searches re-acquired before the sub could sneak away and surface.

When it did surface and crew trying to reach their deck gun were cut down by MG/AA gun fire, the Germans abandoned ship thinking it was going to sink right away from the many small leaks it had. A Canadian whaleboat boarding party boarded and scooped up crypto materials and got off because they suspected scuttling charges were ticking. After escorts rescued as many of the crew as they could, DD Icarus swept in and fired a torpedo that blew the sub out of the water. Footage of this was used in a McHale's Navy episode where his PT boat torpedoes a sub.

Fennel's plot of the sub's movements as it twisted and turned to get away was subsequently used in ASW schools to teach about their evasive tactics.

[BBfanboy]

ORIGINAL: geofflambert

ORIGINAL: crsutton

My rule of thumb is that a solid "hit" on a smaller Japanese RO sub will sink it about 50% of the time.

Gorns don't have thumbs. What am I supposed to do?

Use "rule of tail" then. Humans would do that if they were able. [;)]

[sprior]

ORIGINAL: Anthropoid

Awesome . . . however "Although the hedgehog was amazing effective at the time, today's submarine would laugh at it . ." *glip* <THE END>

what, what, what?? Why would today's submarine "laugh at it!?"

Hedgehog used a contact pistol so had to physically hit the boat to cause damage. That's why it was forward throwing so the ASDIC operator could hold it in his cone as the weapon was launched.

Obviously the boat moved while the bombs were sinking so it was fired at where the boat was plotted to be when the bombs arrived there.

Modern boats a. go much deeper and b. go much faster that the U boats ever did so have much more wiggle room for manoevre, that's assuming the skipper let his boat get within 50yds of an escort in which case he would be in deep doo-doo after anyway for allowing such close contact.

[Sardaukar]

Even modern subs do not laugh at this successor of Hedgehog:

https://en.wikipedia.org/wiki/RBU-6000

[MakeeLearn]

ASW ship crews learn well in game as in RL. Best to keep them aggressive and out after the subs.

[crsutton]

ORIGINAL: BBfanboy

ORIGINAL: Anthropoid

Here is a good one. Not sure if this might be some kinda record:

German U-Boat commander claims some attacks lasted up to 8 hours and they counted 181 'water bombs' in one instance

My Dad's ship Fennel took part in the longest U-boat hunt of the war - they (with several other escorts) kept her down over 24 hours. I am not sure of the total number of attacks made but Fennel took part in four of them and fired on the sub when it surfaced.




There were times when contact with the sub was lost for several hours but the standard box searches re-acquired before the sub could sneak away and surface.

When it did surface and crew trying to reach their deck gun were cut down by MG/AA gun fire, the Germans abandoned ship thinking it was going to sink right away from the many small leaks it had. A Canadian whaleboat boarding party boarded and scooped up crypto materials and got off because they suspected scuttling charges were ticking. After escorts rescued as many of the crew as they could, DD Icarus swept in and fired a torpedo that blew the sub out of the water. Footage of this was used in a McHale's Navy episode where his PT boat torpedoes a sub.

Fennel's plot of the sub's movements as it twisted and turned to get away was subsequently used in ASW schools to teach about their evasive tactics.

Cool story. Thanks for sharing. I think this is what was termed "hunt to exhaustion" or something like that. Later in the war the Allies possessed so many resources that they could afford to saturate an area with patrol ships and aircraft. The sub would be driven under and knowing the maximum range of the sub on its batteries the Allies would just cover that radius with visual and radar searches. The sub would have to come up sooner or later and would be driven back down (but not for long) until there was no choice but to surface and face the music. What type of ship was the Fennel?

[dr.hal]

[/quote]

Hedgehog used a contact pistol so had to physically hit the boat to cause damage. That's why it was forward throwing so the ASDIC operator could hold it in his cone as the weapon was launched.

[/quote]
You mention one of the most advantageous features of the hedgehog, its ability to fire forward of the attacking vessel. First, the attacking vessel didn't have to go at a high speed into the attack in order to "clear" the area so as not to suffer damage from its own depth-charge attack. Second, given the slower speed and the lack of area noise (due to depth-charges exploding usually harmlessly) the attacking vessel retained the ability to remain in contact with the sub throughout the attack allowing for a far more effective subsequent attack if needs be!

[Anthropoid]

ORIGINAL: dr.hal

Hedgehog used a contact pistol so had to physically hit the boat to cause damage. That's why it was forward throwing so the ASDIC operator could hold it in his cone as the weapon was launched.

You mention one of the most advantageous features of the hedgehog, its ability to fire forward of the attacking vessel. First, the attacking vessel didn't have to go at a high speed into the attack in order to "clear" the area so as not to suffer damage from its own depth-charge attack. Second, given the slower speed and the lack of area noise (due to depth-charges exploding usually harmlessly) the attacking vessel retained the ability to remain in contact with the sub throughout the attack allowing for a far more effective subsequent attack if needs be!

It is interesting.

When you watch some of these videos of ships performing attacks one thing that stands out to me is: how relatively proximate behind the ASW attacker the depth charges seem to detonate.

For example in the footage immediately after this point in the Youtube I posted up above:
https://youtu.be/YvyfcmkhFiY?t=2310

Of course those detonations are submerged, but when you consider the depth of the attacking ship's keel, I wonder how far away the center of those detonations are from the attacking destroyer?

[BBfanboy]

ORIGINAL: crsutton

ORIGINAL: BBfanboy

ORIGINAL: Anthropoid

Here is a good one. Not sure if this might be some kinda record:

German U-Boat commander claims some attacks lasted up to 8 hours and they counted 181 'water bombs' in one instance

My Dad's ship Fennel took part in the longest U-boat hunt of the war - they (with several other escorts) kept her down over 24 hours. I am not sure of the total number of attacks made but Fennel took part in four of them and fired on the sub when it surfaced.




There were times when contact with the sub was lost for several hours but the standard box searches re-acquired before the sub could sneak away and surface.

When it did surface and crew trying to reach their deck gun were cut down by MG/AA gun fire, the Germans abandoned ship thinking it was going to sink right away from the many small leaks it had. A Canadian whaleboat boarding party boarded and scooped up crypto materials and got off because they suspected scuttling charges were ticking. After escorts rescued as many of the crew as they could, DD Icarus swept in and fired a torpedo that blew the sub out of the water. Footage of this was used in a McHale's Navy episode where his PT boat torpedoes a sub.

Fennel's plot of the sub's movements as it twisted and turned to get away was subsequently used in ASW schools to teach about their evasive tactics.

Cool story. Thanks for sharing. I think this is what was termed "hunt to exhaustion" or something like that. Later in the war the Allies possessed so many resources that they could afford to saturate an area with patrol ships and aircraft. The sub would be driven under and knowing the maximum range of the sub on its batteries the Allies would just cover that radius with visual and radar searches. The sub would have to come up sooner or later and would be driven back down (but not for long) until there was no choice but to surface and face the music. What type of ship was the Fennel?

Fennel was a Flower-class Corvette - KV in the game.

[BBfanboy]

ORIGINAL: Anthropoid

ORIGINAL: dr.hal

Hedgehog used a contact pistol so had to physically hit the boat to cause damage. That's why it was forward throwing so the ASDIC operator could hold it in his cone as the weapon was launched.

You mention one of the most advantageous features of the hedgehog, its ability to fire forward of the attacking vessel. First, the attacking vessel didn't have to go at a high speed into the attack in order to "clear" the area so as not to suffer damage from its own depth-charge attack. Second, given the slower speed and the lack of area noise (due to depth-charges exploding usually harmlessly) the attacking vessel retained the ability to remain in contact with the sub throughout the attack allowing for a far more effective subsequent attack if needs be!

It is interesting.

When you watch some of these videos of ships performing attacks one thing that stands out to me is: how relatively proximate behind the ASW attacker the depth charges seem to detonate.

For example in the footage immediately after this point in the Youtube I posted up above:
https://youtu.be/YvyfcmkhFiY?t=2310

Of course those detonations are submerged, but when you consider the depth of the attacking ship's keel, I wonder how far away the center of those detonations are from the attacking destroyer?

During one of their attacks on the U-boat Fennel was almost sunk by a combination explosion of an acoustic torpedo plus their own depth charges just dropped. The torpedo went off prematurely a few yards from Fennel's stern when the shallow-pattern DCs went off. The stern of Fennel was lifted about 8 feet out of the water and everyone aboard was thrown to the deck or off balance. The stern developed significant leaks, especially in the seal around the screw shaft. Damage control kept up with the flooding but the ship's speed was cut to about 10 kts. max.
After the battle the Fennel rescued the U-boat skipper who insisted he had sunk an escort during the battle.

PS - if that torpedo had hit, I wouldn't be here - my Dad was in charge of the aft DC racks.

[Anthropoid]

ORIGINAL: BBfanboy

ORIGINAL: Anthropoid

ORIGINAL: dr.hal



You mention one of the most advantageous features of the hedgehog, its ability to fire forward of the attacking vessel. First, the attacking vessel didn't have to go at a high speed into the attack in order to "clear" the area so as not to suffer damage from its own depth-charge attack. Second, given the slower speed and the lack of area noise (due to depth-charges exploding usually harmlessly) the attacking vessel retained the ability to remain in contact with the sub throughout the attack allowing for a far more effective subsequent attack if needs be!

It is interesting.

When you watch some of these videos of ships performing attacks one thing that stands out to me is: how relatively proximate behind the ASW attacker the depth charges seem to detonate.

For example in the footage immediately after this point in the Youtube I posted up above:
https://youtu.be/YvyfcmkhFiY?t=2310

Of course those detonations are submerged, but when you consider the depth of the attacking ship's keel, I wonder how far away the center of those detonations are from the attacking destroyer?

During one of their attacks on the U-boat Fennel was almost sunk by a combination explosion of an acoustic torpedo plus their own depth charges just dropped. The torpedo went off prematurely a few yards from Fennel's stern when the shallow-pattern DCs went off. The stern of Fennel was lifted about 8 feet out of the water and everyone aboard was thrown to the deck or off balance. The stern developed significant leaks, especially in the seal around the screw shaft. Damage control kept up with the flooding but the ship's speed was cut to about 10 kts. max.
After the battle the Fennel rescued the U-boat skipper who insisted he had sunk an escort during the battle.

PS - if that torpedo had hit, I wouldn't be here - my Dad was in charge of the aft DC racks.

So Anti-Subwarfare is pretty hazardous!

[Lecivius]

There is a story, or a book on this some-wheres. I have read bout this [&:]

[Bullwinkle58]

ORIGINAL: Sardaukar

Even modern subs do not laugh at this successor of Hedgehog:

https://en.wikipedia.org/wiki/RBU-6000

Yeah, pretty much they do laugh.

[AW1Steve]

ORIGINAL: Bullwinkle58

ORIGINAL: Sardaukar

Even modern subs do not laugh at this successor of Hedgehog:

https://en.wikipedia.org/wiki/RBU-6000

Yeah, pretty much they do laugh.

It's not the weapon that subs should fear. It's the soviet tactics that were designed to use the weapon. The USSR kept depth charges , and short range mortars in production long after most of the western nations had abandoned them. That's because the Sov's had lots of small craft of little ASW (or any other kind of value). The theory was that if a western boat was found in a defended area , while the relatively usefull asw equipped vessels, helicopters and aircraft hassled and tried to localize the sub, they would bring every available vessel that could carry DC's or asw rockets and mortars as close to the area (what we'd call a datum, but the USSR wouldn't have anything that close) then they'd proceed with "mobbing tactics". They'd poor fire with every thing they had into the general area. Kind of a big (really BIG!) depth charge attack. Obviously it would completely screw up the water from a SONAR point of view, if the boat was unable to clear the area (think a diesel boat vice a USN/RN fast attack nuke) then the sub would at best have a very unpleasant surprise. And even a nuke , if the skipper were to be somewhat dim and NOT figure out what was coming his way could be hurt. (Even a blind squirrel occasionally finds a nut). It wasn't a brilliant or even particularly good tactic. But ya gotta use what you have. [:)]

[Sardaukar]

ORIGINAL: Bullwinkle58

ORIGINAL: Sardaukar

Even modern subs do not laugh at this successor of Hedgehog:

https://en.wikipedia.org/wiki/RBU-6000

Yeah, pretty much they do laugh.

I don't think there is much laughter if that salvo happens to drop on sub. It is more useful in shallow restricted waters, though. Not many submarines would get that close to ASW ship if there is room to maneuver. RBU-class weapons are also used as anti-torpedo weapon. I think there is some sort of misconception that ASW-work is done only in "blue water".

[SheperdN7]

Question about a counter to ships dropping depth charges, why weren't submarines equipped with a kind of floating mine device, one that is released when a destroyer or escort is on an attack run? In concept it would destroy the attacking surface ship and buy time for the sub to escape or at. Least hide itself in the chaos and confusion of what was happening above.

[BBfanboy]

ORIGINAL: SheperdN7

Question about a counter to ships dropping depth charges, why weren't submarines equipped with a kind of floating mine device, one that is released when a destroyer or escort is on an attack run? In concept it would destroy the attacking surface ship and buy time for the sub to escape or at. Least hide itself in the chaos and confusion of what was happening above.

I think the sub sonars of the time were not good enough to get an exact bead on the attacking ship, so the mine was likely to miss. To get exactly in line you would have to behave like Sam Dealy (Skipper of USS Harder) and come to periscope depth, align the boat with the attacking ship ... and at that stage you might as well fire a couple of torps "down the throat". Harder sank something like 8 or 10 Japanese DDs.

[BBfanboy]

ORIGINAL: Lecivius

There is a story, or a book on this some-wheres. I have read bout this [&:]

The overall hunt for this U-boat is covered briefly without much detail in several books about the Battle of the Atlantic. Fennel is hardly mentioned while KV Chilliwack gets mention for sending the boarding party that scooped the crypto intel. Secrecy and the relative modesty of Canadians to tout their war exploits means that detailed accounts were not assembled from the disparate Canadian/British ships involved.

The account I related was oral history told by my father when I was a youngster asking about the war. Here's another anecdote from the same battle:

After the sub's crew began to jump overboard and the surrounding ships ceased fire, they started rescue operations. Fennel was upwind from the sub and started drifting toward it (being much more exposed to the wind it drifted faster than the sub).

The sub's crew saw that this ship would be the closest to swim to and most headed that way. Fennel's crew had scrambling nets over and were also using rope and life rings to pull as many Germans as they could to safety.

But they were being blown dangerously near the sub whose diving planes could open Fennel's side like a tin can, so the Captain reluctantly restarted his engines and turned away from the sub. There were a few men still in the water but they saw the ship starting to move and turn and swam out of the way. Not so a German officer who wore his cap - his eyes could not see past the cap's bill. As the ship swung he was caught in the current and drawn into the ship's screw - and was not seen again.

EDIT: found an account on-line. The U-boat was U-744. http://aleddavies17.wixsite.com/our-family/u-boat--u744