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Post by BathTubAdmiral on Mar 12, 2020 5:35:37 GMT -6
I had my ships shoot lots of HE shells lately, and have observed several "Submerged torpedo flat hit *" that I'm not sure could happen in real life at all? You see, going through the logs I found hits like this: 6 in 8047 yds Submerged torpedo flat hit * (CA Nachi, HE) This was a "normal" IJN 6in (1911) gun, maybe something like the 6"/45 41st Year (a british gun, btw.; and yes, I am allied with them ;-) )
www.navweaps.com/Weapons/WNJAP_6-45_EOC.phpThe target was a german protected cruiser (1909), with 2.5in belt armour. These shells had AFAIU an instant-action nose fuse, so they should detonate on impact on the water, or not at all, because they would tumble after a short way underwater - these are not japanese diving shells ;-)
To actually get to the torpedo flat, the shell must dive under the belt, all the while being a dud and keeping enough energy tumbling through the water to actually penetrate the targets side! And that, IMHO, is next to impossible for a HE shell, very unlikely for a short-fused SAP shell, and really would require an AP shell with long(er) fuze time!
It's hard to find pictures where the location of these submerged torpedo tubes is actually visible, but I found some: USS Florida (BB-30) in drydock, which shows the "bar" that guides the torpedo when it is launched. Friedrich der Grosse 1912 - note the bow tube and the side tubes at frame(?) 24-31 Pre-dreadnought SMS Kaiser Barbarossa, 1901
Drake-class CA 1901 - note the "T" in the 3rd compartment!
 Gazelle-class cruiser small light cruiser with only 1in deck armour (protected cruiser stile) - note how well below the waterline the bow torpedo tube is located!
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Post by Antediluvian Monster on Mar 12, 2020 5:44:49 GMT -6
The torpedo flat hit does not really refer to an underwater hit per se, rather it means that such a hit has ocurred that causes flooding to the torpedo room associated with the submerged tubes. These were generally large spaces vulnerable to flooding, so it's represented by a special critical hit.
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Post by BathTubAdmiral on Mar 12, 2020 5:56:56 GMT -6
Sry, dude, a "torpedo flat hit" means exactly that: a hit to the torpedo flat, which is located below the armour belt and the waterline ... the 1st usually located where the 2nd is! (Unless, o.c., a ship got a bit overweight during refit so her armour belt ended up below the waterline at full load ... ) Where should the flooding come from, you think? From a hole above the armour belt, way above the waterline? What do you think the armoured deck in protected cruisers is for? Hint: what protects everything below the waterline from shells and flooding ... Btw., check the pics. You can see the size of the "torpedo flat" on the "langsschnitt" (longitudinal cut) of Friedrich der Grosse 1912.
The whole room is 2 decks below the waterline, and below the armoured belt.
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Post by Antediluvian Monster on Mar 12, 2020 7:22:35 GMT -6
Sry, dude, a "torpedo flat hit" means exactly that: a hit to the torpedo flat, which is located below the armour belt and the waterline ... the 1st usually located where the 2nd is! (Unless, o.c., a ship got a bit overweight during refit so her armour belt ended up below the waterline at full load ... ) Where should the flooding come from, you think? From a hole above the armour belt, way above the waterline? What do you think the armoured deck in protected cruisers is for? Hint: what protects everything below the waterline from shells and flooding ... Btw., check the pics. You can see the size of the "torpedo flat" on the "langsschnitt" (longitudinal cut) of Friedrich der Grosse 1912.
The whole room is 2 decks below the waterline, and below the armoured belt.
What was the thickness of the belt extended armour of the target? You only gave thickness of "belt" as 2.5-in. If it didn't have any, like many default protected cruiser designs don't, it's possible the game treated the area in way of the torpedo flat as unarmoured and the HE detonation at around waterline caused such destruction of structure that it resulted in flooding of the torpedo flat. If it was less than 2-in (AFAIK, the cutoff for shrapnel immune) it's possible the protected deck was holed by shrapnel around the level of waterline, which then resulted in flooding. Another possibility is that the ship was rolling heavily and at certain stages of the roll the unarmoured bottom of the ship was exposed, so it's also worth asking what was the weather like and whether the ship had narrow armour scheme. It *might* also be a question of non-flooding penetration through the flat part of the protected deck above the torpedo flat. The flat of the deck is rarely above 1-in on protected cruisers and hence vulnerable to being penetrated by shrapnel. Historically, the flooding of the foward torpedo flats played major part in loss of Lützow at Jutland, perhaps the main reason why the mechanic is in the game. |
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Post by BathTubAdmiral on Mar 12, 2020 10:52:22 GMT -6
What was the thickness of the belt extended armour of the target? You only gave thickness of "belt" as 2.5-in. If it didn't have any, like many default protected cruiser designs don't, it's possible the game treated the area in way of the torpedo flat as unarmoured and the HE detonation at around waterline caused such destruction of structure that it resulted in flooding of the torpedo flat. You might be onto something here, although I have seen these kind of hits several times, and not all where on protected cruisers without extended belt armour. Here's what the savegame says: [Armor]
B=5
BE=0
D=3
DE=0
CT=8
T=7
TT=2
SEC=3
ArmorScheme=0
I seriously doubt that the game goes to such lengths as to factor in all this, I'd bet it just rolls for a "critical hit" - like this: 8 in 8334 yds Critical hit *! Salt water enters feed tanks. Machinery disabled! (CA Nachi, HE)
6 in 8047 yds Submerged torpedo flat hit * (CA Nachi, HE)
Quite likely, but Lützow was hit by 2 heavy projectiles from HMS Invincible (1907), and most likely the battlecruisers where shooting AP at each other, not HE ... (btw., Invincible blew up after a turret penetration ...). And that's the point I was trying to make - it needs something like a 390kg AP shell from a BL 12in Mk X naval gun to get down below the belt and still penetrate a ships side - and not some puny 45kg 6in HE shell. And I think there even was such a hit from a 4in gun, but I didn't check thoroughly at that point. |
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Post by Antediluvian Monster on Mar 12, 2020 12:49:05 GMT -6
The British fired tons of CPC and HE at the Germans too. And for her part, Lützow nearly destroyed Lion with SAP.
Though I can't really disagree with the idea that a 6-in nose/contact fuzed HE striking at 8k yards should have impossible time getting a successful underwater hit, it's just that I'm not sure if that is what is really being represented with these hits.
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Post by rimbecano on Mar 12, 2020 13:24:01 GMT -6
Sry, dude, a "torpedo flat hit" means exactly that: a hit to the torpedo flat, which is located below the armour belt and the waterline ... the 1st usually located where the 2nd is! (Unless, o.c., a ship got a bit overweight during refit so her armour belt ended up below the waterline at full load ... ) The shell didn't necessarily hit or explode below the waterline, recall that splinters can penetrate up to 2" of armor. So the shell can explode above the torpedo flat and send splinters through the flat and out the bottom of the ship, and that would flood the flat. OTOH, splinter damage is generally listed as such in the logs, and the shot in question is listed as a penetrating hit. Another factor is that RTW assumes the extreme ends of the ship to be unarmored (which was historically generally the case with flat deck ships, not so much with protected cruisers). So a bow or stern tube is not going to be covered by armor in game (but arguably should be for protected and turtleback ships, at least if there is DE present). But, then again, I've never seen the AI use bow/stern tubes. |
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Post by dizzy on Mar 12, 2020 13:33:49 GMT -6
The USS Texas flooded her Starboard Torpedo room to give a two degree list to starboard so she could shoot some bunkers on the hill during D-Day. Totally off topic, hehe.
I have not seen any torpedo flat hits in my games, 1.17. I’ve been checking the logs furiously for penetration comparisons. So... hope that helps.
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Post by cogsandspigots on Mar 12, 2020 21:03:30 GMT -6
The USS Texas flooded her Starboard Torpedo room to give a two degree list to starboard so she could shoot some bunkers on the hill during D-Day. Totally off topic, hehe. I have not seen any torpedo flat hits in my games, 1.17. I’ve been checking the logs furiously for penetration comparisons. So... hope that helps. Strange how anecdotes can vary so wildly. I see torpedo flat hits all the time in my games. Once every 3 battles or so involving ships with submerged tubes. |
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Post by dizzy on Mar 12, 2020 22:17:32 GMT -6
The USS Texas flooded her Starboard Torpedo room to give a two degree list to starboard so she could shoot some bunkers on the hill during D-Day. Totally off topic, hehe. I have not seen any torpedo flat hits in my games, 1.17. I’ve been checking the logs furiously for penetration comparisons. So... hope that helps. Strange how anecdotes can vary so wildly. I see torpedo flat hits all the time in my games. Once every 3 battles or so involving ships with submerged tubes. I swear I’ve never seen one. I’ve been pouring over the logs to see how my 14-16” guns are doing against enemy armor and checking bomb hits for pens that should or shouldnt happen and have never seen any torpedo flat hit... Edit: Actually, come to think of it, yeah, I had ONE happen to me. But it nearly sunk my ship. The torpedoes detonated and wrecked my ship. It wasn’t a ‘torpedo flat’ notification which is why I didn’t remember it before. Kind of a different type of hit. But that’s the only one I can recall. |
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Post by aeson on Mar 12, 2020 23:16:41 GMT -6
Edit: Actually, come to think of it, yeah, I had ONE happen to me. But it nearly sunk my ship. The torpedoes detonated and wrecked my ship. It wasn’t a ‘torpedo flat’ notification which is why I didn’t remember it before. Kind of a different type of hit. But that’s the only one I can recall. That's probably an above-water tube that got hit, if the torpedoes exploded; I can't recall ever seeing submerged-tube torpedoes explode. |
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Post by dizzy on Mar 12, 2020 23:27:46 GMT -6
Edit: Actually, come to think of it, yeah, I had ONE happen to me. But it nearly sunk my ship. The torpedoes detonated and wrecked my ship. It wasn’t a ‘torpedo flat’ notification which is why I didn’t remember it before. Kind of a different type of hit. But that’s the only one I can recall. That's probably an above-water tube that got hit, if the torpedoes exploded; I can't recall ever seeing submerged-tube torpedoes explode. Maybe you're right. Maybe not. |
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Post by cabusha on Mar 13, 2020 2:32:56 GMT -6
I've seen both. Tons of torpedo flat hits, but just finally saw the "torpedoes explode" crit from a ship with above water mounts.
Basically if it's a ship I expect a need to outrun the enemy consistently, I won't include underwater torpedoes. If I don't care about outrunning, then I'll include underwater torps.
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Post by Antediluvian Monster on Mar 13, 2020 4:58:07 GMT -6
I've seen both. Tons of torpedo flat hits, but just finally saw the "torpedoes explode" crit from a ship with above water mounts. Basically if it's a ship I expect a need to outrun the enemy consistently, I won't include underwater torpedoes. If I don't care about outrunning, then I'll include underwater torps. I stop using submerged tubes on all ships except light cruisers (and even then only the early ones that can't do over 25 knots) around 1905-7 when I reach the dreadnought stage. At the same time I switch from uniform thickness narrow belt to regular belt with splinter protected BE. |
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Post by retsof on Mar 13, 2020 8:39:17 GMT -6
I just want to say thanks for explaining what that means. Until now I thought it was a dud torpedo bouncing off/putting a dent in the hull.
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