Review of armor on IJN destroyers

[el cid again]

There seems to be confusion about armor on Japanese destroyers. After one person posted they really were armored, I decided to do a comprehensive review of the available materials - which I happen to be able to do without going anywhere. I was able to find where this confusion probably came from.

After the London Naval Treaty Japan felt unfairly positioned, and designed the "super" destroyer. It introduced, for the first time anywhere, the concept of a "protected deckhouse." Now this seems to be interpreted by non naval people to mean all the buildings or superstructures on the main deck. But it does not mean that: a deckhouse is the protection for a gun mounting, which prior to this was always open on destroyers. Further, the nature of this protection may be described in two ways: spray or splinter. Both matter a great deal. Sailors in wet boats like destroyers of that era suffer badly from wind, water and even the smallest of shrapnel from exploding shells or bombs or torpedoes or mines. Being inside a deckhouse is a fantastic advantage, particularly in bad weather.

But even "splinter protection" should not be interpreted to mean "armor." The deckhouse on Fubuki (which invented the idea) was 2mm. The late war destroyers with the fantastic 100 mm guns upped that to a whole 3mm! NEITHER of these is close to the 5mm added by some to CHS IJN destroyers. And NEITHER of these is properly interpreted as deck armor or side armor either. They protect magazines and engines - but Destroyer magazines and engines are unprotected. Further, torpedoes and depth charges and ready ammunition magazines for gun mountings on destroyers are ABOVE the main deck - not even the hull or a deck to protect them - and if ANY of these go up it is likely the whole ship blows up! [In the novel version of The Bedford Incident a naval officer contemplates blowing up the entire ship with a 9mm pistol! He just will shoot an ASROC warhead. I think that is how the book ends, actually, but memory is dim. It is not technical nonsense, however. I once had to brief an ASROC security detail about our fate if we put even one round into a warhead.] If you think 2mm or 3 mm - which should be put on the gun mounts - and which I have added for RHS - is significant - consider how you would feel if a tankette were armored to that scale? Even 10 mm is not really enough to protect you reliably from small arms fire, clearly 5 mm is not.

Now there is this: IJN destroyers with reload magazines did have armor on them. But being realistic, it is a lot more than 5mm. I guess we could put that in the torpedo mounts too - never thought of that! But the idea of armor for the bridge was not proposed (as far as I know) until the 1960s (when I proposed it) - and it was not adopted for another generation - modern US destroyers have Kevlar armor for such vital places.

It might be acceptable to rate the hull and decks as armor on a discounted basis. But only if it were done for all stell ships. That is a lot of work data entry wise - and frankly destroyer sailors never felt they were safe if they got hit - no matter what does the shooting. The reason we funded kevlar armor in the modern age was a US Congressional Budget Office study of what a lone rifleman could do with a .30 bolt action!

[rockmedic109]

Question. Was the extra armor added on purpose for game engine/mechanics reasons? Perhaps without the armor, the DDs were vulnerable to being sunk by .50 cal AA mounts?

[DuckofTindalos]

Exactly. You could sink an unarmoured aircraft carrier like the Ranger with .50 cal fire in this game...[:D]

[Tankerace]

But, as Mike explained during WPO beta to me, 1) it confuses the game, and 2) .50 cal MGs could touch off ready rounds, torpedoes, or depth charges on destroyers. So while "unarmored" large ships like the Ranger should have some armor (maybe 5mm), destroyers should still have none unless they were truly armored.

[Ron Saueracker]

ORIGINAL: Tankerace

But, as Mike explained during WPO beta to me, 1) it confuses the game, and 2) .50 cal MGs could touch off ready rounds, torpedoes, or depth charges on destroyers. So while "unarmored" large ships like the Ranger should have some armor (maybe 5mm), destroyers should still have none unless they were truly armored.

How can it "confuse the game"? And the notion that ships are a zero rating is silly because a zero rating in this game means "air" or "butter". Better to leave some amount of "armor" (call it the hull) than remove it all.

[Bradley7735]

I do think the minimum would have to be 1. Unless the ship is made of wood. Even then, wood should still be 1. Maybe 5 is too high, I don't know. I've worked on crab boats in the North Pacific, and they have at least 3mm hulls. Any of the good ones have double hulls, so probably 6mm. I'm not an expert on this subject, by any means. But, I highly doubt a ship the size of a SS or DE or larger would have less than 3 mm of metal in their hull. I know metal hull does not equal armor. But, it does provide more protection than air. Something has to keep the water out of the engine room.

[Tankerace]

Just making the point of what Mike told me and the WPO betas, that it "confuses the game because it doesn't expect actual armor on destroyers and smaller ships".

Part of it has to do with extreme range fires. In beta we had a tin can eat a 10" shell from maximum range, and it failed to penetrate the 5mm deck armor we had at the time. It has been my experience that the game rates this as armor, not as hull thickness. A .50 Ma Deuce would still chew up 3mm of armor plate, let alone a truly unarmored destroyer. It may not sink it (nevermind historic examples of DDs being sunk by .50s), but it would certainly chew it up, if not set off the magazines, torpedoes, depth charges, and kill the crew, all of which would be defeated by adding armor. Having a 0 rating may be unrealistic or gamey, but so is adding anything over 3mm to it.

ORIGINAL: Ron Saueracker

ORIGINAL: Tankerace

But, as Mike explained during WPO beta to me, 1) it confuses the game, and 2) .50 cal MGs could touch off ready rounds, torpedoes, or depth charges on destroyers. So while "unarmored" large ships like the Ranger should have some armor (maybe 5mm), destroyers should still have none unless they were truly armored.

How can it "confuse the game"? And the notion that ships are a zero rating is silly because a zero rating in this game means "air" or "butter". Better to leave some amount of "armor" (call it the hull) than remove it all.

[Ron Saueracker]

ORIGINAL: Tankerace

Just making the point of what Mike told me and the WPO betas, that it "confuses the game because it doesn't expect actual armor on destroyers and smaller ships".

Part of it has to do with extreme range fires. In beta we had a tin can eat a 10" shell from maximum range, and it failed to penetrate the 5mm deck armor we had at the time. It has been my experience that the game rates this as armor, not as hull thickness. A .50 Ma Deuce would still chew up 3mm of armor plate, let alone a truly unarmored destroyer. It may not sink it (nevermind historic examples of DDs being sunk by .50s), but it would certainly chew it up, if not set off the magazines, torpedoes, depth charges, and kill the crew, all of which would be defeated by adding armor. Having a 0 rating may be unrealistic or gamey, but so is adding anything over 3mm to it.

ORIGINAL: Ron Saueracker

ORIGINAL: Tankerace

But, as Mike explained during WPO beta to me, 1) it confuses the game, and 2) .50 cal MGs could touch off ready rounds, torpedoes, or depth charges on destroyers. So while "unarmored" large ships like the Ranger should have some armor (maybe 5mm), destroyers should still have none unless they were truly armored.

How can it "confuse the game"? And the notion that ships are a zero rating is silly because a zero rating in this game means "air" or "butter". Better to leave some amount of "armor" (call it the hull) than remove it all.

In beta we had a tin can eat a 10" shell from maximum range, and it failed to penetrate the 5mm deck armor we had at the time.

That sounds weird that a large calibre plunging shell bounced off 5mm of armor!? LOL Dud?

[Tankerace]

Maybe [:D], but Dud or not, the hit of a shell that size would have still demolished something on a destroyer.... but since the program thought it armored, it treated it as a dud with little or no damage.

[trojan58]

The biggest problem I have with CHS is armour on PT boats. They now cannot be sunk by straffing A/C. 20mm cannon bounce off. Perphaps we should build all ships out of armoured plywood

[Ron Saueracker]

ORIGINAL: trojan

The biggest problem I have with CHS is armour on PT boats. They now cannot be sunk by straffing A/C. 20mm cannon bounce off. Perphaps we should build all ships out of armoured plywood

There is no armor on PTs, or there should not have been.[&:]

[Ron Saueracker]

ORIGINAL: Tankerace

Maybe [:D], but Dud or not, the hit of a shell that size would have still demolished something on a destroyer.... but since the program thought it armored, it treated it as a dud with little or no damage.

Actually, many times the AP shells pass right through the few mm of plating on unarmoured ships. I think the benefits of a few mm to sim hull plating, splinter protection etc outweighs the long shot that a deck hit by a big shell bounces off. I'm still bending my brain around how the program confuses 5mm of armor for anything but 5mm of armor. Makes no sense to me.

[Andrew Brown]

ORIGINAL: Ron Saueracker
There is no armor on PTs, or there should not have been.[&:]

Actually there is. Something I didn't realise. I don't know when it was added.

So, what ships SHOULD have "armour" added to them and for what reason? It already seems that, with the changes to ASW attack routines, there is no longer justification for having it on subs; but what about AKs, APs, TKs, DDs, PGs, SCs, not to mention PT boats?

Andrew

[Don Bowen]

ORIGINAL: Andrew Brown

ORIGINAL: Ron Saueracker
There is no armor on PTs, or there should not have been.[&:]

Actually there is. Something I didn't realise. I don't know when it was added.

So, what ships SHOULD have "armour" added to them and for what reason? It already seems that, with the changes to ASW attack routines, there is no longer justification for having it on subs; but what about AKs, APs, TKs, DDs, PGs, SCs, not to mention PT boats?

Andrew

Probably my fault - the price of using an automated tool!

Anyway, I do not believe there should be any armour on PTs or SCs.

I disagree about armour on most other ships. It may well be possible to sink a DD or large merchantman with MGs but I am not aware of it ever happening in real life. Game mechanics make it more than possible and non-historic armour seems the best answer.

Has anyone heard of a significant ship being sunk by MGs alone?

[Tankerace]

I can think of at least one Japanese DD sunk by .50s (can't remember the name, it was in the Solomon's). The MGs touched off DCs I believe (which can't happen with an armored hull). I mean, we've all seen the gun camera footage of the ship being shot up, and then exploding as ammunition/torpedoes/depth charges explode with it.) However, with armor on the DDs, it would prevent this.

One potential example is the destroyer Kisaragi (sunk at Wake). Some sources cite 100lb bombs, others the Wildcat's strafing runs. It is a definate possibility, but adding armor would prevent this.

As further evidence to allow this, strafing (according to numerous records) has always caused significant damage to destroyers, often touching off AA ammo, and killing crew (which could be reflected in high sys damage). However, adding armor to them would make them immune, which is just as gamey as having them sunk outright.

From Combined Fleet's website, about the destroyer Kagero:

21 September:
Troop transport run to Guadalcanal. Light damage: strafing aircraft caused waterline damage, flooded bow area.

Based on that alone, I say scrap the armor. Destroyers are vulnerable to strafing runs, and here is proof. Yet by adding armor, no damage at all could be inflicted, beyond destroying some small gun mounts.

ORIGINAL: Don Bowen

ORIGINAL: Andrew Brown

ORIGINAL: Ron Saueracker
There is no armor on PTs, or there should not have been.[&:]

Actually there is. Something I didn't realise. I don't know when it was added.

So, what ships SHOULD have "armour" added to them and for what reason? It already seems that, with the changes to ASW attack routines, there is no longer justification for having it on subs; but what about AKs, APs, TKs, DDs, PGs, SCs, not to mention PT boats?

Andrew

Probably my fault - the price of using an automated tool!

Anyway, I do not believe there should be any armour on PTs or SCs.

I disagree about armour on most other ships. It may well be possible to sink a DD or large merchantman with MGs but I am not aware of it ever happening in real life. Game mechanics make it more than possible and non-historic armour seems the best answer.

Has anyone heard of a significant ship being sunk by MGs alone?

[Tankerace]

Interrogation of: Lieut. Comdr. YASUMOTO, Shisei, IJN; Commander of the escort vessel Shiokaze, March 1944 to June 1945; Staff Officer of 103rd Convoy Escort Squadron, Seventh Fleet, from June 1945 to end of war.

Q. To what extent did single search planes flying in the YELLOW SEA interfere with the shipping?
A. They never were much trouble. I think there was some difficulty in the Western YELLOW SEA from four-motored search planes. There we were using nothing but small ships of about 1000 tons in order to use inward passages as much as possible, and on ships of this size strafing attacks were very serious factor.

(from ibolio.org)

So Japanese DEs and most DDs fit within this category. So, we have proof that 1) Strafing could flood out a destroyer, 2) that Japanese commanders acknowledged that it could cause serious damage, and 3) potential proof of one or two sinking by strafings.

I'll try and find more evidence to support this aswell.

[Don Bowen]

Well Justin, I'm about half convinced.

I would consider is possible (to probable) that Lieut. Comdr. YASUMOTO, Shisei was referring to small merchant ships, not DD/DE. Small ships to 1000 tons seems a more likely discription of cargo carriers.

I've always heard that the cause of Kisiragi's loss at Wake was questionable - the ship having been hit by a bomb that started a fire as well as multiple straffing runs.

I also seem to recall that one of the cruisers at wake (Yubari??) suffered some hull damage from MGs.

So, stepping a little aside from history for a minute, the armour was added due to a perception that excessive damage was being caused to ships by MGs in the game.

Is that perception correct??

[Ron Saueracker]

The minimal armor on DDs does not always defeat .50 cals guys. Range plays a role for sure. I have seen penetrating and non penetrating hits at the same range by the same weapon vs the same armour thickness so random element is at play as well.

I'm all for keeping some armor on ships (2-3mm) to simulate the actual hull. Shit, planes have an armour rating!

[witpqs]

I was never been convinced that the perception that MG's were causing excessive damage was correct. It seemed like folks thought of penetrating hits as highly unusual and naval combat as being too dangerous. My sense is that it was more dangerous than maybe games have led us to believe. That fact probably played a large part in the decision making during the war. Unlike us, mere players of a game, the commanders had to live with the vulnerability of their naval assets. We use them a lot and so they get whacked around a lot. Then we (sometimes) complain that the game moves too quickly versus history and is too bloody.

My own view is that I would like to start with historical configurations and then have an objective measurement (to the degree practical) of how damage in WiTP stacks up against damage in the real war before making alterations like adding or changing armor. I realize this might be too difficult to happen, but my point is that I believe various changes were made based on perception such as noted above instead of based on data. At least, that's my perception!

The comparison that planes have armor and they are obviously more fragile than destroyers is irrelevant, what matters is how the code handles them. I doubt the same code is used for damage to ships and planes. I'm sure ships are presumed to have structural hulls in the code, rather than ones made of paper.

[Nikademus]

I was never been convinced that the perception that MG's were causing excessive damage was correct.

They don't. One of my PBEM opponents has been strafing my PT's with MG fire. Based on the combat report he thinks he's been devestating them (dozen hits...two dozen hits etc) I havn't had the heart to tell him that my heaviest hit PT's are walking away with only a few SYS points and no FLT.