Fletcher class DD armored??

[rtrapasso]

ORIGINAL: JeffK

The more I look the less info about armour on a Fletcher class is available, best comment I find is .75" belt armour, is this better or worse than any other class?

Apart from rtrappaso's anecdote about American shipbuilding prowess, which would improve Durability (Fletcher has the highest Durability rating for a DD) I cant find anything except that the Fletcher class was a superb Destroyer design.

i've read this in at least 2 places - i can locate a passing reference to it in Richard Worth's excellent Fleets of World War II on page 275, but i also read the more detailed original recounting of the incident which included the "crying" incident, and, iirc, the fact that were looking at DD construction... i think i read the historical account somewhere on the web, but i am not sure... i will keep looking.

[Reg]

To really resolve this you will probably need to go to the source material, specifically the bill of materials used in the hull construction drawings.

The construction blueprints for the Fletcher class destroyers are available on the net (for a cost) at: Destroyer History Foundation - Store. This is a CD of the original blueprints scanned from microfilm from the National Archives and Records Administration and saved both as TIFF and Adobe Acrobat (PDF) files.

An index of the drawings is available at: Index of Fletcher-class engineering drawings from Bath Iron Works

The information of interest is probably the bill of materials used in drawing 401183T - Outside Plating Details, though 401260T - Outside Plating Stem to Fr. 72, 401172T - Outside Plating fr. 72 to 148 and 401193T - Outside Plating Fr. 148 to Stern are probably also of interest.

As the source material is in the public domain, some of the drawings have already been posted on the net in places like The Blueprints - Plans for Fletcher-class destroyers. Unfortunately I was unable to find on the web the specific drawings listed above which would have detailed the specifications of the hull plating and the details of any dedicated armour plating installations.

I hope you find this information useful for your discussion.

[JWE]

ORIGINAL: CV Zuikaku
were the Fletchers really the world only armoured DDs?? It seems this give them some sort of invunerability in battles vs. japanese DDs. Japanese DD guns are unable to penetrate either deck armour or belt armour of fletcher. In fact, they can not sink them at all unles they hit them with torpedo (which is highly unlikely). I'm seeing japanese DD forces being cut to peaces by single or a pair of escort Fletchers over and over again. Cause of this is allways the same- japanese DD can not penetrate their armour. So were the Fletchers really so immune to japanese DDs??

The OP is quite incorrect. Fletchers are not immune to Japanese DD guns. Japanese guns can penetrate a Fletcher routinely, at every range.

ORIGINAL: JeffK
This is great info, explaining the differences and why its harder to sink a Fletcher than an IJN DD

I am surprised that no other DD rates any level of armour though.

EDIT Gearing class has 5 for both Belt & Deck Armour.
Allen M Sumner which is an improved Fletcher has zero. ??
(Maybe not improved, but "an improvement on", 2 different sites say different things, you just cant trust the internet any more.)

Fletcher was from a BuShips requirement written in 1936, when it was thought desirable to have some protection against small arms fire. The Fletcher belt armor is approximately that of a M2 or M3 halftrack.

Sumner is indeed an improved Fletcher. Improved armament, improved capability, on a similar hull. Beam and length were increased to accommodate the increased topside weight, but by then, people realized armor was useless for a ship of this type, so the frame designations of 17 to 31 went back to regular Ducol, armor plating was removed, and internal welding was extended throughout the midsection.

[CV Zuikaku]

ORIGINAL: JWE

The OP is quite incorrect. Fletchers are not immune to Japanese DD guns. Japanese guns can penetrate a Fletcher routinely, at every range.

ORIGINAL: JeffK
This is great info, explaining the differences and why its harder to sink a Fletcher than an IJN DD

I am surprised that no other DD rates any level of armour though.

EDIT Gearing class has 5 for both Belt & Deck Armour.
Allen M Sumner which is an improved Fletcher has zero. ??
(Maybe not improved, but "an improvement on", 2 different sites say different things, you just cant trust the internet any more.)

Fletcher was from a BuShips requirement written in 1936, when it was thought desirable to have some protection against small arms fire. The Fletcher belt armor is approximately that of a M2 or M3 halftrack.

Sumner is indeed an improved Fletcher. Improved armament, improved capability, on a similar hull. Beam and length were increased to accommodate the increased topside weight, but by then, people realized armor was useless for a ship of this type, so the frame designations of 17 to 31 went back to regular Ducol, armor plating was removed, and internal welding was extended throughout the midsection.

I disagree (and I know this is a rant for you). I've never seen that Japanese DDs "routinely" penetrate armour of the Fletchers at every range. They have a good chanse to penetrate them at ranges below 3000 Yds. I don't remember penetration hits above 3000yds. and I can post a save next time when surface actions happens involving Fletchers and japanese DDs...

ORIGINAL: JWE

Fletcher was from a BuShips requirement written in 1936, when it was thought desirable to have some protection against small arms fire. The Fletcher belt armor is approximately that of a M2 or M3 halftrack.

Sumner is indeed an improved Fletcher. Improved armament, improved capability, on a similar hull. Beam and length were increased to accommodate the increased topside weight, but by then, people realized armor was useless for a ship of this type, so the frame designations of 17 to 31 went back to regular Ducol, armor plating was removed, and internal welding was extended throughout the midsection.

I fail to understand the difference between "hull" and "armour" on DDs and merchants. the hulls of all those ships were made of steel, right?? So they shoul'd all have some armour value. 5mm or 7mm. Armour value of 0 means that hull plates are of standard tickness (whatever that value is) then? And all above that is "armour"?

[kfsgo]

ORIGINAL: CV Zuikaku

I disagree (and I know this is a rant for you). I've never seen that Japanese DDs "routinely" penetrate armour of the Fletchers at every range. They have a good chanse to penetrate them at ranges below 3000 Yds. I don't remember penetration hits above 3000yds. and I can post a save next time when surface actions happens involving Fletchers and japanese DDs...

Yeah, anecdotally 10mm or so of armour seems to be a very significant survivability boost over 0 in daytime. I mostly play the Ironman scenarios (which are...stupid, but in a good way) and the 'new' Japanese and German AMCs (10mm belt/deck/tower) can just about stand up to anything up to and including the older British light cruisers (so ~100mm pen on guns?) at long ranges - I guess that's enough (particularly deck armour, which seems to carry a lot more 'weight' than you'd guess at long ranges - my understanding was always that the gunnery model was built around short-range night fights and started to get a little bit weird at LR, which I guess fits) to at least mitigate most of the damage where rounds occasionally do penetrate. Night-time and/or at short ranges it's less useful (though presumably better than nothing - 4" and below aren't reliable penetrators, but anything above that mostly works)

(incidentally the AMCs are terrifying up close, too, but that's less to do with armour and more with the dozens of torpedoes they puke out)

I fail to understand the difference between "hull" and "armour" on DDs and merchants. the hulls of all those ships were made of steel, right?? So they shoul'd all have some armour value. 5mm or 7mm. Armour value of 0 means that hull plates are of standard tickness (whatever that value is) then? And all above that is "armour"?

Well, there's steel and there's steel - there's a whole range in terms of combinations of how brittle/hard/soft/flexible the stuff is that you can go through; your average merchant is going to be made out of pretty soft (ie cheap) stuff, your average battleship not so much.

[Onime No Kyo]

ORIGINAL: CV Zuikaku

I disagree (and I know this is a rant for you). I've never seen that Japanese DDs "routinely" penetrate armour of the Fletchers at every range. They have a good chanse to penetrate them at ranges below 3000 Yds. I don't remember penetration hits above 3000yds. and I can post a save next time when surface actions happens involving Fletchers and japanese DDs...

Here's a perfect example of why I love these threads.

Leaving all this, "my winky is bigger" stuff aside, I think the various posters have provided enough historical documentation that the Fletchers did have "thicker skin" however you'd like to call it, be it armor, hull or whatever else.

So since you have a point to make, please do everyone a favor and spend some time with the DB editor, play some test combats and post the results. Then you will have some actual data on whether or not a Japanese DD will penetrate a Fletcher's armor outside of 3000m. If they do not, then I'm sure that most of these folks will agree that we do, indeed have a problem. Then we can stop all this back and forth and discuss actual test results.

[stuman]

ORIGINAL: Onime No Kyo

ORIGINAL: CV Zuikaku

I disagree (and I know this is a rant for you). I've never seen that Japanese DDs "routinely" penetrate armour of the Fletchers at every range. They have a good chanse to penetrate them at ranges below 3000 Yds. I don't remember penetration hits above 3000yds. and I can post a save next time when surface actions happens involving Fletchers and japanese DDs...

Here's a perfect example of why I love these threads.

Leaving all this, "my winky is bigger" stuff aside, I think the various posters have provided enough historical documentation that the Fletchers did have "thicker skin" however you'd like to call it, be it armor, hull or whatever else.

So since you have a point to make, please do everyone a favor and spend some time with the DB editor, play some test combats and post the results. Then you will have some actual data on whether or not a Japanese DD will penetrate a Fletcher's armor outside of 3000m. If they do not, then I'm sure that most of these folks will agree that we do, indeed have a problem. Then we can stop all this back and forth and discuss actual test results.

Well mine is.

[Bullwinkle58]

ORIGINAL: stuman


[Well mine is.

Prove it.

Ok, well, don't. [:)]

[Onime No Kyo]

ORIGINAL: stuman

ORIGINAL: Onime No Kyo

ORIGINAL: CV Zuikaku

I disagree (and I know this is a rant for you). I've never seen that Japanese DDs "routinely" penetrate armour of the Fletchers at every range. They have a good chanse to penetrate them at ranges below 3000 Yds. I don't remember penetration hits above 3000yds. and I can post a save next time when surface actions happens involving Fletchers and japanese DDs...

Here's a perfect example of why I love these threads.

Leaving all this, "my winky is bigger" stuff aside, I think the various posters have provided enough historical documentation that the Fletchers did have "thicker skin" however you'd like to call it, be it armor, hull or whatever else.

So since you have a point to make, please do everyone a favor and spend some time with the DB editor, play some test combats and post the results. Then you will have some actual data on whether or not a Japanese DD will penetrate a Fletcher's armor outside of 3000m. If they do not, then I'm sure that most of these folks will agree that we do, indeed have a problem. Then we can stop all this back and forth and discuss actual test results.

Well mine is.

And I suppose it has 18 points of armor too. [8|]

[Yakface]

Could 18mm of plate really stop a 5" shell?

[JWE]

ORIGINAL: Yakface
Could 18mm of plate really stop a 5" shell?

No. It doesn't.

Define a meaningful test.
6 identical TFs each with 6 identical Asashios, facing;
6 identical TFs each with 3 identical Fletchers and 3 identical Bensons;
Each side’s TFs spaced apart by 5 hexes in ‘x’ and each side is displaced from the other by 5 hexes in “y”;
Each side’s index TF meets its opponent in the middle;
Weather clear, daylight, open ocean;
Engagement ranges between 8000 and 17000 yards;
Evaluate damage for each ship vs number of hits taken by the ship;
Determine average amount of damage (Sys, Flt, Eng) inflicted per hit;
Run the test 6 times, in order to obtain 36 engagement results for identically constituted engagements;
Since all parameters are identical, apply statistical analysis to the results.
.Sys ... Flt .... Eng - Fletcher
7.80 - 3.01 - 1.89 - Mean
3.36 - 1.10 - 1.26 - Sigma
2.40 - 0.78 - 0.91 - Deviation
1.01 - 0.03 - 1.45 - Skewness

.Sys ... Flt .... Eng - Benson
7.91 - 2.91 - 1.95 - Mean
3.76 - 1.24 - 1.36 - Sigma
2.52 - 0.94 - 1.01 - Deviation
0.98 - 0.16 - 1.33 – Skewness

There is no difference in either the amount, type, or degree of damage taken by an “armored” Fletcher verses an “unarmored” Benson, against an identical array of Japanese DD guns. In fact, looking at FltDam (where belt “armor” should have an impact) the skewness is small, indicating a near “normal” distribution, with Fletchers and Bensons having damn near identical responses to a Japanese DD gun hitting the hull.

[Tijanski]

Horray!!! That is what I like about this forum. Every now and then somebody who knows what they are talking about makes an answer and makes it clear for the regular people to work with.

[stuman]

ORIGINAL: Tijanski

Horray!!! That is what I like about this forum. Every now and then somebody who knows what they are talking about makes an answer and makes it clear for the regular people to work with.

I have found him to be good at that [:)]

[Yakface]

ORIGINAL: JWE

ORIGINAL: Yakface
Could 18mm of plate really stop a 5" shell?

No. It doesn't.

Define a meaningful test.
6 identical TFs each with 6 identical Asashios, facing;
6 identical TFs each with 3 identical Fletchers and 3 identical Bensons;
Each side’s TFs spaced apart by 5 hexes in ‘x’ and each side is displaced from the other by 5 hexes in “y”;
Each side’s index TF meets its opponent in the middle;
Weather clear, daylight, open ocean;
Engagement ranges between 8000 and 17000 yards;
Evaluate damage for each ship vs number of hits taken by the ship;
Determine average amount of damage (Sys, Flt, Eng) inflicted per hit;
Run the test 6 times, in order to obtain 36 engagement results for identically constituted engagements;
Since all parameters are identical, apply statistical analysis to the results.
.Sys ... Flt .... Eng - Fletcher
7.80 - 3.01 - 1.89 - Mean
3.36 - 1.10 - 1.26 - Sigma
2.40 - 0.78 - 0.91 - Deviation
1.01 - 0.03 - 1.45 - Skewness

.Sys ... Flt .... Eng - Benson
7.91 - 2.91 - 1.95 - Mean
3.76 - 1.24 - 1.36 - Sigma
2.52 - 0.94 - 1.01 - Deviation
0.98 - 0.16 - 1.33 – Skewness

There is no difference in either the amount, type, or degree of damage taken by an “armored” Fletcher verses an “unarmored” Benson, against an identical array of Japanese DD guns. In fact, looking at FltDam (where belt “armor” should have an impact) the skewness is small, indicating a near “normal” distribution, with Fletchers and Bensons having damn near identical responses to a Japanese DD gun hitting the hull.

So from the test it appears the original post:

"It seems this give them some sort of invunerability in battles vs. japanese DDs. Japanese DD guns are unable to penetrate either deck armour or belt armour of fletcher. In fact, they can not sink them at all unles they hit them with torpedo"

is just plain wrong?

[d0mbo]

It appears so.
 

[Sredni]

It would be interesting to see the japanese DD's results from that test.