Armor Plate and Self Sealing Tanks - Aircraft of World War II

syscom3 · 05-11-2009, 11:35 AM

Many people (myself included) talk about the following. But you know, maybe we really don't understand it. I know its different from airplane to airplane, but its probably similar to one degree or another.

For armor protection for the cockpit seats, just how much weight does the armor weigh, and what type of ballistic protection does it afford [like how much weight would the Zero gain if they used armor seat protection]?

What other parts of an aircraft also gets armor protection? Linkages? Fuel line junctions?

For self sealing fuel tanks, just what exactly is the weight and volume penalty?

drgondog · 05-11-2009, 12:29 PM

Quote:

Originally Posted by syscom3

Many people (myself included) talk about the following. But you know, maybe we really don't understand it. I know its different from airplane to airplane, but its probably similar to one degree or another.

For armor protection for the cockpit seats, just how much weight does the armor weigh, and what type of ballistic protection does it afford [like how much weight would the Zero gain if they used armor seat protection]?

What other parts of an aircraft also gets armor protection? Linkages? Fuel line junctions?

For self sealing fuel tanks, just what exactly is the weight and volume penalty?

The fighter armor plate doctrines were all over the place and weight penalties ranged from ~ 45 pounds in a P-51 (1/4" to 5/16" hardened steel aft of seat - only) to 260 pounds for the later model P-39D's. The P-63 cut it down to ~120 pounds. The P-47 was around the 60 pound - all aft of seat.

The Spit (most) had 8mm armor and all aft at about 60 pounds. The IL-2 was at top extreme and the FW 190A-8 had back/side/front armor plus 30mm glass on front windshield (and behind head aft of seat?) This ship also had some cowl armor to provide additional protection to the engine from head on 50 cal fire

The LW doctrine IIRC was geared to stopping a 50 caliber round at 200 yards to protect the pilot

Self sealing tanks usually had a single layer (later a double layer) of rubber/neoprene type lining on outside of cell - usually targeted to withstand a 12.7 ball/api hit.

None of the self sealing tanks were very effective against an explosive 20mm in context of rupture.

comiso90 · 05-11-2009, 01:18 PM

I imagine that when the self sealing tanks took hits, they were drained and properly patched after the mission. The self sealing feature was effective enough to get the pilot home but was not considered an actual seal.. correct?

.

syscom3 · 05-11-2009, 01:50 PM

How much volume in the fuel tank is devoted to the compounds that made it self sealing?

drgondog · 05-11-2009, 02:03 PM

Quote:

Originally Posted by syscom3

How much volume in the fuel tank is devoted to the compounds that made it self sealing?

The only one example I have looked at was about 1/4" thick layer of what seemed to be two laminates (hard to see)

renrich · 05-13-2009, 05:35 PM

According to Dean, "America's Hundred Thousand" the Wildcat held 160 gallons of internal fuel in unprotected tanks and 147 gallons in protected tanks. In the F4F3 the armor weighed 155 pounds, F4F4, 165 pounds and FM2, 223 pounds.

syscom3 · 05-13-2009, 06:51 PM

It doesn't seem that armor plate for the cockpit doesn't add to much weight. Ditto with the self sealing tanks.

I wonder why the Japanese came to different conclusions.

BombTaxi · 05-13-2009, 06:55 PM

I think the Japanese were perhaps hoping to outrun or out-turn anything heavily-armed enough to shoot them down - a bit like the battlecruiser vs battleship debate at sea. This certainly seemed to work for them in the very earliest days in the war, but they obviously didn't think about what would happen when the enemy sussed thier tactics and developed their own responses...

A further thought - at the time the Zero was designed, most a/c were packing 2-8 rifle calibre MGs. 50s and 20mm cannon were rare, so perhaps the Japanese incorrectly anticpated the kind of punishment the Zero et al. would receive?

Soren · 05-14-2009, 05:31 PM

The Japanese were on to something if they could but have kept the speed & climb rate of their a/c to either the same level or higher than that of their enemies.

The Ki-84 was approaching this, and with better built engines, fuels and better trained pilots it could've proven superior to most Allied fighters.

BombTaxi · 05-14-2009, 05:45 PM

The lack of trained pilots later in the war really showed up the deficiencies of Japanese aircraft. The Marianas Turkey Shoot was just one example of how easy it was for poorly trained pilots in substandard aircraft to be butchered by better aircraft flown with greater skill...

FLYBOYJ · 05-14-2009, 07:06 PM

Quote:

Originally Posted by syscom3

It doesn't seem that armor plate for the cockpit doesn't add to much weight. Ditto with the self sealing tanks.

I wonder why the Japanese came to different conclusions.

You'd be surprised how much 150 - 300 pounds affects performance.

renrich · 05-15-2009, 07:41 AM

FB nailed it. In an AC like the early A6Ms, with less than 1000 HP, a few hundred pounds was a big factor on performance. An AC like the Wildcat, with around 1200 Hp, when armor, self sealing tanks, folding wings and extra guns were added had it's performance substantially degraded. Later in the war, the A6M got more HP, which degraded it's range, but bigger MGs, SS tanks and armor kept the airplane from achieving better performance.

tomo pauk · 05-15-2009, 02:29 PM

Quote:

Originally Posted by BombTaxi

I think the Japanese were perhaps hoping to outrun or out-turn anything heavily-armed enough to shoot them down - a bit like the battlecruiser vs battleship debate at sea. This certainly seemed to work for them in the very earliest days in the war, but they obviously didn't think about what would happen when the enemy sussed thier tactics and developed their own responses...

A further thought - at the time the Zero was designed, most a/c were packing 2-8 rifle calibre MGs. 50s and 20mm cannon were rare, so perhaps the Japanese incorrectly anticpated the kind of punishment the Zero et al. would receive?

Hi,
A humble disagreement about the anticipated threats. The P. 24, I-16, Ms-406, P-38, P-39, Whirlwind, Bf-110, Fw-187 and Bf-109E-3 carried canons, and were widely advertised as such.

And the 2 LMGs were destroying bombers, let alone the fighters. At least above Poland.

syscom3 · 05-15-2009, 03:50 PM

Quote:

Originally Posted by renrich

...... An AC like the Wildcat, with around 1200 Hp, when armor, self sealing tanks, folding wings and extra guns were added had it's performance substantially degraded. .....

How much additional weight did that take?

For the Zero, I dont think the addition of a 100 pound armor slab behind the seat would make much difference.

renrich · 05-15-2009, 04:24 PM

The empty weight of the F4F3 was 5426 pounds, the F4F4 was 5778.9 pounds. The armor in the F4F4 was 7.5 pounds more than the F4F3. I would think that the SS tanks would not weigh more than the unprotected when they were full because of the gasoline displaced. The 352 pounds difference must have been mostly the folding wings and the two extra MGs. The early F4F3 lacked armor which weighed 155 pounds, so the startling difference in performance can be chalked up to a difference in weight of around 500 pounds.

05-11-2009, 11:35 AM	#1
syscom3 Senior Member Join Date: Jun 2005 Location: Orange County, CA Posts: 10,814	Armor Plate and Self Sealing Tanks Many people (myself included) talk about the following. But you know, maybe we really don't understand it. I know its different from airplane to airplane, but its probably similar to one degree or another. For armor protection for the cockpit seats, just how much weight does the armor weigh, and what type of ballistic protection does it afford [like how much weight would the Zero gain if they used armor seat protection]? What other parts of an aircraft also gets armor protection? Linkages? Fuel line junctions? For self sealing fuel tanks, just what exactly is the weight and volume penalty? __________________ "Pilot to copilot..... what are those mountain goats doing up here in the clouds?"

05-11-2009, 01:18 PM	#3
comiso90 Senior Member Join Date: Dec 2006 Location: FL Posts: 3,530	I imagine that when the self sealing tanks took hits, they were drained and properly patched after the mission. The self sealing feature was effective enough to get the pilot home but was not considered an actual seal.. correct? . __________________ http://www.BOOKSonWAR.com/ .

05-11-2009, 01:50 PM	#4
syscom3 Senior Member Join Date: Jun 2005 Location: Orange County, CA Posts: 10,814	How much volume in the fuel tank is devoted to the compounds that made it self sealing? __________________ "Pilot to copilot..... what are those mountain goats doing up here in the clouds?"

05-13-2009, 05:35 PM	#6
renrich Senior Member Join Date: Jan 2007 Location: Montrose, Colorado Posts: 3,525	According to Dean, "America's Hundred Thousand" the Wildcat held 160 gallons of internal fuel in unprotected tanks and 147 gallons in protected tanks. In the F4F3 the armor weighed 155 pounds, F4F4, 165 pounds and FM2, 223 pounds. Last edited by renrich; 05-14-2009 at 08:03 AM.

05-13-2009, 06:51 PM	#7
syscom3 Senior Member Join Date: Jun 2005 Location: Orange County, CA Posts: 10,814	It doesn't seem that armor plate for the cockpit doesn't add to much weight. Ditto with the self sealing tanks. I wonder why the Japanese came to different conclusions. __________________ "Pilot to copilot..... what are those mountain goats doing up here in the clouds?"

05-13-2009, 06:55 PM	#8
BombTaxi Senior Member Join Date: Nov 2004 Location: Brownhills, W. Mids, UK Posts: 1,189	I think the Japanese were perhaps hoping to outrun or out-turn anything heavily-armed enough to shoot them down - a bit like the battlecruiser vs battleship debate at sea. This certainly seemed to work for them in the very earliest days in the war, but they obviously didn't think about what would happen when the enemy sussed thier tactics and developed their own responses... A further thought - at the time the Zero was designed, most a/c were packing 2-8 rifle calibre MGs. 50s and 20mm cannon were rare, so perhaps the Japanese incorrectly anticpated the kind of punishment the Zero et al. would receive? __________________ Good generals think about tactics. Great generals think about logistics. "If freedom is to be saved and enlarged, poverty must be ended. There is no other solution." - Nye Bevan "Any man's death diminishes me, because I am involved in mankind; and therefore never send to ask for whom the bell tolls; it tolls for thee" - John Donne, Meditation XVII

05-14-2009, 05:31 PM	#9
Soren Banned Join Date: Feb 2005 Posts: 6,625	The Japanese were on to something if they could but have kept the speed & climb rate of their a/c to either the same level or higher than that of their enemies. The Ki-84 was approaching this, and with better built engines, fuels and better trained pilots it could've proven superior to most Allied fighters.

05-14-2009, 05:45 PM	#10
BombTaxi Senior Member Join Date: Nov 2004 Location: Brownhills, W. Mids, UK Posts: 1,189	The lack of trained pilots later in the war really showed up the deficiencies of Japanese aircraft. The Marianas Turkey Shoot was just one example of how easy it was for poorly trained pilots in substandard aircraft to be butchered by better aircraft flown with greater skill... __________________ Good generals think about tactics. Great generals think about logistics. "If freedom is to be saved and enlarged, poverty must be ended. There is no other solution." - Nye Bevan "Any man's death diminishes me, because I am involved in mankind; and therefore never send to ask for whom the bell tolls; it tolls for thee" - John Donne, Meditation XVII

05-15-2009, 07:41 AM	#12
renrich Senior Member Join Date: Jan 2007 Location: Montrose, Colorado Posts: 3,525	FB nailed it. In an AC like the early A6Ms, with less than 1000 HP, a few hundred pounds was a big factor on performance. An AC like the Wildcat, with around 1200 Hp, when armor, self sealing tanks, folding wings and extra guns were added had it's performance substantially degraded. Later in the war, the A6M got more HP, which degraded it's range, but bigger MGs, SS tanks and armor kept the airplane from achieving better performance.

05-15-2009, 04:24 PM	#15
renrich Senior Member Join Date: Jan 2007 Location: Montrose, Colorado Posts: 3,525	The empty weight of the F4F3 was 5426 pounds, the F4F4 was 5778.9 pounds. The armor in the F4F4 was 7.5 pounds more than the F4F3. I would think that the SS tanks would not weigh more than the unprotected when they were full because of the gasoline displaced. The 352 pounds difference must have been mostly the folding wings and the two extra MGs. The early F4F3 lacked armor which weighed 155 pounds, so the startling difference in performance can be chalked up to a difference in weight of around 500 pounds.

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