Crew protection on heavy bombers?

[Koopernic]

The -24 doesn't seem to feature as much armor, but it's hard to tell. Also, no specifics on thickness for either one:

View attachment 618626

Note that the USAAF often had additional "after market" armor fitted.

There is a statistic around that it took over an average of 20 x 20mm hits to bring down a B17 when fired from the rear, Armour probably made sure that was 20 not 12 hits and that crew casualties halved. Besides armour there was paper mache to absorb splinters.

 

[Thumpalumpacus]

Note that the USAAF often had additional "after market" armor fitted.

There is a statistic around that it took over an average of 20 x 20mm hits to bring down a B17 when fired from the rear, Armour probably made sure that was 20 not 12 hits and that crew casualties halved. Besides armour there was paper mache to absorb splinters.

Looking at pics of shot-up -17s, I'm convinced that quite a bit of that resilience, that toughness, can be attributed to a rugged build, as well as armor.

 

[special ed]

While in the USAF in 1960 I met a veteran at the VA hospital in Denver who had been a fighter pilot in 1918 and wounded. His catch phrase was, "Somebody stole my stove lid". It seems when the Fokker D.VII got into combat the engine had enough power to dive on his opponent and pull up under him, hang momentarily, and fire letting the adversary fly through the gunfire. The stove lid from the wood burning kitchen stoves became prime armor. The pilots sat on them while flying and kept them under their pillows at night. If someone drank too much, his stove lid could be stolen. The veteran had been shot with a single 7.92mm round through his seat directly into his spine. He said he was lucky to fly back and land. What I liked about his story was, since he was in a wheelchair from 18 years old, the VA transported him to Florida in winter and back to Denver for summer because he had no relatives when he enlisted.

 

[SpicyJuan11]

Note that the USAAF often had additional "after market" armor fitted.

Do you know how much and at what thickness? It would be interesting to know the performance loss

(BTW, did you not want to PM anymore? Haven't heard from you in awhile tbh)

 

[pbehn]

Do you know how much and at what thickness? It would be interesting to know the performance loss

(BTW, did you not want to PM anymore? Haven't heard from you in awhile tbh)

The performance loss would be in fuel consumption, or time to climb, you have to maintain the same cruising speed as others.

 

[Greg Boeser]

When we speak of aftermarket armor, it usually means that the crew has brought improvised armor plate aboard. usually an armor plate to sit or kneel on. Someone posted on another thread photos of unit wide field modifications to B-25s in the MTO.
B-25Cs and Ds had factory installed armored bulkheads between the nose compartment and cockpit, the cockpit and bomb bay, and the tail section and gunners' compartment. Contrast that with the B-26 which had armored seat backs for bombardier, pilot and co-pilot, navigator and radioman. The turret gunner was protected by an armored skirt attached to the front of the turret, the waist gunner had to make do with kneeling on some armor plate in the floor when firing the guns. The early B-26 and B-26A, just had a small folding gun shield for the tail gunner, but in the B-26B and later versions the tail gunner had the benefit of a substantial armored bulkhead and bullet proof glass to protect from rear attacks. Armor was also placed to protect vital components onboard like the oil tanks, fuel transfer pump, etc.

 

[tyrodtom]

While in the USAF in 1960 I met a veteran at the VA hospital in Denver who had been a fighter pilot in 1918 and wounded. His catch phrase was, "Somebody stole my stove lid". It seems when the Fokker D.VII got into combat the engine had enough power to dive on his opponent and pull up under him, hang momentarily, and fire letting the adversary fly through the gunfire. The stove lid from the wood burning kitchen stoves became prime armor. The pilots sat on them while flying and kept them under their pillows at night. If someone drank too much, his stove lid could be stolen. The veteran had been shot with a single 7.92mm round through his seat directly into his spine. He said he was lucky to fly back and land. What I liked about his story was, since he was in a wheelchair from 18 years old, the VA transported him to Florida in winter and back to Denver for summer because he had no relatives when he enlisted.

I've heard a different version.
The tale of the cook stove lids being used as armor is also from the very start of WW1.
Everybody flying was nervous about flying over troops, they were aware that anyone down there could fire straight up, and get you where it would really hurt.
And early in the war, the aircraft weren't flying so high, it was a real, but remote possibility.
Sort of a primal fear, even I sat on a extra flak jacket in Vietnam.

Unless those stove top lids were a lot thicker than the one's I'm familiar with, they wouldn't stop anything, unless it was almost spent anyway.
And neither would my extra flak jacket.

 

[Greg Boeser]

Improvised armor never goes out of style. When I was in Iraq in 2003, most US military vehicles were soft sided, so there were a lot of unique adaptations. I saw everything from boilerplate welded to the sides of humvees to racks stuffed with what looked to me like slices of tire treads. I personally rode with a unit of the Florida National Guard which had strung their old nylon flak jackets on 550 cord and lined their humvees with them. (I wore mine.)

 

[fastmongrel]

Wouldn't a stove lid be made of cast iron or stamped mild steel. I think an extra pair of underwear would be just as good.

 

[MIflyer]

My next door neighbor flew B-25C/D in the Med. He said that on his airplane he added two sheets of steel, one on either side of the pilot's seat. That way he could sit back between the sheets and "drive." One time he was flying and they were taking flak, and his new co-pilot stuck his head around the sheet of steel and said, "How bad is this flak? Heavy, light or mediocre?"

They also added tail gun positions to their airplanes, somewhat smaller versions of the factory ones seen on the later H's and J's.

 

[special ed]

My Grand Mother's stove had been a wood burner but by the time I appeared it had been converted to Kerosene with a bottle inverted into a receptacle much like some modern water coolers where the 5 gallon bottle is up ended into the cooler. It is a wonder that more houses didn't burn in those days. The stove was eventually converted to natural gas before finally being replaced. As I Remember, there were two sizes of heavy cast iron lids. I seem to remember the smaller size was about 5 pounds.

 

[Koopernic]

Do you know how much and at what thickness? It would be interesting to know the performance loss

(BTW, did you not want to PM anymore? Haven't heard from you in awhile tbh)

US aircraft aren't my special topic but I do like to read about them. I just asked a question in PM.

 

[fastmongrel]

seem to remember the smaller size was about 5 pounds.

Five pounds of cast iron shrapnel, cast iron shatters like glass when its hit hard.

 

[pararaftanr2]

I think the "flight suit" of that era was in reality an armored forces coverall.

In the photo of the B-24 crewmember wearing a flak suit, posted above, he is wearing the two-piece (jacket and trousers) F-2 electrically heated flight suit. It was designed so the inner jacket and trousers, which contained the electric wiring, was removable. If shot down and captured, the outer jacket and trousers could be worn alone as a conventional uniform. The suit was manufactured in both dark olive drab, for officers, and a lighter shade of olive drab, for enlisted men. In practical use however, this distinction was not always followed. Another variation was the presence, or lack of, the white fleece collar, as seen in the photo. Note in the photo below, from the suit instructions, the jacket lacks a fleece collar.

 

[Joe Broady]

The March 1942 B-24 C/D manual says only that "armor plate is provided for all crew members."

The March 1945 manual covers multiple late war models and has more detail, especially for the B-24 L/M. The nose turret has 2" armor glass and a 3/8" front plate. A 3/8" aluminum belly plate is beneath the bombardier position. Behind each pilot is a 3/8" armor plate. The top turret has 1/2" front armor. The ball turret has 1/4" back armor and 5/16" on seat. The tail gun position is surrounded with a 1/8" aluminum alloy flak curtain on bottom and sides and the illustration appears to show armor glass too.

The book says in late airplanes "flak curtains will be installed in lieu of armor plate behind the pilot's and copilot's seats."

References:

"Handbook of Operation and Flight Instructions for the Models B-24C and B-24D," March 7, 1942.

"Pilot's Flight Operating Instructions for Army Models B-24G, H, J, and M," 25 March 1945. This manual shows a great elaboration in technical detail compared to three years earlier. The quantity of performance charts such as takeoff distance and cruise control would almost do justice to a B-29.

 

[Greyman]

Sounds like the US bombers removed armour as time went on as well (from the fantastic PDF posted by JDCAVE here: Instructional documents on Box Formation flying in the USAAF 8th Airforce? (page 180)

Aircraft
B-17 & B-24

Modification
Flak curtains introduced as a substitute for armor plate

Date Accomplished
Late 1943 & Early 1944

Reason for Modification
To reduce the weight of aircraft

Remarks
Flak curtains were hung in strategic areas of the aircraft and depended upon absorption of impact of the flak by the elasticity of the curtains

 

[pararaftanr2]

The March 1942 B-24 C/D manual says only that "armor plate is provided for all crew members."

The March 1945 manual covers multiple late war models and has more detail, especially for the B-24 L/M. The nose turret has 2" armor glass and a 3/8" front plate. A 3/8" aluminum belly plate is beneath the bombardier position. Behind each pilot is a 3/8" armor plate. The top turret has 1/2" front armor. The ball turret has 1/4" back armor and 5/16" on seat. The tail gun position is surrounded with a 1/8" aluminum alloy flak curtain on bottom and sides and the illustration appears to show armor glass too.

The book says in late airplanes "flak curtains will be installed in lieu of armor plate behind the pilot's and copilot's seats."

References:

"Handbook of Operation and Flight Instructions for the Models B-24C and B-24D," March 7, 1942.

"Pilot's Flight Operating Instructions for Army Models B-24G, H, J, and M," 25 March 1945. This manual shows a great elaboration in technical detail compared to three years earlier. The quantity of performance charts such as takeoff distance and cruise control would almost do justice to a B-29.

If anyone is unifiliar with what a "flak curtain" is, here's one in place. They were rectangular in shape and the armor scales were covered with olive drab cloth, having grommets around
the edges so they could be tied to the frame of the aircraft.

Another example, of a slightly different design, installed behind the co-pilot's seat of a B-17. It's hard to see in the photo, but the stenciled information on the back of the curtains says " curtain, gunfire fragment resistant". Both images from Fold3.com.