500 lb Bomb, type dropped by the AAF during WW2


#1

Does anyone know if any information was published about he typical
500 pound bomb in IAA journal?


#2

Why do I ask? I have been watching the PBS series “The War” and find
it fascinating what happened to Europe from the belly of a B17 or B24, or
Brit Lancaster bomber.

What kinds of bombs were dropped on Europe by the allies?
What had the highest production numbers?
Where where they manufacturred? Frankford Arsenal? Redstone?
How did they detonate?, proximity, impact, etc.?

Occasionaly I see articles outlining the finding of these bombs in Germany,
and the EOD crews that deactivate them. Fascinating.

Anybody like to share some information?


#3

Omega556–I wasn’t in W-II, but I was a Weapons Specialist in Viet Nam and loaded 1000’s of bombs on various Fighters and Bombers, mostly F-4 Phantom, but all the way up to B-52’s. Most of the General Purpose bombs were left overs from WW-II.

I don’t know how much detail you want, but here are the basics. There are many types of bombs: General Purpose, Semi-Armor Piercing, Fragmentation, Gas, Cluster, Incendiary, Leaflet, Photoflash, Smoke, etc. I assume you are mostly referring to the common General Purpose bombs and will restrict my comments to these.

The General Purpose bombs came in the following sizes:
250 lb Mk-81, 500 lb Mk-82, 750 lb Mk-117, 1000 lb Mk-83, 2000 lb Mk-84, 3000 lb Mk-118 and a 10,000lb. I can’t recall the Mark number of the 10,000 lb. bomb.

All General Purpose bombs consist of the Bomb Body, usually made of cast iron, Main Charge, the Adapter Booster, Nose Fuze, Tail Fuze, Delay Elements and Tail Fin Assembly. All these elements (except for the Tail Fin Assembly, which is only for aerodynamics) must be present to have a High Order Explosion. If any of them fail you end up with a Low Order Explosion, which means it only cracks the bomb body open and maybe scatters the main charge around which then burns and does not explode. Or you have a Dud with no explosion. The normal chain of events is as follows: The bomb is released from the aircraft, a small wind vane (propeller) on the nose fuze begins to turn and after a certain number of revolutions (different for each type of fuze) the fuze is armed. when the bomb hits the target, the fuze functions after a delay of 0, 0.1 up to about 1 sec. depending on the Delay Element inserted when the fuze was inserted into the bomb. The choice of the type of Delay Element used varied on the target and how much penetration was wanted before the explosion. The fuze sets off the Adapter Booster which in turn sets off the Main Charge. The Main Charge could be several types of explosive such as Amatol or Tritional, etc. The bombs you see in movies with a wide yellow band on the nose are Tritional filled and were probably the most commonly used explosive.

In Viet Nam, the most commonly used bomb was the Mk-117 750 lb. General Purpose. I think in WW-II the 500 lb. MK-82 was the most common one. I might point out here that these weight classifications refer to the approximate weight of the Explosive Charge, not the weight of the bomb. For instance, the Mk-117 750 lb. bomb actually weighed 867 lbs.

As to where they were made, it as stenciled on the side of each bomb, but, to be honest, I never paid any attention to it, so I can not answer this question.


#4

Ron,
I have to correct you. The 500lb Mk-82 is the current low drag GP bomb. The most common WWII bomb was the 500lb GP AN-M64(A1) with M103 and M100 fuzes. As an EOD expert i have defuzed them many times.

Regards,
Vince


#5

Vince–I’ll defer to your information. I was using 40 year old memories. I agree, the Mk-82 was usually used with the Snake-eye Low Drag Fin Assembly. We seldom used the M103 and M100 Fuzes. We normally used the M904 Nose Fuze and M905 Tail fuzes.

Thank you for the correction.


#6

Thank you for all the information! Do you guys know if these fuses, obviously demil fuses are collectable? During WW2 were these made
by US Arsenals or by private sector companies, i.e. GM Corp.?

Again Thanks!


#7

Most fuzes during WW-II were made by privite companies such as Walthem Watch Co. Almost all the fuzes until late in the war were clock-work types and any company that could make small brass gears may have made fuzes. Fuzes for bombs are completely different from fuzes for artillary shells.


#8

Here are the drawings of the most common fuzes from a 1944 manual:



Regards,
Vince


#9

Vince, You mentioned being EOD Expert, How far down below grade do you find these duds penetrated? Being dropped from over 20,000 feet, and weighing
over 500 pounds it must be substantial. Thanks again.


#10

These bombs can be found at various depths. Usually, the bombs make an upward arc path in the soil, so the endpoint could be from some feets to meters under the ground level, depending on the density of the soil, the angle of impact, the mass and the velocity of the bomb.

Regards,
Vince


#11

I did a photo survey a couple of years ago and became very confused by the variety of colors and makings used on 500 pounders in WW2. Yellow bomb bodies and yellow fin assemblies were used until late in the war. I understand that the yellow color was pre- and early war but changed to OD so bomb dumps wouldn’t be so conspicuous. I could find no rhyme or reason for the variations in the yellow rings around the nose fuse or sometimes also around the base fuse. As a military modeler this has been frustrating. Sometimes the stencilling on the body was white, sometimes black.
Dose anybody out there have a manual with the late war standardized marking?


#12

Regarding collectibility, yes some folks do collect bomb fuzes and the bombs as well, when available. I decided at some point that I needed a representative WWII bomb in the collection and felt the AN-M64 500 pound GP bomb was the one to have. After talking with other collectors and vets I came to the conclusion that it was the most produced and most commonly dropped of the WWII U.S. bombs.

It took me about 8 or 10 years to round up all the parts for a complete bomb assembly. That included the body, fin, lock ring, M103 nose fuze, M123 tail fuze, fuze tins, and arming wire, all of which were acquired from different sources one at at time. A genuine GP body (not sheet metal practice type) was the hardest item to find, followed by the WWII style box fin assembly. The body was plaster filled so the weight was nearly cut in half after chipping out about 250 pounds of white junk, not an easy task.

The markings were fairly standardized by late in the war but I agree the photographic record shows a lot of deviance from the norm. I have copies of the TM9-1980 from November, 1944 and its successor in December, 1950. The later edition supercedes at least 17 additional TBs issued late in or after WWII as new and improved bombs, fillers, and fuzes came rapidly late in the war.

By late 1944, the standard markings for GP and other explosive bombs were:

Olive drab with 1" yellow bands at nose and tail for TNT or Amatol filling, two 1" yellow bands at nose and tail for Comp B filling, and three yellow bands (the center one being narrower than the ones on either side) for Tritonal filled bombs. Stencilling was supposed to be in black.

A few years back I decided there should probably be one representative Vietnam bomb in the collection, as well. I had previously missed the opportunity to buy a 750# Napalm fire bomb from a scrapper and regret it to this day. He had some bright aluminum ones and some that were OD painted with red rings on the nose and tail cones, all new in the open sided crates. Just couldn’t figure out how to get one home 800 miles away other than lashed to the roof of the car.

With that opportunity lost, I set my sights on the other definitive Vietnam bomb that Ron mentioned earler, a 500# Mk82 Snake-eye with folding fins and M904 fuze. I’m currently about 5 years into that project with most of the parts here but no time to get it all together and get it painted and hung up in the shop. The biggest hangup now is getting the concrete filler chipped out of the Mk82 body, even tougher and less accessable than the plaster in the AN-M64. Not fun.

The final bomb I’d like to add to the group would be a Paveway I guided bomb but those parts are even tougher to find than the others. If anyone knows of any steering fins, wobbling nose parts, or any other Paveway bits, please drop me a note. To paraphrase CSAEOD, hey, bombs are ammunition too!