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US 10 000 LB bomb

MINENAZ16

Well-Known Member
Ordnance approved
Hello,

I found (again) with google, picture of an US bomb with markings 10 000lb.

Does anyone have information on this bomb ?

Regards

10 000LB LC.jpg
 
That is an ANM-56, 4,000 pound, light case, high capacity general purpose bomb.

I believe the next size up is the T-14 at 22,000 pounds.
 
Yes, that's what I thought at first but in documentations the length (overall) of the 4000lb Lc is 117.5in (2m98).
I don't know the height of the roof but this bomb seems to be bigger than 4000lb.

Other pictures with people to compare.

Regards

10000LB.jpg10_000Lb_bomb_2.jpg
 
The casing in question is a World War 2 era, 4,000 pound bomb with a period box type fin.

I have been collecting casings for eight years and have never heard of a 10,000 pound ANM casing.

Here is a person beside a 2,000 pound ANM casing.

10242003lg.jpg
 
I did some homework.

These are all the same cases.

8888.jpg999.jpg

Even if the woman in the vintage picture is taller than average, in order for this to be a 10,000 pound casing, the casing would be double plus the size of the ones pictured. The M38a2 practice bomb at her feet is something in the order of 48 inches tall, which would put this casing at 11 feet. Speaking of feet, the man's shoes represent one foot. The shoes in the third picture measure a further distance because the casing is further in the background than the one in the forth image.
 
Furthermore, if this was a 10,000 pound casing; in order for the size to stay the same, a considerable amount of filler would be lost in favor for casing weight.

If this were the case, the casing would become a solid steel, cast SAP (semi armor piercing) or AP (armor piercing) bomb which would not be welded together as seen in all of the above images.
 
The M121 bomb was a very large air dropped bomb used by the U.S. military during the Vietnam War. Originally developed from the British world war II era Tallboy bomb to be dropped from the Convair B-36 bomber, it weighed 10,000 lb (4,500 kg) and contained an 8,050 lb (3,650 kg) Tritonal warhead. Production of the M121 ceased in 1955, but stockpiles were retained until the Vietnam War. I am still looking for better pictures. The not so clear ones show what looks like a big demo bomb with the fins removed, and replaced with the parachute.

The Blu 82 replaced it


 
M121 (T56) Demolition Bomb
Project Combat Trap
Project Commando Vault


The M121 10,000 pound demolition bomb, sometimes called the "Earthquake" bomb, was more often referred to as the "Grand Slam" bomb, a totally misleading nickname. Grand Slam had been a British codename during World War II for a similar 22,000 pound weapon. During the early years of the Cold War, the US Air Force used "Grand Slam" as a code name of a highly classified modification project strictly concerned with atomic matters. The "Grand Slam" modifications would allow the Convair B-36 to carry atomic bombs, which the Air Force believed might weigh more than 40,000 pounds. Modified B-36 bomb bays could also fit the 42,000 pound T12 demolition bomb. Since the 10,000-pound M121, when properly dropped, could inflict the damage of a 40,000-pound bomb, curiosity and rumors most likely explained the ensuing confusion. As a matter of fact, the "Grand Slam" designation was also loosely applied to other conventional bombs of the M121 category. The US Air Force acquired a number of M121s, initially given the experimental designation T56, and similar weapons as a conventional alternative to nuclear weapons for heavy bombers such as the B-36.The M121 bombs found new life after Military Assistance Command, Vietnam began investigating methods for explosively clearing helicopter landing zones in heavy jungle terrain. The extensive use of helicopters in the Republic of Vietnam meant that landing zones had to be rapidly constructed in heavily forested areas, like those surrounding the Kim Son and Soui Ca valleys. Engineers in Vietnam were thus challenged to reduce the landing zone construction time, in order to meet the needs of the quickly shifting tactical situation. Landing zone requirements ranged from the hasty construction of a helicopter pad, from which to provide emergency resupply or medical evacuation, to the development of large landing zones, able to handle sufficient aircraft to support battalion or brigade operations.Experience gained by engineer units in Vietnam led to the development of landing zone construction kits that contained the necessary tools and demolitions to prepare a landing zone for one aircraft. If the engineer team could be landed near the new construction site, they would rappel from the helicopter or climb down rope ladders. W hen sufficient area had been cleared, air-portable construction equipment or additional tools and demolitions were lifted in to expand the new landing zone.Large high explosive detonations would dear trees and brush from an area, leaving a zone suitable for helicopter landings. An added benefit was that the overpressure would often detonate mines and boobytraps. As applied to the helicopter landing zone problem, it was clear that the high explosives had to be detonated at some height above the ground to avoid cratering, for 2 reasons. First, the ground should not be disturbed so much as to make it difficult or impossible for a helicopter to land safely. Second, even shallow bomb penetration would result in the blast being directed at an upward angle, greatly reducing the total surface area affected by the blast. The first attempts to use aircraft bombs to achieve this began in late 1967 using a modified M118 bomb. However, the setup, developed as part of Project Combat Trap, still had to be emplaced on the ground by engineers. MACV subsequently directed Seventh Air Force to develop the capability of delivering specialized ordnance for clearing such heavily-jungled areas. Seventh Air Force conducted tests with M118 and Mk 84 bombs using fuze extenders. The Armament Development and Test Center at Eglin Air Force Base, Florida conducted tests using BLU-1B/B bomb casings filled with explosives.The US Army began tests of the M121 bomb at Fort Benning, Georgia. M121s had been found in storage, having been developed in 1954 for the B-36 and then never used operationally. In the tests, an M121 was statically detonated in a wooded artillery range. The bomb was emplaced by an Army CH-54 "Flying Crane" helicopter at a height corresponding to that planned for an airdrop burst and was statically detonated on 10 June 1968. When the smoke had cleared, the area was surveyed, and an Army UH-1 helicopter was flown in to land in the cleared area. The zone created had usable space approximately 100 feet in diameter.While the results were satisfactory, practical considerations demanded aerial delivery for any employment in Southeast Asia. As a result, the M121 was modified and redesigned to contain 2 independent fuzing systems, one forward and one aft, as well as a stabilization parachute. Continued testing with inert bombs on western test ranges, using both the Army's CH-54 helicopter and the Air Force's C-130, demonstrated the feasibility of using the latter as a "bomber," but eventually resulted in a decision to abandon further employment of the big helicopter in this role.Subsequently, preparations were made to deliver M121s to South Vietnam for operational tests. In December 1968, the 834th Air Division, headquartered at Tan Son Nhut Air Base in South Vietnam conducted a 10-weapon operational test of the M121 in South Vietnam as part of Combat Trap. For air drop, the bombs were fitted with a standard nose fuze and M1 fuze extender (a tube packed with explosives, which was attached to a detonator inside the bomb), to provide for a burst height of about 3 feet. The contact nose fuze was protected with a brush deflector, a locally designed iron basket to enable the bomb to penetrate the tops of the trees without detonation. The sequence of events for employing the weapon involved a number of actions. As the bomb separates from its carrier, pins were pulled from both nose and tail fuzes, and the drogue chute was deployed. The fuzes were armed at a that time to provide safe separation, and the chute quickly stabilized the trajectory of the bomb. Penetrating the top of the canopy, the brush deflector pushed aside the smaller branches and was crushed by the impact with the earth. The fuze then detonated the explosive in the extender tube, which in turn ignited the booster in the bomb, which set off the main charge. All this occurred rapidly enough to ensure that the detonation would occur with the nose of the bomb only slightly less than 3 feet above ground level.The 10,000-pound M121 bomb seemed to work much better in the Southeast Asia jungle than in the Georgia pine woods. The typical Combat Trap helicopter landing zones consisted of an area about 120 feet in diameter completely devoid of vegetation, including stumps. Beyond that, the height of the remaining stumps gradually increased, so that at some 70 feet from ground zero their height was approximately 6 feet, the limiting height for helicopter operations. Damaged and defoliated trees extended to approximately 180 feet from ground zero. The MSQ-77 radar demonstrated a high degree of accuracy in working with the C-130. Drops were made with miss distances from 30 to 150 yards. After the Combat Trap weapon had finished its job, a construction party and equipment were taken by helicopter to the new landing zone to expand it to the desired size. The M121 was given its first tactical employment in support of Operation Taylor Common in I Corps Tactical Zone in December 1968.This test evolved into Project Commando Vault. Commander, US Military Assistance Command, Vietnam's (COMUSMACV) original request, SEAOR 168, had stated that the desired capability was for a weapon that could rapidly create landing zones of 5-helicopter size and that development efforts should be concentrated on the largest weapon compatible with C-130 delivery. Though the M121 was a suitable weapon, the rate at which M121s were being used as a clearing device for helicopter landing zones was rapidly depleting the limited supply of bombs, which had long since been out of production. At the peak of their use, 20 M121s were being requested every month. Ten M121s were dropped just between 12 and 20 December 1968. The possibility of restarting production of the weapons was turned down. However, while the replacement weapon, then known as the CD-1, was in development, M121s continued to be used. A comparative test between the M121 and the CD-1 was conducted on 11 May 1969, sealing
the weapon's fate. However, M121s were used until the supply was entirely exhausted, with the last weapon being dropped on 8 August 1970. At that time, the Commando Vault mission fell entirely to the replacement BLU-82/B.
 
If you are saying the M-121 became the BLU-82, you are correct.

However, the images throughout this thread are of the ANM-56, 4,000 pound bomb.

If there is one thing more I know about ordnance, it is aircraft.

My favorite aircraft is the Consolidated Vultee (Convair) Model-36, or know in the military as B-36 "Peacemaker".

I have been researching this aircraft since I could first read. I own many one-of-a-kind artifacts from the B-36 program, as well as every book written about it.

I can assure you, promise you and guarantee you that a 10,000 pound, ANM-series bomb was never developed, designed nor experimented with in regards to the B-36 program.
 
Additionally, the Air Force did away with box type fins in the late 1940's because they would not hold in speeds indicative to high speed jet aircraft.

If the bomb casings in question were the M121 and were equipped with fins (as it is), the fin would have been a conical type.

All new M series bombs starting with the M117 have conical fins, and all ANM casings were adapted to equip specially made conical fins which is discussed in one of my earlier threads.
 
Not saying it is an ANM bomb (or for the B 36 other then what the different web sites say), just that there was a 10,000 lb one that looked very close to either a GP or demo, just not sure of measurements. I'll be home on couple hours then IO can dig into my library.

I am hoping I have a pic of one from my VN days, pretty sure I ahve (had) one of the M 121 setting next to a half dozen or so BLU 82s and it is obvious there are difference in shape and size
 
Copy that.

I feel the results of further research will be in the order of the casing pictured.

From another forum: "The part about the BLU-82 is true. But in the early days Operation Commando Vault of clearing spaces for helicopters they used the 10,000 M121 without the tail section. They had a bunch of them left over due to the fact no aircraft could lift them after the B-36 was retired."

The pictured bomb is what the B-36 dropped. It is pictured all over the "offensive weapons" sections of my B-36 books.

article-2544549-1AE6EBF300000578-551_634x424.jpg
 
Thanks Guys.

So this bomb could be a 4000lb.

What is the real length of 4000Lb ? In my US documentation it's 2.98m (body : 2.41m), diameter 87cm. Even if this woman is very small the bomb seems to be longer (Sorry Madame !)
The diameter seems to be correct.

Regards

10000lb woman.jpg10_000Lb_man.jpg
 
In support of this statement in regards to the 10,000 pound (T56) M121:

"The part about the BLU-82 is true. But in the early days Operation Commando Vault of clearing spaces for helicopters they used the 10,000 M121 without the tail section. They had a bunch of them left over due to the fact no aircraft could lift them after the B-36 was retired."

danang5tonlzR0000.jpg

The pictured casing must be the M121, because the ogive does not match the profile of the BLU-82.
 
There is an awesome technical manual dealing with US ANM series bombs. It must be easy to find because it was my first source of information when I began collecting and restoring. Now, I cannot find that TM to save my life.

Thanks Guys.

So this bomb could be a 4000lb.

What is the real length of 4000Lb ? In my US documentation it's 2.98m (body : 2.41m), diameter 87cm. Even if this woman is very small the bomb seems to be longer (Sorry Madame !)
The diameter seems to be correct.

Regards

View attachment 97248View attachment 97249
 
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