Now think of a bomb
It's a round thing that falls off a plane ..?
A bomb is a weapon typically deployed from aircraft which relies on gravity for delivery. Bombs can be unguided, guided, or specialized. General purpose bombs are a specific subset of unguided or guided bomb designed to optimize for blast damage (soft targets), penetration (hard targets), and fragmentation (wide-area damage). The primary US GP bombs, also used by NATO, are the Mark 80 series:
Mark 81: 250 pound
Mark 82: 500 pound
Mark 83: 1,000 pound
Mark 84: 2,000-pound
Length: 12 feet, 7 inches
Diameter: 18 inches
Lethal fragmentation to a radius of 400 feet
A detonator at the front, a detonator in the tail, and static tail fins to ensure it drops clean. That’s basically it.
Why 2 detonators?
It’s important that the bomb only arms at a specific point ..
Delayed fusing: sometimes one wants the bomb to penetrate the ground before detonating. (An example of this is bunker busting.) This requires setting up the timing of the detonators.
Some variants:
Snakeye is a modification that uses fins/petals to increase drag and slow the bomb's descent by increasing drag. If you were bombing at low altitude — say 100 feet, along a line of trucks, and you let the bombs off without snakeye, they would fall too quickly, detonate, and damage your own aircraft. The ballute is a a small parachute that slows the bomb’s descent even further.
Structural details:
The casing is forged steel. Why steel?
The bomb needs to maintain structural integrity during the drop.
The bomb needs to be maximally destructive on impact. Steel shrapnel can penetrate buildings.
The filling is usually tritonal: a mixture of 80% TNT and 20% aluminum powder which is pressed into the casing. Aluminum increases the total heat output, and thus the total blast, of the TNT.
The explosion itself happens through a deflagration-to-detonation transition. The DDT occurs when the fuze (can be mechanical or electronic) initiates a small explosive charge.
Deflagration is a subsonic combustion process where the reaction front moves slower than the speed of sound in the material. The energy transfer here is thermal conduction and convection.
Detonation is a supersonic process where a shockwave propagates through the material. The energy transfer here is shock compression.
The steel casing and the bomb’s small volume confines the reaction, which then increases pressure and turbulence, creating a shockwave through the tritonal filler.
Engineers can model the shockwave using equations of state, like the Chapman-Jouguet condition (below).
These bombs were designed by Ed Heinemann in 1946 at Douglas Aircraft, which merged with Boeing in 1997. (Heinemann later worked at Northrop before he became the VP of Engineering at General Dynamics.)
The Mark 80 series is highly modular, which also allows guidance systems to be attached. (This is an advantage against its predecessor, the Mark 117, which is the oldest general-purpose bomb available in digital combat simulators. Retrofitting modularity into legacy systems like the M117 is theoretically possible but comes with significant challenges. However, it’s still in use. Most other bombs used during WWII and the Korean War, though, such as the Mark 65 and the Mark 118, are no longer used.)
Guided Bomb Units (GBUs)
A GBU is a guidance kit for the Mk 80 bombs. There are movable fins in the rear and a laser-guidance kit in the front. The front unit provides guidance, while the rear unit does steering.
Mk 80 bombs (called “dumb bombs”, because they have no guidance) equipped with laser guidance kits are referred to as Paveway bombs (a type of “smart” bomb). Paveways are produced by Raytheon. Some examples:
GBU-10 Paveway II – Mk 84
GBU-12 Paveway II – Mk 82
GBU-16 Paveway II – Mk 83
GBU-58 Paveway II – Mk 81
GBU-22 Paveway III – Mk 82
The little pointy thing sticking out the nose is the laser spot search system. The laser-guidance system continuously searches for a laser spot with a specific code, which can be set up in DCS for the relevant aircraft (like the F/A-18C).
The guidance kit, in the back, is divided in 4 sections. When it spots the laser in one section, it moves the fins to bring it to the center. Those guidance kits do not have a PID system (proportional-integral-derivative), and a lot of energy is lost in guidance because thus the fins move all the way all the time. Thus the laser is only turned on in the terminal phase. Also, the laser doesn't use range information at all, just the position of the dot relative to its longitudinal axis. Also, the lasers can be additionally hindered by uneven terrain and bad weather. Good aim is needed for the initial release.
The Mk series can also be equipped with JDAMs, which turns them into all-weather PGMS (precise guided munitions). JDAMs were developed jointly by the Air Force and the Navy, hence the name: Joint Direct Attack Munitions. During Operation Desert Storm, the Paveway laser guidance bombs would fail amidst dust, smoke, fog, and cloud cover.
JDAMs are GPS guided. Unlike the laser guided bombs we just talked about, once you release a JDAM, that bomb will arrive no matter what you do. JDAMs are manufactured by Boeing. In 2017, Boeing built 130 JDAMs per day. Some examples:
GBU-31(V)1/B , used by the Air Force, Mk 84
GBU-31(V)2/B, used by the Navy and the Marine Corps, Mk 84
GBU-32(V)1/B, used by the Air Force, Mk 83
GBU-32(V)2/B, used by the Navy and the Marine Corps, Mk 83
Unlike its extensive public releases regarding the shipment of weapons to Ukraine, the US government has revealed few details about the munitions sent to Israel. But blast fragments found on-site and analyses of strike footage reveal that the vast majority of bombs dropped on Gaza are U.S-manufactured. The exact quantities are unclear. But all of the aforementioned types of bombs have been sent. From October 2023 until July 2024, the US has transferred at least:
14,000 MK84s
6,500 MK82s
3,000 Hellfire precision-guided air-to-ground missiles (not mentioned in this essay. Missiles are not bombs.)
1,000 BLU-190s (these are penetrator bombs, outside of the Mk series. They have thicker casing and designed to destroy bunkers, reinforced buildings, and underground structures, as opposed to the Mk series, which mostly work on a wider range of softer targets.)
2,600 air-dropped small-diameter bombs (these are lighter munitions, around 100 to 250 pounds, usually precision-guided, designed to engage targets with minimal collateral damage. They are produced by Boeing and Saab Group.)
Around Spring 2024, there was a pause of one shipment of 3,500 MK84s, but no significant change in the supply overall.
I don’t find naïveté charming, I am not going to start singing now about how astonished or puzzled or saaad I am. But you know what’s strange? Whenever there’s another headline about bombs, usually it just says “bombs.” Or, even when the name of the bomb is mentioned, there is no explanation of how that bomb works, or what it does. Not on legacy media, not on Substack, not amongst peers, not by protestors, not by politicians. Neither warhawks nor — the anti-war so-called radical left! How can this be? Is this because it was more empowering, actually, to get arrested? To march across bridges? And then march back the opposite way? Did the “powers that be” not allow the protestors to learn about bombs? Or even to wonder? The more likely explanation: even the protest against the circus constitutes a vital part of the circus, even the protest for change represents frantic activity as a defense against change.
Sorry I didn't write yesterday, I was hanging out and eating fatty and sugary food in Brooklyn. Thanks to Andy for the encouragement.
what yummy things did u have in brooklyn