Conventional — penetrating · United States · 1991
GBU-28
GBU-28 « Deep Throat »
A “bunker-buster” designed in a rush: its casing was machined from surplus artillery gun barrels.
See GBU-28 in the 3D simulator- TNT equivalent
- 0.3 tPublic estimate
- Energy
- 1.26 GJ
- Mass
- 2.3 tDocumented
- Explosive charge
- 286 kgDocumented
- Dimensions
- 5.8 m · Ø 0.37 mPublic estimate
- Type
- Laser-guided penetrating bomb
- Period
- After the Cold War
- Status
- Current
GBU-28 releases about 50,000 times less energy than Little Boy (Hiroshima, 1945).
Key points
- The mass is mostly the steel casing: the explosive is only ~13% of the total.
History
Went from final design to combat use in just two weeks, in February 1991.
- February 1991 Designed and tested in a few weeks.
- 27–28 February 1991 First use near Baghdad.
How does it work?
A conventional bomb releases chemical energy: the explosive decomposes into very hot gases in a few microseconds (detonation).
Order of magnitude: a few megajoules per kilogram of explosive (1 kg of TNT ≈ 4.2 MJ), millions of times less than nuclear reactions for the same mass.
The expanding gases violently compress the air: the shock wave weakens very quickly with distance.
A penetrating bomb has a thick steel casing and a delayed fuze: it buries itself in the ground or concrete before exploding.
Much of the energy is then transmitted to the ground (seismic wave) rather than to the air: surface effects are much weaker than for an airburst of the same energy.
Estimated TNT equivalent = mass of explosive × relative effectiveness factor of that explosive (≈ 1.3 for Torpex or H-6, ≈ 1.05 for Tritonal).
Deliberately general explanations: the application provides no design or manufacturing information.
Frequently asked questions
How powerful is GBU-28?
GBU-28 has an estimated yield of 0.3 t of TNT equivalent, about 1.26 GJ of energy.
What is the history of GBU-28?
First used on the night of 27–28 February 1991, a few hours before the Gulf War ceasefire. Went from final design to combat use in just two weeks, in February 1991.
What does the GBU-28 explosion look like?
The Bomb Simulator shows the fireball, shock wave and cloud of GBU-28 at real scale, over Paris, London or New York, with the sources and reliability of each value.
Sources
- GBU-28 — Wikipedia (overview, to be cross-checked)
Other weapons
- Tallboy — 3.1 t
- Grand Slam — 5.5 t
- FAB-5000NG — 4 t
- FAB-9000 — 4.3 t
- BLU-82 — 5.7 t
- Mk 84 — 0.5 t
- GBU-43/B MOAB — 11 t
- FOAB — 44 t
- FAB-3000 — 1.4 t
- GBU-57 MOP — 3 t
This application is an educational tool. The animations and effect zones are simplified representations meant to illustrate orders of magnitude. They are neither a prediction of the effects of a real weapon nor a military planning tool.