Boeing and Nammo recently completed the first test of their new Ramjet 155 artillery shell. The Ramjet 155 artillery shell is a howitzer round capable of locking on to and destroying moving targets from as far as 44 miles (~ 71 km) away. This far exceeds the range of the Russian and Chinese artillery currently in use, giving Ramjet 155 the potential to become the dominant arm of future land warfare.
The test was performed at the Andøya Test Center in Norway, where the shell’s ramjet engine ignited successfully and it “demonstrated flight stability with a well-controlled engine combustion process.”
The Ramjet 155 shell is the first artillery shell to use a ramjet for propulsion. Ramjets are air-breathing engines that take in air at high speeds and then mix it with gasses produced by fuel combustion. The air and exhaust under pressure is then expelled through the rear nozzle, producing thrust. Other artillery shells use a method called “base bleed,” where gas is injected into their wake, reducing drag as the shell flies or “rocket-assisted projectiles” (RAP), where actual rockets are used to increase range. Ramjet-powered shells, on the other hand, use the oxygen in the air, thus reducing the amount of onboard fuel required and are capable of accelerating over a greater distance, giving them greater speed up until impact.
Ramjet shells do have the disadvantages of being much more expensive than typical artillery shells and they require the incorporation of a guidance package, steering fins, and the ramjet, thus reducing the shell’s explosive payload.