USA and Norway tested a rocket-propelled projectile for cannon artillery

Alexander Sychev

Shooting took place at a target at a distance of about 70 kilometers. “The jet engine started, and the projectile flew steadily all the way with a well-controlled combustion process,” the developers said.

The Americans joined the Norwegian designers, who had long been conducting research on the use of jet engines in cannon artillery, in July 2019. They called the program for the joint creation of a new ammunition XM1155. It is also a munition, the army's future Extended Range Cannon Artillery (ERCA) system. The new howitzer should appear in 2025.

The gun is supposed to be installed on the chassis of an already existing self-propelled howitzer M109 A7, created by BAE Systems. It is known that the gun will have a 9-meter barrel. In addition to the standard 155-millimeter caliber ammunition, the howitzer will fire Norwegian or similar rockets, which the Americans will create on the basis of technologies obtained in Norway. The howitzer will have to fire at a rate of 10 rounds per minute.

Until recently, the Pentagon had a rather cool attitude towards cannon artillery, which practically ran into the physical limits of its modernization. It was believed that all ways to increase the firing range - the length of the barrel, the quantity and quality of the propellant charge, caliber, materials, had already been explored and applied. There is nowhere else to move. Rocket artillery and kamikaze drones are more promising. However, the gunsmiths of a number of countries, including Russia, decided to cross a ramjet engine with an artillery shell, and a direction for development was opened.

Advantages of a ramjet engine: simplicity (there are no rotating parts in it, as in a turbojet), small dimensions and the ability to reach speeds up to Mach 6. But in order to start the engine, the projectile must be accelerated to Mach 3. Only in this case, the air entering the air intake creates the pressure necessary to ignite the fuel.

Of course, the rocket projectile has its drawbacks. Firstly, the installation of a jet engine makes it much more expensive than a conventional artillery shell. Secondly, increasing the range requires the installation of a guidance system and empennage, and this reduces the combat load of the projectile.

According to reports, the Ramjet 155 ammunition under development is also suitable for existing guns - the M777 towed howitzer and the M109A7 self-propelled gun.

And yet, the firing range is extremely important and justifies the increasing costs. After all, the chance of an artillery system to avoid suppressive return fire increases, if, of course, the enemy has a similar cannon artillery. New guns will be able to support ground forces at a greater distance, freeing up aircraft and helicopters for other tasks.

But the appearance of the Ramjet 155 in itself will not change the situation on the battlefield in favor of its owner. Artillerymen need intelligence data for strikes, in which drones and other intelligence-gathering systems need to be combined with long-range artillery and linked by secure communications. This is now being done by two companies.