Bofors 155 Bonus


155 BONUS is a 155 mm artillery cluster round, developed in cooperation between Bofors of Sweden and Nexter of France, designed for a long range, indirect fire top attack role against armoured vehicles. The BONUS base bleed carrier shell contains two submunitions, which descend over the battlefield on winglets and attack hardened targets with explosively formed penetrator warheads.

Design

155 BONUS is a 155 mm NATO artillery round that consists of a heavy artillery projectile containing two autonomous, sensor-fused, fire-and-forget submunitions.
After the submunition is released it opens two winglets. While descending, the submunition rotates, scanning the area below with multi-frequency infrared sensors that compares the detected vehicles with a programmable target database.
The submunitions each contain a high-penetration EFP warhead for use against even heavy armoured fighting vehicles like main battle tanks.

Operation

PhasePictureDescription
1After setting range and target profile, the BONUS round is fired from a standard rifled 155mm artillery tube.
2The round flies on a parabolic arc, with a range of up to
3A timer fuse ignites a small ejector rocket in the nose, which drags the two submunitions out of the shell casing over the target area.
4Once clear of the shell, the submunitions fall toward the target. The shell and the nose assembly fall away.
5The submunitions deploy winglets, and independently corkscrew down over the subject area with 15 rpm, scanning for targets.
6Once a submunition detects a target vehicle beneath it, it detonates its explosive payload, creating an explosively formed projectile which strikes the target vehicle's weak top armour. The high-velocity impactor penetrates the hull and kills or wounds the crew.

Competing systems

BONUS is very similar to the German SMArt 155 system; SMArt 155 descends on a parachute rather than a system of winglets.
The United States developed the similar M898 SADARM system, but this was discontinued in favour of the GPS guided M982 Excalibur round.
US artillery largely deploys the M712 Copperhead laser-guided round for the anti-tank role.

Operators