Bofors/Nexter Bonus
155 BONUS ("Bofors Nutating Shell")[2] 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. Development on BONUS began in early 1985 as a study project for the Swedish Defence Material Administration, with an initial expectation of development completion by 1989 and production start by 1990.[3] By 1990, the development completion date had slipped to 1992.[4] 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.
| 155 mm BONUS | |
|---|---|
 BONUS 155 mm construction | |
| Type | Sensor‐fuzed submunition artillery projectile |
| Service history | |
| In service | Since 1990s |
| Used by | See operators |
| Production history | |
| Designer | Bofors AB |
| Designed | Early 1980s–1994 |
| Manufacturer | BAE Systems Platforms & Services |
| Produced | 2000 |
| Specifications | |
| Mass | 44.6 kg (98 lb) unfused |
| Length | 898 mm (35.4 in) unfused |
| Diameter | 155 mm (6.1 in) |
| Muzzle velocity | 830 m/s (2,723 ft/s) from 39‐caliber barrels |
| Maximum firing range |
|
| Filling | 2 x autonomous anti‐armour and anti‐artillery submunitions |
| References | Janes[1] |
Design
155 BONUS is a 155 mm NATO artillery round that consists of a 47-kilogram (104 lb) 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 and LiDAR[5] 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.
When fired from a 52-caliber barrel, a BONUS shell can travel up to 35 km (22 mi).[6][7]
Operation
| Phase | Picture | Description |
|---|---|---|
| 1 |  |
After setting range and target profile(s), the BONUS round is fired from a standard rifled 155mm artillery tube. |
| 2 |  |
The round flies on a parabolic arc, with a range of up to 35 kilometres (21.7 mi) |
| 3 |  |
A timer fuse ignites a small ejector rocket in the nose, which drags the two submunitions out of the shell casing over the target area. |
| 4 |  |
Once clear of the shell, the submunitions fall toward the target. The shell and the nose assembly fall away. |
| 5 |  |
The submunitions deploy winglets, and independently corkscrew down over the subject area with 900 rpm, scanning for targets. |
| 6 |  |
Once 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, and uses a millimeter radar as altimeter instead of LIDAR.
The United States developed the similar M898 SADARM system (which also descended on a ballute to attack the top surfaces of armoured vehicles), 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
French Army - since 2000[8]
Swedish Army - since 2000[8]
Finnish Army - since 2014[9]
US Army - being procured[10]
Norwegian Army[11]
Saudi Arabian National Guard, since 2012 (1,000 shells ordered in 2011)
Ukrainian Ground Forces - since 2022
Operational history
It has been sent to Ukraine in aid packages by France and potentially Sweden and Norway.
Although rumours mentioned a kill on a Russian Pantsir-S1 system on July 5, 2022, it turned out that it was the SMArt 155 that hit it.[12]
In January 2023 photos of a 155 mm BONUS submunition was found in Ukraine. This is the first confirmed proof of their use in Ukraine.[13]
References
- Janes (2 February 2022), "155 mm BONUS sensor‐fuzed munition", Janes Land Warfare Weapons: Ammunition, Coulsdon, Surrey: Jane's Group UK Limited., retrieved 6 August 2023
- Frost, Roger; Hewish, Mark (1986). "Defence 86 Show Report". International Defense Review. 19 (4): 495 – via Internet Archive.
- Frost, Roger; Hewish, Mark (1986). "Defence 86 Show Report". International Defence Review. 19 (4): 495 – via Internet Archive.
- "Sensor-fuzed anti-tank shell". International Defense Review. 25 (5): 580. 1990 – via Internet Archive.
- "155mm BONUS Anti-Armor, Top Attack Artillery" (PDF). Baesystems.com. Retrieved 17 July 2022.
- Roque, Ashley (19 October 2020). "BAE Systems proposes Archer for US Army's towed howitzer replacement competition". Jane's Information Group. Archived from the original on 27 March 2021. Retrieved 25 December 2020.
- US Army mobile howitzer shoot-off participants emerge. Defense News. 17 December 2020.
- "Fritt Militärt Forum Nr 3 2000". Archived from the original on 4 March 2016. Retrieved 1 March 2015.
- "Finnish defence forces" (PDF). Archived from the original (PDF) on 19 April 2015. Retrieved 19 April 2015.
- Army Concerned Over Ban on Cluster Munitions, Land Mines - Military.com, 2 May 2017
- "Bofors 155mm BONUS Munition". Baesystems.com.
- "SMArt 155 in Action: Use of High-Precision Munitions to Eliminate russians is Geting Large-Scale (Video) | Defense Express". en.defence-ua.com. Retrieved 5 October 2022.
- Boyko Nikolov (4 January 2023). "Proven: Ukraine uses 155mm BONUS anti-tank shells with spaceship tech". bulgarianmilitary.com. Retrieved 5 October 2022.