Top attack munitions are now widely developed for different artillery calibers with offering varied ranges.
While aviation assets now employ precision guided munitions (PGM) and smart munitions on an increasing scale, the land sector has been more cautious as their target sets are different.
A key role of artillery is still to provide suppressive fire against opposition forces using high-explosive (HE) projectiles, with secondary effects including smoke and illumination.
To engage hard targets such as armoured fighting vehicles (AFV) cargo rounds were developed and deployed. These carry a large number of small sub-munitions fitted with a small high-explosive anti-tank (HEAT) warhead to penetrate the vulnerable, lighter armoured upper surfaces of AFVs. These sub-munitions can have a high dud rate and therefore limit the manoeuvre of follow up forces as well as potentially causing later casualties to civilians.
For this reasons such munitions are banned under the Convention on Cluster Munition (CCM) and the Cluster Munition Coalition (CMC) agreements and have therefore been phased out of service with most countries, although they are still deployed by such countries such as China and Russia.
As with all artillery projectiles, the key requirement is target acquisition, especially at long ranges and PGM are expensive and would normally be used against high value targets.
To counter AFVs, more advanced 155mm top attack weapons have been developed and deployed with market leaders in Europe, including the GIWS SMArt 155 and the Bofors/Nexter BONUS.
SMArt is a joint development between the German companies of Diehl Defence and Rheinmetall Weapons & Munitions with export sales being made to Australia, Greece and Switzerland. Some 12,000 have been manufactured. SMArt 155 carries two top attack sub-munitions, each having a heavy metal explosively formed penetrator (EFP) warhead.
Manufacturing was completed sometime ago but the production line is to be restarted to enable German Army stocks to be replenished as well as allowing the potential needs of export customers to be met. These will be essentially the same as the original SMArt 155 but obsolete sub-systems will be replaced. The maximum range when fired from a German Army PzH 2000 155mm/52 calibre self-propelled howitzer (SPH) is 27.5 kilometres (17 miles).
The BAE Systems Bofors/Nexter Bonus was originally developed to meet the requirements of France and Sweden with production lines being established in both countries and with export sales made to Finland, Norway and the Kingdom of Saudi Arabia. The latest version is the Bonus Mk II and carries two sub-munitions which are parachute retarded at the rate of 45 metres per second (147 feet) and have a search area of 32,000 square metres (334,400sq ft) each.
Maximum range when fired from a 155mm/52 calibre weapon is quoted as 35km (21.7 miles) and when fired from a 155mm/39 calibre weapon is 27km (16.7 miles).
Late in 2018 the US Army placed a contract through the NATO Support and Procurement Agency for the Bonus Mk II with deliveries from the Swedish production line now well under way. A second contract was placed in early 2020
The US Army did deploy the 155mm M712 Copperhead Cannon Launched Guided Projectile (CLGP) and this Laser Guided Projectile (LGP) fitted with a HE warhead was used in action in the Middle East, but these have time expired.
The US currently deploys the Raytheon Excalibur 155mm M982 PGM fired from its deployed 155mm/39 cal M777A2 lightweight towed howitzer and the 155mm/39 cal M109A6/A7 SPH. Details of the platform, target and GPS specific data are entered into the projectile’s mission computer through an Enhanced Inductive Fuze Setter (EIFZ).
Excalibur uses a jam resistant inertial GPS receiver to update the inertial navigation system (INS) to provide precision in-flight guidance and according to the US Army “dramatically improving accuracy to less than 2m (6.5ft) miss distance, regardless of range.” It has three fuze options which depend on the target being engage and these are point detonation (PD), PD delay and height of burst.
The current production model is the M982 Excalibur Increment Ib which has a number of improvements including hardware and software updates to improve GPS jamming resistance as well as allowing user defined trajectories for target engagement.
Another development is the Excalibur Shaped Trajectory (EST) which was successfully demonstrated in 2018 and eliminates targets in hard to reach locations by selecting the projectile’s terminal or final phase attack angle.
The maximum range of M982 Excalibur depends on the weapon and charge but for a 155mm/39 calibre artillery system it is 39.3km (24.4 miles) with a Modular Artillery Charge System (MACS) while minimum range is being quoted as 8.7km (5.4 miles).
By early 2020 production of the Excalibur has reached over 14,000 units of which some 1,400 have been used in combat. In addition to the US Army and Marines, export customers include Australia, Canada, India, Jordan, Netherlands and Sweden.
Other weapons that are compatible with the 155mm Excalibur are BAE Systems Archer (Sweden) and AS90 (UK), Nexter’s CAESAR (France), Denel’s G6 (South Africa), Hanwha’s K9 Thunder (Korea), Rock Island M198 (USA) and KMW’s PzH 2000 (Germany).
In mid-2018, Nexter revealed that it was developing the Katana family of 155mm PGM using internal research and development funding. The Katana has sets of control surfaces positioned on its ogive as well as four fins at the rear which unfold after launch. The guidance system consists of an inertial measurement unit/global position system (IMS/GPS) with a maximum range of up to 60km (37 miles) with a circular error probable (CEP) of 10m (32ft).
During trials carried out in Sweden late in 2020 a CAESAR 155mm/52 calibre SP artillery system fired a 155mm Katana during which all of the Canard Actuation Systems (CAS) were successfully tested. The next phase will be for a complete coordinate guided and coordinate controlled firings sometime in 2021.
Leonardo of Italy has been working on the Vulcano 155mm Ballistic Extended Range (BER) artillery projectile for some time and this unguided projectile has been type classified by the Italian Army.
Leonardo is working with the Diehl Defence of Germany for a semi-active laser (SAL) version of Vulcano having a range of up to 80km (50 miles) when fired from a 155mm/52 calibre artillery system. This has an insensitive HE warhead with pre-fragmented tungsten splinters.
Russian Rounds
The Russian KBP Instrument Design Bureau has developed a complete family of LGP, propelling charge as well as their guidance systems.
The 152mm 2K25 Krasnopol guided weapon system (GWS) uses the 152mm 3OF39 LGP with a maximum range of 20km (12.4 miles), fitted with a HE fragmentation (HE-F) warhead and is claimed to have a high probability against stationary and moving targets of up to 80 percent.
This is used in conjunction with the latest Malakhit automated artillery fire control system as well as laser designators/rangefinders including the ID22/ID26, LTsD-3M1 and the French DHY-307.
While the Russian Army and many other countries have large numbers of 152mm artillery weapons, NATO and other countries have 155mm artillery systems and the KBP Instrument Design Bureau has developed 155mm versions.
The first of these is called the 155mm KM-1 Krasnopol GWS and includes the K155 SAL LGP with a maximum range of 20km (12.4 miles) and is also fitted with a HE-F warhead.
The latest is the 155mm KM-1M Krasnopol-M2 which includes the K115M SAL LGP and has range increased to 25km (15.5 miles) and also has a HE-F warhead.
For use with 122mm artillery systems such as the widely deployed D-30 (towed) and 2S1 (SP) artillery systems, the KBP Instrument Design Bureau has developed the 122mm KM-3 Kitolov-2M GWS which includes the actual K122 LGP and propelling charge which has a maximum range of 13.5km (8.3 miles).
China invests in PGM
China has invested in PGM with all of these being marketed by China North Industries Corporation (NORINCO) to potential export customers with the 155mm versions being exported to a number of countries and recently used in North Africa.
These include the GP 155 with a maximum range of 20km (13.5 miles) and the more recent GP155A with range increased to 25km (15.5 miles) with both of these being of the LGP type and have a HE warhead.
To enable targets to be engaged at longer range the GP155B has been developed and this features both the Chinese Beidou satellite positioning system and GPS with NORINCO quoting a maximum range of 35km (21.7 miles).
For 122mm artillery systems NORINCO is marketing the GP122 with a maximum range of up to 14km (8.7 miles).
These Chinese LGP can be used with their Laser Target Designator Rangefinder OL1 and OL2 plus radio communications equipment, fire control system (FCS) and fire control calculator (FCC) and programme setter.
Tank launched precision projectiles
The main advantage of tank launched guided projectiles is they can engage threat targets well beyond the effective range of the main armament of the main battle tank (MBT).
The US Army did have the M60A2 MBT and the M551 Sheridan light tank armed with a 152mm gun/missile launcher, but both of these have now been phased out of service.
The now Northrop Grumman (then ATK) and Raytheon were developing the Mid-Range Munition (MRM) which would have been fired from the 120mm main armament of the M1A1/M1A2 Abrams MBT and the Mounted Combat System (MCS) which was part of the Future Combat System (FCS), but this programme and MRM was cancelled.
Following a competition, Northrop Grumman, Armament Systems, was down selected to continue development of the 120mm Advanced Multi-Purpose Round (AMP) XM1147 which can be fired from the 120mm M256 main gun of the MA2 Abrams MBT fitted with the Ammunition Data Link (ADL).
This HE round can be programmed for one of three modes including point detonate, point detonate delay or airburst but also has a default in which the round functions in PD mode when not set through the ADL.
It has a muzzle velocity of 1,150m/s and a typical target range of 2kmm (1.2 miles) and trials have shown it will punch a hole in an eight inch (20cm) dual reinforced contract wall at zero degrees impact. When fielded it will replace currently fielded HE rounds including the M830A1 HEAT, M908 HE counter obstacle round and the M1028 canister.
In December 2020 the AMP XM1147 had received Milestone C which cleared it for production release with first being Low Rate Initial Production (LRIP).
Northrop Grumman, Armament Systems of the US have already stated that “the company is also evaluating a 105mm AMP concept with internal research and development funding for the Stryker Mobile Gun System and the potential of the US Army fielding a 105mm armed Mobile Protected Firepower platforms, currently being tested for deployment by the Infantry Brigade Combat Teams (IBCT)
The new 105mm AMP cartridge will combine the capability of three currently inventoried rounds which are M456 HEAT, M393 high-explosive plastic (HEP) and M1040 canister, into one round to greatly enhance the capability and effectiveness of our mobile system by allowing a single round to expand lethality in their limited vehicle ammunition stowage.
The on-going investment of 120mm ammunition development is considerable especially in AB HE ammunition such as the German Rheinmetall Weapons & Munitions DM11 HE round which can be programmed in the weapon and is already in quantity production and service with a number of countries.
In mid-April 2021 Rheinmetall stated: “ The DM11 is in service with four countries. Three more countries are interested in procuring the DM11 in conjunction with upgrade programmes or new purchases of the 120mm smoothbore technology.”
The US Marines purchased DM11 for use with their M1A1 Abrams MBTs under the designation of the MK324, but these have now been phased out of service.
The 120mm DM11 can be fired from 120mm L44 and L55 smooth bore tank guns and consists of a warhead with a programmable fuze as well as ballistic cowl, tailfin assembly, drive band, combustible casing with propelling charge and a new design of stub case which contains the primer and an integrated data callable from programming.
The Russian Army has deployed 125mm gun launched LGP for its MBTs with these having a maximum range of 5,000m (3 miles). First versions were fitted with a single HEAT warhead but more recent ones have been fitted with a tandem warhead to neutralise targets fitted with ERA.
The main drawback of these is that the gunner must keep his sight on the target until missile impact which at longer ranges can take up to 17 seconds, by which time the target could have moved and taken cover.
NORINCO is also marketing tank launched LGP with the 105mm one designated the GP2 and the 125mm one GP7. GP2 is a one piece round and has a maximum range of 5,000m while GP7 is in two parts like the Russian tank launched LGP and has a similar range and are fitted with a tandem HEAT warhead to defeat targets fitted with ERA.
The State Kyiv Design Bureau Luch in the Ukraine has developed a complete family of gun launched LGP with calibres of 125mm, 115mm, 105mm and 100mm with the 105mm version being successfully fired from a 105mm rifled gun installed in a John Cockerill Defense two person turret.
France was working on a 120mm Metric Precision Munition for its Leclerc MBTs but work is now being concentrated on a 120mm laser guided mortar round under leadership of Thales.
Israel Aerospace Industries has developed the Laser Homing Anti-Tank (LAHAT) projectile which would have a range of at least 8,000m (4.9 miles) with both 105mm and 120mm versions developed.
Roketsan, the missile systems house of Turkey, is developing the Tanok 120mm LGP for use with the Altay MBT now in production for the Turkish Land Forces Command. This is stated to have direct and top attack modes and have a maximum range of up to 6km (3.7 miles) and is fitted with a tandem HEAT warhead.
by Christopher F. Foss
