Making the Shell Fit the Job
By
Christopher F. Foss
-
December 8, 2020
Nammo’s range extension solutions for artillery range from 40+km range with base bleed to ramjet-powered shells capable of 150km or more.
Published in July/August 2020 Issue – Artillery ammunition developments are driven by greater flexibity of round, the need for more range and increased accuracy.
The fielding of new conventional tube artillery systems, be they towed or self-propelled (SP), is only one part of a total artillery capability that also takes into account the key roles of artillery fire control, target acquisition and ammunition.
While 105mm artillery are still used by air assault and commando type artillery units, 155mm is the most widely deployed calibre and that is the main area where investment is taking place.
For many years the standard 105mm high-explosive (HE) projectile was the United States developed M1 which, when fired from the Oto Melara (today Leonardo) 105mm Model 56 Pack Howitzer, achieved a maximum range of 10.5 kilometres.
New 105mm artillery systems had a longer barrel and fired a new generation of ammunition. The Royal Ordnance (now BAE Systems) 105mm L118 Light Gun fired an L31A4 HE projectile to a maximum range of 17,200m. Other types of round include the L52A2 smoke. Still under development is the XL32E1 HE base-bleed (BB) with a range of over 20km. This uses a gas generator to reduce the vacuum at the bottom of the shell which reduces the drag.
For training, the barrel of the 105mm L118 Light Gun could be changed for a shorter barrel to enable the older and cheaper 105mm M1 ammunition to be used; this version referred to as the L119 Light Gun.
Nexter Munitions 155mm projectile family includes, from left to right, smoke (LU 217), Illuminating (LU 215), HE (LU 211) and HE Insensitive Munition (LU 211 IM).
The only competitor for the 105mm L118 Light Gun is the more recently developed Nexter Systems 105mm Light Gun which, although not adopted by the French Army, has had major success on the export market with sales made to Belgium, Canada, Colombia, Indonesia, Singapore (no longer deployed) and Thailand.
The 105mm Light Gun fires a new family of ammunition developed by Nexter Munitions including HE Hollow Base (HB) with a maximum range of 15km and BB with a maximum range of 18.5km, with other rounds also including smoke.
One of the more recent trends for all types of ammunition is that the user requires them to be Insensitive Munition (IM) compliant and an increasing number of countries, especially those in NATO, are insisting that future ammunition procured must be IM compliant (Insensitive Munitions are designed to withstand stimuli representative of severe but credible accidents).
Part or Whole
In addition to the actual 155mm artillery projectile, other elements include the charge system and the nose mounted fuze. Some countries have competitions for a complete artillery ammunition package while others have a competition for each part.
Conventional 155mm bag charges are giving way to Modular Charge Systems (MCS), or bi-MCS. These are more efficient and well suited to automatic ammunition handling systems and are being fitted to an increasing number of SP artillery systems to increase rates of fire and reduce crew fatigue.
A number of contractors produce MCS including Nexter Munitions/EURENCO, NAMMO, Rheinmetall Weapons & Munitions and Rheinmetall Denel Munitions. In April 2020, the latter announced an $80 million international contract for their latest 155mm Tactical Modular Charges (TMS) for delivery in 2021.
The main types of 155mm ammunition are still HE, smoke and illuminating but the requirement for increased range has been achieved via HB, BB or rocket-assist (RA), with a few 155mm projectiles having a combination of BB and RA.
China North Industries Corporation (NORINCO) market a complete family of 155mm projectiles and associated charges with their 155mm DDBO3 ERFB-BB-RA HE projectile claimed to have a maximum range of 51km when fired from a 155mm/52 calibre weapon.
Rheinmetall Denel Munitions also has a similar projectile called Velocity enhanced Long Range Artillery Projectile (V-LAP) which combines BB and RA to achieve longer ranges.
During a demonstration in November 2019 a KMW/Rheinmetall PzH 2000 155mm/52 cal fired a V-LAP to a range of nearly 67km with a new top charge while the G6 howitzer with a 155 mm/52 cal and a 25 litre chamber with a modified M64 Zone 6 charge fired a V-LAP to a maximum range of 76km.
Another type of 155mm munition is the Extended Range Full Bore (ERFB) which is more streamlined projectile with nubs and which can be of the HB, BB or RA type.
German 155mm DM702 SMArt artillery projectile carries two sub-munitions with an advanced warhead designed to defeat the upper surfaces of armoured vehicles.
Using internal research and development funding, NAMMO has developed and placed in production its new IM HE ER projectile designated NM269 which is claimed to have an enhanced blast effect to defeat armour as well as soft targets. The maximum range when fired from a 155mm/52 calibre ordnance is 41km when using six Rheinmetall DM72 MACS. This is available with a BB or HB unit which can be attached in the field and is supplemented by illuminating, smoke and practice projectiles.
Spanish company EXPAL is now in quantity production of the 155 ERO2A1 HE projectile for the Spanish Army. The ER designation refers to Extended Range which is achieved using a more streamlined shape with filling being of the IM or conventional HE type.
It can be fitted with a HB or a BB unit with the latter achieving maximum range which is 30km when fired from a 39 calibre ordnance and 39km when fired from a 155mm/52 calibre ordnance.
In Turkey, MKEK produce a wide range of ammunition including the 155mm HE Extended Range Mod 274 which has a maximum range of 39km when fired from the Firtina 155mm/52 cal SP artillery system used by the Turkish Army. Like many countries they also make the older US 155mm M107 HE projectile which is cheaper and has less range and therefore ideal for training purposes.
To further increase range a number of contractors are working of 155mm ramjet artillery projectiles including NAMMO (Norway) and Poongsan (South Korea).
The main drawing back of all artillery is that as range increases, so there is a greater dispersion, requiring increased accuracy.
Anti Armour
To counter mass attack by armoured fighting vehicles (AFV) 155mm projectiles carrying sub-munitions have been developed and deployed. These sub-munitions have a small calibre high-explosive anti-tank (HEAT) warhead which was designed to penetrate the vulnerable upper surfaces of AFVS.
Some of these sub-munitions had a high dud rate and were therefore a danger for follow up forces as well as civilians and for this reason these are no longer deployed by many countries, although they are still manufactured by countries such as China and Russia.
A number of 155mm artillery projectiles have been developed and fielded to enable AFV targets to be successfully engaged; these include BONUS and SMArt.
The 155mm BONUS is a joint development between Nexter Munitions (France) and BAE Systems (Bofors) and, in addition to being deployed by France and Sweden, is also fielded by Finland, Norway, Saudi Arabia and more recently the US Army.
BONUS contains two sub-munitions and sensors, and when fired from a 155mm/39 caliber ordnance has a maximum range of 27km or 35km when fired from a 155mm 52 calibre ordnance.
The 155mm SMArt was developed by GiWS, a joint venture company between Rheinmetall and Diehl and contains two sub-munitions with an Explosively Formed Projectile (EFP) warhead to penetrate the top of AFV.
Production was undertaken for Germany followed by Austria, Greece and Switzerland. Although production was completed it is likely to start again as the early shells for Germany are running out of shelf life.
The US Army has fielded the Raytheon Excalibur M982 155mm precision guided projectile which uses a jam resistant internal Global Positioning System (GPS) receiver to update the inertial navigation system (INS). This gives an accuracy of less than two meters.
When fired from a 155mm artillery system such as the M777 used by the US Army and Marine Corps, a maximum range of 39.3km using a Zone 5 Modular Artillery Charge Systems (MACS) is achieved.
Excalibur has three fuze modes: point detonating (PD), PD delay and height-of-burst.
Leonardo of Italy has completed development, industrialisation and qualification of the Vulcano 155mm Ballistic Extended Range (BER) projectile for the Italian Army.
Vulcano features a sub-calibre fin-stabilised airframe which is loaded with IM compliant HE with a patented rings pre-fragmented warhead. It is fitted with a nose mounted multi-function fuze which can be set for height, impact/delayed impact, time or self-destruct functions.
When fired from the PzH 2000 155mm/52 cal SP artillery system deployed by the Italian Army a maximum range of 50km is achieved using four MCS plus one additional charge integrated into the Vulcano projectile.
The follow on Vulcano Guided Long Range (GLR) features an autonomous Inertial Measurement Unit/GPS guidance system, is also IM compliant and fitted with a multi-function fuze. In addition, there is a semi-active laser (SAL) guided version with Leonardo working with Diehl Defence of Germany.
Nexter Munitions is developing the Katana PGM with Katana 1 being of the GPS/INS type which would be followed by 2a INU/GNSS and 2b with a SAL guidance system.
Guidance Kits
US Army has fielded the Northrop Grumman M1156 Precision Guidance Kit (PGK) which is a direct replacement for a standard artillery fuze. It contains GPS guidance using fuzing functions and an integrated GPS receiver to correct the inherent errors associated with a ballistic firing solution. This increases accuracy and reduces the number of projectiles required to neutralise the target so reducing the logistic chain.
This is used with the US 155mm M795 and M549A1 HE projectiles with mission critical data being loaded into the PGK using the Enhanced Portable Inductive Artillery Fuze Setter.
By April 2020 over 50,000 PGK had been produced and export sales made to Australia and Canada. Test firing had been conducted with a number of other artillery systems including the German PzH 2000. This fired a Rheinmetall DM111 HE projectile out to a range of 27km with all 10 rounds landing within five metres of the target.
There are other course correction systems including the Nexter Systems Spacido and the Top Gun from Israel Aircraft Industries IAI) which has been adopted by the Israel Defense Force for its 155mm artillery projectiles.
Northrop Grumman M1156 Precision Guidance Kit (PGK) is a direct replacement for a standard artillery fuze and provides a step change in accuracy.
Laser Guided Projectiles
The US Army did field the 155mm M712 Cannon Launch Guided Projectile (CLGP) and this has seen combat in the Middle East. Production of these was completed by Martin Marietta many years ago.
This was a laser guided projectile (LGP) although the main drawback was that the designator had to be in line with the target. More recently airborne designators, for example installed in an unmanned aerial vehicle (UAV), can also be used to designate the target in addition to ground based laser designators.
NORINCO is currently marketing a complete family of LGP including the GP155 with a maximum range of 20km and GP155A with a maximum range of up to 25km. Both of these have a HE warhead and are claimed to have a hit probability of 90 percent.
A more recently development by NORINCO is their 155mm GP155B projectile with GPS and BEIDOU satellite navigation. This is claimed to have a maximum range of up to 35km and is fitted with a HE warhead with a circular error of probability (CEP) of between 15-20m claimed.
NORINCO also market a 122mm LGP called the GP122 for use with 122mm artillery systems such as the widely deployed Russian D-30 and its numerous SP equivalents.
The Russian KBP Instrument Design Bureau has developed a family of 152mm and 122mm LGP and for the export market developed a 155mm Krasnopol. This is known to have been used by India with its Bofors FH-77B 155mm artillery systems during operations on the border with Pakistan.
The latest 155mm is the Krasnopol-M2 (K155M) which is fitted with a HE fragmentation warhead a maximum quoted range of up to 25km. It is used in conjunction with the Malakhit Automated Fire Control Systems which includes a tripod mounted laser designator and rangefinder unit with a thermal imager, commander’s computer and a radio set. At the firing position is the commander’s computer, radio set and gun transceivers kit.
by Christopher Foss