The thunder of big guns across Europe and beyond

Not only are wheeled and tracked large-calibre howitzers some of the most effective systems now being used by Ukrainian artillery in their defence against Russia, but they also appear to be the favoured route taken by western procurement initiatives and programmes.

As is well known, numerous NATO and Allies have provided Ukraine with a wide range of defence hardware, including large-calibre artillery platforms, both new and old. They have done so by either rerouting new orders from industry directly to the front or by using equipment from their own existing and legacy stocks. Fortunately, many of those nations had new artillery acquisitions and modernisation programmes already underway, even before Russia’s 2022 invasion of Ukraine began and, as a result, gaps left by urgent deliveries to Ukraine should be filled before too long.

On the battlefield, qualified preferences emerge

Ukrainian artillerymen have certainly become well versed in using a wider variety of Western and Soviet-era artillery under fire than any other allied force. As the war has continued over the past 30 months, they have taken delivery of various NATO/Allied artillery pieces in multiple calibres to bolster their armoured inventory. Towed M777 and FH70 155 mm howitzers, for example, have made a considerable contribution to Ukraine’s defence, although they have reportedly experienced a relatively high percentage of losses from counter-battery fire, largely due to their low mobility. Improving on that issue, tracked, self-propelled (SP) 155 mm stalwarts, such as the enduring M-109A3, (some delivered from Norway), newer M-109A6 Paladins (the US delivered 18 from May 2023), UK AS-90s, Polish Krabs, and German-made PzH 2000s (supplied by both Germany and Italy), have all been making their capabilities felt. On the wheeled 155 mm SPH side, Ukraine has received Nexter’s CAESAR in both 6×6 (from France) and 8×8 (from Denmark) variants, along with Archer, DANA, DANA M2, Zuzana 2, and is awaiting receipt of the RCH 155 SPH, based on the Boxer 8×8 platform.

Certainly, some of the older systems such as the M109A3s, still rely on manual onboard methods for laying and firing, which, while fine in terms of accuracy on target, slows firing rates down. Newer platforms such as the CAESAR, PzH 2000 and M109A6 use onboard computerised gun laying systems, in turn helping them deliver improved rates of fire so the guns can get into and out of firing positions faster than the older systems. However, such ‘shoot-and-scoot’ tactics, honed by the Ukrainians after their painful experiences of Russian counter-battery fire in the Donbas during their early confrontations in 2014, are essential to avoid attrition by enemy fire once a fire mission has been conducted – something which can happen in a matter of just a few minutes if Russian detection and location systems are performing optimally. These high-paced tactics mean SPHs must constantly move into position, fire, and reposition, sometimes in excess of five or six times a day. Some platforms have had problems operating under such conditions. A January 2023 news story by Estonian publication ERR reported following a conversation with Ukrainian artillery personnel, that their M109A3s frequently broke down, and other reports have noted that various Western SPHs used by Ukraine have had significant down-time due to automotive and equipment failures, including engines and tracks, as well as high barrel wear.

When it comes to towed platforms, such as M777s and FH-70s, while proving their worth with excellent fire power, their lower mobility has meant fewer gun-position changes than their self-propelled counterparts, resulting in often greater attrition rates to Russian counter-battery strikes. Indeed, in many cases, these towed guns have had to remain dug in and emplaced in the same gun position for extended periods of time, with crews relying on a combination of camouflage and seeking cover nearby when incoming counter-battery fire or drones are detected.

In support of big guns – ammunition and barrels

All that said, Ukraine’s artillery units have expressed gratitude on numerous occasions for the guns provided by allied nations, whether 105 mm or 155 mm, towed or SP systems, old or new. But there is no getting away from the fact that modern SPHs such as CAESAR, PzH-2000, and Krab SPH – for their improved performance, mobility, automated gun-laying, and overall survivability – are the preferred platforms on the battlefields at this time, though more are needed and have been requested.

One major positive factor worth mentioning and applicable to the majority of the guns supplied by Western Allies is that most of them rely on NATO standard 155 mm rounds, and although this ammunition supply has on occasion led to what the Ukrainians have called ‘ammunition famine’, these rounds have, nevertheless, been more readily available than ammunition for legacy 122 mm, 152 mm and 203 mm Soviet-era systems. Indeed, substantial quantities of non-NATO-standard ammunition have had to be sourced by the Ukrainians, often with great difficulty.

A case in point is that Ukraine’s largest calibre legacy howitzer, the 203 mm 2S7 Pion SPH. To keep their 2S7s firing, Ukraine has reportedly been using WWII-era ammunition, possibly provided by Albania in late-2022 or early-2023, which was originally made for the Soviet B-4 203 mm gun. In addition to this, Ukraine also received around 10,000 M106 203 mm HE-FRAG rounds from US ammunition stocks, which surprisingly were compatible with the 2S7. These rounds were previously used by the M110 SPH, which has been long-retired from US service, but remains in use with several nations, some of which may prove a potential source of 203 mm ammunition for Ukraine going forward.

In a brief conversation with ESD about ammunition and the war, Trevor Taylor, Professorial Research Fellow and Defence, Industries and Society Director at the Royal United Services Institute (RUSI), said that the risks Ukraine has had to take, using different shells from various countries and manufacturers, underlines the need for NATO/Europe to adopt an effective shell standardisation plan to improve interoperability of ammunition. At present, 155 mm shells are often made to slightly different design specifications, tolerances, and testing and safety procedures by different manufacturers, which can lead to situations where a given 155 mm howitzer might be compatible with some 155 mm shells, but not others. With the war in Ukraine repeatedly highlighting the importance of maintaining a steady supply of artillery ammunition, improving such an approach is more essential than ever.

Indeed, complementing Taylor’s ammunition sentiments were calls from industry leaders during Eurosatory 2024, for a greater and more urgent allocation of funds to increase NATO-standard 155 mm ammunition production, under the EU’s Act in Support of Ammunition Production (ASAP) programme. This highlighted the increasing emphasis on the use of larger-calibre platforms, including the important role these are playing in Ukraine, and where much of the 155 mm ammunition being produced is destined at this time. In fairness, ammunition makers across Europe, from BAE Systems to Nammo, Rheinmetall and others have most definitely already been ramping up their 155 mm ammunition lines to both bolster supplies to Ukraine, but also replenish the dwindling stockpiles across NATO member countries.

In addition to these large-calibre ammunition machinations, GDELS announced in June 2024 that its Santa Bárbara Sistemas plant in Asturias was reactivating its large-calibre, gun-barrel production lines, including, importantly, for 155 mm artillery barrels. This, it said, was in response to increased demands at both the national Spanish, as well as international, levels. The plant, which has been making gun barrels for over 200 years, has more recently delivered barrels for the GDELS SIAC towed 155 mm L52 mm howitzer, as well as L118 and L119 105 mm Light Guns.

A Baltic stalwart

Moving beyond Ukraine, various NATO countries have undertaken efforts to modernise their artillery fleets. Estonia has placed an order for 24 South Korean K9 Thunder 155 mm SPHs from Hanwha Aerospace in 2018, with the first batch of six delivered in 2020. This order was supplemented by a EUR 36 million contract signed in January 2023 for a further 12 K9s, bringing Estonia’s total requirement to 36 SPHs. In December 2023, the country received its most recent batch of six K9s, bringing their fleet strength to 24, with the remaining 12 guns set to arrive and become operational by 2026.

Estonia’s receipt of the new SPHs made the Baltic nation comfortable enough in 2022 to step up to the mark and support Ukraine within just weeks of Russia’s invasion, when it delivered 36 Soviet-era D-30 122 mm and 24 FH-70 155 mm towed guns, along with associated ammunition and vehicles over the course of several months. Indeed, Estonia has been extremely active in its support for Ukraine, providing significant military aid in relation to its GDP.

To ensure the new platforms can be supported properly, the Estonian Defence Force has been upgrading and building a new heavy weapons workshop and maintenance facilities at its military base in Tapa. Already with warehousing and storage locations for K9s in southern Estonia, the new facilities are intended to enhance the nation’s overall capabilities and support for its indirect fire weapons and accommodate the technical challenges required to maintain the K9, with specialist infrastructure that includes lifting equipment to conduct barrel and turret replacement, engine lifts, and more. The new 1,580 m² workshop facilities, which were officially opened in April 2024, cost some EUR 5.5 million, a small outlay in comparison to the guns themselves.

As an aside, though still on the maintenance, repair and overhaul (MRO) front, CAESAR manufacturer KNDS France, recently announced its deployment of a turnkey, modular MRO facility to Ukraine to support the Caesar 6×6 and 8×8 155 mm SPHs currently in use in the war; the capability is based on KNDS’ containerised Multibox MRO solution.

Estonia’s new K9s were put through their paces from January to July 2024 in Exercise Spring Storm 24, the largest annual exercise in which the Estonian Defence Forces (EDF) participates, and part of NATO’s Steadfast Defender 2024 exercises. During the exercise, K9s of the Estonian 25th Artillery Battalion provided indirect fire support to the EDF’s 2nd Infantry Brigade. Although they have a maximum range, firing a standard HE base bleed (BB) round some 40 km, the EDF website notes that their K9s are able to strike targets accurately up to 70 km away using unspecified ‘precision ammunition’ – this is understood as probably referring to usage of the Leonardo Vulcano Guided Long-Range (GLR) sub-calibre guided projectile, fitted with a semi-active laser (SAL) guidance option. In general, the 47 tonne tracked guns display good off-road capabilities, as well as a 67 km/h maximum on-road speed; they also incorporate extensive armoured protection for their five-person crew. Owing to their semi-automatic loading system, in which the rounds were loaded automatically, while the charges were loaded manually, the K9 and K9A1 variants can deliver a maximum sustained rate of fire of between 6-8 rds/min.

Yet, the latest K9s are far from the end of the current story for Estonia’s ambitions to bolster its artillery capabilities. In June 2024, during the Eurosatory exhibition, Estonia’s National Defence Investment Centre (RKIK), signed a deal with the French Defence Procurement Agency, DGA, and defence company KNDS, for the delivery of 12 CAESAR 6×6 SPHs. According to France’s national armed forces director, General Gazin Diaz De Tuesta, the deal is a joint procurement between Estonia, Croatia and France, which will help increase interoperability between the EU’s ground forces.

In the field, the guns will equip a new artillery battalion that will, according to project officer, Lt Col Rauno Viitman, come under the direct command of the Estonian Division. The first six units are expected to be delivered by end-2024, with the remaining systems during the first half of 2025, taking advantage of ramped-up production lines at KNDS France; which have increased production from two CAESARS a month to six. France’s Minister of Armed Forces, Sébastien Lecornu, said, during a visit to the plant in April 2024, that a target of 12 CAESARs a month will be achieved, soon, with the help of a reduction of the production cycle from 44 months to 18 months. The list of armed forces with CAESAR either in service or on order at the time of writing includes: Armenia, Belgium, the Czech Republic (using a domestic 8×8 wheeled platform), France, Indonesia, Lithuania, Morocco, Saudi Arabia, Thailand, and Ukraine.

More thunder on the horizon

Beyond Estonia, Hanwha Aerospace’s K9s have, without a doubt, become one of the most successful SPHs in terms of exports, and the company continues to forge international industrial partnerships to market its platform to potential new customers, as well as support its exports and successes.

Poland has had a long-standing relationship with Hanwha, which supplied the tracked platform component of the K9 for Poland’s Krab 155 mm SPHs. This relationship was further bolstered in May 2024 when it signed a Letter of Intent with Polska Grupa Zbrojeniowa (PGZ) and Huta Stalowa Wola (HSW) to expand cooperation between the Polish and South Korean defence industries, particularly with respect to ​​technology transfer for K9 MRO requirements, as well as supporting exports to third countries of components used in both the HSW-made Krab and Hanwha’s K9.

In August 2024, Hanwha achieved a major milestone in Australia, where it opened the Hanwha Armoured Vehicle Centre of Excellence (H-ACE), a Hanwha Defence Australia production facility for the Australian variant of the K9 family – the AS9 Huntsman SPH and its associated AS10 armoured ammunition resupply vehicle. The plant is the first production line to be opened by a South Korean defence company overseas and is set to deliver 30 AS9s and 15 AS10s for the Australian Army. Collectively termed the Huntsman family of vehicles, deliveries will commence from 2025. Australia’s Joint Proof and Experimental Unit (JPEU), alongside Hanwha personnel, conducted ammunition verification trials on the AS9 between August and December 2023, to ensure in-service and future ammunition and propellant types don’t exceed the gun’s specifications, thereby ensuring crew safety and reliability in combat. With hundreds of rounds fired over the five-month trial period, ranges of up to 60 km were, reportedly, achieved.

The AS9 essentially a sub-variant of the K9A1 standard, with additional user modifications including enhanced explosive ordnance integration, improved crew protection, and advanced digital capabilities and communications. As with the K9A1 from which it is derived, the AS9 Huntsman can fire three rounds in a 15-second burst, can achieve a sustained rate of fire of 6-8 rds/min, and is possesses a three-round multiple-round simultaneous impact (MRSI) capability, wherein it fires several rounds at different elevations and charge loads, such that they all hit the target simultaneously.

Decisions, decisions – UK’s mobile fires

When the full-scale war in Ukraine began in 2022, the UK’s artillery was already in a state of flux and the UK was in the market for new SP 155 mm platform to replace its AS-90 tracked systems. Nevertheless, the country was able to respond quickly to the Russian invasion and offer significant military support for Ukraine, which, amongst much else, included large-calibre artillery to the tune of 20 units of the 155 mm M109A3 SP howitzer with some 32 AS-90s following not long thereafter.

Hanwha, long with members of ‘Team Thunder’ offered its K9A2 variant to the UK as a possible contender for its Mobile Fires Platform (MFP) programme to replace AS-90. However, it was ultimately not selected for MFP.

What has transpired for the UK’s requirement instead, has been the March 2023 deal to purchase 14 wheeled Archer 155 mm SP systems as ‘gap fillers’ from Sweden as part of a strategic, government-to-government (G2G) agreement involving the Swedish Defence Materiel Administration (FMV); this purchase is focused on both continued support for Ukraine, as well as long-term cooperation around the UK’s new Archer systems. A short six-month timeframe for delivery of the first units has enabled the UK to donate its remaining AS-90s to Ukraine without being left wanting for replacement firepower before a final major MFP decision could be made. Most of the 14 Archers, which have been upgraded to UK specifications by BAE Bofors, are now with 19 Field Regiment RA, based in Larkhill on Salisbury Plain.

However, being a stop-gap solution was not meant to be the end of the UK story for Archer, as, like the K9A2, the wheeled 155 mm gun was also an MFP contender, the Archer Artillery Alliance comprising BAE Systems, Babcock and Rheinmetall BAE Systems Land, or RBSL, having been brought together to make a bid.

As it was, in April 2024, the UK MoD finally announced that the KNDS Remote-Controlled Howitzer 155 mm (RCH 155) 52-calibre based on the Boxer 8×8 platform had been selected to meet the UK’s MFP requirement. The howitzer is intended to enter service with the Royal Artillery by 2030, latest, and will be built in both the UK and Germany, with its RCH module mounted on a Boxer 8×8 drive module. Some senior sources have been reported as saying the whole programme may be worth close to GBP 3 billion, although this is uncertain at this time, as are the number of units to be purchased.

Nevertheless, the new SPH delivers significantly improved range and accuracy over AS-90, together with a higher rate-of-fire of up to 9 rds/min and a range of some 40 km with base bleed rounds. RCH 155 has a 5-round MRSI capability, and despite being on a wheeled platform, can still fire throughout its turret’s 360° arc. A new capability marketed for RCH 155 is its capability to fire on the move. While potentially useful as a means of avoiding counter-battery fire, the platform is limited to moving at slower speeds while aiming and firing to prevent excessive movement of the barrel. Although it introduces an interesting new capability, in practice, firing on the move would be expected to be limited to where the terrain is sufficiently smooth to permit doing so, and would also be expected to be less-likely to be used in scenarios where accuracy is paramount, as being stationary imparts no additional movement on the barrel. Being a Boxer-family variant, the RCH 155 uses the common Boxer drive module, which provides existing boxer users with platform commonality and interoperability.

In a UK MoD statement following the selection of RCH 155, Lieutenant General Dame Sharon Nesmith DCB, Deputy Chief of the General Staff, stressed the importance of collaborating with Germany to develop the RCH 155 as the British Army’s Mobile Fires Platform, saying, “It not only presents an invaluable opportunity to work alongside our vital ally, Germany, but also demonstrates our clear commitment to, and leadership role within, NATO.”

With military chiefs and politicians warning that the UK is potentially in a pre-war situation, opportunities to accelerate the new platform’s delivery timeframe will be examined by the RCH 155 project team, including how to enable faster delivery at lower cost by exploiting the combined capabilities of test and trials centres in both the UK and Germany.

Tim Guest