Nenonen’s heritage, pt 1: The Mission

The future of Finnish artillery is a topic I’ve touched upon earlier as well, in particular this post from a few years back. Much of what I wrote back then is still valid, but as the topic is complex, and certainly deserving of deeper study than a single post thrown together on a train provides, the time has come to revisit it. The two key sources here will be The Future of Fires, a RUSI report by Jack Watling from last year that looks at the situation from a UK-angle but with several aspects that carry over to the general artillery discussion, and Tykistö taistelee tulellaan, a Finnish book from 2017 on the first century of Finnish artillery tactics written by colonel (ret.) Pasi Kesseli, PhD. As is usual with Finland, there are serious gaps in open sources due to the strict focus on operational security, but Kesseli does cover the development from 1990 and up until the current day in approximately ten pages, which provide some interesting insights into Finnish artillery doctrine and organisation, information that can then be fitted into the more general picture provided by Watling.

The current Finnish doctrine divide fires into tactical and operational levels. The tactical fires aim at directly influencing the flow of battle either immediately or within a very short time span. In practice, this means that the firing ranges are often shorter, and the fire missions include both destruction as well as suppression of targets. The missions are usually handled by the organic artillery and mortar units available at the brigade level or below, though support by for example light rocket launchers (122 mm RM-70, locally know as 122 RAKH 89) can also fill the role if so required. Fire direction is also usually handled by the organic C2, sensors, observers, and reconnaissance assets. See Eyeonscandinavia’s post for a more detailed discussion on the role of the observers.

Operational fires on the other hand deals with the critical systems and nodes of the enemy, meaning that if they can be affected the capabilities of the enemy to carry out successful military operations are suffering. These are often found further back from the frontline, but it is important to note that as opposed to earlier Finnish doctrine which did differentiate between tactical and operational fires based on range, the difference is now based purely on the value of the target. This is roughly in line with Watling’s report, which grapple with the question of fires based on four different mission sets:

• Breaking up enemy force concentrations,
• Providing fire support to enable manoeuvre,
• Suppression of enemy fires (counterbattery fire),
• Striking high-value targets.

Of these, the first two can be seen as tactical fires according to Finnish doctrine, while the second two are operational level missions.

The Finnish Army is decidedly artillery heavy, featuring a serious amount of organic indirect fires at all levels starting with the battalion. The core unit in the artillery is the 18-gun battalion, consisting of three 6-gun batteries. These are either light (122 mm D-30 howitzer, locally designated 122H63) or heavy ones (using either Soviet-built 152 mm or Finnish 155 mm equipment), with the whole artillery battalion always using the same calibre. The battalion is treated as a single firing unit, though certain fire missions can be handled by either a single or two of the battalion’s batteries. A key detail is that the battalion has a robust enough C2-system that it can control fire from several battalions. This is based on the M18 combat engagement system provided by domestic supplier Bittium, and which is seen as a key enabler in allowing the Army to conduct dispersed operations at a rapid pace, something which the artillery arm is taking advantage of. Already as part of the now obsolete Brigade 2005 structure any artillery battalion could direct fire from not only it’s own guns, but from another two tube or rocket artillery battalions as well. How many firing units can be controlled by a single battalion’s fire direction centre under the current organisation is not open information.

This modularity is obviously not unique to the artillery, but is part of a more general trend in the Finnish Defence Forces to be able to react to changing situations by tailoring the forces under a given command to meet any particular situation, including combining different capabilities and unit levels (local, regional, operational) to produce the desired order of battle to meet requirements. The switch to more robust baseline units to be able to handle missions at lower levels and be able to absorb some losses without losing combat capability is not unique either, but is also mirrored in how infantry units have grown in size.

The towed batteries which make up the vast majority of Finnish indirect firepower rely on dispersion for protection, spreading out the artillery battalion over an area that can be as wide as 15 by 40 kilometers, with individual guns preferably at least 500 meters from each other. In practice, this reduces the battery from a single high-value target to a number of individual targets of lesser value. Another key aspect in improving the survivability of the batteries have been the continuous improvement of the organic entrenchment capabilities of the units, including heavy vehicles to prepare gun positions and close-in defence positions for the riflemen. The latter is also increasingly important as under the most recent doctrine (Maavoimien uudistettu taistelutapa) there is a focus on having the guns placed close to the front and having stored “an abundance of rounds” in these forward fire positions, to be able to cause the enemy a large number of casualties and disruptions from the get go. The obvious downside to dispersed positions and forward locations is the risk of the individual guns being overrun by advancing enemy units, as their location makes them vulnerable and a concentrated defence becomes more difficult.

While many of the concepts presented in Watling’s paper largely correspond to current Finnish artillery doctrine and the general trends identified in Finland, there is a key difference, namely the relatively narrow frame of reference provided in looking at a UK division fighting in a defensive expeditionary war as part of a NATO corps structure. While this is comparable to the question of what kinds of fires Finland might have a need for in the direction(s) that is the focus of operations, the broader Finnish question include what kind of fires are needed in secondary directions as well. The modularity is also more critical from a Finnish point of view, to be able to quickly create a concentration of fires in a certain area. Here it should also be noted that the Finnish force structure above the brigade level is not public information, and hence it would be incorrect/uncertain to talk about division or corps assets within a Finnish framework. However, the Finnish system does sport a number of high-end systems which are described as not being part of the brigade structure, and the role of these higher-level assets correspond to those associated with the British division and corps assets (including both providing additional tactical firepower when the need arises as well as providing operational fires). The most probable Finnish organisation is that these higher level assets are found in independent battalions, which are then attached to higher level formations as appropriate.

The current British top-of-the-line tube artillery is the two regiments of AS90 self-propelled 155 mm howitzers. As opposed to many newer systems such as the K9 and the PzH 2000, the AS-90 is equipped with a shorter L39 barrel. A British artillery regiment is in fact corresponding to battalions in other countries, although the British Army uses an eight-gun battery structure, giving the regiment 24 guns. This is something that the Finnish Army also has studied in detail, and the idea was given serious thought in the late 90’s as it would have made it possible to keep performing fire missions while constantly having one of the battalion’s three batteries on the move. In the end, it was opted against this setup, amongst other things due to the difficulty in finding suitable firing positions for a dispersed eight gun battery.

Watling envisions a very similar kind of tactic for the British regiments, although he calculates with firing ranges for 52-calibre howitzers and not for the current AS90:

Across the 24-gun group, with two guns firing on each fire mission, and the firing pair handing over at two-minute intervals, the group could prosecute four separate fire missions delivering eight rounds per minute to each, and sustaining this rate of fire – assuming a magazine capacity of 40 rounds per gun – for 30 minutes. If the battery is reduced to three sustained fire missions then six guns can replenish their magazines so that the rate of fire can be sustained as long as ammunition continues to be moved forward, as per the existing carousel system for resupply. The elegance of this system is that for an enemy artillery commander, they would only observe two isolated firing positions at any given time, which would change frequently.

[…]

If such a regiment were deployed 12km behind the contested zone, its rearmost gun would be able to deliver effects 24km into the contested zone, while the regiment could deliver MRSI 16km into the contested zone, thereby remaining able to deliver – given a six-round salvo per gun – between 144 simultaneously impacting and 3 salvos of 48 155-mm shells to any point within the operating area of an opposing MRB.

Watling’s conclusions are that no high-readiness brigade can operate on the modern battlefield with less than 24 155 mm self-propelled guns, as these are the bare minimum for the tactical fire missions that can be expected when operating within a NATO structure where additional divisional and corps fires can be expected to handle the counterbattery role and other operational level missions. For a whole divisional support group that also would handle some of these operational tasks, the need would be a minimum of 72 guns, as well as a regiment (battalion) of heavy rocket launchers. For these to be able to go toe to toe and match the Russian capabilities, different kinds of modern area effect and sensor-fused (sub-)munitions are required to achieve a higher effect than traditional unitary warheads. The latter notion isn’t uncontroversial, as it partly runs counter to the Oslo Convention on Cluster Munitions (CCM), of which the UK is a signatory (as opposed to Finland, Russia, and the USA). However, it is notable that if encountering a corresponding Russian unit, a British division of today would be outgunned both in numbers as well as firing ammunition that produces a less lethal effect compared to their Russian counterparts.

However, with 72 heavy guns providing operational fire missions, Watling feel that 155 mm is overkill for the tactical supporting fires. Currently the light fires in UK units comes from the ubiquitous 105 mm L118 light gun, which is towed. As Watling argues for all guns to be self-propelled, and as the battalion support gun in British service will need to be airmobile (i.e. below the eight-tonne lift capacity of a Chinook), he notes that the most viable solution would likely be that battalion-level fires would be provided by a 120 mm mortar on a light vehicle such as the Supacat. The firepower of this solution is not completely unlike the Swedish solution to provide battalion fires with a twin-barrelled 120 mm mortar mounted on a CV90 chassis, though the reasoning behind is rather different (Sweden having arrived at the solution by focusing tactical mobility as part of the mechanised battlegroup rather than higher level mobility). As there is no Finnish requirement for airmobility for the battalion fires, especially not for the local forces, this line of reasoning has less relevance for the Finnish situation. However, if we for a moment stays with the UK divisional example, Watling end up with the following total:

• One battery of anti-tank guided weapons per battlegroup.
• One battery of 120-mm mortars per battlegroup.
• 72 155-mm 52-calibre howitzers with anti-armour area-effect munitions or DPICM.
• A regiment of MLRS with a compliment of sensor-fused sub-munition dispensing
rockets, and LRPF.

These are then supported by corps-level assets, but contrary to many NATO-centred analyses Watling actually does not expect much in the way of support from the air during the early stages of the conflict, a starting assumption that does mirror the Finnish situation.

As noted, it isn’t possible to make an apples-to-apples comparison for a Finnish order of battle as the Finnish wartime OOB is a) secret, and b) less formal in nature than a British expeditionary force would be. However, it is notable that during the first decennium of the millennium (newer numbers are secret) the standard according to Finnish doctrine was that an attacking brigade would be supported by an additional 72 to 108 guns or rocket-launchers from higher assets in addition to the brigade’s organic 18 gun battery, numbers that come very close to the divisional support group argued by Watling. 72 is by the way an interesting number in that it is a multiple of both 18 and 24. We’ll be back to multiples of 24 in a week or two, as one has appeared in an unexpected place.