This article appeared in the 2021 edition of The Bridges Papers.


The provision of logistic support to the fighting force, the task known as Combat Service Support (CSS), encompasses a broad range of actions that each have their own complexities, and yet are critical to maintaining combat power.[1] Yet often these specific activities are not considered in detail, instead being grouped into CSS ‘sub- BOS’, such as ‘distribution’, failing to capture the tactical nuances inherent in their execution. This paper is written to provide the CSS planner and all-corps staff officers an understanding of the considerations in supplying artillery with ammunition. It will discuss the flaws in the current approach to artillery ammunition resupply and offer focus areas for closing these gaps.


Ammunition is arguably the single most critical supply class; without which the battle can not occur. Within the CSS arm, Class V, like all classes of supply, is often viewed as a monolithic consideration – specific commodities are rarely, if ever singled out during planning by generalist logisticians. The grouping of commodities into supply classes lends itself to this mindset, which is reinforced during individual training of CSS officers, warrant officers and senior non-commissioned officers on courses such as LOBC, LOIC and WOCSS.

With such a broad range of supply items for which a staff planner must anticipate demand, develop replenishment methods, and coordinate tactical execution; it can be easy to overlook specific considerations for commodities such as 155mm artillery ammunition. Resupply of artillery organisations with ammunition – far from being a unit-level consideration – is a critical CSS activity that must be planned, synchronised and executed by multiple levels of C2 from the artillery regimental headquarters to the Force Support Group (FSG). It must be considered as a critical CSS action in its own right, from the commencement of pre-H planning through all phases of an operation.[2]

The reasons for this are manifold. The most obvious one is that without effective and efficient resupply, the guns of the Combat Brigade (Bde) will fall silent – a culmination of one of the most critical organic assets of the Brigade Commander, essential for enabling manoeuvre. But what might not be as readily apparent to generalist planners (CSS and otherwise) are the practical complexities of artillery ammunition planning. The current structure of the artillery regiment provides sufficient lift at the A1 echelon to achieve their short Operational Viability Period (OVP). The A2 echelon is not structured to support artillery ammunition resupply, doctrinally holding no additional OVP at the regimental level.[3] However; with the introduction of the HX77 ILHS platforms, a small ammunition transport capability can be generated with a limited acceptance of risk to staffing in other areas. Therefore; the execution of artillery ammunition resupply must be prepared to commence from D+1 to ensure a weight of fires is sustained. Decisions will need to be made pre-H as to the positioning of stocks within the BMA, how much, and whether at any stage divisional CSS echelon FE will distribute forward of the BMA – as has been the common ‘go-to’ course of action for third to first line interaction. A CSS staff officer may find themselves needing to coordinate critical resupply of artillery for any number of reasons, from an inappropriate combat load of ammunition relative to a requested effect (e.g. carrying mostly HE when large scale illumination required), to an obstacle breach lasting longer than expected and additional obscuration being required.[4]

Shot, over – The planning considerations of artillery ammunition resupply


155mm howitzer projectiles are the heaviest commodity of EO, round for round and in terms of volume occupied. Weight, dimensions, and anticipated consumption rates have direct implications of the amount of lift required. Current doctrine provides the maximum planning figures for artillery ammunition expenditure.[5] What this doctrine does not provide to the generalist CSS planner though is an understanding that 155mm projectiles comprise only half the requirement, with attendant fuses, primers and charge bags rounding out the demand (hereafter collectively referred to as CLVArty) imposed by artillery.[6]

As has been learnt during training activities since the introduction of L121 MHC: for every ILHS flatrack fully laden with 155mm projectiles, another flatrack is required to lift the supporting ancillaries. This is further complicated by load configuration. It is tactically unsound to transport 155mm projectiles separate from the ancillaries, due to the risk of loss of a platform destroying the entirety of one munition type (i.e. CSS best practice is to achieve two-point dispersion of loads). As such, it is preferable to configure a flatrack as a combat load-out, holding projectiles with the ancillaries needed to arm them on the same platform. This then reduces the capacity of the flatrack, more than doubling the amount of lift required. This demand of projectiles of varying types (HE, illumination, smoke, SMArt, etc) and ancillary items, forms a significant distribution burden.


The longevity of an operation rests on the ability of CSS to sustain it.[7] The concept of CSS for an operation must take into consideration the ongoing demand for CLVArty and be prepared to meet this. This operational endurance should also include a surge capacity, as the commonly used expression ‘days of supply’ (DOS) does not always accurately capture spikes in consumption cause by unplanned actions, friendly or enemy initiated.

Distance & Destination

As an operation continues, planners should generally expect increasing lines of supply. There are exceptions to this (such as retrograde operations), but generally the length of the CLVArty supply chain will reach from the FSG Ammunition Point (AP) forward to the artillery regimental AP to the gunline, via the Brigade Maintenance Area (BMA) or bypassing as required. This increase in distance will have impacts on the responsiveness of the supply chain. The destination will also impact the configuration of loads – bulk resupply intended for the BMA AP will be loaded differently to a replen intended for the A1 echelon of a gun battery.[8]

It is worth noting that these considerations are largely based around land-based distribution. The contemporary operating environment will likely see forces operating in littoral or riverine battlespaces, further complicating resupply as commodities are distributed via multi-modal assets such as water transport or rotary wing.


Dispersed operations are common for the Brigade artillery regiment. Gun batteries in direct support of manoeuvre battlegroups (BGs) may be found operating along different axes of advance, increasing the complexity of coordinating concurrent replenishment. The planning of CLVArty replenishment must take into consideration the way artillery callsigns operate, ensuring coordinating instructions and control measures support artillery manoeuvre areas (AMAs) and gun positions without interrupting planned fire missions. When capacity does not exist to effect concurrent replenishment, priority must be allocated based on an understanding of which fire unit is supporting the main effort – this can change between fire missions and is dependent on the support relationship (direct support, reinforcing or general support) with the BGs.


In logistic terms, velocity of the supply chain refers to the ability to complete an activity as quickly as possible.[9] This concept is particularly pertinent to the activity that is CLVArty resupply. As described above, the nature of the CLVArty supply chain is unique, consisting of an extended supply chain (both geographically and in terms of the span of command it crosses), with a dispersed dependency and a large demand, both in terms of consumption and physical loads. If not appropriately resourced with adequate distribution assets, the velocity of the CLVArty supply chain risks slowing to a point of culmination.

The requirement articulated above may not seem so insurmountable, upon consideration. While a not-inconsiderable amount of lift must be assigned to distribute CLVArty each day, the introduction of L121 MHC capability (specifically ILHS platforms) provides a one-time lift capacity in both the BSG and FSG not enjoyed previously. The physical lift in support of a single regiment is only part of the problem, however. Consideration must be given to ‘future-proofing’ the CLVArty supply chain.

Shot, out – The future

With the increasing prominence of land-based fires to the force, CSS planners should expect to see additional dependencies within the force in the future. The raising of a divisional, long-range fires asset is the best such example; whilst still little more than a concept at present,[10] such a unit would also require direct support from the FSG. With multi-domain operations increasing the emphasis on the importance of long-range fires, the sustainment requirements would likely be significant. This provides impetus to commence the transformation of CSS to meet these needs now – a change imperative that has only been discussed in the broadest terms by the CSS arm.[11]

The procurement of the long-discussed protected mobile fires (PMF) capability will change the nature of the artillery supply chain as well. With the impending procurement of PMF platforms, an understanding of how it will impact these considerations will aid in future-proofing the provision of CSS to artillery. For example, self-propelled guns have clearly defined quantities of rounds they can hold integrally to the platform. This limitation will require the A1 echelon ammunition lift assets to hold the remainder of the battery first line ammunition, rather than an additional line for immediate replenishment. This will limit the OVP of the gun battery, necessitating regular resupply of CLVArty – potentially as much as every 24 hours.

Splash, over – Rounds not on target

Is the Army currently at a standard where it could sustain the demands of an artillery regiment in a protracted high-intensity warfighting scenario? Beyond the simple physical transport requirements, far more crucial is the ability of CSS planners in multiple C2 nodes (FSG, Div J4, Bde HQ, CSSB and the artillery regiment) to coordinate and synchronise an effective resupply plan that is integrated with the fires plan. The easiest way to achieve this unity of staff effort is through accurate doctrine, reinforced during training.

The current depth of doctrine and SOPs regarding operational resupply of CLVArty is limited, to say the least. LWP-CSS 4-0-1 Combat Service Support in the Theatre makes mention of support to artillery only by noting that dumping behind gun lines may be required.[12] LWD 3-4-1 Employment of Artillery provides a greater depth of detail, but introduces concepts not mirrored in other CSS publications – such as the use of third-line serviced replenishment parks or the delineation of responsibility between force-controlled resupply and brigade-controlled. In short, the available doctrine would not eliminate ambiguity as to the correct demands and responsibilities amongst CSS and OS FE, even if all were readily conversant with it.

This is borne out by recent experience of the force on collective training activities. The H17 Sustainment Evaluation Report[13] identified EO resupply (not specifically CLVArty, but including tank/HE natures) as a required focus area for subsequent collective training, yet the subsequent SLS18 Sustainment Evaluation Board[14] did not evaluate this in detail.[15]

At the tactical level, EO resupply was assessed[16] through the injection of one deliberate and three related reactive serials into the MESL.[17] Whilst encouraging, this activity represented a ‘once-off’ deliberate action by the FSG that did not replicate the sustained demand real-time support would require. It is not enough that CLVArty replenishment is conducted as a reactive, deliberate task initiated only upon receipt of a demand from the fires echelon in the battle. Rather, identification of likely demand and prepositioning of stocks, through the time-proven process of warning orders and the use of forward CSS nodes, would serve to increase the velocity of the supply chain and CSS responsiveness.

Finally, the artificial limitations of a collective training activity such as HAMEL or TALISMAN SABRE do not allow for the tyranny of distance that may be imposed by a Combat Brigade advancing away from the FMA, nor truly represent the length of time such an effort must be sustained; less the deployment and retrograde activities either side, major exercises tend to last less than two weeks.

Splash, out – Adjusting fire

In order to ensure the CSS network is ready to meet the demands of CLVArty resupply in high-intensity warfighting, a reframing of the way CSS planning is conducted needs to commence now. CLVArty resupply needs to be identified early in any operational staff planning process as a priority, requiring integration of multiple staff planning processes achieving commonality by the universal application of doctrine and SOPs.

Usage estimates must be aligned with the tempo of the F-ech and account for munition types, not just a catch-all ‘X rounds per day’. This information must be fed to S4 branches at all echelons above the artillery regiment. Dedicated transport FE should be assigned to CLVArty at both the general and close support echelons. Robust control measures are required to ensure the execution of replenishment is tactically sound and well-coordinated. This may require a refinement of CSS TTPs. For example, US Army artillery Forward Support Companies (FSCs) make use of Ammunition Transfer and Handling Points (ATHPs) to pre-stage ammunition resupply convoys forward in designated geographic locations.[18] These packets are then readily available during key moments in the battle (for example a deliberate attack or SOSRA) to replenish gunlines and A1 echelons.

The utility of such control measures should not be overlooked, as they enable the CSS network to achieve a high level of responsiveness and elements from higher echelons (such as FSG) to operate forward with less friction.[19] CSS planners must have a working understanding of the different replenishment methods available and their utility to the supported force. It is all too common for a generalist CSS planner to hand-wave away the problem with a comment on dumping CLVArty in large quantities; this does not take into consideration the propensity of the gun battery to ‘shoot and scoot’, the available terrain, or environmental effects degrading the stocks.

The introduction of the ILHS platform provides an opportunity to refine CLVArty distribution like never before. The force now has a commonality of platform from the FSG transport squadron to the gun battery A1 echelon, without the need to use MHE to cross load stocks. Having prepared flatracks of CLVArty at the FSG and BSG APs, in configurations dictated by S4 staff on advice from fires planners, would further increase the velocity of the supply chain. The ability for a fires echelon S4 to call forward a standardised first line ‘Unit Basic Load (UBL) of CLVArty, or an obscuration (smoke/WP heavy) line of ammunition, or a precision munitions line, at a moment’s notice would reduce friction and increase responsiveness.[20]

Equipment scales would require some minor adjustment also. The pre-packaged lines of ammunition concept noted above would require a ‘rule of threes’ approach to flatrack management: one on the gunline, one on the distribution asset, one empty at the ammo point being pre-loaded. Dedicated transport elements require the correct allocation of load-restraint gear; the entitlement of 2.5t and 5t strap to each flatrack when issued was 10, a 155mm laden rack requires 15.

The final and most important factor in ensuring responsive CLVArty resupply is the CSS staff officer. It is imperative for CSS planners at all levels to understand the fires plan, the implications of different effects on the munitions demanded, and the correct use of control measures. Allocation of operating and reserve stocks, both in quantity and geographic location, should be linked to EFATs[21] and have clear triggers for resupply to avoid latency in the fulfilment of urgent demands. Unlike other bulk commodities, CLVArty will often find CSS echelons above brigade operating in the tactical space to effect resupply – conceivably direct to gunlines. This will require clear C2 and delineation of responsibilities (for example, FSG distribution elements TACON to BSG when entering the Bde TAOR). Ensuring the distribution plan is integrated with the fires and manoeuvre plan, and the tactical execution thereof is synchronised with other force elements is crucial.


The resupply of the artillery regiment and any future divisional fires echelon is a critical CSS task, one that has not been truly tested on operations or on exercise in many years. Furthermore, the complexities of CLVArty replenishment is not fully understood by generalist CSS planners, due to lack of exposure and failure of the training continuum. Replenishment of artillery in both planning and execution spans numerous organisations from the FSG, to divisional J4, to Bde HQ and the BSG before reaching the dependency. This demands a level of integration and synchronisation beyond the classic ‘push 1, 3 and 5 and pull all other’ concepts of distribution often offered as the panacea of planning.

Understanding the concept of fires to anticipate likely demand (including munition types), allocating dedicated distribution assets to prepare, pre-load, and transport of CLVArty, staging reserve stocks forward in CSS nodes to mitigate culminating points and CSS risk are all critical to ensuring the responsiveness of the supply chain. Longer term, the refinement of extant doctrine to standardise in-use concepts and terminology, and the creation basic loads of common CLVArty types based on effect will decrease friction between fires and CSS staff. These measures must be addressed now, to ensure that when on operations, the artillery regiment does not find itself ‘rounds complete’.