Abstract
The mortar is the only organic indirect fire support available to Australian Army infantry battalions. The author argues that detailed consideration of the mortar as a battalion asset has been neglected during the Army’s prolonged commitment to peace operations. This article examines the Army’s mortar training and employment requirements in light of future operations and capability development initiatives. The author concludes with options for further developing this battalion asset.
Fire Mission
‘Fire mission, section’ echoes through the night.
I race to show my aiming light;
To rip the cover from the mortar,
And hear the next staccato order.
The CP has the information,
To tell me ‘where’ and ‘elevation’.
Then – thump – I spin the bipod round,
And stamp the legs into the ground.
And then with accuracy and care
We’re ready to bring fire to bear.
My mate checks the charges near the fin
And, on command, out comes the safety pin.
The round is blasted to the sky –
I know our boys will not deny
They feel relieved to hear our sound –
The ‘crump’ of friendly incoming round.
The enemy try to escape the ‘shrap’.
But find they’re in a deadly trap.
When it’s all over, it’s ‘end of mission’,
And for the results we keenly listen.1
Introduction
Australian Army doctrine describes the mortar in complicated fashion as a high-trajectory crew-served indirect-fire support weapon with a relatively short range and a high rate of fire.2 The mortar is also highly mobile, which makes it well suited to close support of manoeuvre units. It is ideal for engaging targets on reverse slopes, narrow gullies, in an urban environment and other areas that are difficult to reach with low-trajectory weapons such as artillery.3 The mortar is organic to an infantry battalion and is its only form of guaranteed indirect fire support.
The mortar came into being in the early 1700s when siege warfare became the predominant form of combat in Europe. The cannon of the time could not fire into fortresses and could only inflict piecemeal damage on the thick walls. A new type of weapon was needed to fire a projectile high enough to get over the wall but not too far over the other side. A short cannon that could fire almost straight up into the air was developed—and the mortar was born. During World War I the mortar was purpose-designed to lob an explosive in a high-angle arc so that it would land in narrow enemy trenches. The artillery available at the time was hindered by its flat trajectory and could not lob rounds at an angle which allowed them to land inside the enemy trenches. Mortars, on the other hand, designed to send a round almost straight up and almost straight down, were perfectly suited to the task.
The medium calibre 81mm mortars came of age during World War II, providing a lethal and previously unseen level of support to the infantryman. Countless promising attacks were literally torn to pieces by a single, violent, accurate barrage of often only brief intensity. In the offense, mortars could stun the enemy defenders long enough to allow riflemen to move into the close battle. Of all the weapons at his disposal, the mortar undoubtedly provided the battalion commander his most lethal tool.4
This analysis will examine the Army’s current mortar capability, the strengths and weaknesses of the 81mm F2 mortar and those of the mortar platoon itself. This discussion will also explore what the future holds for the battalion’s only organic indirect fire support.
The Current Mortar Platoon
The structure of the mortar platoon has not changed since the Vietnam era. The platoon still consists of the joint offensive support coordination centre (formerly the fire support coordination centre), observer group, platoon command post, mortar line (three sections of two mortars) and the administration group. Unfortunately, the two aspects that have changed since Vietnam are the availability of ammunition and the use of the platoon’s skills. Many of the Army’s ‘mortarmen’ would argue that the mortar is underrated, under-utilised and under-funded.
Australian mortars have not fired in anger since Vietnam, as the Australian Defence Force (ADF) has not committed to large-scale offensive operations since that time. The ADF’s operational commitments have largely comprised peace enforcement, peacekeeping or peace monitoring—operations that have altered the ADF’s focus from warfighting and training for war. As a result, the training of mortarmen has suffered over the last few years.
Training the Army's Mortarmen
Problems in the mortar training regime were highlighted by the Australian infantry battalions’ inability to field fully qualified mortar platoons at the mortar concentration held in Townsville in May 2004. The conduct of basic mortar courses has continued throughout the years—largely limited to training within the battalions. While the training management plan has been badly neglected, the battalions have been able to ensure that there were at least a minimal number of qualified soldiers in the battalion to post to positions in the mortar platoon.
One vital issue concerns the training of mortar non-commissioned officers and officers by the School of Infantry—to ensure that mortar-specific skills and corporate knowledge are maintained. The degradation of mortaring skills began when the original officer/non-commissioned officer mortar course of six weeks’ duration was replaced with the advanced mortar course of two weeks’ duration and supplemented by artillery joint offensive support team modules at the School of Artillery. The results of this change in training were the loss of danger close qualifications, loss of tactical considerations in the employment of the mortar platoon, and loss of badly needed observer training for mobile fire controllers.
To the professional mortarman, the fact that potential mortar officers and noncommissioned officers were trained by members of the Royal Australian Artillery seems ludicrous to say the least. This may well have been a major contributing factor in the loss of skills and under-utilisation of mortars. Happily, mortar training has now reverted to the province of infantry instructors who possess a detailed knowledge of infantry tactics and specialist weapons.
Mortars as an Asset: The Pros and Cons
Mortars are a key asset in support of infantry operations for a number of reasons. These include the fact that mortars are responsive—in most cases they are controlled by the commanders of small units. Mortars are relatively inexpensive and are lightweight, which makes them extremely mobile. The mobility of mortars provides them increased survivability from counter-battery fire and also allows their use in raids, harassing and interdiction missions.
Mortars have the ability to quickly shift and fire on multiple targets simultaneously and through obscuration. The mortar platoon has a smaller signature and combat service support trail than its artillery counterparts. Mortars have a higher trajectory, which enables them to fire onto targets in less accessible locations such as creek lines, reverse slopes and urban environments. This also means, however, that the time of flight is longer than that of artillery. Mortars are man-portable, which allows their deployment in rugged terrain inaccessible to vehicles or by air. Within a fire support base, mortars are easier to protect as a result of their ability to fire from smaller field defences. The mortar round is usually not as powerful as an artillery round; however, it is more easily acquired by the company, platoon or section. While the intimacy that mortars provide is an advantage, they are vulnerable while firing and require local protection. Artillery, on the other hand, is typically a shared combat asset whose fires are directed by those an echelon above (and some distance from) the unit that needs the support of the big guns.5
Ammunition - Bang for your Buck
The purchase of the new Denel 80mm ammunition has forced a number of changes in the use of mortars. First, the minimum safe distance6 has moved from 550 metres to 900 metres and the minimum safe limit7 has increased from 200 metres to 300 metres, provided troops are in a danger close bunker. A source of frustration to mortarmen is the fact that artillery has a minimum safe limit of 150 metres from troops in pits without overhead protection. Given that the minimum safe distance of artillery is 600 metres, the implication is that the lethality of the Denel mortar round exceeds that of an artillery round.
Unsurprisingly, offensive support experts refute this implication. They argue that the minimum safe limit for artillery is shorter because of the gunners’ ability to survey their gun positions while providing close support. This is cold comfort for the average mortarman who is unable to realistically train for danger close missions despite the benefits of today’s advanced simulation technology. Such technology allows computer fire controllers working with mortar laying systems, GPS and laser range finders to increase the accuracy to a target round on the second or third adjusting round. Doctrine also provides safety measures in its prescriptive requirements for the positioning of the mortar line; procedures for calling in close fire missions; proving targets; and safety staff regulations aimed at reducing risk during the conduct of battle practice.
Unfortunately for the mortarmen, limited ammunition supplies restrict their ability to conduct regular high explosive activities and thus their opportunities to demonstrate their ability to support an attack at the point of break-in. On average, battalions are receiving an annual allocation of mortar ammunition that, according to the 1st Division Fire Power Policy, equates to what should be used in a quarter.8
One solution to the current shortage of mortar ammunition in the ADF may lie in the use of different types of ammunition. Globally, the armed forces of the world use a diverse mix of mortars and ammunition. There are three categories of mortars most commonly used, described as light, medium and heavy. Light mortars are those up to 60mm with a maximum range between 500 and 2 000 metres; medium mortars are those between 60 and 100mm with a maximum range of 2 000–6 000 metres; and heavy mortars are generally over 100mm with a maximum range over 6 000 metres.9
Mortar Characteristics
Each type of mortar has its own set of characteristics and uses. Light mortars, for example, have a number of advantages over their heavier counterparts. The 60mm mortar increases the company’s firepower substantially by providing quick, effective and always guaranteed indirect firepower. The light mortar is capable of firing to greater effective ranges than any other weapon available at company level. The range of 60mm ammunition increases the flexibility and manoeuvrability of the company. Use of the light mortar relieves the heavier calibre weapons of some of their smaller tasks, thereby enabling them to remain concealed from sound-ranging devices and mortar-locating radars until the last possible moment.10
Yet the light mortar also has a number of disadvantages. For example, its use necessitates the incorporation of another type of ammunition into the administrative system. The light mortar increases the load of the already heavily loaded infantryman. In addition, recent operational experience in Afghanistan has shown that, when employed in a support by fire position, the enemy rapidly outran the 3 700-metre maximum range of the lightweight company mortar. The Mk 19 quickly became the weapon of choice due to its reduced set-up time and the shorter time of flight of the 60mm mortar.11
Medium calibre mortars have been the most commonly used since World War II. This is often because these mortars are more lethal than light mortars but they remain easily portable for the light infantry battalion. Medium mortars also have a lower logistics signature and their collateral damage in an urban environment is less than that of the heavy mortar. Yet the range of the medium mortar limits it in a mechanised battalion, as the mortar’s operating system often cannot keep pace with a rapid advance.
Heavy mortars are gaining considerable popularity throughout the world given the changing nature of operations. Many operators believe that 120mm mortars have greater utility in terms of both potential lethality and the ability to fire newer natures of ammunition.12 However, heavy mortars are just that—heavy. They are not man-portable and require vehicles to transport both the weapon system and ammunition and thus they have an increased logistics signature. In addition, they are easier to detect than smaller mortars and not as mobile in counter-battery drills if they are not vehicle-mounted.
Despite their disadvantages, many of the world’s armies are increasing their mortar capability from medium to heavy in favour of that mortar’s increased lethality and ability to use a greater variety of ammunition. Since the ADF is predominantly budgeted for a limited mechanised and motorised capability, medium mortars appear best suited to its current needs. So what does the future hold for mortars?
The Future of Mortars
In Australia, as in many other nations, mortars traditionally have been treated as the Cinderella of weapons systems. Tanks and other armoured fighting vehicles, artillery, anti-armour rockets and missiles, surface-to-air missiles and others have all registered in the land forces’ development budgets during the last fifty years. Mortar weapons, conversely, have received almost no investment—even in nations with almost limitless defence budgets such as America—until now.13
Current and future military operations are primarily centred on what is referred to as ‘peace support’ and, therefore, are infantry-centric in nature. Units deployed on peace support operations are being equipped on a lighter scale than for previous full-size warfighting missions. However, peace support operations still present a requirement for offensive fire support, which in the past might have been provided by close support artillery units. Moreover, peace support operation missions often take place in urban areas where it is difficult to engage many targets with low-angle artillery fire.
With this in mind, the future looks reasonably bright for the mortar. At present there is considerable research and development being conducted into the production of precision-guided munitions that will enable mortar teams to fire a target round every time. Research continues also into non-lethal mortar ammunition which would increase the functionality of the mortar for different types of operations such as population protection and control.
The 2000 Defence White Paper announced a new requirement for a 120mm mortar system mounted on an unspecified ‘light armoured vehicle’. That requirement has since been constituted in the Defence Capability Plan as the Land 135 program. This program now seeks to develop a long-range mortar capable of firing in-service ammunition which is infantry-portable and can be vehicle-mounted. The program also seeks to increase the range of the mortar currently in service.
Conclusion
Given the current trend in operations, it is increasingly likely that mortars will be required to support the battalion in a more complex environment. This increased requirement for mortar support should be met with a commensurate increase in investment in resources and training to ensure this asset does not become a reduced capability within the battalion.
The training regime for future mortar soldiers, officers and non-commissioned officers must be examined to ensure the skill of mortaring does not become a lost or black art. This training must remain in the hands of Infantry Corps instructors who are best equipped to maintain high standards of mortaring in order to provide timely, accurate and safe support to the infantry battalions.
This training must be complemented by an increase in ammunition allocation to the Combined Arms Training Centre so as to ensure that the appropriate number of courses are conducted. This will increase the pool of qualified officers and non-commissioned officers to man the mortar platoons now and in the future.
Additionally, each battalion’s 81mm mortar ammunition allocation must be increased in accordance with the Divisional Firepower Policy so as to allow effective and realistic training within battalions to realise the goal of the mortar platoons’ achieving their required proficiency levels.
An increase in training and resources will lead to increased exposure to and awareness of the capabilities of the mortar platoon. This, in turn, will result in a more effective employment of mortars in training and on operations. The introduction of new technology will also be assisted by an increased level of skill within the mortar platoon.
The mortar is a battalion asset that has been particularly neglected over the last ten years since the commencement of peace operations. This is a capability that cannot be allowed to degrade into a non-viable specialist platoon. Budget and training considerations must ensure that the mortar platoon remains the most intimate and effective indirect fire support in the battalion’s arsenal.
Endnotes
1 Major A. R. Roberts (ed.), The ANZAC Battalion, Printcraft Press, Australia, 1972, p. 105.
2 LWP-CA (OS) 5-2-7, Mortar Platoon Tactical Employment and Fire Control, Land Warfare Development Centre, Puckapunyal, 2004, p. 1. 5a.
3 Ibid.
4 See http://www.stormpages.com/garyjkennedy/Tactics/Formations/FireSupport/m…
5 John G. Roos, ‘Indirect fires: Army recoiling from Crusader loss, but has bright spot in “lowly” mortars’, Armed Forces Journal, December 2002, p. 24.
6 The minimum safe distance is defined as the minimum range for the first round of a mission.
7 The minimum safe limit is that distance from the burst of a projectile beyond which there is an acceptable degree of risk of casualties to unprotected troops in the majority of operational circumstances. In artillery the term is expressed as safe splinter distance.
8 Major General A. J. Molan, 1st Division Fire Power Policy, 15 June 2001. Annex E illustrates this in tabular form:
| Unit | HEPD | M/O | ILLUM | WP |
| 1-2 RAR | 1984 | 432 | 248 | 336 |
| 3-6 RAR | 1488 | 324 | 186 | 252 |
| 25/49 RQR | 496 | 108 | 62 | 84 |
9 Mortar Platoon Tactical Employment and Fire Control, p. 3.2.
10 Subalterns – D Coy 2/4 RAR, The Combat Arms Journal, no. 1, 1982, p. 86.
11 Lieutenant Colonel M. F. Belcher, Commanding Officer 3rd Battalion, 7th Marine Regiment, 1st Marine Division, After Action Review and Lessons Learned from Operation Iraqi Freedom, Enclosure 5 - Fire Support and Aviation, April 2003.
12 See http://www.defenseworld.net/html/features/Mortars%20Are%20Back_S.htm
13 Roos, ‘Indirect fires’, p. 24.
