UNSC Army Line Battalion Structure

Line battalions are the battalions formed from infantry and armor units which comprise the main fighting forces of UNSC Army divisions and brigades. They combine line forces, indirect fire, unmanned aerial systems (UAS), scouts, and sustainment into a versatile unit for frontline combat. 
== Structure ==
Battalions are structured according to tables of organization and equipment (TOEs) created by Army headquarters. Deviation from these TOEs is common for all manner of unit, since unique operational needs, manpower shortages, or differences in available equipment may necessitate changes. However, these deviations are typically minor for line battalions. 
=== General Template ===
There are multiple types of line battalion defined by the platforms that they use to move and fight. While their capabilities differ widely, they all follow the same general template, which has been continuously refined and adapted for centuries. The battalion is commanded by a Lieutenant Colonel, with Captains in charge of each company and a First or Second Lieutenant for each platoon.
Three line companies serve as the battalion’s frontline fighting component. The company headquarters section contains the commander, executive officer, first sergeant, operations sergeant, a few drivers, a small UAS team, and a few trucks to support the company. Any type of infantry company has three rifle platoons, which typically contain two rifle squads and one weapons squad, plus a platoon headquarters and UAS team. Many types of company include a mortar section, which typically uses 60mm mortars to provide indirect fire support. Companies regularly receive attachments from higher headquarters, such as fire support teams from artillery units and field maintenance teams in mechanized or armored units.
One weapons company provides heavier weapons in support of the line companies. They have standard headquarters sections, with three weapons platoons divided by function. An antitank platoon provides armor-defeating weapons, a machine gun or support weapons platoon provides suppressive fire, and an assault weapons platoon provides explosive firepower and other options suited to reducing enemy defenses shortly before an assault. Either the support weapons platoon, assault weapons platoon, or both will have some weapons capable of very short-range air defense. These platoons are then broken down into teams and squads and assigned to the operational control of line companies on a per-mission basis. Some weapons companies have a sniper squad.
The forward support company (FSC) provides logistical support to the battalion. It contains a field feeding section, a distribution platoon, and a maintenance platoon. The distribution platoon typically has several general supply trucks, two or more fuel & water trucks, and at least one forklift or other cargo handling equipment. The maintenance platoon has a maintenance control section and a field maintenance section that varies in size between battalion types, with some battalion types adding other subunits to the platoon. 
The headquarters & headquarters company (HHC) contains the command & staff group which runs the battalion along with several supporting assets. The command & staff group includes the commander, executive officer, sergeant major, and staff shops for administration, intelligence, operations, logistics, and signal. A small retransmission team is grouped under the signal shop, but often moves and operates separately. The HHC has a medical platoon, which contains a medical treatment section, a forward evac squad, and an area evac squad using unarmored ambulances. A mortar platoon provides fire support with medium or heavy mortars, a UAS section provides aerial recon, and a scout platoon containing six vehicles or teams arranged into two or three sections provides ground recon & security. 
=== Light Infantry Battalion ===
Light infantry battalions fight primarily on foot, with a few unarmored trucks providing mobility for a limited portion of the battalion. They rely on assets from higher echelons to move long distances quickly, but this is relatively easy to arrange since they can be easily airlifted and require less rolling stock or shipping volume to move overland, over ocean, or through space, respectively. They can fight effectively in terrain that severely restricts vehicles, and their logistical needs are modest compared to other battalion types. However, their tactical mobility is largely restricted to marching pace, their mobility assets provide no protection, and they are mostly limited to man-portable weapons.
The infantry companies follow the standard layout, with some unarmored trucks in the headquarters and mortar sections. The weapons company uses dismounted heavy machine guns, grenade launchers, gauss cannons, antitank guided missiles, rockets, and a sniper squad.
The FSC has only a few fuelers in its distribution platoon and a modestly sized field maintenance section in its maintenance platoon. The HHC’s scout platoon generally uses Warthogs in both transport and gun truck configurations, while the mortar platoon uses Warthogs as mortar carriers for 81mm or 120mm mortars. Whether to use medium or heavy mortars depends on the mobility requirements of a given mission. The medical platoon uses Warthog-based ambulances and light truck-based mobile surgical theaters.
Light infantry battalions are found in light infantry divisions and brigades. 
==== Air Assault Battalion ====
Air assault battalions are a subset of light infantry who regularly deploy using vertical-lift aircraft. This requires some additional training and a somewhat lightened equipment load. They differ from light infantry battalions in having more of the FSC’s equipment carried in pieces that can easily be loaded under aircraft, rather than mounted on trucks. The scout platoon often uses Mongoose or Jackrabbit all-terrain vehicles as an alternative to Warthogs. 
Air assault battalions are found in air assault divisions and brigades.
=== Intermediate Infantry Battalion ===
Intermediate infantry battalions are entirely motorized with lightly armored trucks. They require more rolling stock or lift capacity to transport than a light infantry unit, but are still feasible to airlift. Through their motorization, they can drive long distances with little difficulty and no transport assets attached from outside the battalion. Intermediate units require significantly more fuel & maintenance than light units, and they face greater limitations in restrictive terrain, but their tactical mobility is good, they have modest protection, and their vehicles carry more firepower than any light unit. 
The line companies have armored trucks organic to each platoon and section. These trucks serve to transport the infantry to dropoff points near objectives, while providing security and some support by fire with their machine guns. Similar trucks serve as mortar carriers, providing the mortar section with highly mobile autoloaded weapons. The weapons company uses a mix of vehicle-mounted systems and dismounted heavy weapons in each platoon, in addition to a sniper squad. 
The FSC’s distribution platoon has a few more fuelers than that of a light battalion, with a modestly expanded field maintenance section. The HHC’s scout platoon uses a mix of armored transport trucks carrying dismount scout teams and trucks built purely as combat recon vehicles, while the mortar platoon uses similar trucks as carriers for heavy mortars. The medical platoon uses lightly armored ambulances and mobile surgical theaters.
Intermediate infantry battalions form a heavier, fast-moving component within light infantry divisions & brigades, and a lighter component within mechanized divisions & brigades. 
=== Mechanized Infantry Battalion ===
Mechanized infantry battalions use wheeled armored vehicles, often the Mastodon family plus a lighter vehicle, to move and fight. They are not feasible to airlift at any large scale, and they require lots of rolling stock or shipping capacity to transport, but they can drive long distances with only minor maintenance needs and no external augmentation. Their off-road mobility is limited, and they require robust fuel and maintenance support. Mechanized units benefit from having moderate armor protection for all combat assets and a significant quantity of heavy weaponry. 
The line companies use armored personnel carriers (APCs) to move towards objectives and provide some support once in combat, while lighter armored vehicles serve as mortar carriers, often armed with rapid-firing mortars, in the mortar section. The APCs allow rifle platoons to keep heavy weapons on hand in the vehicle and carry them when needed. As such, the weapons company forgoes dismounted weapons in favor of using fighting vehicles, with the exception of the sniper squad. 
The FSC has several fuelers in its distribution platoon and a large field maintenance section. Its maintenance platoon adds a dedicated service & recovery section, which uses wrecker trucks to recover disabled vehicles, and three field maintenance teams which are habitually attached to each line company in order to provide field repair and recovery. The medical platoon uses light APC-based ambulances and mobile surgical theaters. The HHC’s mortar platoon invariably uses heavy mortars, while the scout platoon is mounted in cavalry fighting vehicles that combine sensors, firepower, and transport capacity. 
Mechanized infantry battalions are found in mechanized divisions and brigades.
=== Combined Arms Battalion ===
Combined arms battalions (CABs) mix tanks and infantry mounted in tracked armored vehicles into the same battalions. They are too heavy to feasibly airlift, take up lots of transport capacity, and incur serious maintenance costs if they drive long distances on their own power. Rail or maritime transport is preferred for long-distance movement, and they require large quantities of fuel and maintenance support. However, their tracked platforms have excellent off-road mobility in unrestricted terrain, they are heavily protected, and they have more firepower than any other class of line unit.
CABs come in three varieties which vary only in their line companies. Armored CABs (CAB-ARs) have two tank companies and one infantry company. Infantry CABs (CAB-INs) have two infantry companies and one tank company. Heavy Armored CABs are identical to CAB-As but use heavy tanks such as the Grizzly. 
Tank companies contain three platoons with four tanks each, typically Scorpions, while extra tank crews stay with the headquarters section and ride in tracked APCs. Infantry companies use tracked infantry fighting vehicles (IFVs), which can transport infantry squads into combat while fighting alongside tanks. Their rifle platoons have three rifle squads and no weapons squad, since the IFVs provide enough firepower to support the platoon, and can carry heavier dismounted weapons for the rifle squads to use when needed. None of these companies have a mortar section. The weapons company does not use dismounts, lacking a sniper squad, in favor of tracked weapons platforms like the Sun Devil or Tarantula.
The FSC is quite large. It has several fuelers in the distribution platoon to sustain the armored vehicles’ energy-intensive operations. The maintenance platoon has an enlarged field maintenance section, a service & recovery section, and four field maintenance teams. The HHC’s mortar platoon uses mortar carriers derived from an APC design, typically something lighter and cheaper than the IFVs, while the scout platoon uses cavalry fighting vehicles derived from the battalion’s IFV family. The medical platoon uses tracked APC-based ambulances and mobile surgical theaters.
All types of CAB are found in armored divisions and brigades.
=== Divisional Tank Battalion ===
Divisional tank battalions provide mobile, protected firepower to light infantry divisions. They require more fuel, maintenance, and transportation support than the rest of the light infantry division, but one tank battalion is small enough to not overburden the division. 
The three tank companies structurally differ from the tank companies in a CAB. They contain four tank platoons, which each include three tanks and a section of three Warthogs. The Warthogs provide recon and security for the platoon, finding targets for the tanks to kill. M808 and M820 Scorpion families are the most common types of tank, though some battalions use Vipers.
The weapons company and FSC are similar to that of a CAB. However, the battalion is not intended to fight as a single unit, but to parcel its tanks out to infantry battalions as direct fire support. As such, the HHC does not have mortars, scouts, or UAS.
==== Divisional Weapons Battalion ====
Divisional weapons battalions are a lightened version of divisional tank battalions used in air assault divisions. Each line company contains two tank platoons, organized the same as those in a divisional tank battalion but more often using Vipers, and two platoons of armed exoskeletons. The weapons company typically uses lighter armored vehicles as well. 
== Heritage ==
Like many echelons of the UNSC Army, line battalions commonly trace unit heritages back for centuries through a messy, and largely imaginary, lineage. Many of these are tied to a particular regiment or brigade that the battalion was historically affiliated with, whether or not that parent unit still exists.