Types of units in US Military

Factual Questions
1

I’m not big into the ins-and-outs of military but I keep hearing about all the troops being deployed to Southwest Asia.

Now here’s my question…

What is the difference between the different types divisions/brigades/units? I hear about amphibious assault, mechanized, airborne, infantry, et al. Does the infantry brigades divisions mean they are soldiers that help with equipment, or are they still a relic of the past and do just fighting with mostly small arms?

Also, what is so important about the 101st Airborne? I hear a lot about them, but are they more ‘elite’ then other airborne units?
Just had been wondering this for a bit.

(BTW, sorry if my question didn’t make any sense, can clarify it if you’d like me to)

2

Lets take an example. I was in a 9th Air Force medium bomb group in WWII. The group itself consisted of the personnel to operate and maintain the planes.

Along with the group were units from the Engineers to build and maintain the facilities and other support. As an example the Engineers furnished the fire fighters.

There were also Signal Corps people for communications. The Control Tower was operated by them along with ground communications such as telephone and telegraph lines.

The Medical Corps furnished doctors and medics.

The Transportation Corps did the obvious.

Qartermaster and Supply kept us in food and other logistic support.

Ordnance Dept. took care of bombs and guns.

Chaplain Corps for the obvious.

Other organizations are the same. An Infantry Division consists of the troops who do the fighting along with their command structure. Attached to the Division or its subsidiary Regiments, Battalions etc. are Engineers, Ordnance, Transportation, Signal Corps, Quartermaster Corps, Supply and so on.

3

And oh yes, and an Infantry Division was usually organized for fighting purposes into Regimental Combat teams which included an infantry regiment along with attached artillery, armor, combat engineers, signal corps etc. so as to be self contained fighting unit.

4

Thank you for the fast answer.

I also thank you for your service to our country. :slight_smile:

5

Not sure it this is the type of info you are interested in but:

I was in the Marine Corps in Vietnam. The following is a rough breakdown of how we were set up. Starting at the smallest unit:

A fireteam. From 2-4 riflemen.

A squad. 2-4 fireteams.

A platoon. 3 squads plus the platoon commander (usually a lieutenant), platoon sergeant, radio man, and a Corpsman. A platoon generally had between 35-45 men.

A company. 3 rifle platoons and a weapons platoon. Weapons platoon had the machine guns, rockets, and 60mm mortars, though most of these were sprinkled out among the 3 rifle platoons. A company was generally commanded by a Captain and ran around 175-210 men. The command group might have 2-3 FO’s (forward observers for artillery and airsupport, though liason might have been a better word.), the captain, the gunnery sergeant, 2 radio men.

A battalion. 3 rifle (or line) companies and a H&S (Headquarters and Support) company. A battalion might run around 1,000 men and was usually commanded by a Lt. colonel. H&S company had the 106 recoiless rifles, larger, less transportable, mortars, an attached artillery company, etc.

A regiment. 3 battalions plus an H&S. Commanded by a colonel and had around 3,500 men. It might have it’s own attached helicopter unit and larger artillery such as 175mm and 8" cannons. I think a tank battalion was attached also.

A division. 3 or 4 regiments. 10-15,000 men and was commanded by a general.

In the Marine Corps that was about as far as we went. The Army, I understand, uses brigades which are of 2-3 division strength. So obviously we are getting into some major size here.

I think brigades are combined to make armies.

6

What about the 128 mech Battlemech regiment and 12 mech command compan… oh real worlld…sorry.

7

Units are broken up by type, which reflects the specialist role of each unit, and by size. As mentioned above, divisions, brigades, regiments and battalions are sizes of unit, although there is not objective standard for defining each. Units can be created for ad hoc tasks, or reinforced with other units for particular missions. An infantry unit might gain a small tank unit to bolster its firepower. Additionally, the unit sizes vary from country to country and type to type. A British tank regiment is more or less the same as a US armoured battalion; a Russian motorised rifle regiment is closer to a US mechanised infantry brigade in size and role.

Armoured units are fairly self-explanatory: tanks, first and foremost to punch holes in enemy defences and use speed and firepower to knock down the enemy. Infantry units are the most numerous, reflecting the range of missions. Mechanised infantry units are transported in armoured vehicles, designed to offer greater protection and mobility to accompany tank units. Motorised infantry units generally use trucks or wheeled vehicles, with great mobility but less firepower and protection.

Parachute infantry (aka airborne infantry) units are also self-explanatory; airmobile (aka air assault) units are generally carried over shorter distances by helicopter. Amphibious assault missions (i.e. establishing beach-heads) are generally performed by non-army units – e.g. the USMC, the Royal Marines, Russian Naval Infantry.

8

As a slight addendum to SandyHook’s post:

A weapons company in the Marines today is made up of 81mm Mortars, Heavy Machine Guns (.50 Cals) and anti-tank (Javelins).

9

A division is supposed to be about 10,000-12,000 fighting men, plus whatever is needed to support them.

Its primary subdivision in the Marine Corps and one arm of the Army is the regiment, but in the others is the Brigade. (Back in Civil War days there were 2-3 regiments to the brigade, hence the distinction.) A Brigade is, not surprisingly, normally commanded by a Brigadier General.

An average of three to five divisions constitutes a Corps, which is in the Army commanded by a Lieutenant General (at present, many have full Generals in command, since there’s a shortage of jobs for full generals). For obvious reasons of both size and nomenclature, the Marines do not have this category.

Two to five corps constitute an Army (as opposed to the Army) with a full General in command; if the U.S. Army gets that large, two or more armies may be combined into an Army Group.

10

Like the 82nd Airborne Division (82nd ABN DIV), the 101st is a rapid reaction force. They are light (not armored) and can be sent in quickly. They cannot, however, go for more than a few days without resupply. You also would not want to send them up against tanks that knew they were coming. The 101st ABN DIV specializes in Air Assault: rappelling out of helicopters on ropes.

Here are pages on deployment and uses of types of units:
http://www.cadre.maxwell.af.mil/warfarestudies/wpc/wpc_txt/army/capable.htm
http://www.cadre.maxwell.af.mil/warfarestudies/wpc/wpc_txt/army/deploy.htm

And organization:
http://www.cadre.maxwell.af.mil/warfarestudies/wpc/wpc_txt/army/org.htm

The regiment no longer exists as a functional combat entity within the US Army (with a few exceptions like the Armored Cavalry Regiments (armored scouts)). Batteries and Squadrons are also limited to a few different types of units.

Below battalions (as said above) there are companies, platoons, squads (or sections) and teams.

A division is really the smallest type of unit that has all the support that it needs. Brigades have their own mechanics, technicians, supply personnel and cooks plus a bunch of staff advisors and planners, but they don’t have a lot of the 2nd level technical and logistical support that you find in a division.

11

Is the 101st still required to be airborne jump qualified?

I know that during the 2nd World War, the 101st was jumping out of airplanes. Their mission later changed to “air assault”, rappelling out of helicopters. I know that during my basic back in '83, those people who were going to the 101st were required to go to jump school. I’m just curious as to whether they still are.

12

No. The 101st is an air-assault or air-mobile unit these days. Instead of jump school they must go to air-assault school where they learn the in and outs of un-assing from a helicopter.

If you’re curious, air-assault school is 2 weeks long and located at Ft. Campbell, KY, while jump school is 3 weeks and is located at Ft. Benning, GA.

13

The way it lays out in the Air Force is

Element: 2 or more people
Flight: 2 or more Elements
Squadron: 2 or more Flights
Group: 2 or more Squadrons
Wing: 2 or more Groups
Air Force: 2 or more Wings
MAJCOM: 2 or more Air Forces

The last two can get goofy, as I fall under AFSOC (MAJCOM) and the ANG, but not an Air Force.

Still, all things considered, it’s easier to remember than Brigades and Battalions and the like, or at least it is for me since they beat it into my head at BMT.

14

You, of course, would know more than me about it Airman Doors, USAF being active duty and all, but do they use the term “Element” outside of BMT? I was on “shifts” and “Crews” but never in an “element” outside of basic. I was a SEP-RAT in tech school so I dont remember if they used the term there.

Yes they can. My last duty station went something like this
GLCI=Flight
755th Computer Squadron
55th Com Group
55th Wing
12th Air Force (is my guess, but I think I’m totally wrong there)
ACC=Majcom
The confusing part is that the equipment I worked on was for 2 other MajComs(StratCom and SpaceCom) and not for ACC.

15

Divisions are the smallest units that (alegedly) have all the corps, branches and services within it. That is to say a Division is a combined arms team that includes everything from Chaplains to Air Defense to Artillery and Armor.

The 101st Airborne is unique. It uses helicopters not only as a means to get to battle but as a means to fight the battle. Imagine them as the helicopter version of a tank division.

OK, all the other divisions fall into one of two types; Heavy or Light. (Of course they have historic designations like Armor or Mountian or Airborne, but more or less there are only two types.)

Light divisions (and light units in general) are more or less what you see in World War II movies. They tend to walk into (and in) battle. These units are good in rough terrain and are easier to deploy as they have less heavy equipment. Examples include the 82nd Airborne (our only jump-qualified division) the 10th Mountain and a few others. These kind of units are seeing action in Afganistan right now.

Heavy divisions include units with the historic Armored and Infantry designations. They include either two Armor (tank) brigades and one Mechanized Infantry Brigade (in the Armor divisions) or the reverse (in the Infantry Divisions). ALl divisons include an Aviation Brigade and an Artillery Brigade (although it is called something else).

In truth the difference between the two kinds of Heavy Divisions (Armor and Infantry) are small. Both types generate huge amounts of combat power and exceptional mobility over most types of terrain.

In combat each division cross attaches units down to at least the Battalion level. My Infantry Battalion gives up a company of troopers who go over to Bob’s Armored Battalion. Bob returns the favor by giving me a company of tanks. I also gain some Engineers, additional medics and so on.

So in action there is little difference between my Infantry unit and his Armored one. These units are difficult to deploy (tanks are much to heavy to fly as a practical matter) but are the most powerful ground units on earth.

The Infanty in heavy units has transmuted beyond the recognition of the WWII generation. They go into battle in Bradley Fighting Vehicles, which civilians insist on calling “little tanks.” The ride into battle and (at least in some situations) fight the battle from their “Brads” they can roll over enemy units without even stopping. Pretty impressive stuff.

Any other questions?

16

Elements aren’t generally used except in formations, but I included them because they are the smallest official division in the Air Force and they were analogous to the Army fireteam.

I personally haven’t heard element used since Tech School, where I had to march Elements and Flights all over the place.

17

SandyHook nailed it for the Marine Corps…

Only left out one small unit…The STA platoon (Surveillance and Target Acquisition) Sometimes known as the Sniper platoon.

This unit is usually attached to the H&S Company or the Weapons Company of a Marine Battalion and is supposed to be manned by 21 Marines…but is usually chronically short of personnel.
(Sniper School has a very high failure rate)
Stranger OUT
8541
1987-1996

Semper Fi

18

Nothing substantive more to add to what’s gone before, but I couldn’t resist picking up how I misread Airman Doors’s first line above, which was actually:

but which I misread as

And not even then much since Hannibal’s day! :slight_smile:

19

Unless, of course, the enemy has any sort of AT capability whatsoever, in which case they serve as a “coffin for 8 brothers”, as the Russians say. The civilians aren’t that wrong - the Bradley is an underarmored light tank with far to much firepower for its own good.