Military
Military in the time of Avatar Aang
During the Hundred Year War, the Earth Kingdom suffered less than the other two Nations who were opposing the Fire Nation. This is due to its large military.
Divisions
Infantary
In the Earth Kingdom, Soldiers, both Benders and Non-benders carry an array of different weapons. Soldiers are typically given sombrero-like hats, which have been shown for use against Fire Blasts.
Probably because of their weaknesses in battle, Non-Bending soldiers are shown to have much more protection than their fellow benders
The Earthbenders don't wear any shoes in order to utilise their full bending capacity. Higher ranking soldiers wear yellow, instead of the usual green armour.
The uniforms are also colour coded for different regions.
Infantry Ranks
Council of 5
The Earth Kingdom's Military is controlled by the Council of 5, an organisation of the most influential and powerful generals.
General
The rank of General is the highest in the earth Kingdom Military. A General is in charge of Bases around the earth Kingdom, and can serve as members of the council of 5.
Captain
A Captain is the second in command in a squadron of soldiers. It was shown that a captain is high up enough to be able to talk to King Bumi.
Corporal
Corporal is a rank slightly higher than that of Private. But a corporal was considered powerful enough to be left with the Powerful General, Iroh.
Private
Private is the lowest rank in the earth Kingdom Army.
Transportation
The Earth Kingdom Army's core mode of Transportation is on Ostrich Horses. The Ostrich Horses are basically like the Earth Kingdom's version of the Komodo Rhino, the main difference being that the Ostrich Horses are also used throughout the Earth Kingdom for domestic purposes.
Ostrich Horses often wear Armour and are used for carrying supplies or as Mounts for Non-Bending Soldiers.
Ostrich Horses
Komodo Rhino
Tanks
The Mechanist, an Earth Kingdom Inventor living in the Northern Air Temple invented a type of Tank which is powered by Earthbenders pushing it, much like the monorail in Ba Sing Se.
The Tanks are also made of various segments. Allowing them to bend if going over uneven surfaces. In Day of The Black Sun, they are even shown to be so thick that they aren't even damaged when blasted by Fire.
Later on, the tanks were officially added to the Earth Kingdom army.
Earthbending Tanks
Supply Trucks
The Supply Trucks were also invented by the Mechanist. They carried Bendable elements in the backs of the trucks to help the benders find enough materials.
Artillery
Earthbenders use coin like stones to catapult or roll. The Stones also have other uses, such as forming a wall or shield. They can also be stacked to form a makeshift look-out tower.
Earth Coins
Navy
The Earth Kingdom used to have a Navy, but it was destroyed when fighting the 5th Nation pirates. It is shown that the Navy was rebuilt, but it remained much smaller than that of the Fire Nation. It is mentioned in The Kyoshi Novels, but is never seen in any of the Series' or comics.
Air Force
Shortly after the end of the Hundred Year War, the Earth Kingdom got hold of the blueprints for the Hot Air Balloons, previously exclusive to the Fire Nation's Military, adding them to the Earth Kingdom's extensive army. They were only shown in The Promise comic, used as Earth King Kuei's transport.