Earth Kingdom supply truck

The Earth Kingdom Supply Trucks are motorized, metallic vehicles that first appeared in "The Day of Black Sun, Part 1: The Invasion".

Overview
These vehicles were supposedly designed by Sokka in preparation for the invasion of the Fire Nation on the Day of Black Sun, and were in turn manufactured by the Mechanist. These vehicles were designed to carry weapons and bendable elements for use by the benders and warriors who made up the invasion force. These vehicles operate very much like the trucks of our world, except they drive entirely on treads. They are driven by a single driver and are made entirely of metal. They possess a large flatbed that can carry earthen boulders, jugs of water, fire bombs, etc.

History
These trucks were driven by Earth Kingdom soldiers during the invasion of the Fire Nation Capital. At least eight are confirmed to have participated in the battle. They trailed alongside the benders and dropped off water and boulders for use as weapons against the enemy. Those trucks carrying fire bombs were used to blast holes into the walls separating the Royal Plaza from the Capital City, providing paths for the invaders. These trucks ensured that the invaders maintained their prowess on the battlefield.

By the end of the battle, the eclipse had passed and the invasion force was defeated by the Fire Nation Air Force. If any of these trucks survived the battle, they were likely captured by the Fire Nation.