Class four container transport

Class four container transports, also referred to simply as Imperial cargo ships, were tetrahedron-shaped, hyperspace-capable freighter starships used by the Galactic Empire to haul large numbers of crates and containers. Their crew notably included an inventory droid tasked with tracking and monitor all the freight. In the third year before the Battle of Yavin, one such ship was stolen from Horizon Base by the rebel astromech Chopper, with the help of the craft's own inventory droid, AP-5.

Characteristics and role
The class four container transport was shaped like a tetrahedron resting on the longest of its six edges. The bridge module was located in front of the ship, at the narrowest vertex of the recumbent tetrahedron, and resembled that of the Imperial light cruiser. An assembly of up to 210 big containers was attached to the rear triangular side of the ship, encased between the sublight engines positioned at each of the three angles.

In addition to its sublight drives, the Imperial cargo ship was equipped with a hyperdrive, which allowed it to travel through hyperspace. It was also armed, boasting one top-mounted double-barreled turbolaser battery and two side-mounted laser turrets.

Every Imperial cargo ship required the presence of an inventory droid to track and monitor all the goods. Imperial cargo ships were used to haul large quantities of containers and crates from spaceport to spaceport. For security purposes, Imperial cargo ships had a security complement of at least five Imperial sentry droids.

History
"You stole an Imperial freighter?"

- Hera Syndulla, to Chopper

The Galactic Empire, an authoritarian pan-galactic regime, made use of Imperial cargo ships during the dark times that followed the end of the Clone Wars and the rise of its sole ruler, Emperor Palpatine. In 3 BBY, the rebel astromech Chopper stowed away on an Imperial cargo ship docked at the Horizon Base. Eventually, the astromech joined forces with the ship's inventory droid, an RA-7 protocol droid called AP-5, to steal the vessel from the Empire. In order to do so, Chopper managed to trap the stormtroopers serving aboard the ship in the freight assembly, before jettisoning the soldiers along with the containers. AP-5 then managed to transmit the coordinates for the planet Atollon to Chopper's Lothal rebels and the Phoenix rebel cell despite the opposition of the Imperial captain. Chopper then rendezvoused the cargo transport with the rebels above Atollon.

In 2 BBY, the Weequay pirate Hondo Ohnaka and the crime lord Azmorigan acquired the flight plan for a cargo transport. They managed to disable the transport with ion mines. However, the ship drifted into the upper atmosphere of the planet Wynkahthu where it was trapped in a storm. Most of Hondo's Ugnaught crew with the exception of Melch were lost while boarding the ship. Hondo and Azmorigan managed to reach the ship with the help of the Lothal rebels and AP-5, who was familiar with that class of ships. They managed to restart the ship's power and steal a cargo of proton bombs and treasures. However, the recovery team was forced to flee when they accidentally activate the sentry droids. The recovery team managed to flee back to their ship Ghost before the cargo ship descended into the vortex and exploded.

Behind the scenes
The Imperial cargo ship appears in the Star Wars Rebels series, first appearing in the second season episode "The Forgotten Droid." Dave Filoni, supervising director of the show's first two seasons, built a model of the cargo ship out of a manila folder when the show's crew was breaking the story of "The Forgotten Droid."