Multi-Troop Transport
(Text from Star Wars: Episode I Incredible Cross Sections, annotated by the webmaster.)
The Trade Federation's Baktoid Armor Workshop has long designed armaments for Trade Federation customers. When called upon to design and build vehicles for the Trade Federation droid army, it easily turned its resources to the creation of deadly weapons made to ensure a long line of future customers. The Trade Federation MTT (Multi Troop Transport, or simply large transport) was designed to convey platoons of ground troops to the battlefield and support them there. Its deployment on Naboo is its first use in major military action (WEBMASTER: Note that it says "major"...it could've been used in a limited capacity earlier!), and many large transports have seen only training exercises on remote worlds before being used there. They are designed for deployment in traditional battle lines, hence their heavy frontal armor. Reinforced and studded with case-hardened metal alloy studs, the MTT's face is designed to ram through walls so that troops may be deployed directly into enemy buildings (or "future customer buildings," as the Trade Federation often prefers to say). When ready to deploy, it opens its large front hatch to release the battle droid contingents from its huge storage rack, extended on a powerful hydraulic rail. Two droid pilots direct it according to instructions transmitted from the orbiting Droid Control Ship.
Heavy Lifting
The MTT's engine works hard to power repulsorlifts that carry a very heavy load of troops and solid armor. The repulsorlift generator's exhaust and cooling system is vented straight down toward the ground through several large vents under the vehicle. This creates a billowing storm of wind around the MTT, which lends it a powerful and menacing air.
The Baktoid Signature in Design
The MTT (large transport) was designed by the same Baktoid workshop that developed the AAT (battle tank) for the Trade Federation secret army. The distinctive Baktoid style gives both vehicles a look reminiscent of heavy, jungle-dwelling animals. Both are designed for use in formal battle lines and place vital equipment such as reactor and main engines at the rear, protected by the heavy armor of the front surfaces.
The Deployment Rack
The original design of the MTT called for an open staging chamber inside it, but the Baktoid Armor Workshop is known for its original designs, and the MTT has the unusual job of conveying soldiers that were not living beings, but droids. The Baktoid engineers worked out a system that would load battle droids folded into a very small configuration into a giant deployment rack. This rack would more than double the troop capacity of the MTT, extending to release the compressed troops which would then unfold into fighting configuration. At the conclusion of a battle, troops are reloaded into the rack and safely carried back to their base. The original open-staging chamber MTT design was retained for carrying wheel-like destroyer droids.

Battle Droid Transport stats
Craft: Baktoid Armor Workshop MTT
Type: Troop Transport
Scale: Walker
Skill: Repulsorlift Operation: Heavy Equipment
Crew: 5 battle droids (1 pilot, 1 gunner/engineer, 2 rack operators, 1 lift operator)
Passengers: 4
Cover: Full
Cargo: 40 destroyer droids (open-staging chamber model) or 112 battle droids with blaster rifles (rack-equipped model)
Move: 12/35 kmh
Maneuverability: -2D
Body Strength: 6D; 9D frontal surface
Weapons: