The RA-PT is named after the technology used on the first prototype of the vehicle. It was created when a Jedi, while working on his lightsaber, discovered a method to alter the flow of antiprotons from the adegan crystal in the hilt while the saber was in operation. He collaborated with Republic engineers to utilize this new discovery as a vehicle weapon.
The result was a pair of what were, essentially, oversized lightsaber hilts mounted to the top of a quad-repulsion-based hovercraft. The blades would ignite from the cannons at approximately 6 times the diameter of a handheld lightsaber. The length of the blades was adjustable from inside the cockpit thanks to the Jedi�s circuitry discovery, so the weapon could project up to a mile away.
The problems with this design were quickly found out it test and live combat scenarios. For one, accidentally shortening the �blade� projected from the cannons too far would cause a buildup of antiproton energy in the tank, leading to more than a few of these vehicles spontaneously exploding in combat. For another, a lightsaber�s final step of construction involves the Force to allow the blade maximum efficiency. This limited production greatly as a Jedi had to help build each cannon. Also, the massive draw of power when the beams of the weapon would strike a target was often enough to overload the tank�s generators and stall the craft, leaving it open to attack.
The weapon system was later replaced with an anti-aircraft missile system, but the craft still retains its original name: The Republic Adegan Prototype Tank. A few RA-PTs are said to still exist, modified by Jedi with power restrictions and failsafe systems to prevent overloading and energy exhaustion, but this has not officially been confirmed nor denied by the Republic.
Dean: Thank you, I only classify it as Star Wars at is was made for a Star Wars contest. My building style is very un-Star Wars so I pulled the random back story to make it work. I guess to answer your question, nothing.
I went through brickshelf today and I found your models are great, especially tank and TatooineStreet is wonderful ...
I have a plan to make small computer animation (using lego models) for myself. Can I put your model (tatooine) in? write me to my email pls..thanks :-) marek