Use a lift-jump to reach the top corridor in the middle of the map.
Trivia
Beta/UC version levelshot.
UC (Beta version) levelshot.
The lightning/shield platforms are absent in the Championship/UT2003 beta version. It's replaced, instead, by a big tank.
The beta version of the map, found in the Championship beta, can be described as a mix between DM-DE-Ironic's general feeling, and the console version of this map, because of the tanks.