The SRB42 sublight engine, a product of Girodyne, served as a sublight engine. Its most prominent application was in the YT-1300 light freighter, where it was configured as a "wide bar engine," stretching across the craft in a lengthy strip.
Girodyne engineered the SRB42 as a type of sublight engine specifically for Corellian Engineering Corporation. It was integrated into the company's YT-1300 light freighters. The SRB42 was widely recognized as one of the most effective engines available for freighter applications. The engine received power from a fusion reactor that converted fuel into charged particles to operate the sublight drive. These particles underwent ignition within a primary combustion chamber. After compression, they were channeled toward the engine's final stage unit.
Within the SRB42's final stage units, a powerful turbine increased the velocity of the energized particles, directing them towards reactant injectors that forced them into the stabilizer chamber. This chamber ensured the thrust was sufficiently stable for re-ignition within the high-pressure afterburner. With occasional assistance from the ship's hyperdrive boost pumps, the particles were expelled through nine exhaust nozzles. The resulting energy generated a powerful propulsive force, enabling thrust. Thrust vectors were used to alter the ship's course. During hyperspace jumps, a servomotor-operated plate could be lowered to impede particle emissions. The engine exhaust, slightly radioactive and intensely hot, could instantly vaporize accumulated debris, leading CEC to classify the engine as 'self-cleaning'.
To withstand radiation and inter-dimensional shift stress, the engine was constructed from a chromium-titanium alloy. Its adaptable design allowed YT-1300 owners to install a SubLight Acceleration Motor (SLAM), enabling the redirection of spare power from other systems to the engines when needed. For this purpose, power cables were carefully routed around the pressurized engine sections to deliver SLAM power to all components, while fuel supply lines were strategically placed near the boost pumps and exhaust nozzles to provide additional fuel as required.