M577 APC Roof turret (Aliens movie)

The installation of the A3's particle accelerator guns was made possible due to the introduction of a Martin-Continental micro magnetohydrodynamic turbine, capable of generating the 20 mW of electrical power required to run the weapons. The turret contains sufficient turbine fuel to power the guns for 50 seconds firing, along with 300 kg of deuterium to provide particle beam mass.[5] The weapon is effective against light armored targets up to 3,000 m, and is still capable of disrupting unshielded electronics at even longer ranges. Notably, an M577A3 model was deployed to Hadley's Hope aboard the USS Sulaco, although it was subsequently destroyed on site.