SDA2 is an AC-DC-AC transmission diesel locomotive operated on narrow-gauge rails and used for trunk freight. It adopts three-axle radial bogies with a 20t axle load, whose indicators can be improved through adding weights. The locomotive employs a outside corridor and underframe load-bearing structure with single cab, installed with MTU 20V4000R43 diesel engines, and adopts transmission solutions of integrating main alternators with auxiliary alternators, KNORR ECP+WAP+DP60 distributed electro-pneumatic brake systems, and microcomputer control systems based on CAN-OPEN bus. It features distributed multiple-unit running, full power self-load, low and constant speed control, self-extinguishing in power rooms, forward video capture, emergency escape from front windows, biochemical toilets and mute cooling fans.
This type of locomotives has formally put into service in Australia, with good traction and brake performance, as well as reliable quality.