SDD 6 diesel locomotive is developed and manufactured for Namibia and Angola as passenger, freight and shunting locomotive. It is equipped with Cummins QSK60-L1 diesel engine with maximum service power 1640kW. Main AC-DC transmission is employed with DC and AC transmission for auxiliary system. Two center-plate-less radial bogies with three axles for each and single pull rod for axle box are used. The mechanism of four low-position tractive rods is utilized for transmission of tractive and braking efforts. The car body is of load bearing centre beam and outside corridor. The braking system is equipped with double-purpose brake of air and vacuum. It is capable of 4 units in consist.

Basic locomotive parameters:
1. Purpose: passenger, freight and shunting locomotive
2. Applicable environment: operate normally in severe sand, dry, hot and desert areas
3. Gage: 1067mm
4. Transmission mode: AC-DC transmission
5. Axle arrangement: Co-Co
6. Wheel diameter: 914mm
7. Axle load: 16×(1±3%)t
8. Calculating locomotive weight with full service: 96×(1±3%)t
9. Maximum service power of the engine: 1640kW
10. Locomotive speed (calculated at half worn driving wheel as 880mm):
Maximum running speed: 120km /h
Continuous speed: 21.7km/h
11. Locomotive tractive effort at wheel rim (calculated at half worn driving wheel as 880mm):
Starting tractive effort: 313kN (starting current limit)/310kN (adhesion limit)
Continuous tractive effort: 200kN
12. Minimum curvature radius negotiated: 80m
13. Fuel tank capacity: 4000L
14. Oil volume: 281L
15. Water volume: 500kg
16. Sand volume: 300kg
17. Center line of coupler above rail head: 889mm±10mm
18. Locomotive length: 18100mm