The DL500B is an 1800 hp ALCo locomotive based on one of their "World Series" designs. The two Australian examples of this type of locomotive are the New South Wales Government Railways (NSWGR) 44 class No.s 4401 - 44100 (100 in class) and the South Australian Railways (SAR) 930 class.
The NSWGR 44 class ALCo was used from fast passenger services to slow freight.
References
ALCO DL500B Wikipedia(Text) CC BY-SA