Flash Butt yard BHP's stored Goninan WA ALCo C636 to GE C36-7M rebuild unit 5506 awaits its fate. Rebuilt in 1987 at Goninan's Welshpool factory from a 1968 AE Goodwin built ALCo C636 with serial number G6012-4 and road number 5455 and assigned new serial number 4839-01 / 87-071. It was delivered in Mount Newman Mining orange and was named Mt Goldsworthy. 5506 was the first unit in the world where an ALCo C636 had been rebuilt into an GE C36-7. Late 2001.