50 cents - Charles III 1st Portrait - Steam Giants - Commonwealth Railways G Class G1

The Commonwealth Railways G class diesels were ordered in the early 1950s to work the Trans-Australian Railway, one of the longest stretches of straight track on earth — 478 kilometres without a curve across the Nullarbor Plain. The G1, delivered in 1954, was among the first of the class and helped end steam operations on the TAR ahead of schedule.

Pad printing on circulating-format coinage remains a technically finicky process; colour adhesion on cupro-nickel is notoriously inconsistent under circulation conditions, which is precisely why these are issued as collectibles rather than released to general commerce.