Melbourne Cup Day brings to mind the mentions of horse racing in my research about the lock building communities. In addition to setting up the footy oval, cricket pitch and tennis courts, the men also made a race track for race meetings.
Lock 4 and Lock 7 communities both enjoyed the races. This article from TROVE details some fun at the Lock 4 races in October 1928.
The second image from the Searcy Collection SLSA depicts horses at a country meeting in SA in the 1920s.