In 1920 there were a number of ambulance services operating in Adelaide and its suburbs: SA Ambulance Transport, SA Police (Civil Ambulance), and various private groups. St John Ambulance Brigade used to borrow a vehicle from SA Railways to provide assistance at the Victoria Park horseraces.
This resulted in many or no ambulances arriving at a scene. Usually, only minimal pre-hospital care was provided at the scene or on the way to hospital.
By 1934, several private services had disbanded, leaving three main ones: SA Ambulance Transport, Northern Districts Ambulance Service (owned by Prospect Council), and a service run by Hindmarsh Council.
In 1940 St John Ambulance Brigade established a close association with SA Railways staff in country townships. As a result, many St John first-aid divisions were established by railways staff in townships such as Naracoorte, Peterborough, Port Augusta, Port Lincoln, Strathalbyn and Tailem Bend.