Quorn's role as a crossroads was lost when a standard gauge railway connection was opened between Port Pirie Junction and Port Augusta in 1937, meaning east–west trains bypassed Quorn. However, during World War II, Quorn was a vital service point for trains heading north to Alice Springs and carried over 1,000,000 troops heading to Darwin and on to Papua New Guinea. Trains services through Quorn peaked at over 50 per day during and immediately after the period of World War II. Services during this time also included coal mined at Leigh Creek being moved to the newly opened Playford A Power Station in Port Augusta.