Les
may have got the story a little mixed up. There WAS a railway branchline used to take POWs and internees to a camp (known officially as the
German Concentration Camp!
. That name wouldn't ring so nice 25 years later.), but it was not near Campbelltown. The Holdsworthy (as it was spelt then) branch left the Main South Line at Liverpool station and crossed the Georges River (the bridge supports are still there, now a pedestrian/cycleway) and ran along what is now Heathcote Road to around the position of the current East Hill line, where it turned due south and into the current Holsworthy Military training area. It was 5Km long.
The camp was opened in WW1, and closed in 1920. The railway branch was built with Internee labour and opened to traffic in 1917. The end of the branch into the GCC was closed with the closure of the camp in 1920, but the middle section continued for many years to serve the warehouses in the Holsworthy Base, and also brought special passenger trains for weekend shooting competitions at the Anzac Rifle Range. The branch finally closed in 1974.
Being securely enclosed within the Military base, the remains of the railway formation and GCC are somewhat preserved, including lots of German grafitti and names carved in the sandstone outcrops around the site of the railways station. The camp buildings were burnt in a bushfire many years ago, but the stone remains of the commandant's house and mess hall still remain, with modern buildings all around them.
Pity the AWM's site has gone all funny, as there are lots of photos of the camp and railway in their online collection.