A narrow gauge railway opened on the island of Upolu in what was then German Samoa shortly after the outbreak of World War I in 1914. A 4km main line served to convey materials from the waterfront at Apia to a newly constructed wireless station at Mount Vaea; a further 4km of branch lines connected to coconut plantations.
Less than a month later, the island was occupied by New Zealand forces. The railway had undergone some damage, but was restored and used for troop movements to and from camps on the island. The one and only locomotive was rebranded NZR, for New Zealand Railways. The wireless station was never restored to working order, and the last of the German owned coconut plantations had ceased operations by 1916, so troop movements were the sole remaining activities on the line until the end of military occupation in 1920. Thereafter, the line fell into disuse.