The Sandringham line is a commuter railway line in the city of Melbourne, Victoria, Australia. Operated by Metro Trains Melbourne, it is the city's fourth shortest metropolitan railway line at . The line runs from Flinders Street station in central Melbourne to Sandringham station in the south-east, serving 14 stations via South Yarra, Balaclava, Elsternwick, and Brighton. The line operates for approximately 20 hours a day (from approximately 5:30 am to around 12:20 am) with 24 hour service available on Friday and Saturday nights. During peak hour, headways of up to 5 to 10 minutes are operated with services every 10-20 minutes during off-peak hours. Trains on the Sandringham line run with a two three-car formations of Siemens Nexas train sets. Sections of the Sandringham line opened as early as 1859, with the line fully extended to Sandringham in 1887. A limited number of stations were first opened, with infill stations progressively opened between 1860 and 1912. The line was built to connect Melbourne with the suburbs of Balaclava, Elsternwick, Brighton, and Sandringham, amongst others. Minor upgrades have occurred since its opening, including historical level crossing removal works and regular infrastructure upgrades. History 19th century The Melbourne and Suburban Railway Company opened their line from Princes Bridge (later amalgamated with Flinders Street station) to a temporary station on Punt Road in February 1859, then to Cremorne (now closed) in December of that year. Shortly after, the St Kilda and Brighton Railway Company opened their railway line from St Kilda to Bay Street (now North Brighton) in December 1859. Twelve months after that, the Melbourne and Suburban Railway Company extended their line from Cremorne to Chapel Street (now Windsor) station, on the St Kilda and Brighton Railway Company's line, providing a second route to the city from the Brighton line. The following year, again in December, the St Kilda and Brighton Railway Company extended their line to Beach (now Brighton Beach). The link between St Kilda and Windsor, disused since 1862, was dismantled in 1867, although part of it at the Windsor end was used as a siding for some time afterwards. In 1865, the Melbourne and Hobson's Bay Railway Company, who owned the St Kilda line, purchased the Melbourne Suburban Railway Company and became the Melbourne and Hobson's Bay United Railway Company, and subsequently bought the St Kilda and Brighton Railway Company, which was in financial difficulties, for £99,500. The