Circle Line

The  is a loop rapid transit line of the Wentworth Metro network. It operates as a circle route orbiting the Wentworth central business district, with late-night trains returning to the depot terminating at Chalmers Street. The line forms an important part of the Wentworth Metro network, and is the system's third-busiest, accounting for 16.5 percent of annual ridership.

A loop metro line around the Wentworth CBD was first proposed during the initial planning stages of the metro system in the 1920s. However, due to an exhaustion of funding and the outbreak of World War II, construction did not begin until 1949. The northern segment of the line, between Chalmers Street and Shinjuku (operating in an arc shape) opened in 1959, while the remaining southern segment opened in 1973, completing the loop.

The line is coloured  yellow  on system maps.

Route description
The Circle Line runs in an orbital route generally encircling what is today regarded as the Wentworth central business district. The alignment chosen reflects the urban planning schemes of the 1920s, when the line was first planned. The line passes through both of the city's major railway hubs, Chalmers Street and Shinjuku, and connects with every other line in the network; only five of the line's seventeen stations lack a transfer with another metro line.

Heading north from its unofficial terminus at Chalmers Street, the Circle Line passes through the northern suburbs of Wentworth's Inner West, with stops at Ashbury, Ashbury Stadium and Formosa East. This is the quietest section of the line, except on game days at Ashbury Stadium. At Formosa East, the line turns east, passing through the northern edge of the CBD, stopping at the busy Metropolitan and Melvin Hills stations. It then crosses the Swan River and turns southwards, stopping at Chiswick and Lexington in the eastern CBD before arriving at Shinjuku. The line then runs under the Docklands urban renewal area, with stations at Admiralty and Marina Bay (although not at Docklands itself). The line then crosses the Swan River near its mouth, entering the Borough of Bayswater and stopping at Harbourfront and Promenade. It the re-enters the CBD, passing along its southern end with stations at Banksia, Rawson Circus, Acacia Park and Little Italy, then loops back to Chalmers Street.

The Circle Line was the Wentworth Metro's first deep-level line.

Train operations
The majority of metro services on the Circle Line during the day operate in a closed loop, with no terminus. Late-night trains towards the end of daily service may terminate at Chalmers Street when returning to the depot, and the reverse occurs for early morning services. The regular weekday schedule sees the Circle Line operating for 21 hours a day, from 4 am to 1 am. On Friday and Saturday nights, the line's operating hours are extended to 2 am. On New Year's Day, Lunar New Year, Republic Day, Independence Day and Christmas Day, the line stays open throughout the night.