Flinders Street Viaduct

The first railway in Melbourne was opened in 1854, running from what is now Flinders Street station to Sandridge (now Port Melbourne), and was later known as the Port Melbourne line. New railway lines continued to be built, many of which used Flinders Street station and the adjacent Princes Bridge station as their city terminals. At the same time, a number of country railway lines had been built to the north and west of Melbourne, using Spencer Street station (now Southern Cross) as their terminus.

Many residents saw the Spencer Street terminal as undesirable and inconvenient, as it was at the edge of the then city, and as early as 1861 a deputation of residents called on the Railway Commissioner to improve matters.[1] It was not until 1879 that the Melbourne Railway Station Junctions Act was passed, which authorised a ground level connection. Three quarters of a mile long, it was classified as a tramway and had limits on the operational speeds, noise, and motive power allowed. In addition, it could only be used at night, and had a level crossing at Queensbridge Street.

The Octopus Act of 1884 finally authorised construction of a permanent link, as well as 64 other railway lines around the state. A single track of the viaduct was opened in November 1891 before the whole double line opened for goods traffic the next month, however teething problems limited the viaduct to a single line during February 1892.[1] The viaduct was both designed and its construction and duplication supervised by Frederick Esling. He was also the author of a technical paper which identified a puzzling problem related to the horizontal forces on the viaduct due to braking, in combination with side forces from wind-pressure.[2]

The ground level tramway was cut back, but a short section was retained as a siding to serve the Melbourne City Markets on Flinders Street, not being lifted until 1929.

From December 1894 suburban traffic on the Williamstown and Essendon line began to use the viaduct, after the construction of additional platforms at Spencer Street station. To provide for the growing amount of traffic, the viaduct was duplicated in 1915 to provide four tracks in total.[3] These new tracks were built to the immediate south of the existing viaduct, which was then closed and strengthened, before being reopened in 1917.[1]

Until the 1970s the viaduct remained virtually unchanged, when in conjunction with the underground Loop project, the existing four tracks were made part of each of the four independent loops around the Melbourne central business district. Two additional tracks were built to the south, but not adjacent to the older lines. This time, instead of steel spans supported by brick pillars, precast concrete box girders 722 metres (2,369 ft) long, on concrete supports were used, each girder carrying a single rail track with each span 30 to 35 metres (98 to 115 ft) long.[4] Unlike the older viaduct tracks, the new ones were able to take a straighter path because the now disused turning basin had been partly filled in. Work began in December 1975,[5]^{: page 93} with the new viaduct opened on 11 December 1978.[6][7] Work then began on rehabilitating and upgrading the older four lines, with two tracks being taken out of use at a time. The new viaduct was signalled to allow trains to travel in one direction only on each line, whereas the four tracks on the older viaduct were resignalled for bidirectional use, since it was planned that the direction of travel in each Loop would be reversed between the morning and afternoon peaks.[5]^{: page 95}

The land under the Viaduct has been used for various uses, for example when the King Street Bridge was built in 1958 the land was turned over to the City of Melbourne, who used it as a car impound yard for parking offences.[8] This was repealed in 2003 when the Flinders Street overpass of King Street was demolished.[9] The original viaduct was re-decked in 2000, from near Spencer Street through to near Market Street.[10]

In 1997 the Northbank area was redeveloped, with the turning basin restored in part and the newer viaduct bathed in blue light by night[11] in an artwork titled 'Blue Line' by Peter McNeill-Stitt, that includes 1,400 metres (4,600 ft) of neon tubing.[12][13] The Melbourne Aquarium was built under and around the newest viaduct between February 1998 and December 1999,[14] and as of 2008 is being expanded under the four track viaduct towards Flinders Street. As part of the Northbank Place development in the late 2000s, three 11-storey mixed-use towers were built on the former Melbourne City Markets site,[lower-alpha 1] and resulted in the railway signals needing to be altered due to the altered sight lines for trains coming around the curve.[15][16] The corresponding area on the south side of the viaduct, including the site of the old Fish Market, has become Batman Park and includes a pathway named "Rebecca Walk" in reference to the Schooner Rebecca.

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  The four track viaduct in 1928, with the Sandridge Bridge crossing the Yarra and the turning basin still in use.
• 
  Viewed from Flinders Street itself, looking east.
• 
  Looking east from a train on the new Viaduct, towards Southern Cross and a train on the old viaduct.
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  The new Viaduct viewed from the Yarra River.
• 
  The new viaduct by night.

• Railways in Melbourne