Editing City Loop (section)

===Construction===
[[File:Melbourne City Loop Museum Station, now Melbourne Central, under construction 1974 on the corner of La Trobe and Swanston Streets 1.jpg|thumb|Construction of Museum station in July 1974, showing cut and cover excavation of [[La Trobe Street]], with the [[State Library Victoria|State Library of Victoria]] in the background.|alt=Construction of Museum station in July 1974, showing cut and cover excavation of La Trobe Street, with the State Library of Victoria in the background.]]

Following the [[1969 Melbourne Transportation Plan]], the Melbourne Underground Rail Loop Act 1970 was introduced into parliament by Transport Minister [[Vernon Wilcox]], and the Melbourne Underground Rail Loop Authority (MURLA) was created on 1 January 1971 to oversee the construction and operation of the loop. The [[City of Melbourne]], the [[Melbourne & Metropolitan Board of Works]] and the [[Victorian Railways]] all made annual contributions to support the operating costs of the authority.<ref name=lee191 /> An unsuccessful request for funding was made to the Federal Government.<ref name="elect92" />

The project was financed using [[debenture]]s, with the State Government paying 60% of the cost and a special city levy from 1963 funding the remainder. The levy was supposed to be in place for forty years (until 2003), but was ended in 1995.<ref name=lee191 /> A consortium of four engineering companies was established to construct the project: one from Australia, one from the United Kingdom, one from Canada and one from the United States of America. On 22 June 1971, the [[groundbreaking|first sod]] of the project was turned by Wilcox in the middle of the [[Jolimont Yard|Jolimont rail yards]].<ref>Melbourne Underground Loop: Construction Work Inaugurated ''[[Railway Transportation]]'' August 1971 pages 19-22, 36</ref><ref>Melbourne's underground takes shape ''[[Network (periodical)|Network]]'' September 1971 page 1</ref><ref name="elect93" >{{cite book | author = S.E. Dornan and R.G. Henderson | title = Electric Railways of Victoria | publisher = Australian Electric Traction Society | page = 93 | year = 1979 | isbn = 0-909459-06-1 }}</ref>

[[File:Melbourne City Loop Museum Station, now Melbourne Central, under construction 1974 with Coop's Shot Tower 1.jpg|thumb|Construction of Museum station in July 1974 looking towards [[Coop's Shot Tower]].|alt=Construction of Museum station in July 1974 looking towards Coop's Shot Tower.]]

[[Tunnel]]ling works under the city streets commenced in June 1972, using a [[tunnel boring machine]] built by Richmond engineering firm [[Jaques Limited]].<ref>[http://www.theage.com.au/victoria/key-role-in-digging-rail-loop-20100523-w3zf.html ''The Age'' 24 May 2010, 'Key role in digging rail loop' Obituary GEOFFREY KEEGAN, AM, ENGINEER, CONSULTANT 20-10-1924 – 22-4-2010]</ref> as well as conventional boring methods. At North Melbourne, Spencer Street and Jolimont Yard, [[cut and cover]] tunnelling was used to build the access ramps, with the above ground running lines being slewed from time to time as work proceeded. The first completed [[tunnel]] was the [[Burnley, Victoria|Burnley]] Loop, with the final [[Tunnel hole-through|breakthrough]] made on 8 June 1977 near the Museum station site.<ref name="elect93" />

The loop comprises four [[single track (rail)|single-track]] tunnels on two levels, and includes +four pre-existing elevated tracks between Flinders Street and Spencer Street stations. A new [[double track]] [[concrete viaduct]] was erected beside the existing [[quadruple track]] [[Flinders Street Viaduct]] in order to replace capacity for non-loop trains. Construction began in 1975 and was completed in 1978.<ref name="elect93" /> Of the three new stations, Museum was built using the [[Tunnel#Construction|cut and cover]] method in a {{Convert|26|m|ftin|adj=mid|-deep}} box,<ref name="elect93" /> while Flagstaff and Parliament were excavated using [[mining]] methods. During the excavation of Museum station, [[La Trobe Street]] and its [[tram track]]s were temporarily relocated to the south onto the site of what is now the [[Melbourne Central Shopping Centre]] from December 1973, and were moved back in 1978.<ref name="elect93" />

The total length of tunnels in the loop is {{convert|12|km|mi|abbr=on}} with {{convert|10|km|mi|abbr=on}} of circular tunnels, and {{convert|2|km|mi|abbr=on}} of box tunnels. The four tunnels have an average length of {{convert|3.74|km|mi|abbr=on}}, with a further {{Convert|1|km}} of track connecting with surface tracks. Some {{convert|900000|m3|yd3|0|abbr=on}} of earth was removed and {{convert|300000|m3|yd3|0|abbr=on}} of [[concrete]] poured to form the stations and line the tunnel walls.<ref>{{Cite book |url=https://books.google.com/books?id=bZZdDwAAQBAJ |title=Australia's Railways |publisher=Alison Hideki |year=2018 |pages=23|isbn=9781925630763 }}</ref>

[[File:Promotional poster for Museum Station, Melbourne, now Melbourne Central - Beginning a new era - Stage 1 of the City Loop, c. 1981.jpg|alt=Promotional poster to celebrate the opening of Museum station, now Melbourne Central, in 1981, with illustration of station platform.|thumb|Promotional poster to celebrate the opening of Museum station, now Melbourne Central, in 1981.]]

A "double sleeper" floating track system was used to solve the problem of ground-transmitted vibration and track noise, and the loop has some of the best-designed and quietest underground stations in the world.<ref name="lee191" /> At the time of its construction, Parliament station had the Southern Hemisphere's longest escalators.<ref name="murlbook">{{cite web |author=Metropolitan Transport Authority |title=MURL Booklet |url=http://www.doi.vic.gov.au/doi/doielect.nsf/2a6bd98dee287482ca256915001cff0c/44507f9d12a4406cca25700c0012fe36/$FILE/MURL%20booklet.pdf |url-status=dead |archive-url=http://webarchive.loc.gov/all/20090628211644/http://www.doi.vic.gov.au/doi/doielect.nsf/2a6bd98dee287482ca256915001cff0c/44507f9d12a4406cca25700c0012fe36/$FILE/MURL%20booklet.pdf |archive-date=28 June 2009 |access-date=20 July 2008 |publisher=doi.vic.gov.au}}</ref>

Traction power was turned on in October 1980,<ref name="doi">{{cite web |url=http://www.doi.vic.gov.au/Doi/Internet/transport.nsf/AllDocs/74164766E0CEAF95CA25700500122952?OpenDocument |title=Public transport – City Loop history |author=Department of Infrastructure|publisher=doi.vic.gov.au |access-date=20 July 2008 |url-status=dead |archive-url=http://webarchive.loc.gov/all/20090520044857/http://www.doi.vic.gov.au/DOI/Internet/transport.nsf/AllDocs/74164766E0CEAF95CA25700500122952?OpenDocument |archive-date=20 May 2009}}</ref> and the first test train ran on 4 December 1980.<ref>Off and Running ''[[VicRail News]]'' March 1981 page 3</ref><ref name="vicrail6283">{{cite book | author = Vincent Adams Winter | title = VR and VicRail: 1962 – 1983| year = 1990 | isbn = 0-9592069-3-0 <!-- This is a corrected ISBN and may not match the number printed in the book. --> | page = 206 }}</ref> In 1965, the cost of the project had been estimated at between £30 and £35 million but, by 1975, [[inflation]] had resulted in it rising to $255,600,000.<ref name="lee191" /> While the final cost was $500 million, the opening of the loop helped reverse a 30-year trend of falling suburban rail patronage.<ref name="murlbook" />