City Loop

Comeng train exiting the Caulfield Group tunnel at Southern Cross

Before the Loop was constructed, Flinders Street and Spencer Street (now called Southern Cross) stations were connected only by the four track Flinders Street Viaduct beside the Yarra River. The suburban terminus of Flinders Street had become seriously congested by the 1970s, with a throughput of only ten trains per platform per hour (roughly 1,700 trains a day) — compared to a maximum of 24 if there was through running.[1] Many trains were through routed from the southern and eastern suburbs through to the north and west, but the flow was imbalanced and a number of trains were required to reverse direction.[1] The Epping and Hurstbridge lines stood alone from the rest of the network, having Princes Bridge station for their own exclusive use.

Several plans had been proposed over the preceding decades to alleviate the bottleneck. The one that was adopted was the building of a circular railway allowing trains to continue past Flinders Street, turn around and return to the suburbs. It was expected to boost platform capacity, allowing more trains per platform per hour on the same number of Flinders Street platforms. The loop would also bring train commuters directly into the northern and eastern sections of the CBD, delivering workers closer to their offices, students closer to RMIT University, and government officials directly to the Parliament buildings. Although the city's tram network already covered the CBD extensively, trams are not as efficient as trains when bringing large numbers of commuters into the city.

Parliament Station platform

Melbourne Central Station platform

Flagstaff Station platform

Plans for an underground city railway in Melbourne are almost as old as electrification of the network itself. In 1929, the Metropolitan Town Planning Commission released a report recommending an underground city bypass from Richmond to North Melbourne stations via Exhibition and Victoria streets.[2] The 1940 Victorian Railways Ashworth Improvement Plan recommended a different approach, with additional platforms at the Flinders Street/Princes Bridge station complex to be built over two levels, along with a connection to an underground City Railway.[3] The Victorian Railways promoted another route in 1950 as part of the Operation Phoenix rehabilitation plan, the line running from Richmond towards Jolimont station, under the Fitzroy Gardens and Lonsdale Street then turning north to North Melbourne station. A branch line turned north from William Street, and went through the Flagstaff Gardens.[4] In 1954 the Melbourne and Metropolitan Board of Works released their Planning Scheme for Melbourne report, which included the Richmond - North Melbourne Lonsdale Street route.[2]

A Parliamentary Committee on Public Works reported favourably on a city loop in 1954, and in 1958 a City Underground Railway Committee was appointed by the Transport Minister. It stated bluntly that the aim of the loop was not just to relieve crowding at Flinders Street, but to win back patronage from private cars, and if it did not then the project was a waste of time and resources.[5] The plan included four stations, being cut to the present three by the elimination of one under Latrobe Street.[1]

The 'City of Melbourne Underground Railway Construction Act' was passed in 1960, and test bores were sunk by the Mines Department in 1961, but no funding was provided. Throughout the next few years many proposals were made for providing more car parking in the city, so in 1963 the Government set up the Metropolitan Transportation Committee to look at both road and rail transport. It released a report in 1965 that included the same rail plan as the 1960 Act.[6]

Melbourne Underground Rail Loop Authority logo

Following the 1969 Melbourne Transportation Plan, the Melbourne Underground Rail Loop Act 1970 was brought forward by Transport Minister Vernon Wilcox, with the Melbourne Underground Rail Loop Authority (MURLA) created on 1 January 1971 to oversee the construction and operation of the Loop. The City of Melbourne, the Melbourne and Metropolitan Board of Works and the Victorian Railways all made annual contributions to support the operating costs of the authority.[6] Requests were made to the Federal Government for funding but no assistance was given.[1]

Funding of the project was through debentures, with the State Government paying 60% of the cost, while a special city levy from 1963 was to fund the remainder. The levy was to be in place for forty years (until 2003), but was ended in 1995.[6] 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. The first sod was turned in the middle of Jolimont Yard on 22 June 1971 by then Transport Minister Vernon Wilcox.[7]

Tunnelling works under the city streets commenced in June 1972, using a tunnel boring machine built by Richmond engineering firm Jaques Limited.[8] 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 Loop, with the final breakthrough made on 8 June 1977 near the Museum station site.[7]

The Loop comprises four single-track tunnels on two levels, and the use of 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.[7] Of the three new stations, Museum was built using the cut and cover method in a 26-metre deep box,[7] while Flagstaff and Parliament were excavated using mining methods. During the excavation of Museum station, La Trobe Street and its tram tracks were temporarily relocated from December 1973 to the south onto the site of what is now the Melbourne Central Shopping Centre, and was moved back in 1978.[7]

The traction power was turned on in October 1980,[9] and the first test train ran on 4 December 1980.[10]

Queen Elizabeth II toured Museum station during her visit to Australia in May 1980, and opened the plaza on top of the Swanston Street entrance, which was named Queen Elizabeth Plaza. Two short documentary films, Loop and Action Loop, were commissioned by the MURLA to advertise the new railway to Melburnians, as well as abroad. (These videos can be downloaded from the Department of Infrastructure). A third film was planned, but never shot.[9]

The Loop was opened gradually between 1981 and 1985. Museum station and the Burnley and Caulfield tunnels opened first, on 24 January 1981.[9] The City Circle tunnel opened with special services on 6 December 1981, and Clifton Hill services started using the Loop on 31 October 1982. Parliament station opened on 22 January 1983, the Northern tunnel on 7 January 1985 (14 January 1985 with limited services) and Flagstaff station on 27 May 1985.[9]

Inside a section of bored tunnel

The total length of tunnels in the Loop is 12 km (7.5 mi) with 10 km (6.2 mi) of circular tunnels, and 2 km (1.2 mi) of box tunnels. The four tunnels have an average length of 3.74 km (2.32 mi), with a further kilometre of track connecting with surface tracks. Some 900,000 m³ (1,200,000 cu yd) of earth was removed and 300,000 m³ (390,000 cu yd) of concrete poured to form the stations and line the tunnel walls. 30,000 tonnes (33,000 short tons) of steel reinforcement were used, with another 10,000 tonnes (11,000 short tons) used temporarily during construction.

The General Manager and Chief Engineer of MURLA, Frank Watson liaised closely with the engineers working on Sydney's Eastern Suburbs Railway and was struck by their 'degree of unpreparednesses' and sought to improve on the contemporary project. The 'double sleeper' floating track system used solved 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.[6] At the time of construction Parliament station had the Southern Hemisphere's longest escalators.[11]

In 1965, the cost of the project had been estimated at between £30 and £35 million, by 1975 high inflation had resulted in it rising to $255,600,000.[6] While the final cost was $500 million, it resulted in the reversal of a 30-year trend of falling suburban rail patronage.[11]