High rises derail hopes of train link to northern beaches: mayor The prospect of a future train service to the northern beaches is all but sunk because high-rise development over Chatswood railway station failed to leave room for extra rail lines, Willoughby Council says, sending a warning to the state government as it opens Sydney's main rail corridor to developers. The government said this month it would seek bids from around the world to develop three kilometres of railway corridor from Central Station to Eveleigh, signalling a crop of high-rise towers and structures built over rail lines. But the project faces serious hurdles, not least concerns that any development could restrict the expansion of Sydney's overworked public transport network. Manhattan West: New York Rail Corridor. Willoughby mayor Pat Reilly pointed to the outcome of a $360 million redevelopment of Chatswood station, which began in 2005, including residential towers and a transport interchange. He said an enclosure built over the rail lines was only wide enough for four tracks, leaving no room for a rail link to the northern beaches should a future government pursue that option. The only alternative is to tunnel under the existing rail lines, but that would be obstructed by three levels of basement car parking, which have been sold to developers, Cr Reilly said. Broadgate Tower: Liverpool Street Station, London. Residents of Sydney's northern beaches face long bus journeys to the city and a rail line has long been suggested as the answer to the region's transport woes. The O'Farrell government is instead investigating a potential bus rapid transit system from the City to Mona Vale, linking to Chatswood. However, Cr Reilly said a new bus interchange at Chatswood, part of the station redevelopment, is already over capacity and it is "unclear" where extra bus services would be able to stop. The council's advice to the previous Labor government on problems at Chatswood "was eroded down to what we have now," he said. Vision: NSW has called for expressions of interest for the renewal of the railway line corridor between Central Station and Eveleigh that has potential to provide thousands of new homes and jobs. A parliamentary inquiry into building over rail corridors last year warned a lack of strategic planning could have "unfortunate consequences." It heard evidence from Transport for NSW that a redevelopment of North Sydney station was hampered by the sale of space above and around the site, which constrained passenger movement between platforms and the concourse. A spokeswoman for Planning Minister Brad Hazzard said a clear planning framework will be in place "before any major changes happen" in the Central Station to Eveleigh project and feedback from industry and the public would be considered. A Transport for NSW spokeswoman said existing development near Chatswood station constrained the width of the corridor but it was wide enough to meet future needs, including integration with the north-west rail line. City's main rail corridor plan attracts global developers with big ideas and legacies The architecture firm behind the world's tallest building has signalled it wants to develop Sydney's main rail corridor, as the state government fields global interest in a project to remake the central business district's southern edge. Former federal Liberal MP Ross Cameron has also flagged a bid, after his plan to build more than 150 Chinese-made high rises along the corridor was rejected last year. The government will later this year call for expressions of interest to develop underused rail land from Central Station to Eveleigh, including apartment and office towers and structures built over the rail line. Skidmore, Owings & Merrill marketing manager Jayme Gately, whose American architecture and engineering firm designed Dubai's Burj Khalifa building - the world's tallest - said it was interested in "potentially pursuing the project." "We believe we could bring highly applicable expertise ... we certainly understand the strategic approach and the necessary public process for a project such as this," she said. We look forward to further understanding the project goals and objectives. Skidmore, Owings & Merrill designed central London's Broadgate Tower - a 165-metre-high office block suspended over rail lines at Liverpool Street Station. It is also devising the central Barangaroo masterplan. The government has compared its rail corridor plan to Broadgate, La Grande Arche in Paris, Transbay terminal in San Francisco and New York's Manhattan West project. Skidmore, Owings & Merrill's Broadgate managing partner, Jeffrey McCarthy, said the London project encountered several challenges likely to arise in Sydney. Vibrations from trains must be prevented from travelling to the buildings above through "base isolation." The method is used to protect buildings from earthquakes and can substantially add to a project's cost. At Broadgate, the construction of columns at track level had to be co-ordinated with seven different rail companies while maintaining train services, Mr McCarthy said, adding that buildings and public space built above the tracks must be carefully integrated with the city below. But he said the problems "should not be viewed as a constraint" and that the government's plan would "stitch this part of Sydney together [and] unlock new economic growth." The highly complex construction task has prompted industry forecasts that buildings of record heights - perhaps up to 90 storeys - may be required to cover developer costs, and that these must be pushed through despite community opposition. A spokeswoman for Planning Minister Brad Hazzard said several overseas companies had contacted the government to discuss the concept. The government development agency UrbanGrowth NSW will begin talks with Australian firms next month, followed by discussions with international developers. The plan has echoes of a rejected proposal by Mr Cameron last year for at least 150 skyscrapers prefabricated in China and erected from Central Station to Strathfield, which he claimed would have financed the M4 East motorway. Mr Cameron said "you don't need to be a rocket scientist to recognise the apparent overlap" between the two concepts, adding that his Chinese-backed consortium Aspire Sydney was "seriously considering" bidding for the project. His revised proposal would not necessarily include Chinese labour and materials, he said, saying "the revenues in the project would allow an entirely Australian solution at higher cost." However, his bid may retain plans for a new port at Blackwattle Bay and an overhead conveyor system to transport building materials.