FOR a vicious battle, the railway dispute between BHP Billiton and Fortescue Metals had a surprisingly tame beginning. Three years ago, colourful Perth entrepreneur Andrew "Twiggy" Forrest picked up a bunch of prospective iron ore tenements in Western Australia's remote Pilbara region and launched his latest investment vehicle, Fortescue. But like other potential entrants to the Pilbara iron ore game, Forrest's company faced a multibillion-dollar hurdle: it lacked a railway. BHP Billiton and Rio Tinto own the only railway lines in the region. And the iron ore giants consider the railway far more than just a method of transport - they argue it's an essential middle piece of an integrated production process which starts at the mine and finishes at the port.