the section between Broadmeadow and Maitland one of the busiest freight lines in Australia. Developments The line was hampered by the rugged terrain and a change of gauge at Wallangarra for traffic to Queensland. The line was superseded as the principal route to Brisbane by the completion of the North Coast Line in 1930. Despite being bypassed, the line remained busy for many years afterwards, with the line instead becoming the major freight link to the wheat and wool regions of northern and north-west New South Wales. In 1988, the newly elected Greiner State Government commissioned a report into the State Rail Authority by Booz Allen Hamilton. As a result, the line between Tenterfield and Wallangarra was closed. The last train to operate north of Tenterfield was an Australian Railway Historical Society charter on 15 January 1988 hauled by diesel locomotive 4487. The last train to operate north of Glen Innes was hauled by steam locomotive 3001 on 22 October 1989 after which the line was formally suspended from operations."Glen Innes" Railway Digest December 1989 page 412 Following the Northern Tablelands Express'' being truncated in February 1990, the line north of Tamworth saw little use until the Xplorer service was introduced to Armidale in October 1993. The line to Glen Innes was still open in July 1992 when diesel locomotive 4499 operated a crew training service. There have been attempts to revive freight or tourist traffic to as far as Glen Innes, although these plans have not yet succeeded. A section of the line between Waratah and Maitland is quadruple track, with one pair being used exclusively for coal trains within the Hunter Valley coal trains and the other pair being used by passenger trains and general freight. The coal tracks from Port Waratah join the line on the eastern side of the other tracks at Scholey Street Junction and pass underneath the other tracks at Hanbury Dive just west of Maud Street, continuing to Maitland on the western side of the other tracks. In November 1989, a fourth track was added between Eastwood and West Ryde. In the mid-1990s a loop was constructed at Cowan. The Sandgate Flyover was constructed in 2006 to allow the two passenger/freight tracks to rise and pass over the coal tracks that branch off to Kooragang Island in order to eliminate a capacity restriction caused by the long coal trains crossing the other tracks