Main Northern railway line

The Main North Line (also known as the Great Northern Railway) is a major railway in New South Wales. It runs through the Central Coast, Hunter and the New England regions. The line was the original main line between Sydney and Brisbane, however this required a change of gauge at Jennings/Wallangarra. The line is now closed north of Armidale, and the main route between Brisbane and Sydney is now the North Coast line.

Route
The line starts as a branch from the Main Suburban line at Strathfield in Sydney. The line heads north as a double track electrified line through the northern suburbs of Sydney, crossing the Hawkesbury River, before passing through the Central Coast.

At Fassifern, a former branch line to Toronto divides off in an eastwards direction. The line continues north to Broadmeadow in the inner western suburbs of Newcastle. North of Broadmeadow is Islington Junction - the triangle junction with the Newcastle Branch Line. Electrification of the main line ends at Broadmeadow but continues along the Newcastle branch line.

The line then swings westwards through the outer suburbs of Newcastle to Maitland, with two extra tracks dedicated to coal trains in this section. Maitland is the junction of the North Coast line which continues to Brisbane. The line becomes double track immediately west of Maitland and heads through the Upper Hunter Valley through the townships of Branxton and Singleton before reaching Muswellbrook. The line is presently single track from Antiene to Muswellbrook, but Australian Rail Track Corporation are altering the layout of the Muswellbrook yard in preparation for duplication of this section.

Muswellbrook is the junction point for the cross country goods line to Sandy Hollow and Gulgong. The Main North continues northwards through the Ardglen Tunnel to Werris Creek, where the Mungindi Line branches off northwest to Moree, and a cross country line continues to Binnaway and ultimately Dubbo.

The line continues north, but sees limited traffic from Werris Creek northwards. The line reaches the major New England towns of Tamworth and Armidale, the latter being the northernmost extent of service on the line. Until the mid-2000s freight traffic continued to the disused station at Dumaresq (a township a few kilometres north of Armidale) which is home to a now-also-disused agricultural fertilizer depot. There is now wire across the corridor at several points between Armidale and Dumaresq, after which the line is for all intents and purposes closed onwards to Jennings/Wallangarra. A baulk is placed across the tracks at kilometre 590 (a short distance on from Dumaresq), and north of Glen Innes the line - particularly its bridges - has fallen into considerable disrepair.

Branch lines
Several lines branch from the Main North Line, including:
 * the Newcastle Branch Line between Broadmeadow and Newcastle Interchange (formerly continuing into Newcastle)
 * the Richmond Vale railway line at Hexham
 * the Merriwa Line to Sandy Hollow and on to the Sandy Hollow- Gulgong line
 * the Mungindi Line from Werris Creek to Narrabri and Moree
 * the Toronto Line from Fassifern to Toronto (now closed and converted to cycleway)
 * the Belmont Line from Adamstown to Belmont (now closed and converted to a cycleway called The Fernleigh Track)
 * the Morpeth Line from East Maitland and Morpeth (now closed).
 * the Barraba Branch Line from West Tamworth to Barraba (now closed)

Other information
The line controlled by Sydney Trains south of Islington Junction, and by ARTC north of Islington Junction. The line is in the wide width classificiation south of Berowra and medium width classification north of Berowra. The line is electrified south of Islington Junction. Automatic Train Protection (ATP) is operational in two sections: Newcastle - Warnervale and Point Clare - Berowra, and under test in all other sections operated by Sydney Trains.

History
The first section of the Main North Line was built from the port of Newcastle to Victoria Street, Maitland in 1857 and extended to Singleton in 1863, Muswellbrook and Murrurundi in 1872, Werris Creek and west Tamworth in 1878, Armidale in 1883 and Jennings/Wallangarra, Queensland in 1888.

The Sydney to Newcastle section, Homebush to Waratah, had difficult topography to overcome, including crossing the Hawkesbury River, traversing the Mullet Creek bank and constructing the Woy Woy Tunnel. From the south, the line was opened between Homebush and Hornsby in 1886, then extended to Hawkesbury River in 1887. From the north, the line opened between Waratah and Gosford in 1887. Progress in the construction of the last section between Hawkesbury River and Gosford occurred when the Woy Woy Tunnel opened in 1887, then Mullet Creek to Gosford in 1888 and finally Hawkesbury River to Mullet Creek in 1889 when the original Hawkesbury River Railway Bridge was built.

Developments in the 20th century
The line was hampered by the rugged terrain and a change of gauge at Jennings/Wallangarra for traffic to Queensland. The line was supplanted 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 New South Wales government abandoned the line between Tenterfield and Jennings/Wallangarra. The line was later abandoned to as far south as Tamworth before services were returned to Armidale in 1993. Since that time, there have been attempts to revive freight or tourist traffic to as far as Glen Innes, although these plans have not yet succeeded.

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 at grade. Because of the location of the overpass relative to the branch to Kooragang Island, a short section of the line has 6 parallel tracks. The bridge carrying Sandgate Road over the lines had to modified to allow for the additional lines.

Services
NSW TrainLink operates several intercity and regional passenger services along the Main North line: Sydney Trains also operates their suburban T1 and T9 lines along the Main North line, between Strathfield and Berowra.
 * between Strathfield and Maitland
 * between Strathfield and Armidale
 * between Strathfield and Islington Junction
 * 🇭🇺 between Islington Junction and Scone

The section between Strathfield and Maitland forms part of the trunk line between Sydney and Brisbane and sees intermodal goods traffic carried between the two cities. The section of line in the Hunter Valley sees intensive coal train working, in fact the section between Broadmeadow and Maitland is one of the busiest goods lines in Australia.