South Coast line

The South Coast Line (SCO) is in the interurban service operated by NSW TrainLink. It serves the coastal region to the south of the Sydney metropolitan area including the Illawarra region, most notably the city of Wollongong, and extended services reach as far as Bomaderry in the Shoalhaven region.

Most services on the line are serviced by OSCAR H Sets and Endeavour railcars. Occasionally Tangara T Sets also operate on the line.

Suburban Segment
See T4 Illawara Line for more information about this section

The Illawarra line (the name of the physical line used by South Coast services) commences at the Flying Junctions south of Central. South Coast line trains begin at Central (Sydney Terminal) during the weekday off-peak, using the Illawara Dive to cross under all the other lines to reach Illawara Junction, a major junction between most suburban lines south of Redfern. At the other times, South Coast line trains commence from Martin Place or Bondi Junction on the Eastern Suburbs Railway, which also emerges at Illawara Junction.

South Coast line services join the Illawara line at Illawara Junction. From the here, four tracks head south through the stations of Erskineville and St Peters to Sydenham. South Coast line trains, along with T4 suburban trains, use the eastern pair of tracks (informally known as Illawara Main), while T3/8 suburban trains use the Illawara Local, the western pair of tracks. To the west of the four tracks between Erskineville and Sydenham there is a reservation for a further pair of tracks with partially constructed platforms at Erskineville and St Peters stations. There have been plans to connect these tracks in the past.

South of Sydenham, the Bankstown line branches off in a westwards direction. The Botany Goods Line crosses over the Illawarra line via a flyover. The line then reaches Tempe station, before crossing the Cooks River. South of the Cooks River lies Wolli Creek station, where the East Hills line branches off to the west. The Illawarra line continues south as four tracks through a rock cutting to the stations of Arncliffe, Banksia, Rockdale, Kogarah, Carlton, Allawah and Hurstville.

South of Hurstville, the line becomes 2 tracks with bidirectional signalling. The line passes through Penshurst and Mortdale (island platforms). At Mortdale is the Mortdale maintenance depot which lies on the eastern side of the tracks with access points from the south of the station. The line then continues past Oatley, then crosses the Georges River using the Como Bridge, which opened in 1972 replacing an older single track bridge which still exists to the east of the present structure and is used as a cycleway. The line enters the Sutherland Shire, passing through Como and Jannali before reaching Sutherland. The Cronulla Line branches off in an eastwards direction south of the station. The former short branch line to Woronora Cemetery branched in a westerly direction at the south of the platforms.

The line then continues south through Loftus, Engadine, and Heathcote. South of Loftus, the former Royal National Park line branched off, which has now been converted into a tram line connecting to the Sydney Tramway Museum. The final station for the operation of suburban services is Waterfall station, where there is a train stabling yard and turnback south of the station. South of Waterfall is the site of the 2003 Waterfall train disaster, when a G set Tangara, set G7, on the South Coast line derailed and flipped while going around a bend.

Interurban Segment
The line then heads south through the challenging terrain of the Royal National Park and Illawarra escarpment. The line makes a steep descent down to Wollongong. The original alignment through the towns of Helensburgh and Lilyvale which opened in 1888 was bypassed by a new route in 1915. A new station at Helensburgh was subsequently opened with the new alignment. A set of points allows the turnback of trains at Helensburgh. The line then proceeds through several tunnels down the Illawarra escarpment through the hamlets of Stanwell Park and Coalcliff, where there are sidings for coal loading. South of Coalcliff, the line becomes single track as it passes through the Clifton Tunnel, before becoming double track again near Scarborough station.

The line then proceeds south through the northern suburbs of Wollongong, then Wollongong and its southern suburbs. A terminating platform is provided at Thirroul, which is used to terminate peak hour services from Sydney, as well as local services. At Coniston, south of Wollongong, an electrified branch line heads east to Port Kembla. At Unanderra, the line to Moss Vale branches off to head west over the Illawarra escarpment to join the Main South line. Double tracking ends at Unanderra, and the line continues south as a single line track. The line continues south through Kembla Grange where a simple platform serves the Kembla Grange racecourse. The line then reaches Dapto where a passing loop is provided. Dapto was the southern extent of electrification until 2001.

The line then passes south through the hamlet of Albion Park Rail (where another crossing loop is provided) to reach Kiama, the current extent of electrification. South of Kiama, the line continues as a single track non-electrified line through rolling dairy pastures via several tunnels to the towns of Gerringong and Berry before arriving at its terminus at the town of Bomaderry on the northern bank of the Shoalhaven River. At Bomaderry, sidings connect to The Manildra Group's starch mill. This was still controlled by electric staff up to 2015.

Port Kembla Branch
At Coniston, an electrified branch line proceeds east to the industrial suburb of Port Kembla with three intermediate stations. The line is double track as far as just west of Port Kembla North and is used by freight trains as well as South Coast line services. A stabling yard is provided at Port Kembla for overnight storage of electric trains.

History
A Sydney to Kiama railway was authorised by the New South Wales Parliament in April 1881. Construction of the various sections was awarded by tender and commenced in October 1882. The Illawarra Line branched off the Main Suburban Railway south of Redfern, at Eveleigh (Illawarra Junction). The line opened to Hurstville in 1884, Sutherland in 1885, Waterfall in 1886 and Clifton through to Wollongong and North Kiama (Bombo) in 1887. The missing Waterfall to Clifton section comprised four large brick-arch culverts (and many small ones) and eight tunnels with a total length of over 4 km, delaying its opening until 1888. Kiama and Bomaderry (servicing Nowra) opened in 1893.

The line was originally double track to Hurstville and continued as a single track, but was duplicated to Waterfall (except for the Como to Sutherland section) in 1890. In 1886 a branch line was opened to Audley in the Royal National Park, which closed in 1991.

A steep ruling grade of 1 in 40 faced up (Sydney bound) trains almost all the way between Stanwell Park station and Otford. The main problem was the 1550 m long Otford Tunnel, which took the railway through Bald Hill from the coast at Stanwell Park to the Hacking River valley. The steep 1 in 40 grade and tight clearances meant that soot, smoke and heat could become unbearable, especially when a south-easterly wind blew into the southern portal or when a train stalled in the tunnel. A Mr B Chamberlain wrote about a stalled passenger train in 1890: Regarding the crew, Chamberlain wrote: Attempts were made to overcome the problem with a ventilation shaft and chimney in the early 1890s and a blower system installed in 1909.
 * Even with the windows closed, the carriages were filled with smoke and steam, women fainted and children screamed until the train backed down to Stanwell Park, and was finally staged up to Otford in two trips.
 * While the passenger with closed windows in an up train had an unpleasant journey… the unfortunate enginemen underwent a shocking ordeal. On tender engines both knelt on the footplate, coats over heads, to breathe the air coming from under the engine, the apron plate being raised for this purpose. Though the air was hot from passing around or through the ash pan, it was none the less welcome.

Many goods trains were routinely divided at Stanwell Park and taken through to Waterfall in stages, effectively increasing the number of train movements on the line. The increasing congestion and steepness led to construction of a double track deviation, which opened between Waterfall and Helensburgh in 1914, Helensburgh and Otford in 1915, and Otford and Coalcliff (bypassing the by now infamous Otford Tunnel) in 1920. The deviation avoided the steep grades with a more winding route featuring sharp curves, deep cuttings, new tunnels and a curved viaduct over Stanwell Creek that required 3 million bricks in its construction. Although the new route was 5 km longer it reduced the ruling grade from 1 in 40 to around 1 in 80. Of the original eight tunnels in this section only the Clifton Tunnel remains in use and is the only single track section between Sydney and Unanderra.

In 1924, work began on a 57 km line connecting Unanderra with Moss Vale on the Great Southern line, which opened in 1932. It enabled the transportation of limestone from the Southern Highlands to the coast at Port Kembla. Electrification of the South Coast Line was completed in stages reaching from Sydney to Loftus in 1926, Waterfall in 1980, Helensburgh in 1984, Wollongong in 1985-86, Dapto in 1993 and Kiama in 2001. The Kiama to Nowra section remains unelectrified. Major structural problems with the Stanwell Creek viaduct were identified in late 1985, with one span close to collapsing and another badly cracked, requiring substantial repairs and stabilising work.

On 31 January 2003, a interurban Tangara passenger train, set number G7, derailed at high speed south of Waterfall station after its driver suffered a heart attack. The Waterfall train disaster resulted in seven fatalities and multiple injuries. G7 was later scrapped in its entirety in 2005, with all four carriages (OD6831 - ON5816 - ONL5866 - OD6832) damaged beyond repair.

Fleet
The South Coast line passenger services currently consist of OSCAR H Sets that operate between Bondi Junction or Central and either Wollongong and Kiama. Tangara T Sets occasionally run the local services, which connect off Sydney services at Waterfall or Thirroul and run to Port Kembla, stopping all stations. Endeavour railcars connect at Kiama and operate to Bomaderry.

V Sets and Tangara G Sets (since converted to T Sets) have operated on the line in the past. Although electrified to Wollongong in 1985, several diesel trains operated between Sydney and Bomaderry until 1991, one of which was the South Coast Daylight Express, operated as a locomotive hauled train of Budd and Tulloch type passenger cars which included catering facilities.

In the next few years, as the D sets enter service, they will progressively replace T/H sets on the South Coast line. The Kiama to Bomaderry section operations will be replaced by new bi-mode regional trains in 2023. After the D sets enter service, it is expected that services will no longer run to Bondi Junction, as the platforms on the Eastern Suburbs Line are not long enough for 10-car D sets.

Stations
Indented stations are passed by express services, key terminating stations in bold

Eastern Suburbs Line (peak/weekends only)

 * Bondi Junction
 * Edgecliff
 * Kings Cross
 * Martin Place
 * Town Hall

Main Line

 * Central
 * Redfern
 * Wolli Creek
 * Hurstville
 * Sutherland
 * Loftus (limited service)
 * Engadine (limited service)
 * Heathcote (limited service)
 * Waterfall
 * Helensburgh
 * Otford
 * Stanwell Park
 * Coalcliff
 * Scarborough
 * Wombarra
 * Coledale
 * Austinmer
 * Thirroul
 * Bulli
 * Woonona
 * Bellambi
 * Corrimal
 * Towradgi
 * Fairy Meadow
 * North Wollongong
 * Wollongong
 * Coniston
 * Unanderra
 * Kembla Grange (request stop, weekends and race days only)
 * Dapto
 * Albion Park
 * Oak Flats
 * Shellharbour Junction
 * Minnamurra
 * Bombo
 * Kiama

Bomaderry Branch (unelectrified)

 * Gerringong
 * Berry
 * Bomaderry

Port Kembla Branch

 * Lysaghts (request stop)
 * Cringila
 * Port Kembla North
 * Port Kembla