The Woy Woy railway tunnel is a heritage-listed railway tunnel located between Wondabyne and Woy Woy stations on the Main Northern railway line in New South Wales, Australia. The dual-track tunnel was opened on 16 January 1888. It was added to the New South Wales State Heritage Register on 28 June 2013.

Description

Woy Woy Tunnel is a double track railway tunnel passing beneath a sandstone ridge between Brisbane Water and Mullet Creek. The tunnel is of brick construction throughout. The tunnel was originally built for double track service and thus did not require widening when the line was duplicated in 1906. The brick portals feature a brick string course, but are otherwise plain. The tunnel is horseshoe shaped, straight and has an average 1 in 150 gradient. There is a long cutting in bedrock leading to both portals.

Woy Woy Tunnel

At the time of its completion in 1888, the tunnel was the longest railway tunnel in Australia.

Woy Woy Tunnel

Construction history

Construction commenced on 1 March 1884. There was a breaking through ceremony on 17 July 1886; and the official opening was held on 16 January 1888. During construction the tunnel entrance had a crimson streamer stretched across it with the Latin phrase Labor omnia vincit, meaning, Hard work conquers all. A hill rises above the tunnel. Construction took place without cessation, night and day, excepting only upon Sundays; and approximately 300 men were employed in the excavation works; and over of gunpowder and of dynamite. Perforation work for the tunnel was provided by ten percussion rock-drills using compressed air obtained from a engine. Approximately of rock were excavated and approximately 10,000,000 bricks were laid, supplied by Gore Hill Brickworks. A local shipbuilder and shipowner, Rock Davis, was given the task of transporting, over the water, the bricks for the tunnel lining. No less than 10,000 cement casks were used.

Woy Woy Tunnel

Flooding of the area occurred in 1887, resulting in an inspection of the site by Henry Deane,

The Herald reported:

Homebush-Waratah line

The construction of the Homebush-Waratah line was broken up into sections: Hornsby-Hawkesbury, opened 7 April 1887; Hawkesbury River Railway Bridge-Mullet Creek, , opened 1 May 1889; Mullet Creek-Gosford, , opened 16 January 1888; Gosford-Waratah, , opened 15 August 1887.

Between April 1887 and May 1889, the Woy Woy Tunnel's major benefit of significantly reduced travel times were not able to be fully appreciated by passengers until the completion of the Hawkesbury-Mullet Creek section of track which involved the construction of the first Hawkesbury River railway bridge. Prior to the opening of the Hawkesbury-Mullet Creek section, which was dictated by the opening of the Hawkesbury River bridge, passengers disembarked from either Hawkesbury River, from the south, and Mullet Creek (closed 11 September 1897), from the north. Mullet Creek was located north of the current Wondabyne station and from the western entrance to the Tunnel. Passengers were required to catch a ferry between Hawkesbury River and Mullet Creek that met with trains at both terminus.

Gauge and loading gauge

The line was built with tracks and a loading gauge that accommodated carriages on double track with centres. In 1910, a new nation standard loading gauge was adopted for all mainland states, which was applied to all new works. In the 1920s, in the Sydney electrified area, the wider standard allowed for 3+2 seating in lieu of 2+2 seating.

Problems started to arise when in 1960 when the line though Woy Woy was electrified using so-called narrow stock. More problems arose in the 1972 with the introduction of double deck carriages, which required the removal of brickwork in the top corners of the circular tunnel profile with the roadbed lowered. In the 1990s so-called medium width stock of , such as the Tangara trains, were allowed through Woy Woy Tunnel.