Woy Woy Tunnel is a 1.69-kilometre-long (1 mi 4 ch) 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.

At the time of its completion in 1888, the tunnel was the longest railway tunnel in Australia.
Woy Woy Tunnel is a 1.69-kilometre-long (1 mi 4 ch) 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.
At the time of its completion in 1888, the tunnel was the longest railway tunnel in Australia.
Woy Woy Tunnel