Edited 26 Oct 2019 21:59, 2 years ago, edited by Lockspike

Seriously RTT. The old tunnels are not going to be re used to Wollongong. A new alignment might be built but the old stuff is staying closed.

The old tunnels are not suitable for the use of modern trains as the cross section is too small, however, I believe the alignment is mostly quite good. It would be a simple matter in engineering terms to enlarge and widen. Cawleys tunnel could be easily converted into a cutting. The major challenge would be managing the environmental aspects (and rightly so).

Please explain what is the difference between the closed tunnels and the older Clifton Tunnel still in service?

The original single line alignment from Waterfall to Coalcliff was shorter (but not without some sharp curves). There were a number of tunnels: Waterfall, Cawleys, Helensbugh, Metropolitan, Lillyvale Nos.1&2, and the infamous Otford Tunnel, (Google it). Increasing traffic brought the need for double track, and as in so many other places in NSW in conjunction with double tracking, they introduced a lessser graded but longer more circuitous alignment which enabled the steam power of the day to haul more economical loads. The all still in use 'new' double track tunnels are: Helensburgh, Metropolitan, Lilyvale, Bald Hill, and Stanwell Creek Nos.1&2. Today, as you drive along Lawrence Hargrave Drive between Stanwell Park and Coalcliff, you are driving on the old formation.

The original and still in use Clifton Tunnel is immediately South of Coalcliff. The Clifton Tunnel is not without its trials. It was a tight fit for the 57 class, the length of the 60 class made bad conditions even worse for enginemen, the hill that the tunnel pierces is slowly but surely falling into the sea. All the existing tunnels had their floors lowered during electrification works and the Clifton Tunnel had extensive rectification to straighten and level it again.
I remember my father telling me that Uncle Sam wanted to blow the hill into the sea during WW2 and build a new road and railway through the resultant modified landscape, (I've never checked the bona fides of the story).

Edited 26 Oct 2019 21:56, 2 years ago, edited by Lockspike

Seriously RTT. The old tunnels are not going to be re used to Wollongong. A new alignment might be built but the old stuff is staying closed.

The old tunnels are not suitable for the use of modern trains as the cross section is too small, however, I believe the alignment is mostly quite good. It would be a simple matter in engineering terms to enlarge and widen. Cawleys tunnel could be easily converted into a cutting. The major challenge would be managing the environmental aspects (and rightly so).

Please explain what is the difference between the closed tunnels and the older Clifton Tunnel still in service?

The original single line alignment from Waterfall to Coalcliff was shorter (but not without some sharp curves). There were a number of tunnels: Waterfall, Cawleys, Helensbugh, Metropolitan, Lillyvale Nos.1&2, and the infamous Otford Tunnel, (Google it). Increasing traffic brought the need for double track, and as in so many other places in NSW in conjunction with double tracking, they introduced a lessser graded but longer more circuitous alignment which enabled the steam power of the day to haul more economical loads. The 'new' double track tunnels still in use are: Helensburgh, Metropolitan, Lilyvale, Bald Hill, and Stanwell Creek Nos.1&2. Today, as you drive along Lawrence Hargrave Drive between Stanwell Park and Coalcliff, you are driving on the old formation.

The original and still in use Clifton Tunnel is immediately South of Coalcliff. The Clifton Tunnel is not without its trials. It was a tight fit for the 57 class, the length of the 60 class made bad conditions even worse for enginemen, the hill that the tunnel pierces is slowly but surely falling into the sea. All the existing tunnels had their floors lowered during electrification works and the Clifton Tunnel had extensive rectification to straighten and level it again.
I remember my father telling me that Uncle Sam wanted to blow the hill into the sea during WW2 and build a new road and railway through the resultant modified landscape, (I've never checked the bona fides of the story).

Edited 26 Oct 2019 21:54, 2 years ago, edited by Lockspike

Seriously RTT. The old tunnels are not going to be re used to Wollongong. A new alignment might be built but the old stuff is staying closed.

The old tunnels are not suitable for the use of modern trains as the cross section is too small, however, I believe the alignment is mostly quite good. It would be a simple matter in engineering terms to enlarge and widen. Cawleys tunnel could be easily converted into a cutting. The major challenge would be managing the environmental aspects (and rightly so).

Please explain what is the difference between the closed tunnels and the older Clifton Tunnel still in service?

The original single line alignment from Waterfall to Coalcliff was shorter (but not without some sharp curves). There were a number of tunnels: Waterfall, Cawleys, Helensbugh, Metropolitan, Lillyvale Nos.1&2, and the infamous Otford Tunnel, (Google it). Increasing traffic brought the need for double track, and as in so many other places in NSW in conjunction with double tracking, they introduced a lessser graded but longer more circuitous alignment which enabled the steam power of the day to haul more economical loads. The 'new' double track tunnels still in use are: Helensburgh, Metropolitan, Lilyvale, Bald Hill, and Stanwell Creek Nos.1&2.
The original and still in use Clifton Tunnel is immediately South of Coalcliff. The Clifton Tunnel is not without its trials. It was a tight fit for the 57 class, the length of the 60 class made bad conditions even worse for enginemen, the hill that the tunnel pierces is slowly but surely falling into the sea. All the existing tunnels had their floors lowered during electrification works and the Clifton Tunnel had extensive rectification to straighten and level it again.
I remember my father telling me that Uncle Sam wanted to blow the hill into the sea during WW2 and build a new road and railway through the resultant modified landscape, (I've never checked the bona fides of the story).