There are issues with the Blaney to Demondrille line and the Branches to Eugowra and Grenfell. Grain crops are still fairly common on the southern end of the line and branches with some silos still being used for storage and all grain obviously coming in and going out with road transport.
Rail has to compete with the price per ton delivered to the port that trucks can do it for.
In many cases rail is far cheaper but this line is an exception to this and most other lines closed that had silos. Trucks have a far more direct route by road from say a silo at Cowra or Young to Port Kembla than rail does. Factor in also the need for more locomotive horse power due to the 1 in 40 gradients and rail can't compete unfortunately. Axel loadings also limit the type of locomotive that can be used and how much wagons can carry.
Loading trains at Cunningar not far from Demondrille or locations further south is competitive to Port Kembla as grades facing a loaded train on main south are better with ruling gradient being 1 in 66 so less horse power required to haul same train. Wagons can also be loaded to 92 ton Gross and no locomotive restrictions.
Also the Carcoar tunnel has clearance issues that cause rolling stock limitations.
There is a plan to reinstate Demondrille to Young section of the line but no activity yet.
That was my point with the line and grain being not the commodity it was on the Blayney end, while the branch line issues are old, it would not take a lot to fix much of it. The Eugowra line could be viable as far as Canownindra but the bridge wash away just short of the town is the primary issue, aside of course that all the wooden sleepers now would be rotted away from white ant damage, which would be the case with all the wooden sleepers in the whole area. Therefore nothing short of a full steel or concrete sleeper replacement would work, given that much of the main part of the line from Cowra to Demondrille is predominately steel sleepered now, 2nd hand heavy rail from other main line replacement programs could help fix the line.
The washed out section is worse now only because nothing has been done since the closure, same with so much of the line being overtaken by tree growth which would likely affected the formation and its foundations, rabbit burrows likely would not help either.
Certainly the 1:40 grades are problematic but with track upgrades it allows for more MP up front as is happening in other areas with the more loco lash ups on the trains.
As for Carcoar, the biggest issue now with the tunnel is the heritage listing on it, meaning it cannot be demolished and opened up. However given the actual track gradient and curvature at that spot, a by pass of the tunnel to the west could readily solve much of the problem, as the area has a lot of rock and the property on that part would want compensation for the loss of any land, an opening up and large half Armco pipe positioned under the highway and through the property, then covered over with spoil and dirt is not a hard option.
That could also actually bypass the station area allowing the station and surrounds to be a nice heritage area fitting well with the history of the town. Carcoar like Millthorpe attracts a lot of tourists who go on to Cowra and Canowindra owing to their "old world charm".
What many do not realise is that the Cowra region is still a productive one and Cowra itself has grown significantly, and there are a lot of businesses that want to use rail as against road, much of the reason is that most of the road transport operating in and out of the town come from elsewhere and mostly larger areas and capital cities, they see employment for the area as a benefit.
The line will re-open beginning with the Section to Maimuru ready for the next decent cropping season, and that's up to the weather to come good. There is still a 6-8 week window for general wheat and a bit more for the short season varieties to get enough soil moisture for sowing.