Assuming (per statements elsewhere) that the speed on the SSFL is 115kmh between Glenlee and Glenfield and 80kmh and Glenfield and Enfield West, 1800m signal spacing appears to be good enough (back of the envelope calc) for 80kmh running (assuming the GW40 braking curve and gradient >1:100 falling).
Villawood-Carramar signalling works are planned for this weekend.
I note that SSFL signals are NSWR double-light style. One wonders why the single light indications could not have been continued along the SSFL. Cityrail trains will not run on it. (Apologies if this question has been aired previously).
The last signals on the SSFL at Macarthur are Single Light, though the changeover point from double light to single light is unclear.
I don't know, but if I were a betting man I'd say between Leumeah and Campbelltown per the RailCorp network.
The signals approaching the various Home signals such as loop Home signals are Distant signals with no Upper Red lamps. The spacing between these Home and Distant signals may be enough to allow a higher speed than 80km/h.
The crossing Loop Home signals appear to be 200m-300m from the tip of the points so that this distance from the Home signals to the Loop starting signals would be about 1800m+100m+200m=2100m, also perhaps allowing more than 80km/h. This is like CTC loops on the North Coast.
The interesting signals in terms of spacing are the Up Distant and Home at Glenfield. From what I remember, the Up Home is near the carpark at Glenfield and the Distant is on the country side of Macquarie Fields substation. Is this right? If so, that's about 2.5km spacing, which is good enough for 115kmh running.
Thing that might be of interest awsgc24 is that the allowable speed (excluding all other factors) approaching an interlocking is dependent on signal spacing (Distant to Home in this instance). The distance in advance of the Home Signals to the opposing Starting Signals is the overlap - which is as you'd know your 'margin' of safety. Now to seemingly contradict myself, when a full overlap isn't available or is obstructed, then speed restrictions are applied to rail traffic (viz the Low Speeds used on CTC loops etc).
The Loop home signals have G/Y/R+G/Y/R+2*RI+Subsidiary Y-or-G?
You never know - they may go for both G and Y subsidiaries, depending on the design. If not both, I'd bet the subsidiary would be a yellow to allow for shunt moves to occur.
The redrawn ARTC Curve and Gradient Diagrams for Liverpool-Glenlee show that gradients are generally better than 1 in 100, mostly uphill towards Glenlee, though it is hard to calculate the true average figure.
ARTC have been installing nominal rather than full overlaps at the new loops they are building on the North Coast, and Running Lanes between Junee and Melbourne, say 500m instead of say 2100m. Thus the Starting signals at Yerong Creek are 500m from the end of the loop, not 2100m.
Subsidiary signals can of course be Bi-Polar and show both Yellow and Green lights. The small green would be for a low speed arrivals, while a small Yellow would be for shunting and for track circuit failures, such as miscounts of the Axle Counters.
If an axle counter over a set of points miscounts, there are two problems:
* the points fail;
* being an "A" track, it can fail the Shunt signals.
* There may be therefore some sense in making the tracks over points Jeumont Scheider track circuits, so there is no miscount problem to worry about.
* It remains to be seen how the miscount problem will be tackled.
It remains to be seen if there will be any Intermediate Block Signals between crossing loops, to enable closer headway for following moves.
At Villawood, the old cement siding has been replaced with a dead end Ballast siding, pointing the other way (facing up trains). It remains to be seen if this is temporary or permanent.
Would the SSFL be equipped with any kind of AWS/TrainStop/ERCTS/etc ? ARTC are working on some kind of control system for country lines, especially those with little or no signalling.