Once again, gentlemen, I must apologise for the radio silence; I haven't got much work done this year yet. One project, though, has been an amendment to the Station South Control Panel, mainly for the sake of smoother operation. The layout was designed with this primarily in mind.
When designing the new layout I extended the main line tracks leading away from the station to the "north" (clockwise) and "south" (anticlockwise). The power supply for these was taken from track sections 1 and 16 at the north end and 8 and 9 at the south (pic 597 shows the south panel, 628 the tracks). Section 8 also contains the double slip crossing DS12 that gives access to the headshunt. Any shunting manoeuvre traversing DS12 needed section 8 to be switched from the green cab (anticlockwise main line) to the blue (yard). Because section 8 stretched all the way along the anticlockwise track to the far end of the contrun1 and southern approach bridges, any change to the switching of section 8 would affect a southbound train, and would have to wait for the engine of such a train to clear the bridge. Because shunting manoeuvres, especially to the industrial estate, which uses platform 4 as its own little headshunt, have to wait for a "window" between main line train movements in both directions, such delays are better avoided.
The solution adopted was to create two new track sections, 8A and 9A on the anticlockwise and clockwise tracks, respectively, of the southern approach. A southbound train goes from section 8 to 8A almost immediately on leaving the station. Only 8A is truly indispensible; 9A was included for symmetry's sake. The further reaches of sections 8 and 9 had already been provided with supplementary bus cables to compensate for voltage drop. These were reassigned to sections 8A and 9A.
The measures adopted were:
1. Isolation of the southern approach tracks beyond the end of the original sections 8 and 9;
2. Creation of new track sections 8A and 9A, stretching from the south end of the station to the far end of the contrun1 and south approach bridges;
2. Insertion of rotary switches for them on the Station South Control Panel;
3. Transfer of existing bus cables for sections 8 and 9 to control panel outlets for 8A and 9A.
Panel modification:
Two new 9mm holes were drilled in the lower plate of the Station South Control Panel (see pix 717/8). Corresponding holes were drilled in the upper plate (see pix 720/1). The new rotary switches were mounted in the lower plate like the existing ones and wired to the red and green bus (clockwise and anticlockwise) but not to the blue bus (yard) (see pic 719); the main line is not to be used as a headshunt. New wires were installed to carry power to the 8A and 9A buses. A new label was printed and stuck in place (see pic 722).
The pluggable carrying power to the 8 and 9 bus plus section 31 (headshunt) and common return drew its power from the station south manifold. This was modified such that sections 8A and 9A replaced 8 and 9, respectively and 31 and T remained unchanged (see pic 723). The bus connections before the bridges were left unchanged, merely relabelled (see pic 724).
Testing was successful and the panel was connected up and normal operation resumed. The total work effort was some three hours.
The work is documented, as usual, on flickr:
https://www.flickr.com/photos/53775591@N06/
Cheers,
Artur
Mine looks like an unravelled ball of wool.