Point Control
This is a definitive list of all points on the South Downs Railway
DAC20 | Point | Location | Point Motor |
---|---|---|---|
1 | 1-4 | Entry to GREEN fiddle yard | Seep |
1 | 5-8 | Exit from ORANGE fiddle yard | Seep |
2 | 9-12 | Entry to ORANGE fiddle yard | Seep |
2 | 13-16 | Exit from GREEN fiddle yard | Seep |
3 | 17 | Junction from main line GREEN to Clanfield | Seep |
3 | 18 | Junction from Clanfield to join main line ORANGE | Seep |
3 | 19-22 | Crossover on entry to Clanfield | Tortoise |
3 | 23 | Platform selection in Clanfield | Tortoise |
3 | 24 | Clanfield platform 1 to factory | Seep |
4 | 25 | Main line GREEN exit from Petersfield | Seep |
4 | 26 | Main line ORANGE entry to Petersfield | Seep |
4 | 27 | Main line GREEN entry to Petersfield | Seep |
4 | 28 | Main line GREEN entry to Petersfield | Seep |
4 | 29 | Main line ORANGE exit from Petersfield | Seep |
4 | 30 | Aux railway interface from Green fiddle yard | Seep |
4 | 31 | Entry to Petersfield loop from ORANGE fiddle yard | Seep |
4 | 32 | Spare | |
5 | 33 | Main line ORANGE entry to Eastleigh depot | Seep |
5 | 34 | Main line ORANGE Chalton Junction | Seep |
5 | 35 | Main line GREEN Chalton Junction | Seep |
5 | 36 | Main line ORANGE exit from Lovedean Lines | Seep |
5 | 37 | Main line GREEN entry to Lovedean Lines | Seep |
5 | 38 | Main line GREEN junction from Petersfield Loop | Cobalt |
5 | 39 | Crossover on main line at Petersfield | Seep |
5 | 40 | Crossover on main line at Petersfield | Seep |
6 | 41 | Main line ORANGE entry to Lovedean Lines | Seep |
6 | 42 | Main line GREEN exit from Lovedean Lines | Seep |
6 | 43 | Main line GREEN entry to Portsmouth Loop | Seep |
6 | 44, 45 | Entry to Portsmouth Loop | Seep |
6 | 46, 47 | Exit from Portsmouth Loop | Seep |
6 | 48 | Main line ORANGE exit from Portsmouth Loop | Seep |
7 | 49, 50 | Double slip on entry to Eastleigh | Seep |
7 | 51, 52 | Far end Eastleigh | Seep |
7 | 53-55 | Near end Eastleigh | Seep |
7 | 56 | Spare | |
8 | 57 | Crossover on entry to Portsmouth | Seep |
8 | 58 | Crossover on entry to Portsmouth | Seep |
8 | 59 | Entry to portsmouth container yard | Seep |
8 | 60, 61 |
Crossing in station throat to platforms 1,2 |
Seep |
8 | 62, 63 | Portsmouth platform selection | Seep |
8 | 64 | Access to head shunt and engine shed at Portsmouth | Seep |
9 | 65 | Engine shed or headshunt at Portsmouth | Seep |
9 | 66, 67 | 3 way point at near end of container yard | Seep |
9 | 68, 69 | 3 way point at far end of container yard | Seep |
9 | 70 | point to carriage siding from good yard line | Seep |
9 | 71 | Loco storage road in Portsmouth station | Seep |
9 | 72 | selects second carriage siding | Seep |
10 | 73 | Dapol signal by engine shed | Dapol signal |
Points are always THROWN for the LEFT hand path, CLOSED for the RIGHT hand path.
DAC20 serial numbers:
DAC20 | serial number | location |
1 | 8 | fiddle yard |
2 | 7 | fiddle yard |
3 | 6 | Clanfield |
4 | 5 | panel under Petersfield |
5 | 3 | panel under Eastleigh |
6 | 4 | panel under Portsmouth |
7 | 2 | Eastleigh |
8 | Portsmouth | |
9 | Portsmouth | |
10 | 465 | Portsmouth |
When the railway starts up, the PC control software "Traincontroller" needs to know the position of all points. It remembers them from last time, but they could have changed if the railway was used without the PC connected.
The Digitrax system includes an "interrogate" process at power up, which causes all LocoNet devices to report their state. Unfortunately Traincontroller ignores this information at that stage, for reasons that aren't obvious! However, Traincontroller has a "track power on" pushbutton on the toolbar. This causes all the positions to be queried again, and the program then knows all of the states - even if they changed after the program was last run.
The DAC20 has a unique capability: it can generate the necessary "Turnout Feedback" messages even if the points don't have a feedback microswitch. It remembers all the positions even when power is removed, and it can generate the messages from the "stored" information.