SWAMP CREEK & WESTERN
RAILROAD ASSOCIATION

211 Railroad Ave. Edmonds, WA 98020

LAYOUT ELECTRICAL MANUAL

Established December 5, 2000

Revised by page

X. - GORGE BY-PASS CIRCUITS

X. - GORGE BY-PASS CIRCUITS:

The Gorge by-pass is simply a completion of the layout as a circle. What complicates it is the fact that we want to carefully control its use. At certain times we want to be able to simply run our trains around in a circle but on the other hand, as it was originally designed, the two ends are not supposed to be connected and we use the reversing loops in our normal operation.

The following circuitry was designed to accomplish both modes of operation.

A.   Gorge Operation:

The Gorge is operated either under local control or in remote by-pass. Under local control the Gorge is accessed by throwing the local turnout toggle. As a fail-safe this action deactivates the opposite turnout toggle so another party cannot attempt to enter from there. A lamp will indicate the switch is disabled. Track power is routed into the Gorge by the local turnout's switch machine relay. The operator can then enter their train. Occupancy indicators will light up on both panels. The operator shall stop the train at a certain point so indicated and then throw the turnout back to normal.

Yes, trains will be limited to the capacity of the track. The turnouts are power routed by a safe distance to protect against run-throughs.

The operator shall then walk around to the opposite end and take control from there, throwing open that turnout and departing the Gorge.

With these fail-safe procedures we should avoid the potential for accidents. The train movements are carefully controlled.

When through (circle) operation is called for the remote by-pass switch can be thrown. It deactivates the local controls and throws both turnouts to the Gorge by-pass. The local power routing is also disabled (less it might conflict if both ends were not set to the same cab). An E-W toggle determines which side will power the Gorge trackage. The E-W toggle aside, a (4PDT) relay is employed to shorten the wire lengths. It operates on 12v DC.

B.   Gorge Wiring Diagrams:

The Gorge by-pass wiring diagrams are split between track power and switch machine controls.

C.   Gorge Track Power:

The (+) rails are towards the isle and are connected with YELLOW wire.

The Gorge is either fed power by which ever local turnout (Waitsburg or Holden) is thrown into it -or- by the E-W priority switch located at the remote override panel (on the end of the center peninsula near the dispatch panel) when it is activated.

The (+) power originates from either end's cab selector and is fed to the respective switch machine's auxiliary relay contacts which in turn are connected to remote override relay contacts and then on to the Gorge (+) rail. Thus, whenever a local turnout is thrown when the remote relay is not activated the power will route through to the Gorge track. By way of a lockout both turnouts cannot be activated locally at the same time. The turnout leads are isolated and power routed locally to protect against run-throughs.

When the remote override relay is activated the power connection described above is interrupted. Instead, the power is routed through the E-W toggle located on the remote override panel which feeds in from either end (connected at the respective switch machine's auxiliary relay contacts). Another contact in the remote relay isolates the connection between the switch machine auxiliary contacts which would otherwise be connected together with the activation of both switch machines and could cause problems if both sides were not turned to the same cab and direction.

The remote relay is located at the junction of the peninsula and back wall sections, just to the left of Coldwater. The remote override relay is powered by 12v DC coming from the central power supply and is activated by one side of the remote override toggle (DPST) located at the remote override panel.

Remote override is indicated at all three panels by use of an extra contact in the remote override toggle (DPST) which (+)AC powers the BLUE wire LEDs.

The common rail (-) towards the back wall is connected to the WHITE common return buss with BLUE wiring.

D.   Gorge Switch Machine Controls:

The Gorge turnouts are either thrown independently by which ever local toggle (Waitsburg or Holden) is thrown first -or- both turnouts are thrown by the remote override toggle located at the remote override panel (on the end of the center peninsula near the dispatch panel).

Under local control (+) AC power is fed into the center tab of the first pole of the local turnout (DPDT) toggle. Just as with all other switch machine toggles, the two respective tabs are connected to opposite polarity diodes that in turn fed either (+) or (-) via RED wire towards the switch machine. However, in this case that power first runs over to the other end's respective toggle's second pole which acts as a lockout. From there it passes through remote override relay N/C (normally closed) contacts and then finally on to the switch machine motor.

Under remote override the circuit above is by-passed and (+) AC power of the correct polarity (by use of diodes) is fed directly to both switch machines thereby aligning them to the Gorge.

Turnout alignment LED indicators are wired in the normal fashion but appear on all three panels. (orange and white) wires are used, with (orange, green, brown, slate) used on the buss line between the remote relay and the remote override panel.

Lockout is indicated at both local panels by use of the second tab on the second pole of the switch machine toggle (DPDT) which feeds(+)AC power of the proper polarity through (blue) wire to LEDs on the far panel, thereby lighting it.

E.   Gorge Track Detection Circuits:

Occupancy of the hidden Gorge tracks is revealed by the use of optic sensors as described in another section. Sensors in the Gorge are wired independently of the two loops and LEDs appear on all three panels. This is done via parallel hard wiring of the outputs at the DT-4 detection units.

Refer to section XI. Hidden Track Detector Circuits for further details.

SWAMP CREEK & WESTERN
RAILROAD ASSOCIATION

211 Railroad Ave. Edmonds, WA 98020