Signals on the Coastal Mountain

1. Signals on the Coastal Mountain Operations and Atlas Signal Applications

2. Who (what) is the Coastal Mountain RR? Why implement signaling? How is it accomplished? Signals on the Coastal Mountain

3. Signals on the Coastal Mountain • Originally an offshoot of the HUB Module Group • Modules generally conform to HUB standards • Main difference is in the placement of the “third” track • HUB is centered at 9” • CMR is centered at 10” • Layout is always a linear (“dogbone”) arrangement Who are we?

4. Prototypical Operation Block protection At Springfield, the layout is 100+ feet long Protect switching moves from incursion Possible future expansion to Dispatcher control Audience Education and Interest Show more action than just trains moving around Demonstrate the use of signals Illustrate different signal types on various roads Signals on the Coastal Mountain Why have signaling?

5. Design Constraints K.I.S.S. At least initially, pure block system Later, maybe dispatcher control NO MODIFICATIONS to unsignaled modules Inter-module connections to be kept as clear and simple as possible System is self-contained No external devices required for operation Signals on the Coastal Mountain How is it implemented on a modular RR?

6. Photo detection No need for resistive wheelsets or lighted caboose/FRED to maintain occupancy after the engines have left the block Normally done via sensors in the track Simple detection requires one per train length One at entry and exit from a block Requires logic to determine that a train has entered and then left a block Needs ambient light to operate CMR engages in night operations Signals on the Coastal Mountain Methods of detection

7. Current flow For a DC system, this is non-trivial Need a trickle current even when train is stopped Circuit to detect and report occupancy can be complicated Not a consideration for CMR, since the RR is DCC-only For a DCC system solution is much simpler Decoders always draw current, even when train is stopped Circuit to detect and report occupancy is very simple Since DCC has AC characteristics, a simple toroidal transformer works For trains shorter than a block, requires a lighted caboose/FRED For trains longer than a block, requires some resistive wheelsets No more than 10% of the freight cars on a system should need resistive wheelsets Signals on the Coastal Mountain Methods of detection

8. Objective: K.I.S.S. Feed all the power for the block through one detector Detector is located on the same module as the signal protecting that block Intermediate modules are NOT modified As on a static (“home”) layout, the blocks are like limbs on a tree A “raw” power bus is the trunk of the tree Signals on the Coastal Mountain Current Flow Detection

9. Signals on the Coastal Mountain Power wiring - Standard modules

10. Signals on the Coastal Mountain Power wiring - Block

11. Signals on the Coastal Mountain Power wiring – Signaled Module

12. Why Atlas? Complete solution to Automatic Block Signaling Self-contained; no external control required Simple to connect Atlas Type G signals work “out of the box” Allow for expansion Facility to interconnect boards Allows computer connection Provision for Far Signal (Yellow) aspect Provision for Red aspect override Signals on the Coastal Mountain Atlas Signal Control Board

13. Signals on the Coastal Mountain Atlas Signal Control Board and signal

14. Signals on the Coastal Mountain Atlas Signal Control Board • J1 & J2 are used for the Atlas “Multiple Integrated Installations” • J3 is the RJ-14 (6P4C) connector to the signal • J4 is the (dual) power connections • J5/RIN is the Red aspect override • J5/DOUT is Detector Out, an Open Collector copy of the DIN input • J5/DIN is Detector In – the block detector is connected here • J5/YIN is the Yellow aspect override • JP1 – “Approach” Lighting • JP2 – Searchlight signal present

15. Signals on the Coastal Mountain Atlas Signal Control Board • The Coastal Mountain currently uses only: • J3 (signal connection) • J4 Power and ground connections • J5/DIN (Detector In) • J5/YIN is used on the turnaround modules • Plans are for J5/YIN to be propagated via the Blue CAT-5 cable

16. Signals on the Coastal Mountain Atlas Signal Control Board Color Code used for J3 Pin 2 = Black, Pin 3 = Red, Pin 4 = Green, Pin 5 = Yellow Pins 1 & 6 = N/C

17. Signals on the Coastal Mountain Visuals

18. Signals on the Coastal Mountain Other signals

19. Signals on the Coastal Mountain Semaphores • Tomar Industries offers a semaphore activation package consisting of: • Tortoise Switch Machine (Circuitron) • Remote Signal Activator (Circuitron) • Edge connector/Circuit Board (Tomar)

20. Signals on the Coastal Mountain Semaphores • The Tomar edge connector requires a four wire connection – • Red (Ground) • Green (Ground) • Yellow (Groundd) • Common (+12 VDC) • The Atlas SCB provides a four wire connection – • Red (+1.0 mA) • Green (+1.0 mA) • Yellow (+1.0 mA) • Common

21. Signals on the Coastal Mountain Semaphores • This presents a problem. • Solution: • Build an interface board to convert the 1.0 mA current drivers to 12 VDC Voltage drivers • Objective: DON’T DAMAGE THE SCB! • Use an Optocoupler (aka Optoisolator) • Completely isolates the output from the input

22. Signals on the Coastal Mountain 3 Optocouplers • Connect the (-) terminal of the output to Power Supply Ground • Connect +12 VDC from the Power Supply to Tortoise Common • Connect the (+) terminal of the output to the Tortoise edge connector R/Y/G terminal • Connect the Anode of the LED to the SCB R/Y/G signal output • Connect the Cathode of the LED to the SCB signal common • When the LED is driven, the output transistor switches on (grounding the Tortoise input.

23. Signals on the Coastal Mountain Which Optocoupler? • I used California Eastern Laboratories PS2562 • Fairchild FOD852 has a somewhat higher CTR, and is a little cheaper • YMMV

24. Signals on the Coastal Mountain What Circuit board? • I used Radio Shack p/n 276-150

25. Signals on the Coastal Mountain Semaphore Visuals

26. Signals on the Coastal Mountain Semaphore – Yes, it works.

27. Signals on the Coastal Mountain Planned signals

28. Signals on the Coastal Mountain Planned signals • Since the planned signals all use LEDs instead of motors, the problem becomes slightly different with regard to the interface board. • Searchlight signals (with 3-wire LEDs) are directly supported by the Atlas SCB • The 1.0 mA current limit is a little low for the NJI signals (and probably Tomar), but it works. • The yellow aspect my be adjusted to be a little less Red by varying the currents to the Red and green LEDs • PRR Position Light and B&O Color Position Light signals require more current than what the SCB provides. • The solution to all three of these cases is to use the Interface Board, but with current-limiting resistors, sine it is acting as a current source rather than a voltage source (Semaphore case).

29. Signals on the Coastal Mountain • NOTE: • If you plan on using an LED-based signal without an interface board, it MUST be a “Common-Cathode” mode signal • The instructions must tell you to apply (+) current to the color leads of the signal. • If they tell you to pull the color lead to ground, don’t use the SCB without an interface board!

30. Signals on the Coastal Mountain Stay tuned – there’s more to come out of the signal shops of the CMR!