Simplified Signaling for Modelers Rule 281 Clear 1 Author: Gary Evans North Central Region, Division 3 garytrain47@frontier.com Revision: May 05, 2014 Handout: NORAC Signal Aspects Sheet 2 Introduction Welcome to the world of That place where those lights shine brightly and those blades move slowly. That place that can be so fascinating and so bewildering. That place that just has to be duplicated in your own scale world. Beware that place SIGNALS Rule 282 Approach Medium 3 1
A signal system is a layout enhancement that can be intensive, extensive, complicated, and expensive. It can quickly become an unpleasant experience if its scope is not carefully planned. Rule 292 Stop Signal This presentation discusses the basics of signal systems and proposes a simplified approach for modelers. Rule 281 Clear 4 Presentation Objectives 1. Discuss basic concepts of prototype signals. 2. Introduce NORAC rules and signal aspects. (Northeast Operating Rules Advisory Committee) 3. Suggest simplified modeling practices. 4. Present case study of working model system. 5. Demonstrate train movement scenarios. 5 Generally speaking, our objective is to create a model signal system that fairly represents a prototype situation. The prototype would never make a mistake in their signaling 6 2
Fostoria, Ohio, September 2007 Looking East Show complex prototype signal here 7 Fostoria, Ohio, September 2007 Looking West Approach (285) Medium Clear (283) 8 Bucktown, Indiana, May 2010 Indiana Railroad, Bear Run Mine Spur Milepost 0 - Solar-powered, 3-color signal connected by RF link 9 3
What do signals tell us? Signals indicate: Track integrity Track occupation Track routing Route speed (likely in U.S.) Signals do NOT indicate: Permission to occupy track 10 The need for signals Rear-end collision from second train (or use time spacing of trains). Grade crossing with another railroad (or use manual stop for all trains). Facing / passing meets on single track (or use timetable train order). 2 or more trains on 1 track need control. 11 First U.S. signal Trains magazine The first U.S. signal installation was on the New Castle & Frenchtown Railroad in 1832. The NC&F signals were peach baskets suspended from masts by pulleys. By their position (high, middle, or low) and color (black or white), they conveyed information to trains and stations, whose staff observed them with telescopes. With refinements, this "ball" type signal became widely used, its aspect for "proceed" giving us the stirring term "Highball! 12 4
Time for Definitions By definition, A signal conveys an Indication (proceed, for example) by displaying an Aspect (a green light) having a name Clear Each aspect should correspond to a single indication so that the signal itself conveys complete instructions, but... Different operating rules apply in timetable and train order, manual block, automatic block interlocking, and centralized traffic control territories. 13 The track circuit - clear Track battery supplies current that flows through rails to energize (pull up) the relay. Relay is physically mounted as shown so that gravity pulls armature down. 14 The track circuit - occupied Any disruption of battery current causes relay to drop. A disruption is a shorting wheelset, broken rail, or open electrical contact, e.g. track switch, rock fence, flood gauge. 15 5
The track circuit continuous rail Jointless track circuits use audio frequency tuned circuits (shunts) to create block joints to signaling frequency currents. The track is resonated with the tuning components to create a pole and a zero. Coding is used to identify each circuit. Several circuits (e.g. train signals, road crossings) can be superimposed on track. 16 Speed Signaling When diverging routes come into consideration: Top head indicates condition for full permissible speed. Second head indicates condition for medium speed (typically 30 MPH). Green signal shows whichever speed route is set. Third head indicates a route for which slow speed must not be exceeded (typically 15 MPH) / / No full, No medium, Yes slow speed. Yellow serves as approach warning for each head. 17 Three speeds. Three heads. The higher on the pole, the higher the permitted speed. More speeds Add flashing, lunar white, position bars, etc. 18 6
Route Signaling Some U.S. railroads adopted route signaling. Indicates whether straight or diverging route. Top light indicates the main line (main = straight = normal). Next light down indicates diverging route. And so on for more lights and routes. Train crew must refer to timetable/ rule book/ special instructions for permitted speeds. 19 Three colors. Three meanings. B lock 1 B lock 2 B lock 3 B lock 4 B lock 5 This illustrates signaling for traffic headed right. The track is divided into blocks, each with its own circuit. The train occupies Block 4. The signals protect the rear of the train. 1. A signal is if the block beyond it is occupied. See signal 3. 2. A signal is Yellow if the second block beyond it is occupied. See signal 2. 3. A signal is Green if the two blocks beyond it are clear. See signals 1 and 4. 20 Rules are good, but Signaling by Rule xyz carries with it: Long history of practical development. Prototype operations (life or death situations). Complexity in logic, wiring, and signals. Inclusion of safety appliances (e.g., slide fence). Expectation of adherence to all wording. In the modeling world, purist interpretations (no offense intended). 21 7
Simplified defined Desire - to have signals on our model railroad. Practices - we are willing to perform. Constraints - we are willing to accept. Costs - we are willing to pay. Each modeler decides his/her own combination of factors (with no life or death situations). 22 Rule Choice: Acme Box Situation You are here. The situation: 1. You were given permission to occupy all tracks shown here. 2. You left your train on the passing track. 3. You delivered two cars to the Acme Box siding. 4. You returned to the main line to pick up your train. 5. You backed to the signal and stopped. It is over because: a: the track switch (turnout) is thrown to the passing track and b: the passing track is occupied by your train. 6. What do you do now? Referring to your railroad rulebook: 1. You know that over is Stop and Proceed; you get your train. OR 2. You contact the dispatcher to have the signal set to Restricting ( over Yellow); wait for the signal; then get your train. 23 Suggested Simplified Practices (1) Use signals with one and two heads. (top head = Normal route and bottom = Diverging) 1 st - Define and as. It is your decision to use. 2 nd - Define any combination with as because of known obstruction. 3 rd - Define as looking for obstructions (as always). 24 8
Suggested Simplified Practices (2) In other words: Route signaling, with Maximum of two signal heads, and Best signal indication of Proceed with caution. Permitted speeds are given via instructions. 25 Case Study: - Map Loop is fiddle yard area on NoWhere Line. Direction of traffic is counterclockwise. 1 3 2 Main line consists of blocks 2, 3, and 4 4 Track 2 Track 1 controls entrance and exit < < 4 detected blocks, 7 detected turnouts (crossover pair) 26 - Goals No dispatcher. Active detection handles bi-directional traffic. Signals indicate diverging / open turnouts. No separate controls for train crew. Signals summarize situation for entire Loop area; engineer is responsible for train once past entrance signal. 4 names Clear, Approach, Restricting, Stop 27 9
Track 2 - Clear Track 1 - Clear / / 28 Track 2 - Stop Track 1 - Restricting / / Yel 29 Track 2 - Stop Track 1 - Restricting / / Yel 30 10
Track 2 - Stop Track 1 - Stop / / 31 Track 2 - Stop Track 1 - Stop / / 32 Track 2 - Stop Track 1 - Approach Yel/ / 33 11
Track 2 - Approach Track 1 - Approach Yel/ Yel/ 34 Track 2 - Stop Track 1 - Approach Yel/ / 35 Track 2 - Stop Track 1 - Stop / / 36 12
Track 2 - Approach Track 1 - Stop / Yel/ 37 Track 2 - Approach Track 1 - Stop / Yel/ 38 Track 2 Clear Track 1 - Clear / / 39 13
Track 2 Clear Track 1 - Clear / / 40 Light Emitting Diodes #1 Single-color LEDs have 2 wires. Signals can be wired common anode or common cathode. Two-color LEDS can have more than 2 wires. This package is common anode. 41 Light Emitting Diodes #2 Multi-color LEDs have different construction. Back-to-back packages change color with DC polarity. AC shows both colors ( + = Yel) Side-by-side packages have wires for all colors. Make sure your LEDs are compatible with your electronics. 42 14
Pricing - Sample Signal BLMA Modern Single Pole Block Signal Assembled w/dual Heads and 6 Micro LEDs Walthers Part # 176-4035, p. 284 Walthers 2010 HO Scale Reference HO scale, $44.95, in stock at Walthers 43 Pricing Sample Detector Digitrax Quad Occupancy Detector 4 Detection Sections, Outputs For Panel Mounted LEDs, For Use w/ds54 or SE8C Walthers Part # 245-BD4, p. 817 Walthers 2010 HO Scale Reference All scale, $29.95, in stock at Walthers This unit provides cost-effective occupancy detection for four sections. Unit features outputs for panel-mounted LEDs (sold separately) to display occupancy. It will detect any powered loco, and unpowered rolling stock equipped with resistor wheelsets. Requires DS54 or SE8C, both sold separately, to transmit occupancy information to the LocoNet System. 44 Pricing Digital I/O Board Signals by Spreadsheet >> Input/Output Board DIO/D29 (Distributed I/O for Digitrax LocoNet) 29 Input or Output Terminals Each Terminal Independently Configured as Input or Output Communicates with computer via Digitrax LocoNet Works in Conjunction with SBS Software 5VDC Logic Inputs/Outputs Can Drive Signal LED's Directly (with Series Resistor) Price: $80.00 S&H: $3.00 45 15
Do It Yourself? Yes, you can. Use the simplification ideas to model what you think is important on your layout. Many different choices in technology, complexity, manufacturers, and interfaces (discrete, modules, DCC buses, computer). Start small; keep it modular. You can always expand later; always ask yourself what your objectives are. Do not go beyond your level of interest or cost. 46 Presentation Objectives 1. Discuss basic concepts of prototype signals. 2. Introduce NORAC rules and signal aspects. (Northeast Operating Rules Advisory Committee) 3. Suggest simplified modeling practices. 4. Present case study of working model system. 5. Demonstrate train movement scenarios. 47 This presentation is available on the NMRA North Central Region (NCR) Division 3 Library web page http://div3.ncr-nmra.org/library 48 16
Appendix A Signaling Scenarios Rule 281 49 Scenario 1 Single train Assumptions: No approach lighting, always on; No dispatcher input; automatic circuit operation. Layout: 6 blocks single track, bi-directional Demonstrate 3-color sequence to rear and front of single train. 50 Scenario 1 Single train Step A Initial condition, no train, all Clear. 3 4 5 6 Step B Eastbound train in Block 1. # 3 4 5 6 Yel 51 17
Scenario 1 Single train Step C Eastbound train in Block 2. 3 4 5 6 Yel Yel Step D Eastbound train in Block 3. # 3 4 5 6 Yel Yel 52 Scenario 1 Single train Step E Eastbound train in Block 4. 3 4 5 6 Yel Yel Observe: -Yel- signal sequence precedes and follows train. 53 Scenario 2 2 train head-on Assumptions: No approach lighting, always on; No dispatcher input; automatic circuit operation. Layout: 6 blocks single track, bi-directional Demonstrate fault situation for 2 trains and simple signal system. 54 18
Scenario 2 2 train head-on Step A Eastbound in 1; westbound in 6. 3 4 5 6 Yel Yel Step B Eastbound in 2; westbound in 6. # 3 4 5 6 Yel Yel Yel 55 Scenario 2 2 train head-on Step C Eastbound in 2; westbound in 5. 3 4 5 6 Yel Yel Yel Yel Step D Eastbound in 3; westbound in 5. # 3 4 5 6 Yel Yel Yel Yel 56 Scenario 2 2 train head-on (Step D Eastbound in 3; westbound in 5.) 3 4 5 6 Yel Yel Yel Yel Step E Eastbound in 3; westbound in 4. 3 4 5 6 Yel Yel (()) 57 19
Scenario 2 2 train head-on (Step E Eastbound in 3; westbound in 4.) 3 4 5 6 Yel Observe: Eastbound sees signal drop to right in his face, no time to stop. Solution: Overlay dispatcher fleet control; assign direction of travel to whole single track section. Yel (()) 58 Assumptions: No approach lighting, always on; No dispatcher input; automatic circuit operation. Layout: Unsignaled passing siding, bi-directional, signaled switch section Demonstrate meet for 2 trains. 59 Step A Initial condition, diverge, no train. 3 4 5 6 Yel Yel / Yel Yel 60 20
Step B Eastbound in 1, westbound in 6. 3 4 5 6 Yel Yel / Yel Yel Yel 61 Step C Eastbound in 1, westbound in 5. 3 4 5 6 Yel Yel Yel / Yel Yel 62 Step D Eastbound in 2, westbound in 5. 3 4 5 6 Yel Yel Yel / Yel Yel 63 21
Step E Eastbound in 2, westbound in 4. 3 4 5 6 Yel Yel / Yel Yel 64 Step F Eastbound in 2 & 3, westbound in 4. 3 4 5 6 Yel Yel / 65 Step G Eastbound in 3 & 4S, westbound in 4. 3 4 5 6 Yel Yel / 66 22
Step H Eastbound in 4S, diverging. 3 4 5 6 Yel Yel / Yel 67 Step I Normal, westbound in 4. 3 4 5 6 Yel Yel / 68 Step J Westbound in 3 & 4. 3 4 5 6 Yel Yel / 69 23
Step K Westbound in 2 & 3. 3 4 5 6 Yel Yel / 70 Step L Westbound in 2. 3 4 5 6 Yel Yel / 71 Step M Westbound in 1. 3 4 5 6 Yel / 72 24
Observe switch section handled as detection block. Signals around switch encompass multiple detection blocks. 73 Conclusion Model signaling system can become extensive, intensive, complicated, and expensive. Always keep in mind your objectives. Simulate before you build paper, MS Excel, custom software 2 build approaches: Customized hardware (not flexible) Generic software (computerized) 74 This presentation is available on the NMRA North Central Region (NCR) Division 3 Library web page http://div3.ncr-nmra.org/library 75 25