simplified signaling for modelers · first u.s. signal –trains magazine the first u.s. signal...

“Simplified” Signaling for Modelers

Rule 281 Clear

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• Author: Gary EvansNorth Central Region, Division [email protected]

• Revision: May 05, 2014

• Handout: NORAC Signal Aspects Sheet

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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…

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SIGNALS

Rule 282 Approach Medium

• 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.

• This presentation discusses the basics of signal systems and proposes a simplified approach for modelers.

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Rule 292 Stop Signal

Rule 281 Clear

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.

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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…

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Fostoria, Ohio, September 2007Looking East

• Show complex prototype signal here

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Fostoria, Ohio, September 2007Looking West

Approach (285) Medium Clear (283)

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Bucktown, Indiana, May 2010Indiana Railroad, Bear Run Mine Spur

Milepost 0 -Solar-powered, 3-color signal connected by RF link

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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

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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.

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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!“

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Time for Definitions

By definition,

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.

A signal conveys an Indication (proceed, for example)

by displaying an Aspect (a green light)

having a name Clear

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The track circuit - clearTrack 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.

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The track circuit - occupiedAny 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.

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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.

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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)

• Red/ Red/ Grn No full, No medium, Yes slow speed.

• Yellow serves as approach warning for each head.

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Three speeds. Three heads.

• The higher on the pole, the higher the permitted speed.

• More speeds –Add flashing, lunar white, position bars, etc.

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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.

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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 Red 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.

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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).

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“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).

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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 Red over Red because:

a: the track switch (turnout) is thrown to the passing track andb: the passing track is occupied by your train.

6. What do you do now?

Referring to your railroad rulebook:1. You know that Red over Red is Stop and Proceed; you get your train. OR2. You contact the dispatcher to have the signal set to Restricting (Red over

Yellow); wait for the signal; then get your train.

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Suggested Simplified Practices (1)

• Use signals with one and two heads.(top head = Normal route and bottom = Diverging)

• 1st - Define and as .It is your decision to use .

• 2nd - Define any combination with as

because of known obstruction.

• 3rd - Define as looking for obstructions (as always).

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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.

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Case Study: CP Triple - Map

1

3

2

4

Loop is fiddle yard area on NoWhere Line. Direction of traffic is counterclockwise. CP Triple controls

entrance and exit

4 detected blocks, 7 detected turnouts (crossover pair)

Main line consists of blocks 2, 3, and 4

Track 2Track 1

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<

<

CP Triple - 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

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CP Track 2 - Clear

Triple Track 1 - Clear

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1 2 Grn/ Grn/Red Red

CP Track 2 - Stop

Triple Track 1 - Restricting

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1 2 Red/ Red/Yel Red

CP Track 2 - Stop

Triple Track 1 - Restricting

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1 2 Red/ Red/Yel Red

CP Track 2 - Stop

Triple Track 1 - Stop

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1 2 Red/ Red/Red Red

CP Track 2 - Stop


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CP Track 2 - Stop

Triple Track 1 - Approach

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1 2 Yel/ Red/Red Red

CP Track 2 - Approach


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1 2 Yel/ Yel/Red Red

CP Track 2 - Stop


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1 2 Yel/ Red/Red Red

CP Track 2 - Stop


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1 2 Red/ Yel/Red Red



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1 2 Red/ Yel/Red Red

CP Track 2 – Clear


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CP Track 2 – Clear


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Light Emitting Diodes #1

• Single-color LEDs have 2 wires.

• Signals can be wired commonanode or common cathode.

• Two-color LEDS can have more than 2 wires.

• This package is common anode.

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Light Emitting Diodes #2

• Multi-color LEDs have different construction.

• Back-to-back packages change color with DC polarity. AC showsboth colors (Red + Grn = Yel)

• Side-by-side packages have wires for all colors.

• Make sure your LEDs are compatible with your electronics.

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Pricing - Sample Signal

BLMAModern 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

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Pricing – Sample Detector

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.

DigitraxQuad Occupancy Detector

4 Detection Sections, Outputs For Panel Mounted LEDs, For Use w/DS54 or SE8CWalthers Part # 245-BD4, p. 817 Walthers2010 HO Scale ReferenceAll scale, $29.95, in stock at Walthers

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Pricing – Digital I/O BoardSignals by Spreadsheet >> Input/Output BoardDIO/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: $80.00S&H: $3.00

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http://www.signalsbyspreadsheet.com/?page_id=7&category=3&product_id=4

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.

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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.

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This presentation is available on the NMRA North Central Region (NCR) Division 3 Library web page –http://div3.ncr-nmra.org/library

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http://div3.ncr-nmra.org/library

Appendix A

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Signaling Scenarios

Rule 281

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.

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• Step A – Initial condition, no train, all Clear.

• Step B – Eastbound train in Block 1.

• #

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1 2 3 4 5 6

Grn Grn Grn Grn Grn Grn

Grn Grn Grn Grn Grn Grn

1 2 3 4 5 6

Red Yel Grn Grn Grn Grn

E >

Red Grn Grn Grn Grn Grn


• Step C – Eastbound train in Block 2.

• Step D – Eastbound train in Block 3.

• #

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1 2 3 4 5 6

Grn Red Yel Grn Grn Grn

E >

Yel Red Grn Grn Grn Grn

1 2 3 4 5 6

Grn Grn Red Yel Grn Grn

E >

Grn Yel Red Grn Grn Grn


• Step E – Eastbound train in Block 4.

Observe: Red-Yel-Grn signal sequence precedes and follows train.

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1 2 3 4 5 6

Grn Grn Grn Red Yel Grn

E >

Grn Grn Yel Red Grn Grn

Scenario 2 – 2 train head-on

• Assumptions:



• Layout: 6 blocks single track, bi-directional

• Demonstrate fault situation for 2 trains and simple signal system.

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• Step A – Eastbound in 1; westbound in 6.

• Step B – Eastbound in 2; westbound in 6.

• #

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1 2 3 4 5 6

Red Yel Grn Grn Grn Red

E > < W

Red Grn Grn Grn Yel Red

1 2 3 4 5 6

Grn Red Yel Grn Grn Red

E > < W

Yel Red Grn Grn Yel Red


• Step C – Eastbound in 2; westbound in 5.

• Step D – Eastbound in 3; westbound in 5.

• #

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1 2 3 4 5 6

Grn Red Yel Grn Red Yel

E > < W

Yel Red Grn Yel Red Grn

1 2 3 4 5 6

Grn Grn Red Yel Red Yel

E > < W

Grn Yel Red Yel Red Grn


• (Step D – Eastbound in 3; westbound in 5.)

• Step E – Eastbound in 3; westbound in 4.

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1 2 3 4 5 6

Grn Grn Red Red Yel Grn

E > < W

Grn Yel Red ((Red)) Grn Grn

1 2 3 4 5 6

Grn Grn Red Yel Red Yel

E > < W

Grn Yel Red Yel Red Grn


• (Step E – Eastbound in 3; westbound in 4.)

Observe: Eastbound sees signal drop to Red right in his face, no time to stop.

Solution: Overlay dispatcher fleet control; assign direction of travel to whole single track section.

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1 2 3 4 5 6

Grn Grn Red Red Yel Grn

E > < W

Grn Yel Red ((Red)) Grn Grn

Scenario 3 – 2 train siding

• Assumptions:



• Layout: Unsignaled passing siding, bi-directional, signaled switch section

• Demonstrate meet for 2 trains.

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• Step A – Initial condition, diverge, no train.

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1 2 3 4 5 6

Grn Red Yel Grn Grn

Grn Yel Red/Yel

Yel

Grn Grn

none


• Step B – Eastbound in 1, westbound in 6.

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1 2 3 4 5 6

Red Red Yel Grn Red

E > < W

Red Yel Red/Yel

Yel

Yel Red

none


• Step C – Eastbound in 1, westbound in 5.

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1 2 3 4 5 6

Red Red Yel Red Yel

E > < W

Red Yel Red/Yel

Yel

Red Grn

none


• Step D – Eastbound in 2, westbound in 5.

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1 2 3 4 5 6

Grn Red Yel Red Yel

E > < W

Yel Red Red/Yel

Yel

Red Grn

none


• Step E – Eastbound in 2, westbound in 4.

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1 2 3 4 5 6

Grn Red Red Yel Grn

E > < W

Yel Red Red/Yel

Yel

Grn Grn

none


• Step F – Eastbound in 2 & 3, westbound in 4.

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1 2 3 4 5 6

Grn Red Red Yel Grn

E > E > < W

Yel Red Red/Red

Red

Grn Grn

none


• Step G – Eastbound in 3 & 4S, westbound in 4.

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1 2 3 4 5 6

Grn Red Red Yel Grn

E > < W

Grn Yel Red/Red

Red

Grn Grn

E >

none


• Step H – Eastbound in 4S, diverging.

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1 2 3 4 5 6

Grn Red Red Yel Grn

< W

Grn Yel Red/Red

Yel

Grn Grn

E >

none


• Step I – Normal, westbound in 4.

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1 2 3 4 5 6

Grn Grn Red Yel Grn

< W

Grn Yel Red/Red

Red

Grn Grn

E >

none


• Step J – Westbound in 3 & 4.

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1 2 3 4 5 6

Grn Red Red Yel Grn

< W < W

Grn Yel Red/Red

Red

Grn Grn

E >

none


• Step K – Westbound in 2 & 3.

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1 2 3 4 5 6

Grn Red Yel Grn Grn

< W < W

Yel Red Red/Red

Red

Grn Grn

E >

none


• Step L – Westbound in 2.

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1 2 3 4 5 6

Grn Red Yel Grn Grn

< W

Yel Red Grn/Red

Red

Grn Grn

E >

none


• Step M – Westbound in 1.

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1 2 3 4 5 6

Red Yel Grn Grn Grn

< W

Red Grn Grn/Red

Red

Grn Grn

E >

none


Observe switch section handled as detection block.

Signals around switch encompass multiple detection blocks.

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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

http://div3.ncr-nmra.org/library

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