21^st CENTURY SIGNAL SYSTEM

Since selling my first signals back in 1988, I have searched for an electronics system that would offer the o-scale operator a simple, yet prototypical way to operate signals. From weight triggers to relay systems to timing circuits to optic sensors to infrared to computer interface, each has its pros and cons. 

As many of you know, Atlas-O and Custom Signals have been working on a new signal system for O-Gauge trains. Atlas-O is producing a single target signal and marketing it under the 21st Century Signal System™. This part of the system is basically what is called an ABS (Automatic Block Signal) system. It is used to space trains traveling in the same direction on the same track. It is controlled by block signal controllers (BSC-1) which are included with the signals. Here are some of the characteristics of an ABS system and the Atlas-O 21st Century Signal System™. 

LIGHTING The signal control boards are designed to operate signal targets with:

1. Individual LEDs (red, amber, green) such as the type G and type D signals.
    
2. Two and three LED position light signals such as the N&W and the PRR.
    
3. Three 5-volt bulbs such as those used with Keil-Line signals.
    
4. Three terminal, bicolor LEDs such as the SA searchlights signals.  The circuit boards will give all three aspects (red, amber, green) from three terminal bicolor LEDs.

As second exclusive lighting feature is the APPROACH LIGHTING option.  Your entire signal system can be wired for continuous lighting of all signals at all times.  The layout can also be wired so that with the flip of a switch any part of your layout or the entire layout can go to approach lighting.  This means that only the lights on the signal facing the train as it approaches that signal go on.  This is how most railroads have operated their systems for years.  Returning the switch back to its original position will again give you continuous lighting, it’s your choice.

POWER AND DETECTION The signal controllers will operate on 6-22 volts, AC or DC.  I do recommend that operators use a separate, filtered 12-volt DC power source.  The controller has BUILT-IN INSULATED 3^rd RAIL DETECTION so that there is no need for additional detectors in most cases.  This systems will detect any piece of 3-rail rolling stock even without track power.  An optional CURRENT SENSING DETECTOR is available for non-insulated 3-rail track or 2-rail operators in all scales.

STAND ALONE OPERATION The block signal controller will give all three-color aspects by two different methods. When the train enters the block past the signal, the detector will give a red aspect in either case. When the train clears that block, a built-in timer will give a yellow signal for a fixed amount of time. After that time, the signal will go back green. If a more prototypical operation is desired, the yellow input can be connected directly to the track in the second block and the signal will stay yellow for as long as the train is clear of the first block and in the second block. Once the train clears both blocks, the signal will return to green. This second option will also give bi-directional operation of the signal if the train comes from the opposite direction. Although the approach function is part of the integrated system, you can still have approach lighting in the stand alone mode.

INTEGRATED OPERATION By using the modular connectors, the Block Signal Controllers will integrate together to give you full bidirectional operation. Add the optional controllers from the CUSTOM SIGNALS MODULAR SIGNAL SYSTEM to give your layout full APB signaling. More on that below.

ADDITIONAL FEATURES If this were not enough, there is also a DETECTOR OUTPUT for optional accessory control, lighting on a control board or other complex signaling options.

The 21^st Century Signal System is designed as a fully automatic block signal system (ABS).  If you prefer, the 21^st Century Signal System gives you a CENTRAL TRAFFIC CONTROL (CTC) option.  Which means you can wire your layout so that you can over ride any target on any signal on the layout to change the aspect from green to either red or amber.  This gives the option of a CENTRAL DISPATCHING STATION, which is found on many large private and club layouts.

Finally, the 21^st Century Signal System is designed for EASY INSTALLATION.  The signals are connected to the control boards with telephone jacks and the control boards are interconnected the same way.  The rest of the connections are screw-down terminals which means in most cases no soldering is necessary like some other systems.  Refer to the LAYOUT DESIGN AND INSTALLATION section for more information.

CUSTOM SIGNALS' MODULAR SIGNAL SYSTEM™ 

Custom Signals will be offering all the features of the Atlas-O's ABS system and taking this to a more complex stage. Custom Signals will be producing what is called an APB (Absolute Permissive Block) signal system. This is used on the real railroads where tracks meet at a junction, interlocking, passing siding, diamond, or anywhere one train passes, opposes or crosses over the path of another. It will be marketed as THE CUSTOM SIGNALS MODULAR SIGNAL SYSTEM™. It will have all the features of the Atlas-O system and use both the Atlas-O signal controller (BSC-1) and the optional Atlas-O current sensing detector (CSD-1) where necessary. 

The CUSTOM SIGNALS MODULAR SIGNAL SYSTEM™ will market 2 and 3 target block and interlocking signals and the additional control boards necessary for the APB signal system. The optional boards will consist of: 

1. TSC-1, Turnout Signal Controller which will give the correct signal aspects at junctions, passing sidings, crossovers and interlockings.
    
2. TDC-1, Tumble-Down Signal Controller for advanced signaling of bi-directional train movements helping to prevent head-on meetings. This will also work for rail crossings at grade. 
    
3. BSF-1, Block Signal Flasher for changing a steady aspect to a flashing aspect. This will allow the operator to expand the number of aspects beyond the 3 aspect system. 
    
4. PSD-1, Photocell Sensing Detector for optional and overlapping detection. 
    
5. GCF-1, Grade Crossing Flasher/Detector for integrating grade crossing signals into the system. 
    
6. GBC-1, Gate and Bell Controller for adding a crossing gate and bell to the GCF-1. 

All of these boards will integrate together in a modular system allowing the user to have advanced signaling without excessive hard wiring or confusing computer coding. Custom Signals will also be marketing many accessories to help with installation of the system. These will include: 

1. A Track Configuration Library which will take typical track layouts and give the corresponding circuit board layout for easily adapting the system to your layout.
    
2. Circuit Panel Boards for easily mounting and connecting the printed circuit control boards listed above.
    
3. Electronic and modular parts for easier wiring and connections.
    
4. A signal layout design, circuit board assembly and installation service if desired. 

See the electronics section for more information.

LAYOUT DESIGN AND INSTALLATION

There are basically four phases of a complete signal system.  I can do any one or more of these depending on how involved you, the customer, want to get.

PHASE I, DESIGN

The first part of this phase would be to DESIGN A BLOCK SYSTEM.  This means to designate the blocks that the layout would be divided into for prototypical signal operation.  This would require a detailed, somewhat scaled, drawing of your layout including all sidings, crossover, interlocking, etc.  Photos of the layout are also very helpful especially when multilevel is involved.  Each of the blocks would then be numbered for further reference.

   BLOCK  LAYOUT   

The second part of this phase would be to DETERMINE SIGNAL TYPE AND LOCATION of the signals for each block.  Each signal would be numbered for the block it would be protecting and the direction of train travel approaching it.  (For example, two signals standing side by side facing opposite directions on a single track between blocks 5 and 6 could be called 5E and 6W because those would be the blocks they protect and the direction the train travels as it approaches each signal.)  The cost of this phase depends on how “busy” your layout is.  I have done 40’ X 60’ layouts that were less work than much smaller ones because of fewer turnouts and track work.  If there is a need, then the possibility of some custom work will be discussed at this stage.

   BLOCK   LAYOUT with SIGNAL  TYPE  AND  LOCATION   

With all this in mind and some personal preferences, a final agreement on the total number of signals needed for the layout would be reached.  Then a completed drawing with an itemized list of the parts needed and an estimate of the cost would be supplied.

PHASE II, SIGNALS

The second phase would be to PURCHASE ALL THE SIGNALS that would be required for the layout.  If custom work is needed, such as a BRACKETED TOWER, it would have to be built at an additional cost.

PHASE III, ELECTRONICS

There are basically two parts to this phase, DESIGNING and BUILDING the electrical system for the layout.  You could do this entirely by yourself or I can do one or both parts for you.  The signal control boards are interconnected with telephone wires making most of the entire system modular.  There may be some unique situations that would require some custom applications, but almost anything is possible.

If you do not choose to do this, I can DESIGN THE PANEL LAYOUT of the circuit boards for you.  This will show the location of each circuit board and the connections to be made.  It will also show any custom applications that may be necessary.  It would then be up to you to build and assemble the panels yourself.

   PANEL  BOARD  LAYOUT   



Click on the above image for larger view

If you choose not to do this, I can also BUILD THE PANEL BOARDS for you and ship them to you completely assembled and interconnected.  The electronics would be mounted on large panels and secured under the layout in either a central location or various locations around the layout depending on the size of the layout.  Each signal will come with one or more RJ11 modular jacks on the end of the wires and the panel boards will have the signal controller with a corresponding socket.  A basic data wire extension and coupler would be use to connect the two together.

   PANEL  BOARD   



Click on the above image for larger view

PHASE IV, INSTALLATION

Once Phase 3 is complete, the final phase is the INSTALLATION of the entire system.  This is much easier than one would think considering the complexity of the system.  You would simply have to:
 

   PANEL  BOARD  with  WIRES  running  to  LAYOUT   



Click on the above image for larger view

 If you would like me to come to your layout and install the system, I can do that too.  This would include one or all of the above.  I will have to charge for travel, time and expenses, so call for more details. Also, Custom Signals supports the use of RR-Track and Atlas RTS Software which is a FREE download; just click HERE.

COST

I charge a set rate of $40 per hour or $300 per day for each phase plus materials and traveling expenses.  I will try to keep the cost as reasonable as possible, but this does take a lot of time to do correctly.  You may choose to do any part yourself which will help to lower the cost.

DESIGNING A BLOCK
SYSTEM YOURSELF

Draw a simple tack diagram for your layout with a single line for each track. Show all the sidings, diverging routes, interlockings, rail crossovers, yards, etc. Here is a sample of what your track diagram might look like:

Figure 1. Basic Track Diagram

Next, Mark off the number of blocks starting with the number 1 as you leave the yard. Blocks should terminate at passing sidings, interlockings and rail crossings. In modeling, this is sometimes not possible or practical. Use your own judgment in leaving enough length for the blocks to look prototypical, but always try to use the turnouts as guides. Although a minimum block length should be greater than the longest train, this is not always possible in O-gauge. My sample diagram should then look like this:

DETERMINE SIGNAL TYPE AND
LOCATION YOURSELF

A single head (target) block signal is used on main lines to indicate the termination of a one block and the beginning of a new one. There is usually a milepost sign attached to the signal and the train has no other option but to continue travel in the same direction on the same track. When one track crosses over another track and again the train may only stay on the same route, a single target block signal would also be use. This signal usually has three aspects (colors) and tells the engineer about the block occupancy ahead of the train and any speed restriction. Bi-directional movement on a single track requires signaling in each direction. Many railroads now mount two block signal targets on a single mast, one for each direction of train movement, (see the OG-15). Double track mains with bi-directional movement on each track require a block signal for each track and for each direction of travel. The bi-directional signals or single direction signals mounted on BRACKETED TOWERS are commonly used here.

When the train has an option of changing tracks or direction, the signal now serves multiple purposes and must have two or three target heads. Yards, diverging routes, passing sidings and interlockings require double or triple target signals. The B&O was an exception where upper and lower marker lights are used. Multiple target signals tell the engineer what route is to be taken, about speed restrictions and block occupancy. Just how were these used? Very simply, the upper head indicates the status of the main line, while the lower head indicates the status of the diverging route.

1. If the turnout is set for the main line, the lower target head is red and the upper target head determines the status of the main line: G/R clear; A/R approach; R/R stop

At a yard entrance, a two or three target mast signal is also used. Dwarf signals are most often used exiting yards and in restricted areas so as not to be confused with block signals. After selecting the correct model of signal for each location, the next step is to complete the block signal diagram. Indicate and label the signals needed on the diagram. Each circle represents a target head and the number of aspects required. (3 = G, A & R; 2 = A & R; R = red only). The signal itself is labeled according to the block it is protecting and the direction of train travel it faces.

At this time, you may choose to signal your whole layout or only part of your layout. Don’t sacrifice correct signaling now just to try and fill the layout. This is a major job and can be done in stages, but each stage should always be done correctly. Command control is the future and correct signaling is a must to have safe, independent operation of trains by different people at the same time.

Each three-aspect target will require one control board, but the control boards come with the signals. Each turnout (switch) will require a TURNOUT SIGNAL CONTROLLER (TSC-1), which must be purchased separately from Custom Signals. If additional assistance is required for designing and building the electronics system, go to the LAYOUT DESIGN AND INSTALLATION page.

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