At this writing, the only signals available in Z-Scale are of European prototypes.  There is always the possibility that American prototype signals will be available at some time in the future, but for the moment, this is all that we have.  There are two general types of signal:

• Color Light
• Semaphore

Color light signals are the more modern of railroad control signals, while semaphores date back to the late 1800’s. In parts of southern Germany, semaphores are still in use, although they are now slated for removal. Semaphores give both a color indication and have an arm which gives additional indication.  Color lights, however, are generally immune to the effects of ice and snow, which can jam a semaphore arm.

Märklin has manufactured an earlier pair of signals and a signaled grade crossing.  These earlier signals are now being replaced with a series of German prototype color light signals and semaphores which are more realistic. The earlier signals are still in the marketplace and may be more than sufficient for your purposes.

1^st Generation Märklin Signals

The 8939 color light signal shows a red and a green indication. 

Here is a wiring diagram for a single color light signal with the 8946 manual signal controller:

Courtesy Märklin

In this wiring situation, the train is operating from the right side of the diagram to the left. At the right, the transformer feeds track power to the rails.  A yellow wire is run to the yellow connection of the signal.  Please note the two 8598 Isolating Track pieces, which define a segment of track (marked “X”).  The 8598’s are earlier part numbers; the current track piece is No. 8588. The two Isolating tracks create a segment of track which is not directly connected to the rest of the railroad.  Instead, one of the Isolating tracks has two red wires which are connected to two terminals on the manual signal controller.  On the right side of the 8946, one wire is connected to the gray terminal on the transformer; the other two wires are connected individually to the two light bulb connections of the signal.  A schematic appears below:

The color light signal and manual signal controller combination can be used on small Z-Scale layout to effectively control several trains.  Not immediately apparent is the fact that in the above track diagram, if a train is moving from left to right (against “traffic”) as soon as it enters the controlled section and the signal is set to “red”.  Under normal circumstances, the signal only governs traffic moving right to left, so this is a problem which can be solved by adding a diode oriented to allow electricity flow when the track polarity is set for trains moving from left to right.  Needless to say, this complicates matters considerably from a signal logic standpoint, so it may be easier to have all train traffic moving in one direction only (as on the Noch “Cortina” factory made layout).  The signal & controller combination can also be used for train control on dead end sidings, where a train is backed into the siding when the signal is green, the switch is then turn to red and the track power to the siding is then cut off. Another siding is turned on and another train can operate on the railroad.

     A more common application used with the color light signal employs the 8945 Relay instead of the manual controller. This relay is wired internally the same as the 8946, but has two solenoid coils which operate the contact points. The relay also has a manual lever, but the coils allow for remote operation of the relay.  At this juncture, it would seem that the 8945 relay is overkill in this application, but all will become apparent in the Automatic Operation segment of these pages.

     The 8940 Semaphore performs the same functions as the color light signal, but it has a pair of solenoid coils to operate the semaphore blade.

It has the following connections:

• Red - The 8940 has two red wires which are connected to an 8588 Isolation Track; either a second 8588 is used to define the segment or an insulated rail joiner can be used on the “red” rail.
• Yellow - A yellow connection is made to provide power to the two solenoid coils inside the 8940.
• Blue - Two blue wires connect the 8940 to the control box which operates the semaphore. As with the relay & color light combination, more information about using the semaphore in automatic operation is located elsewhere on this site.
• Gray - Because the semaphore has an internal light bulb to illuminate the colored lenses of the semaphore blade, a gray wire provides the necessary ground.

Both the 8939 and 8940 signals are “Home” signals, meaning that when a train approaches such a signal in the “red” position, it must stop & stay there until the signal is set to “green”.  In railroad usage, “red” is usually referred to as “Stop” and green is referred to as “Clear”.

2^nd Generation Märklin Signals

Märklin has introduced a series of color light and semaphore signals which are considerably more sophisticated than the 8939 and 8940.  These signals have finer detail and use LED’s for reliable lighting.

The 89391 (left) is a Block Signal, typically found on main line railroads away from stations.  Red means “Stop”; green indicates “Proceed”.

The 89392 (right) is an Entry Signal, found at the entrance to station areas. Red means “stop”, green means “proceed” and green/yellow indicates “proceed slowly”.

The 89393 (left) is an Exit Signal, governing trains departing from stations.  Red means “Stop”, green means “Proceed”, green/yellow means “Proceed Slowly” and the two white lights indicate “Switching Allowed”.

The 89390 (right) is a “Distant Signal”.  It is located some distance before the other color light signals, and advise the train engineer of the indication of the next signal, allow the train crew to prepare to stop if necessary.

   In addition to these color light signals, there are two semaphores:

The new signal line includes three “Yard Signals”, which are used to govern switching movements within railroad car marshaling yards.

The 89395 (left) is a high mounted signal.  Red indicates “Do not proceed” while white indicates “Proceed [prepared to stop]”

The 89394 (right) is a ground level mounted signal.  Red indicates “Do not proceed” while white indicates “Proceed [prepared to stop]”

Dating back to the semaphore era, the 89403 is an earlier Yard Signal. A horizontal bar indicates “Stop”.  The signal currently indicates “Proceed [prepared to stop]”.

Operation of the 2^ndGeneration Signals

Because these new signals have LED’s, the accessory voltage provided by the Märklin transformer is more than sufficient to illuminate them.  Operating them is another matter.  Because these signals are more complicated than the earlier 8939 and 8940, providing signal logic for the different indications can be complex. In the case of the 89391 and other two indication signals, the 8945 relay remains sufficient for the job.  But with the more complicated 89392 (which has three indications and the 89393 (which offers four indications) mean more complicated wiring.

This problem becomes more apparent with the Märklin Factory recommendation of the 7244 Universal Relay:

The 7244 is a relay from the Märklin H0 product line, and it requires 16 volts to operate unlike the 10 volts of the Z-Scale relay.  Obviously, it has many more contacts than the 8945, but using this relay means that you will need a separate power supply to provide the necessary voltage. And, with several of these color light signals, you need two of the 7244’s and in the case of the 89393 you need an astonishing four.  In all cases, only two or three of the contact sets are used for each relay.

In short, this is the culmination of electromechanical technology, with the attendant complicated wiring of trying do so little with so much.  I am not completely versed with the new signal technology, but it seems that the current instruction sheet that uses this approach is simply occupational therapy for the model railroad enthusiast until digital logic becomes available.

Of course, there have been persistent rumors about Z-Scale command control; I wrote about them in the Greenberg book in 1988.  We seem to be no closer but I’m probably being a bit pessimistic here. In fact, given that the signals use LED’s, it seems quite possible that the model railroad enthusiast seeking to create a complicated signal system on their railroad could use off-the-shelf Märklin Digital or DCC (Digital Command Control). This would be combined with a computer program such as Railroad & Co. to provide signal logic.  The Z-Scale railroad itself would remain pure, while the signals are operating in their own environment, receiving data from the railroad via circuit tracks.  This one is your call, and a lot of this remains a question of what will be coming next from Märklin or other manufacturers. 

I love the subject of signaling and of automatic operation. It really enhances the model railroad experience and if you simply parse things down to their basic elements, you can create, step-by-step a model railroad with interesting detail.