North American Railroad Signals


North American Railroad Signals


N-scale layout "C"orin Subdivision

This modelrailroad layout is based on my image of Orin subdivision in Powder River Basin in WY. I named as Corin subdivision, assuming close to Orin subdivision and in Rocky Mts. area around Wyoming or Utah. Unlike Orin line, this line is operated not only for coal trains but also for the other types of trains, as shown in these photos.

This North-american signaling system was developed by the modificaton of Japanese signaling system which I developed two years ago. After I learned the real railroad signal rules, this implemented signal system is mainly designated to be based on BNSF main line but slightly modified to increase the variations of signal aspect for my interest.

In these photos, PC auto-control of RRandCo's TrainController is applied for the full-auto operations of trains and signals. However, this signaling system can be automatically operated "without" PC auto-control software, such as RRandCo and JMRI. In other words, this signal system can be manaually operated by usual DCC command station, where the signal aspect is automatically calcurated depending on the train detection units and serial communication between signal boards. In that case, the interlocking signals, such as departure signals, are only manually operated by users.

Emty coal train starts heading to a loop section. In usual, the helper is AC motor engine but today's helper is Dash9 colored with Heritage I color scheme. Head of this train consists of SD70MAC and AC4400CW. This helper Dash9, the motor unit has been removed and hence a dummy engine, as a trial to examine the multiple-engine long train.

Emty coal train is running on main line and full coal train running over the loop section. On the lefthand side, six intermediate signals can be seen.

Viewing from a main yard section to the loop section.

This is a homemade speed meter unit operated with two photo sensors embedded on the track. When a train passes this track, the speed is automatically measured and displayed at MPH scale. In a few second, this unit is automatically reset and prepared for the next coming train.

UP's full coal train passes the loop section. The double header consists of SD9043MAC and the helper is AC4400CW.

The most righthand intermediate signal is indicating the advanced signal of Yellow/Green which means that the next entry signal is medium diverging clear aspect Red/Green/Red. The middile-lower signal is Yellow/Red which means that the next entry signal is Red/Red/Red.

These two signals are triple-head Entry signals of main yard. The lefthand signal is indicating Slow diverging approach medium (R/R/FL-Y). In this layout, Slow diverging means that the next double-crossing switch is set to be crossing, as you can see here.

The righthand entry signal is indicating Medium diverging approach. It means that the diverging route is set to either of the 2nd or 3rd track in main yard. In this case, the double-crossing switch is straight.

In every track of main yard, a intermediate (non-interlocking) signal is located on each track to increase the capacity of trains in the yard section.

Those double-head signals are used to indicate the advanced signal aspect because the next departure signals have diverging routes.

The middle intermediate signal is indicating Yellow/Yellow as one of the Advanced signal aspect. It means that the next entry signal is set to be Medium diverging approach, Red/Yellow.




Sometimes, many trains waiting for departure stagnate around this double-crossing switch. With respect to the traffic control, this double-crossing switch is a bottle neck because every traffic route intersects here.

After adjusting the timetable setup of PC software RRandCo, the traffic became fairly smooth, as shown above. Waiting trains are few.

This loop section is also a bottle neck for the traffic operation. Because, the section length is very long and the traffic control must be bi-directionally operated in spite of single track. By improving the software setup, two trains can simultaneously run in the same direction on this loop section. In this photo, the upper-side black coal train is finishing the loop section and the lower-side silver coal train is starting to climb the loop section.

Tail to nose. At max, two trains can stop.on each siding track. Hence, also here, the traffic control is very tight.

More than two trains in this main yard can simultaneously and slowly proceed in the same or opposite direction. So, very busy ! It looks like Powder River Basin.

Today's Corin line is very busy.

As the traffic becomes busy, this track cleaning car also becomes busy.

Tomix's yard light tower (Japanese modeltrain company).

This is the switchboard panel of RRandCo TrainController V5.8. Many push buttons and toggle switches are located to manually operate the signaling system. If you want, these buttons and switches may be replaced by DCC command station equiped with the route function by which more than two DCC accessary decoders can be operated by a single action.

E.g., when one of these is selected and clicked by a mouse of PC, the selected departure signal is changed to be green (clear) and all the neigboring signals are changed to red (stop). At the same time, turnout tracks along the selected route are also automatically changed. At this point, if there is any train on the next blocks, green may be automatically modified to red, yellow, flashing-yellow or one of diverging signal aspects.

In order to increase the traffic density, some flagman (logic) indicators are located on this panel.

Download yrs-file for RRandCo TrainController V5.8 for setup of signaling system

Download yrr-file for RRandCo TrainController V5.8 for setup of signaling system


Marklin HO's screws to fix tracks. Kato supplies nails for Unitack rails. But, this adjustment is easier.

Train detection units used here require that every car basically draws current for its motor, lights, onboard DCC decoder and so on. But, freight cars have not such function. Instead, the wheel shaft may be modified like this using R=1Kohm1/8W.



This layout is portable and extensionable. I can carry to any exhibitions. I am sometimes working as a voluntary lecturer in Japanese model railroad convention (JAM) and so on, for the railroad signal system and PC train control. I am plainning to insert a delta-type track section in this layout, which is like Nacco Jct. in Powder River Basin.

Under construction.




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