Dark Territory

Across America today, many Class 1, regional, and short line railroads require trains to travel for long distances through remote, isolated areas called dark territory. The term dark territory refers to areas that are not controlled by train detection systems or signals.

Dark territory poses a special challenge for railroads looking to improve safety and efficiency with a train detection system. Operators must carefully weigh the capabilities and characteristics of available technologies to determine the best way to address the challenge of dark territory.

Common dark territory challenges

Limited track section lengths and inflexible design


Track section lengths are limited with conventional train detection systems, which means more equipment must be purchased. Furthermore, implementing a track circuit based system requires drilling of the rail and installation of bonds and wiring for each individual unit.

Frauscher Benefits

Unlimited track section lengths and flexible design

Frauscher axle counting systems offer unlimited track section lengths, a capability that requires less equipment to be purchased, installed and maintained. The flexibility of a decentralized architecture allows for compact systems with short cable runs, connected to wayside enclosures that are in close proximity to the sensor. These huts are connected via Ethernet.

Systems requiring frequent maintenance are not feasible


The frequent maintenance required with standard train detection systems in any location is costly and time consuming. Since maintenance personnel are not stationed in dark territory's remote areas, it would take significant time and expense for crews to travel to outlying locations to conduct required regular maintenance. Travel time and performing this maintenance keeps personnel away from daily responsibilities at their home base. Operators must weigh the benefits of increasing the safety of their rail line with the reality of additional costs and man hours required for maintenance.

Frauscher Benefits

Minimal maintenance requirements

The maintenance cycle for Frauscher wheel sensors is just once in two years, involving a simple visual and functional inspection that takes just minutes per sensor to complete. Reducing the need for track access to conduct maintenance procedures is invaluable in remote areas, by decreasing long distance travel for work crews to complete this maintenance. Conventional systems require frequent maintenance and tuning which could be cost prohibitive in these areas.

Remote diagnostic and maintenance capabilities

The Frauscher Diagnostic System FDS and Remote Monitoring Display RMD provide remote access to system operation and predictive maintenance information from all outdoor equipment locations in dark territory. This remote access capability allows the operator to troubleshoot the system from their operations center. Preventive and targeted maintenance can then be performed, often remotely, minimizing the need for long distance dispatch of work crews for periodic resets and maintenance.


Reliability issues due to weather are difficult to rectify


Conventional train detection equipment is negatively impacted by conditions such as flooding, snow, ice, and extreme temperatures. These factors can cause reliability issues for any conventional system; however, in remote areas the difficulties are magnified. Due to the time required for maintenance crews to travel to the problem area to address the problem, downtime and costs will be increased.

Frauscher Benefits

High availability, superior reliability in all weather conditions

Frauscher systems offer superior reliability over track circuits as they are not affected by adverse weather conditions such as snow, flooding, ice, or extreme temperatures. These conditions can be severe in some remote areas, and local personnel are usually not available to address the issue. A train detection system that is highly reliable and robust is crucial in these conditions.

High power consumption


Conventional train detection systems consume large amounts of power, which can be difficult to supply consistently in remote areas. The use of solar energy is on the rise and offers significant benefits, particularly in areas where grid power is not available near the railroad tracks. However, the level of solar energy required for proper function of conventional systems requires larger and more expensive panels and batteries, adding to overall budgetary requirements.

Frauscher Benefits

Low power requirements

Frauscher systems have very low power requirements compared to conventional systems. This is advantageous in all applications, but especially important in remote areas. Solar energy is becoming increasingly prevalent, and the advantage of a low power system is that the panels and batteries that supply them can be smaller and less expensive.

Shunt issues due to vegetation and debris


It is often difficult for operators to maintain tracks in remote areas due to factors such as rapidly growing vegetation or debris that can collect on the tracks and alter ballast resistance. Conventional signaling systems can experience shunt issues in these situations, causing false presence detection or trains that go undetected.

Frauscher Benefits

Immune to shunt issues due to vegetation and debris

The inductive operating principle of Frauscher wheel sensors makes them immune to shunt issues common to track circuits. Unavoidable conditions in remote areas such as overgrown vegetation, fallen leaves, mud and dust that can collect on tracks can be difficult for the operator to mitigate regularly, due to logistical issues for work crews.

Reliability issues can affect safety


If the availability of a train detection system is decreased due to the environment or other issues, the affected area reverts to dark territory status. When an operator makes an investment in safety through the addition of a train detection system, this system must perform reliably in all weather, temperatures, and conditions. Frequent downtime reduces the safety benefits of the system and is costly to the operator.

Frauscher Benefits

High reliability for maximum safety

The high reliability of Frauscher axle counting systems allows operators to feel confident in the investment that was made to signal dark territory. By providing a high level of performance regardless of weather and other adverse conditions, the operator can depend on maintaining high levels of safe operation without interruption. The high reliability provided by Frauscher systems also improves safety, by avoiding frequent track time for workers to perform regular maintenance and repairs required with other signaling equipment.

Limitations of available information


An operator will decide to signal dark territory to improve safety and acquire data to identify a train’s position at any given time in its journey. A conventional signaling system detects track section occupation, but this is the only information it can provide. For an operator, investing in a conventional system to signal dark territory will not offer the full array of benefits that an alternative train detection system could provide, such as the capability to provide direction, axle count and speed data.

Frauscher Benefits

Track section occupancy, direction, axle count and speed

Frauscher axle counting systems can provide valuable information that is not available from conventional systems. Track circuits only provide track section occupancy data, which limits the value of the system. Frauscher axle counting systems provide track section occupancy and train direction data vitally, while train speed and axle count are provided non-vitally.


Frauscher axle counters and wheel sensors provide a wide range of solutions for dark territory applications. These systems ensure safety and high availability, while offering significant lifetime cost savings compared to conventional systems. For the most part, dark territory exists because conventional signaling systems are expensive to install and maintain. The lower installation and life cycle costs of Frauscher axle counting systems provide an alternative that is more budget friendly, allowing operators to significantly increase the safety of workers, drivers, passengers, and rolling stock in remote areas.

Our waterproof (IP68 rated) wheel sensors are highly reliable, even in harsh environmental conditions that are often present in remote areas. Modifications to existing track structure is not required for installation. Via Ethernet, Frauscher systems can interface in a vital manner to an existing system located in the operator's closest signaled territory. This is an important feature in expansive dark territory settings.

Frauscher axle counting systems require preventative maintenance just once in two years. This is a key advantage for operators dealing with remote areas, significantly reducing their maintenance requirements and costs. Advanced tools such as the Frauscher Diagnostic System FDS support remote diagnostics and data logging for further ease of maintenance. The remote diagnostic capability can also reduce overall maintenance and life cycle costs by allowing many checks to be handled from the central station. This offers a strong advantage in situations where work crew travel would be required to deal with the problem onsite.

Frauscher wheel sensors and fail safe axle counting systems provide a cost effective solution for train detection in dark territory, offering unparalleled performance in terms of safety, reliability, and reduced maintenance.