Axle Counting: A well-established technology

When introduced in Great Britain the FAdC was met with great interest, with initial installations taking place soon after market launch. The strong interest and confidence in the FAdC has continued to grow over the years, with countless projects successfully designed and implemented. The FAdC is installed on many lines across the UK and used in a variety of applications, helping to make the British railway network one of the most modern and efficient networks in the world.

Due to the high flexibility of the FAdC, Frauscher was also able to customize applications to meet specific customer requirements over the years, which could include adapting individual components. The experience gained over the years has helped Frauscher grow the portfolio of solutions it can offer its customers. The relevant developments of the FAdC can be divided into three areas:

• Robustness and reliability of the wheel sensors

• Flexibility in the system and interface design

• Implementation of additional functionalities

Since wheel sensors are installed on the track and therefore exposed to the elements, they must function reliably even in difficult conditions. Vital train detection requires a robust design that can withstand extreme temperatures, adverse environmental conditions, and mechanical influences. International projects have also demonstrated that electromagnetic influences may require specific adaptations. When installing a system in the British Isles, electromagnetic influences were identified at the neutral sections of the overhead line, which presented EMI levels that well exceeded the values safeguarded for during tests.

In order to find a solution, Frauscher analyzed the situation extensively on site and then assessed the acquired data in the company's laboratories. The wheel sensor RSR123 was updated accordingly to handle the increased levels of electromagnetic interference. This optimized version of the RSR123 demonstrated superior resistance to electromagnetic influences compared to the original version.

Since the RSR123 can now be used on rail networks with direct current and on those with alternating current; it essentially can be used on all lines in the UK. Once the sensor had been successfully installed at Crossrail and in Manchester, it soon came to be the go-to choice for nationwide applications.

In the modern railway industry, it is becoming increasingly critical for data to be flexibly and easily available. Equipped with parallel and serial interfaces, the FAdC is considered to be extremely future-proof in this context. Depending on the project-specific requirements, it can be easily and quickly integrated into different infrastructures.

The benefit of this flexibility feature was realized in 2017 when designing the first FAdC tram project in Great Britain. Its integration was realized via three different relay interfaces. During the course of the project, the FAdC also provided additional operational advantages to the rail network.

The serial interface of the FAdC is one of the reasons this axle counter was considered as an option for modernizing a substantial proportion of the 6,400 grade crossings managed by Network Rail. Its design enables customer-specific software protocols to be used, as well as the Frauscher Safe Ethernet FSE protocol.

In addition, the ability to quickly and easily connect the axle counter to the grade crossing control system can lead to significant cost reductions. Wireless connections can be established in some situations, such as via mobile networks. Furthermore, additional savings can be achieved if the same wheel sensor is also used as the activation point and for train detection in the signaling system.

As illustrated by the level crossing example, axle counters with different interfaces offer a high level of flexibility when it comes to the architecture of systems. This allows significant savings to be made in both safety-relevant and non-safety-relevant applications.

While reliability and accuracy are already technical prerequisites where our inductive wheel sensor technology is in use, Frauscher has also developed additional innovative features that can further increase availability. Frauscher has developed two optional features that are now being offered as standard: Counting Head Control CHC and Supervisor Track Section STS.

The Counting Head Control CHC function was originally developed based on the Axle Counter System ACS2000. Its first version was designed to suppress the damping of sensors by trolleys used in India. The CHC function is now used in many markets and countries, such as the Toronto Transit Commission in Canada. The TTC Yonge-University line has a CBTC system that required a secondary system for increased safety and availability. With Frasucher axle counters deployed as a CBTC secondary system, the Counting Head Control function was incorporated to manage situations that can occur on urban lines, such as metallic debris that interferes with the system. In short, CHC can suppress a configurable number of false presence detections from metallic interferences, if adjacent track sections are clear.

The FAdC also provides useful diagnostic information via the Frauscher Diagnostic System FDS. Railway operators have the ability to implement predictive maintenance strategies to solve emerging problems quickly. Short installation times and long maintenance windows can increase the safety of trackside personnel, with less time spent in hazardous areas when axle counters are used instead of to track circuits.

The examples in this article from the UK and other railway markets show that in order to make axle counters future-proof, they must be able to easily and quickly provide data via flexible interfaces. A combination of reliable hardware and innovative software functions can increase availability and reduce life cycle costs. Modern axle counters are able to combine a proven level of reliability and high flexibility that will stand the test of time. Frauscher axle counters will continue to adapt and evolve based on the needs of global rail markets.