Geofence Technology Is a Solution against Misplacement of ZKLs

Dual Inventive introduces geofence technology for the localization of workplace security equipment, such as the self-signaling short-circuit lance (ZKL).

On 28 September, during the Railcenter Rail Festival, there will be the first opportunity for a demonstration of the international innovation that makes misplacements of ZKLs a thing of the past.

geofence technology

Self-Signalling Short-Circuit Lance

ZKLs are used daily during work activities as a second layer of security when the track is taken out of service. The ZKL short-circuits the two rails of a section with track circuit, so that this section is reported as occupied to the train protection. This prevents the risk of collision for railway workers.

In the Netherlands there are two categories of ZKLs, namely with and without a short-circuit connection that can be switched remotely. The remotely switchable ZKLs (ZKL 3000 RC) are semi-permanently installed well in advance of the work at a suitable time. These can then be used again without entering the track. The so-called manual ZKL, on the other hand, is installed in the track immediately prior to the work. Misplacements have proven to be a risk when using manual ZKLs.


The ZKL technology has the highest level of safety and it functions well, but due to increasing work pressure, manual ZKLs are regularly installed in other places in the track than intended. These are called misplacements. It also happens that a ZKL is placed on the wrong side of an ES weld or signal. The installer may make a mistake about the location or interpret the Workplace Extraction Drawing (WOT) incorrectly.

Due to insufficient available working hours, the installer is regularly under pressure, and therefore sometimes works too hastily and does not check sufficiently whether the ZKL has been placed at the planned location.

Collision Hazard

Every year, dozens of incidents are reported to the railAlert foundation, but the actual number of misplacements of manual ZKLs may be higher. The track that has been taken out of service is then not properly protected against approaching trains, as a result of which it is not possible to work safely on the track.

This is not an issue with the remotely switchable ZKL 3000 RCs from Dual Inventive, but the internationally active technology company from Brabant also wants manual ZKLs to work more safely. Finally, Dual Inventive also supplies a manual ZKL. To prevent the misplacements, forces have been joined with Tended from the United Kingdom.


Tended has developed geofence technology that provides virtual parameters around a location that can be pre-set via an online platform, for example based on the WOT. An accuracy of 14 millimeters is achieved with the help of a small, portable device including GPS.

The device indicates to the installer when he is at the planned location, so that the workplace safety device, such as a ZKL, can be installed at exactly the right location in the track and is therefore within the pre-set virtual barrier. In addition, rail workers can be warned via the portable device when they leave a safe zone or approach the border of an unsafe zone.

Lex van der Poel, CTO of Dual Inventive, says:

“With this international collaboration, we mitigate misplacements of ZKLs, create the basic idea for using a digital border guard and improve the safety of rail workers.”

During the Rail Festival, Dual Inventive, also in collaboration with Railcenter, will present a new work zone application, including hardware (RSS 3000), for remote switching of work zones within train security. In the United Kingdom, this RSS 3000 is in the final phase of approval and can be used in conjunction with the ZKL 3000 RC for remote switching of work zones.

This article was originally published by Dual Inventive.

View supplier

Contact Dual Inventive

Use the form opposite to get in touch with Dual Inventive directly to discuss any requirements you might have.

    We'd love to send you the latest news and information from the world of Railway-News. Please tick the box if you agree to receive them.

    For your peace of mind here is a link to our Privacy Policy.

    By submitting this form, you consent to allow Railway-News to store and process this information.

    Follow Railway-News on LinkedIn
    Follow Railway-News on Twitter