Smart railway sleepers with multi-sensor solution
Testing ground for innovative sleepers
The Dutch company ProRail (responsible for all railway tracks in the Netherlands) is testing new types of sleepers in a testing ground on a stretch of track between Zwolle and Heino. The test takes two years, and trains continue to run during the test.
Prorail is looking for replacements of the current (often concrete) sleepers. Concrete is not the best option when it comes to noise reduction and vibrations and does not have a good CO2 footprint. With the test Prorail wants to investigate whether the use of new sleepers ensures less noise and more sustainability on the track.
The ultimate goal of the test is to develop sustainable sleepers that can be used by contractors as an alternative to the standard concrete sleepers. With around 170 sleepers per 100 metres of track, a lot of CO2 can be gained.
Smart sleepers made of recycled plastic
Lankhorst Rail has developed an innovative set of sleepers for the Prorail testing ground. The KLP® Hybrid Polymer Sleepers from Lankhorst consists of 100% recycled plastic reinforced with steel. To measure whether these sleepers indeed cause less noise and vibrations Lankhorst has contacted Althen Sensors & Controls. For this project we came up with a concept where a set of instrumented sleepers could be made with a fully integrated multi-sensor solution.
Multi-sensor solution measures various parameters
For measuring deformation and forces at various positions in the sleeper, several high-quality capacitive accelerometers are integrated in the sleepers. A number of temperature sensors are also integrated to measure the temperature of the sleepers and the outside temperature. All sensors are connected to a high-tech data logger for (real time) monitoring and analysis.
About Lankhorst Mouldings
Lankhorst Mouldings is part of Royal Lankhorst Euronete, founded in 1998 following a merger between the Portuguese company Grupo Euronete and the Dutch company Lankhorst. Lankhorst supplies innovative and sustainable products made from recycled plastic. Products manufactured include risers, bridges, decking, fishing nets, ropes and sheet piling.
Measuring system with high frequency response
The integrated capacitive accelerometers have a frequency response of 700 Hz, so the sensors generate an extreme amount of accurate data. With this data the behavior of every sleeper can be analyzed very precisely.
The high-tech ASC 4421MF Capacitive Accelerometers measure vibrations and acceleration and from all this data other parameters can be calculated such as force, deformation and displacement (of the sleeper) and speed and direction of the trains on the track. In this way, the forces exerted on the sleepers, by passing trains, are charted in great detail.
The sensors measure minimal movements of a sleeper such as deformation in the material and displacement of the sleeper itself. With these measurements, the construction and behavior of the sleepers is analyzed extremely accurately, under various circumstances.
To measure the ambient conditions, a number of temperature sensors are also integrated, these measure the temperature of the sleeper and the outside temperature.
Plug & Play Acceleration Measurement System
All accelerometers and temperature sensors are connected to a Graphtec GL7000 Data Platform via cables and two special Althen Glet Modules (Junction Boxes). The measurement data can be retrieved by Lankhorst (remotely) via Ethernet. The data can then be monitored, analyzed and stored in real time.
The data platform is delivered as a plug & play data system at the customer's location, including pre-configuration of the complete data logger, per channel and per (calibrated) sensor. The required power signal per sensor is also included in the junction box. In this way connecting all sensors to the data acquisition system is facilitated.
The data acquisition system is set up in such a way that it only stores data at a fixed event, in this case when a train passes over the rails.