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Episode 3: Add actuating force measurements to documentation

Preventive and predictive

Electric point machines are used to change the direction of switches. They have 3 main tasks:

•  Changeover: is driven by the electric motor, works mechanically or hydraulically and fulfils the task of unlocking as well as changeover.
• Holding: purely mechanical for holding and driving.
• Monitoring: has the task of electrical end position indication. The contact control is positively driven.

Point-setting systems therefore must be monitored; as a rule they are checked once a year in order to detect imminent faults at an early stage (predictive) and to be able to intervene in time (preventive). The inspection of point setting systems usually consists of:

•  visual testing (VT = Visual Testing) of the components,
• Measurement of the mechanical adjustment,
• function test, and
• Force measurements as essential components of the test.

 Setting resistance, setting force and tongue tension are the results of the force measurement. Often, however, these valuable measurement results are not or not sufficiently evaluated, let alone used as input for maintenance planning. This is a pity, because the information content of the force measuring is enormously high when analysed professionally. However, the interpretation of the measurement and the derivation of the correct corrective measures require special knowledge of the technical context and practical experience.

The seminar "Force measuring at switches - vignol and grooved rail" is therefore a fixed component of the BahnWege-Seminar programme. Here, the participants get familiar with the application, evaluation and interpretation of the measurement results of point machines. In addition to the handling of the common force measuring technology, the evaluation criteria are also taught.

 Example of documentation a force measurement of a turnout with MR.pro(R) Software

A short video handling force measurements in MR.pro(R)

Sensor monitoring 

Force measurements have also become the focus of continuous monitoring for some years now. For remote monitoring, turnouts now get equipped with sensors to detect deviations in power consumption and infer the changeover resistance in order to direct repair teams to the object as early as possible in the event of deterioration.

Holistic diagnosis and documentation

The more information about objects is collected, the better, one would think. In principle this is correct, but too much data can quickly turn into the opposite, to disinformation. Therefore an intelligent analysis of mass data is important to literally fish the important out of the sea of data. Mass data analysis is a core function of MR.pro?. The system is designed for a lifelong documentation of object data: inventory data & condition data. This enables infrastructure managers to access up-to-date information regarding the condition, planned and executed measures at any time. And all this in a metre-precise grid. This means that operational maintenance measures can also be tracked exactly in terms of their location and situation - which opens up the possibility of weak-point analysis or warranty claims in addition to effortless tracking of maintenance success.

Analysis and information content

There are no concrete guidelines for the evaluation and interpretation of force measurements regarding good or bad. The monitoring systems work on the basis of object-related deviation analyses - which requires a broad data basis. For cyclical monitoring, therefore, concrete target and limit values are absolute required. RSV has developed these empirically from many years of experience and translated them into error classes with corresponding recommendations for action.

MR.pro

In addition to track measurement data, positioning force measurement data from safeTEC and HZM devices can also be imported into MR.pro, assigned to the objects, graphically displayed and documented. Two data formats are available for import. Data can be imported in XML, CSV or XLSX format.

Any number of measurement results can be stored clearly arranged and evaluated according to error classes (SR scheme).

Placing a check mark, the measurement curve is displayed in the lower area. A maximum of two values can be marked simultaneously to superimpose the measurement curves for a direct comparison.

Results of the force measurement are stored in the objects and can be viewed in the plant overview under the "Actuating force measurement" tab.

• The asset management software MR.pro? is a hybrid of expert system and technical information & control system.
• All objects of the track infrastructure are visualised as digital twins and geographically located, so that both the inventory data (as built) and the condition and its development can be exactly traced.
• Person responsible for the installation, benefits from a metre-precise overview of development of the condition and the measures commissioned or already implemented - and that for the assets lifetime.
• From an interactive workflow, an unprecedented transparency and traceability over the entire life cycle is created - without double entries.