State-of-the-art technology today enables recording and analysis of the track with highest precision using electronic track recording cars. The Emsat was developed to record the absolute track geometry correction values exact to the millimetre allowing high-capacity tamping machines to correct the track faults accurately. The Bahnbau Group is in a position to deliver the entire range of services required for all aspects of pre-measuring for tamping machines. Our Emsat is equipped with ballast profile measuring system.
The EM-Sat 120 from Bahnbau Group carries out mechanised track surveys in preparation for capital repairs and the renewal of track. Measurements of the absolute track geometry are taken using fixedpoint measuring devices. Track adjustment values can be forwarded in diskette form to the tamping equipment.
How does it works?
A laser receiver camera is fitted on the front tensioning trolley of the main-machine. This camera is mounted on a vertically and horizontally adjustable linear unit. The adjustable unit is controlled in such a way as to ensure that the camera always receives the laser and can measure its actual position on the camera receiving surface. This measured position is compared to the nominal position of the laser beam calculated by the WINEMSAT-Program. The correction values for level and alignment are calculated from the difference between the measurement position and the target position. According to these correction values the machine is guided automatically along the nominal track geometry.
The nominal geometry and the position (kilometre location on the track) of the machine or the laser have to be known. The machine works towards the laser transmitter which is located at a mast (fixed point).
The EMSAT is designed and optimised as a recording car from the point of view of the machine and the personnel. It offers an optimum engineering procedure because after the EMSAT measuring run, the exact analysis and planning is performed in the office of the planner responsible for the railway. The EMSAT performs the measurements faster and can record the survey data for several tamping machines. Furthermore, it is used several weeks prior to maintenance which means that work can be planned optimally (preparatory work before tamping: depositing of ballast, consideration of the track distances for level correction, rail stress, pre-setting of maximum lifting and lining values, etc.).
Ballast profile measuring system
The Emsat 120 is equipped with a non-contact, laser-assisted ballast profile measuring system which records the actual ballast profile continually. In combination with the Emsat the planning engineer is able to make decisions to further reduce costs (saving a line inspection, ballast management) The lifting values measured by Emsat are read in and incorporated into the volume calculation for the ballast requirement. The bar diagram shows the total value from the profile measurement and the ballst requirement which will result from the lifts to be performed.