The Plasser & Theurer research and testing department represents an important component in the development of track maintenance machines and above all the technology used in those machines.

The entire department has a great deal of experience and know-how in all aspects of track laying and track maintenance. The new developments emerging from this department are a key element of future technological solutions made by Plasser & Theurer.

An important field where a lot of effort has been invested in basic research and development right up to the final serial production stage, is measuring technology and particularly pre-measuring and surveying of the track geometry.

A combined levelling and lining laser for straight track has been used to guide tamping machines since 1995. This enables simultaneous measurement of alignment and longitudinal level faults using a dot laser beam which strikes a laser receiver camera.

All functions of the laser on straight track are now also available for work in curves. This curve laser can work on all known track geometries. It is used mainly in track renewal for the first tamping passes and for secondary lines. Another option is to apply the curve laser in switches for application in the branching line and in curved switches.

A new development, the CAL-SAT, combines the functions of the curve laser and the machine-mounted fixed-point measuring system. During construction work it provides low-cost guidance of the machine and ensures greater operational safety by reducing the number of staff in the track.

The quality of the track geometry that can be achieved by a tamping machine is only as good as the specified correction values. Therefore it is very important to calculate the correction values as accurately as possible and with the correct long-wave consideration.

The EM-SAT offers a system which is designed according to the engineer's procedure. After the EM-SAT has measured, the data is analysed by the person responsible at the railway and the forthcoming maintenance operations can be planned precisely. In contrast to surveying by tamping machine, the EM-SAT measures faster and can produce surveying results for several tamping machines. The machine is put to work several weeks in advance so that the operations can be planned in an optimum way (preparatory work before tamping: pre-depositing the ballast, taking into account the track spacing for alignment corrections, rail tensions, specification of maximum lifting and lining values, etc.)

The application of GPS (Global Positioning System) leads to a further automation of track surveying work. In combination with the laser reference chord measurement, the GPS data supply highly accurate track coordinates. The GPS system is used to determine the track geometry at the chord end points of the laser reference chord. The survey of the track geometry is performed in the usual way using the laser reference chord and with measuring accuracies smaller than 1 mm, but without having to carry out a regular calibration with the fixed points positioned alongside the track.

The machine-mounted fixed-point measurement system enables non-contact measurement of fixed points. Measuring accuracy and simple handling are the outstanding features of the remote controlled fixed-point measuring unit made by Plasser & Theurer. The marking bolts are aimed at by a video camera from the driver's desk of the EM-SAT. The correction values are transmitted to the EM-SAT and entered into the computer system. Compared to manual fixed-point measurement, the mechanical process is much faster whilst offering greater accuracy and safety.