The need of very high accuracy for track surveying methods on the one hand and the use of transparent software combined with light modular equipment on the other one had induced the Austrian company Rhomberg Bahntechnik in the last years to develop in-house surveying systems to support its adjustment and concreting methods by involving the track survey in each step of track construction from the beginning on.

“Hergie” was the first and total-station guided product, used successfully on 126 km of the German high speed line between the cities of Cologne and Frankfurt.

The very satisfactory performance of the system was the basis for further developments.

Recently Rhomberg Bahntechnik exported Hergie-trolleys to the Taiwan Track Partner Joint Venture (TTPJV), all equipped with an additional feature for the measurement of rail inclination (including documentation) as well as on-line reported versines and deviation changes, the latter giving at any time a reliable and for everyone transparent documentation of longer waves even during the time of construction.

An independent measurement of the inner accuracy will also be done by Rhomberg’s improved high precise system Plasma. This method produces nowerdays also absolute co-ordinates by linking the measurement data only at a few points to the absolute surveying system.

All results in the past have shown the correctness of the approach for the system development and the interoperability of the different systems.

Rhomberg will use both independent systems also for the 35 km long Tunnel Loetschberg in Switzerland to guarantee the required high track quality on 51 km of slab-track even under difficult conditions during the time of construction.