Olaf Gröpler
System Engineer, ETCS
- In-depth expert knowledge of ETCS braking curves and models as well as braking technology and brake operation
- Comprehensive expertise in the interaction of braking and train control systems
- In-depth knowledge of the operational aspects of railway operations
- Many years of experience in national and international committee work
Contact Olaf Gröpler at the Berlin office
Olaf Gröpler is a system engineer at NEXTRAIL GmbH in the field of ETCS and interfaces to neighbouring systems. With over 25 years of professional experience in the railway system, he is a nationally and internationally recognised operational and technical expert in the highly relevant economic and safety-related topics of braking and braking behaviour of rail rolling stocks in the context of ETCS and the desired increase in track capacity on the lines.
Before joining NEXTRAIL, he held various positions at DB Systemtechnik GmbH from 1996 to 2024, specialising in braking technology and brake operation. These included many years as head of the ‘Brake Operation, Simulation and Couplings’ and ‘Brake Operation and Train Dynamics’ departments. During this time, he has built up unrivalled expertise in operational, methodological and technical processes in the context of the European Rail Traffic Management System. This also applies to the associated braking-relevant aspects of train control systems such as PZB, LZB, ETCS, GNT and ZBS.
He is also characterised by his extensive knowledge of the technical management and cooperation of interdisciplinary teams. Since 1999, he has worked in UIC, ERRI and EEIG working groups together with European and international railways, the Union Industry of Signalling (UNISIG) and the European Union Agency for Railways (ERA) on the optimisation, further development and detailing of braking curves and braking models for ERTMS/ETCS. He also has extensive experience in the creation and application of CEN standards and national regulations, such as the braking regulations.
Mr Gröpler graduated with a degree in engineering from the ‘Friedrich List’ University of Transport, Dresden, in the field of rail rolling stock technology. He then worked there and at the TU Dresden as a research and teaching assistant in the fields of rolling stock deployment and driving dynamics, stochastic journey time and energy consumption calculation and energy-saving driving.
Personal project references for Olaf Gröpler
ETCS Baseline 3, UIC/ERA. Increased safety thanks to an improved braking curve model.
New Cologne-Rhine/Main line, DB Netz AG. Development and parameterisation of the LZB-CE-II braking curves.
VDE8 and Stuttgart 21, various railway companies and rolling stock manufacturers. Provision of gamma brake models for the calculation of ETCS braking curves.
JBV ERTMS Programme, Ramboll Norge AS. National Values for the ETCS braking curves in Level 2 in Norway.
The braking curves and models were specified very openly as part of ETCS Baseline 2. For this reason, the ERRI and UIC working group B126.15, in collaboration with the EEIG, has further developed the ETCS braking curve system so that it could become part of ETCS Baseline 3 as an improved and more specific braking curve model. A key component of this new model is the UIC conversion model for Lambda trains. In addition, the current system of safety margins for braking curves was developed in cooperation between UIC and ERA.
For the new Cologne-Rhine/Main line with gradients of up to ± 40 % and speeds of up to 300 km/h, the existing LZB braking model would have led to excessive braking distances. To ensure the safe and economical operation of the line, the LZB braking curves therefore had to be further developed and concretised in line with deadlines. Together with the LZB consortium and DB Netz, a solution was developed that enables comfortable, low-wear braking with high operational efficiency on the challenging route. The necessary rolling stock-specific braking curve parameters were optimised during test runs.
The solution developed was subsequently adopted for the first main line of the Munich S-Bahn, where it also enabled a sustainable increase in line capacity.
Gamma models for ETCS had to be created for high-speed trains as well as for suburban and regional trains. Among other things, this model requires an exact definition of the nominal characteristics of the braking performance, such as the braking decelerations and the brake development times. In addition, the correction factors Kdry_rst and Kwet_rst must be precisely defined for dry and wet braking conditions. To achieve this, the brake system architectures of the rolling stocks were analysed, brake and wheel slide protection tests were evaluated, stochastic and failure parameters were compiled and finally analysed and evaluated in detail using Monte Carlo simulations.
As part of the complete renewal of the control-command and signalling system, from the control system and interlockings to train protection, the Norwegian railway infrastructure authority Jernbaneverket (JBV) started the implementation of ERTMS in Norway in 2013. ETCS Level 2 was introduced as the new train protection and control system. The task of the project was to develop a concrete and detailed proposal for the national values of the ETCS braking curves.
