EUROPE: A Voith electrical connection has been selected as the standard design for freight trains equipped with Digital Automatic Couplers, and approved by the European DAC Delivery Programme Supervisory Board.
The E-Coupler component of the DAC carries an inter-vehicle energy supply as well as the data and communications connections, linking all wagons and locomotives in what is now being described as the ‘Full Digital Freight Train’.
Following extensive testing with four prototypes, a Scharfenberg latch design was selected for the mechanical element of the DAC in September 2021. However, no decision was made at that stage about the electrical and data connection. Two alternative designs proposed by Voith and Knorr-Bremse were shortlisted for a final assessment.
Testing and selection of the E-Coupler element has been undertaken through the Europe’s Rail research programme, under the FP5-TRANS4M-R project. Key objectives for that project were to reduce by at least 40% the time needed to assemble or split up a freight train, and train preparation time of at least 45%, while enabling the operation of trains up to 1 500 m long. The project is developing and testing various technologies through three workstreams: Full Digital Freight Train Operation, Seamless Freight Operation and Innovative Freight Assets.
A ‘transparent’ selection process for the E-Coupler began in autumn 2023 with the definition of selection criteria by an expert group of train operators, which were subsequently agreed by the manufacturers. These criteria focused on both the technical aspects and life-cycle costs.
There was then a four-month test campaign, when the prototype E-Couplers were tested in the FP5-TRANS4M-R Train Test Laboratory and on a Swiss demonstrator train. Further trials were undertaken using DAC4EU test train and the manufacturers own test benches.
According to the research team, both designs achieved ‘a high equal evaluation’ in their technical assessment, which emphasised the innovative strength of both manufacturers. However, the life-cycle cost assessment showed an advantage for the Voith design, which the expert group therefore recommended to the FP5-TRANS4M-R Steering Committee.
According to Voith, its E-Coupling was particularly convincing when it came to assessing the costs, as the module could be retrofitted to the coupler head with just two screws. This made the assembly easy to maintain. The manufacturer added that decoupling the electrical coupling movement from the mechanical through a ‘delayed release’ offered an advantage that the E-Coupling always moved at the same speed. This reduced wear and tear, and ensured that the electric coupler and contacts remain protected at impact speeds of up to 12 km/h.
The recommendation from the expert group was approved by the Steering Committee at the end of February 2024, and the choice of the Voith design was endorsed by the EDDP Programme Board in April. Sign-off by the Supervisory Board in July paves the way for the next stage of the research programme, which includes the development of ‘a comprehensive safety and security concept’ including a thorough risk analysis.
The chosen E-Coupler design will be incorporated into the standardisation of interfaces in the relevant Technical Specifications for Interoperability as part of the regular review processes of the EU Agency for Railways.
