🇨ðŸ‡Validated the Swiss way: Under real operating conditions
Field testing is not a final step in PTB development — it has been a guiding principle from the beginning following Switzerland’s rail innovation philosophy: Technologies are validated in operation before large-scale deployment.
Digital Automatic Coupling introduces new technical territory. Laboratory verification alone is insufficient. Backbone performance must be demonstrated under real mechanical, environmental and operational conditions.
PTB has therefore been validated through multi-year field trials in international and Swiss test programmes.
Validation Philosophy
PTB validation has followed a consistent principle:
•Test under real rail freight operational conditions
•Validate before deployment
•Characterise system behaviour at full train length
•Expose architecture to diverse coupling scenarios
This approach ensures that backbone reliability is not inferred from simulation or the lab — but demonstrated in rail freight service.
European Demonstrator: DAC4EU
Within the DAC4EU consortium (www.dac4.eu/dac), PTB was evaluated as one of the communication backbone technologies shortlisted by the European DAC Delivery Programme (EDDP) in diverse environmental and operational conditions across multiple rail networks.
DAC4EU test train:
•About 20 freight wagons of different types
•Equipped with Scharfenberg-type DAC couplers (Voith, Dellner)
•Tested across 7 countries
•Over 10’000 km of test drives
DAC4EU evaluated and compared three backbone technologies:
•Powerline PLUS Train Backbone (PTB)
•Single Pair Ethernet (SPE)
•Wireless LAN 802.11
Results presented in November 2022 showed that PTB achieved:
•The most reliable performance in terms of message loss
•Reliable train integrity monitoring
•Robust wagon sequence detection
Testing continued until June 2024.
Swiss DAC+ Demo Train – Operational Validation
In parallel, PTB underwent extensive validation in the Swiss DAC+ Demo Train programme. A major goal was to validate PTB as the communication backbone for the major train functions (Basic Package).
Test setup
The train consisted of
•Six Sgnss freight wagons
•One measurement wagon (locomotive emulation)
•PJM’s WaggonTracker system (https://pjmonitoring.com/en/automatic-brake-test/) integrated into PTB
•Voith’s DAC Control Unit (DACCU) (https://www.voith.com/corp-en/scharfenberg-couplers/digital-automatic-coupler.html?undefined%5B%5D=0) integrated into PTB
•Push-button and remote tablet-controlled uncoupling operations
•Three e-coupler prototypes:
•Voith fixed head
•Voith movable head
•Knorr Bremse movable head
Field trials were conducted in two phases (February–December 2023), covering
•Shunting operations in various yard environments
•4’211 km long-distance drives across Switzerland
•Alpine and Jura routes with tunnels and curves
•Loaded wagons (60 tons each)
•Different weather conditions
•144 million messages transmitted
After these field trials in 2023 the PTB communication system has been continuously operational on the Swiss DAC+ Demo Train.
•Continuous backbone operation
•Over 20 billion messages transmitted
Verified Automated Train Functions
The trials validated PTB’s ability to support critical Full Digital Freight Train functions.
PTB Communication Performance Metrics
Compatibility Across Coupler Prototypes
Throughout field trials, PTB demonstrated consistent performance across all three e-coupler prototypes. This confirms
•Independence from specific coupler designs
•Robust performance across mechanical interface variants
•Compatibility with potential future DAC standards
Technology Readiness Level
Based on European and Swiss validation programmes and sustained operational performance, PTB has achieved Technology Readiness Level 7:
•System demonstrated in real freight train operations under diverse conditions
•Performance validated beyond prototype level across multiple coupler types and environments
•Industrialisation of the next-generation PTBN platform toward certified production readiness is underway, targeting large-scale deployment from 2028.
