The objective of GRAIL-2 is to develop and validate a GNSS based ETCS prototype/application in Rail Low Density Lines. Starting from the work of GRAIL, GRAIL-2 goes further in the implementation and testing of one of its applications so that a real validation of the application against user needs can be performed, thus achieving a system/application closer to a final product.
The proposed application is Absolute Positioning, combined with Train Integrity, in a context of Low Density Lines.
Absolute Positioning is considered to be a very promising application as it can achieve a full on-board localisation of the train, thus reducing or eliminating the trackside equipment for localisation (balises). Besides, combined with the Train Integrity application, we can achieve the “positive train detection” that allows a future implementation of “moving block” systems (future ETCS level 3). That is also compatible with other initiatives like Low Cost ETCS or Regional ETCS. Freight transport will also benefit by knowing the completeness of the train.
The framework of low density lines is considered to be more adequate for a short-term implementation of the GNSS applications:
- The operational requirements of the application are less demanding.
- There is no need for interoperability in short term, therefore, we can propose an application without the need of a formal adoption of the changes needed in the ETCS specification, but allowing for a future interoperable implementation when the ETCS specifications will be upgraded.
- Costs are kept low: The current ATP/ETCS means great investments in the LDL but this is not feasible because of the limited budget dedicated to the LDL in the railway community.
The ETCS environment is also preferred because ETCS is a standard system whose features are well defined and already proven. Besides, it should be noted that ETCS is suitable for all kind of lines and it is flexible and easily adaptable as demonstrated in GRAIL.