One of our clients in charge of tracks maintenance, recently faced an issue with a balise located at the exit of their warehouse. Every time a train was leaving the warehouse, the On Board Unit couldn’t read properly the balise group and triggered an emergency brake action.
They analyzed the defective balises with their portable balise reader but they didn’t actually detect any apparent issue, as the portable balise reader concluded both balises were 100% ok.
They decided to schedule a run with one of their maintenance vehicles equipped with BaliseLifeCheck (BLC) and to analyze the problematic balise group.
On its first try, the BLC helped them discover that one of the balises of the group was sending out the correct telegram but had electromagnetic parameters’ issues that could affect the correct telegram decoding by a train On Board Unit.
We clearly see in this graphical result provided by the BLC that the balise electromagnetic parameters are out of the specifications requested by subset 36 (red lines). For Eurobalise specialists, the parameter out of bounds was about central frequency: its value was between 4.44 and 4.42 MHz, whereas it should be between 4.06 MHz and 4.41 MHz.