A second class passenger car of class 63 with personal number 51 52 25 63 034 - 9 , standing on central railway station Sofia in composition of express train "Diana" from Iambol.Explanation of the numbers: "51"- passenger car with perennial wheel base , sertificied to UIC / RIC - Regulations concerning the reciprocal use of cars in international passenger traffic ; "52" - the ID number of BDZ (Bulgarian Railways) ; "25" - second class passenger car type "Salon" ; "63" - class of passenger car , it`s determinied by 140 km. per hour and 2 kinds of electric heating - 1. alternating current of electricity 1500 V ~ 50 Hz and 2. direct current of electricity: 1500 V= ; "034" - number of the unit ; "9" is the control digit.

Digital photo Veselin Malinov , e-mail: veso_bog@abv.bg