IF articles

Summary - The current version of Fiche UIC 421 on the interoperability of freight trains is characterised by an approach, called "relative", for the purposes of defining new configurations of trains with weights and/or lengths greater than those of a family of trains admitted to circulation. The work, carried out using the UIC TrainDy calculation soft- ware, statistically calculates the longitudinal forces in com- pression and traction limit values of freight trains, with mass and length values allowed by Fiche UIC 421 and rep- resentative of a widespread type of traffic. Furthermore, it is shown that freight trains with hauled mass values and/or length exceeding the limits prescribed by Fiche UIC 421, but characterised by longitudinal forces smaller than those previously calculated, can be accepted for circulation.