TrainDy software

TrainDy is a UIC-approved software program that calculates longitudinal forces along trains.
A key feature of TrainDy software is its capacity to solve both pneumatic problems (venting of brake pipe and filling of brake cylinders) and mechanical problems (computation of relative movement between consecutive wagons). This feature makes TrainDy particularly useful for studying new freight trainset compositions.
TrainDy can be used to:

  • analyse train failures (derailment, disruptions, etc.)
  • understand the influence of technical parameters or operating conditions
  • optimise train productivity (increasing train mass or length, defining new driving rules for trains or design rules for rolling stock)

TrainDy software is managed and developed in Matlab (international standard programming language) by the UIC TrainDy Special Group.

TrainDy Special Group

The current members of the TrainDy Special Group are Trenitalia, DB Systemtechnik GmbH, SNCF, University of Rome Tor Vergata, Faiveley Transport, Knorr-Bremse and the University of Berlin. The University of Nebrija has also recently become a member. The group is currently chaired by Mr Robert Karbstein (DB).

The objectives of the special group are to keep the TrainDy software and database up to date and to increase its membership in order to maximise use of TrainDy among freight operators and deliver services to customers interested in productivity gains.

Ongoing activities

The TrainDy Special Group is involved in the following two projects:

Revision of UIC Leaflet 421
The current version of UIC Leaflet 421 allows train compositions exceeding the length/mass limits if longitudinal forces are assessed with multibody dynamic software such as TrainDy, and describes a statistical method for generation of random trains in accordance with technical and operational parameters such as wagon type, train mass (or length), wagon payload, etc. However, TrainDy software does not currently have a tool to generate random trains taking into account varying technical parameters. A statistical tool was developed in 2019 by the University of Rome Tor Vergata and has been validated by the TrainDy Special Group in order to create random trains in accordance with UIC Leaflet 421.

Long Trains project
Long Trains is a UIC project which, in cooperation with EU Shift2Rail, aims to increase and optimise freight train tonnage/length using TrainDy software and the UIC 421 methodology for generating random trains. The results for longitudinal compression forces are compared with reference trains (750 m – heavy load train in G) for the following coupled trains:

  • 750 m trains with two locomotives (long locomotive brake regime for the first train, GP for the second)
  • 1,050 m trains with two locomotives (long locomotive brake regime for the first train, GP for the second)
  • 1,500 m trains with four locomotives

The results of this study will be made available in 2020 as report B177-4/RP3.

Activities concluded in 2019

New TrainDy module for LL composite brake blocks
TrainDy software originally had a module to determine the friction coefficient for cast-iron blocks only. In the meantime, mathematical friction laws for two types of K block, i.e. the Cosid 810 and the Jurid 816M, have been integrated into TrainDy. Due to the increasing use of LL composite brake blocks (fitted on wagons to reduce noise in freight traffic), an additional specific module for determination of the composite brake block friction coefficient was necessary for TrainDy software. Starting with dynamometer experimental data for a number of UIC-certified composite brake block products, a series of polynomial laws to describe the evolution of the friction coefficient with speed were obtained for various values of normal force between brake blocks and the wheel and at various initial braking speeds. The work began in 2017 and was completed in 2019 by the University of Rome Tor Vergata. The new “LL module” has been added successfully to the TrainDy software and will be available in the next software release.

New TrainDy module for control valves
The new control valve module, created by the University of Rome Tor Vergata on the basis of data provided by Faiveley, is now ready to be integrated in the next TrainDy software release.

Accessing TrainDy and/or service delivery

Membership of the UIC TrainDy consortium is required for access to TrainDy. The experts within the consortium are available to help interested parties to define their specific needs.

UIC contact

For more information, please contact the TrainDy Special Group at

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