Braking Questions - Basic principles for the 5th edition of UIC Leaflet 544-1 (Braking power)

Some difficulties and a lack of clarity concerning the execution and analysis of brake assessment tests had come to light in the course of implementing UIC Leaflet 544-1, 4^th edition. Moreover, it had become apparent that additions were required.

At its meeting in January 2008, the UIC “Braking” Sub-Committee therefore tasked WG B 126.19 with updating the leaflet.

The present report summarises the main amendments that have been made in preparing the 5^th edition of UIC Leaflet 544-1, as well as providing explanations and extrapolations.

The amendments and additions include:

• Appendix F on the test procedure,
• a new procedure for brake assessments under 100 km/h,
• new definitions for the assessment of parking brakes,
• a new procedure for determining braking distances of multiple units operating in multiple traction on the basis of the test results of individual multiple units,
• a harmonised procedure for determining braking power through decelerations with the High Speed TSI,
• extension of the reduction factors for train lengths over 700 m,
• inclusion of provisions for ETCS,
• definitions of terms and masses harmonised with the current ENs and TSIs.