EVS-EN 15551:2017

This European Standard defines the requirements for buffers with 105 mm, 110 mm and 150 mm stroke for vehicles or units which use buffers and screw coupling. It covers the functionality, interfaces and testing procedures, including pass fail criteria, for buffers.
NOTE 1  Typically, buffers with a stroke of 105 mm are used on freight wagons and locomotives, buffers with a stroke of 110 mm are used on coaches and locomotives and buffers with a stroke of 150 mm are used on freight wagons.
It defines the different categories of buffers, the space envelope, static and dynamic characteristics and energy absorption.
It includes a calculation method to determine the minimum size of the buffer head to avoid override between buffers.
It defines the static and dynamic characteristics of the elastic systems.
It also defines the requirements for buffers with integrated crash elements (crashworthy buffers) for tank wagons for dangerous goods.
The requirements of this European Standard also apply to buffers of locomotives and passenger coaches which need to meet the crashworthiness requirements of EN 15227 for normal service only. The properties for the energy absorbing function are defined in EN 15227 and the requirements specified in Clause 7 for tank wagons for dangerous goods are not applicable to the buffers of these locomotives and passenger coaches.
Diagonal buffers are excluded from this European Standard.
For the crashworthy buffers of locomotives, cab cars or passenger coaches according to EN 15227, and tank wagons for dangerous goods or buffers which form part of a combined system consisting of a special buffer and a deformation element, interchangeability with freight wagon buffers is not required, and therefore the requirements of 5.2 (Fixing on vehicle and interchangeability), 5.3 (Buffer dimensions) do not apply, those of 5.4 (Mechanical characteristics of buffers) and 5.6 (Marking) apply with restrictions.
NOTE 2  For tank wagon subjected to dangerous goods regulation, see [35].