BS EN 16729-2:2020 pdf download.Railway applications – Infrastructure Non-destructive testing on rails in track.
BS EN 16729-2 is applicable to testing of rails installed in track for detecting rail surface cracks.BS EN 16729-2 applies to testing equipment in inspection-trains or reprofihing machines and manual systems.BS EN 16729-2 specifies the requirement for testing principles and systems in order to produce comparable results in respect to the location and the characteristic of surface cracks.BS EN 16729-2 is not aiming to give any guidelines for managing the result of eddy current rail testing. BS EN 16729-2 does not define the requirements for vehicle acceptance. BS EN 16729-2 is not concerned with production testing of rails in a production plant. BS EN 16729-2 applies only to rail profiles meeting the requirements of EN 13674-1.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. Forundated references, the latest edition of the referenced document (including any amendments) applies.
EN 1323 1-5, Railway applications — Track — Acceptance of works — Part 5: Procedures for rail reprofihing in plain line, switches, crossings and expansion devices
EN 16729-1:20 16, Railway applications — Infrastructure — Non-destructive testing on rails in track — Part 1: Requirements for ultrasonic inspection and evaluation principles
3 Terms and definitions
For the purposes of BS EN 16729-2, the terms and definitions given in EN 16729-1:2016 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
d’ depth to be machined (depth of the crack rectangular to the surface including to a safety distance to ensure the removal of the crack)
a’ penetrating angle
1 gauge side
A sectional plane
Figure 3 — Depth to be machined depending on the head checks position
capability to recognize, discover and register surface cracks with the help of a testing system
conformity of several results from the verified test system
5 Basic principles
With the help of eddy current testing, surface cracks can be detected in electrically conducting materials (ferromagnetic or non-ferromagnetic materials).
Eddy current testing is based on the induction of electric current in electrically conducting material. The measured and analysed size refers to the distribution of the induced currents (eddy currents). The distribution of the eddy currents in the material is governed by physical laws; the density of these eddy currents drastically decreases with the distance to the surface.
To determine the depth of a head check crack, the pocket length of the crack and the penetrating angle are used. The penetrating angle can vary depending on steel grade, traffic, tonnage and support conditions of the rail. The penetrating angle a’ (see Figure 3) commonly used for testing head checks in rail is 25 .
Parameters influencing the testing results are:
— conductivity of the material.BS-EN-16729-2-2020