Validation of insulated joints

Abstract

In track engineering, insulated joints are widely used as a key component in the signaling system to electrically insulate track sections and thereby locate trains. However, many problems with track deterioration and signaling malfunction are re- lated to them. In spite of this, the requirements on validation testing to assure the mechanical quality of insulated joints are rather low. Trafikverket (Swedish Transport Administration) has a standard that specifies tension tests for insulated joints. However the related bending test is not specified, which makes comparisons between tests cumbersome. There is therefore a need to establish a standardized bending test to compare and evaluate the quality of insulated joints. This thesis outlines such a standardized test. Further, a crucial part in the validation is operational testing. This thesis scrutinizes the issue of how tests should be designed to assure a high statistical confidence.