Under the Association of American Railroads’ (AAR) Strategic Research Initiatives (SRI) program, MxV Rail performed a simulation study to better understand the effect of higher brake pipe (BP) flow on brake application and release. Technology Digest  TD24-002 1, published earlier this year, focused on brake cylinder pressures using the same simulations. These studies were made possible using a new feature of MxV Rail’s modeling software, TOESTM, that allows modeling of concentrated BP leakages from specific cars on a train. BACKGROUND The BP leakage test is an integral part of the Class 1 and No. 1 brake tests in the United States and Canada.2,3 The test can be conducted using either the traditional timed leakage test or the newer air flow method (AFM) test. Currently, the AFM test requires the train to have no less than 75 psi at any point in the train. For trains with a single locomotive consist,…