Joint resistance The normal rail joints are designed to allow the rail length variation due to temperature. To do this the joints have a well-defined maximum gap and a set of installation parameters to provide an optimum behaviour at temperature variation and a good maintenance regime. Any modern rail joint has a standard bolt tightening torque…
In the previous article, Jointed track breathing, was described for jointed track the complex activation phenomenon of the track resistance forces that oppose to rail thermal length variation. In the case of the jointed track this activation takes place on the entire length of the rail. As the rail length increases a greater temperature variation…
The crossing is the track arrangement which ensures the intersection of two opposite running edges of a turnout or diamond crossing. It usually has one crossing vee and two wing rails (BS EN 13232-1:2003). The crossing, in the common setup, has a gap section to allow the passage of the wheel flange on both directions. The safe…
Rail breathing Normally on the railway track the rail is fixed through a set of superstructure elements (fastenings, sleepers, ballast) that opposes the rail tendency to expand or contract due to temperature variations. This fixation is achieved through friction forces and once the rail axial forces are above these friction forces, the rail will start…
Note: This article presents the Joint Closure Temperature (JCT) for free thermal expansion (FTE) track superstructure ; it is directly related and should be read in conjunction with the following articles: When can a rail be called long? presenting the definition of the concepts long rail and short rail, from thermal behaviour perspective. Track longitudinal resistance presenting the two…
All the railway track fishplates for mechanical joints are designed to provide a gap to the rail web. This gap, together with the wedge shape of the fishplate section ensure, by tightening the joint bolts, the correct alignment of the rail head between the two jointed rails. The bolt tightening torque is developing in the bolt a…
Motto: Tolle lege! Perhaps the best and most complete technical book about track is “Modern Railway Track” written by Dr Coenraad Esveld, Professor of Railway Engineering at Delft University of Technology. A detailed Table of Contents of the second edition can be found here together with a brief selection of the book. The second edition, written…
I’ll be a Berliner, just for a day … joining the fellow railway engineers from around the world at InnoTrans 2016. InnoTrans is the largest rail industry event in the world, held every two years in Germany, at Messe Berlin – ExpoCenter City. Sub-divided into the five segments Railway Technology, Railway Infrastructure, Public Transport, Interiors and Tunnel…
Track measurement The importance of knowing the track geometric quality arose in the middle of 20th century, when European infrastructure managers developed their own track recording vehicles allowing a continuous measurement of track geometry and based on this, their own track geometry quality evaluation standards (EN 13848-6). Periodic track measurement is required to evaluate the…
There are two types of railway track superstructure from the point of view of the response to rail temperature variation: free thermal expansion (FTE) track superstructure which allows the rail to freely vary its length due to temperature variation. This superstructure does not provide reliable constant and easy to control and maintain track longitudinal resistance…
A railway track blog 