The location of the stress transition zone is not only limited to the extremities of a continuous welded rail (CWR) track, the case presented in a previous article – CWR stress transition zone. A stress transition zone may also be present between two fixed zones, inside the CWR. These internal stress transition zones are shorter…
ΔG = αLΔT°. Free expansion For a free thermal expansion jointed track the rails expand and contract freely and the track components do not provide any resistance to oppose this rail length variation. The joint gap varies linearly relative to the rail temperature. The figure below presents the joint gap variation for a jointed track formed…
Perhaps I’m splitting hairs here, but it is a fair question to ask: When a 20 m rail is 20 m long? Please, have your say and feel free to comment below, after voting! And this is not a trap question like “Which weighs more: 1 kg of steel rail or 1 kg of feathers?”. Later edit: By…
The thermal behaviour of the jointed track can be analysed throughout a full annual temperature variation and used to define the joint expansion gap variations. The joint gap varies between the maximum value and zero and this is related to the way the rails are allowed by the track resistance forces to contract and expand in…
This is the presentation I gave to the West of England Section of the Permanent Way Institution:
I feel very honoured and proud to see the article “An introduction to rail thermal force calculations” I wrote with my friend, Levente Nogy, published and featured on the front cover of the Journal of the Permanent Way Institution.
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…
