Description
In normal main tracks, transition curves shall always be arranged to provide a smoother transition between straight tracks and a circular curve or between two circular curves of different radius. Transition curves shall be performed with linear change of curvature (klotoid). Transition curves shall be arranged on the line and on the normal main track within an operational site but are also recommended to be arranged in deviating main tracks where possible. The curves start and end at tangent points marked by cant signs on the inside of the foot of the outer rail with a maximum longitudinal deviation of 0.5 m. The transition curve is included as a trace element in the description of the track geometry and is part of the plane geometry, which also includes straight lines and circular curves. The track geometry represents the projected geometry and refers to the track centre. The data product contains the radius of the transition curve in the tangent points, the type of geometric function, the length and the method used to capture the data. Type of geometry = R indicates that the transition curve has linear change of curvature (klotoid) which is the most common type and the only one used in the construction of new tracks. Type of geometry = S indicates that the transition curve has curved curvature (fourth degree parabola). This type of transition curve is relatively rare and is not used in new construction. When geometry has the attribute Origin = G (Measured Geodetic), the data is coordinate-determined and comes from the GAD system or is transferred from the Geosecma system. The data product then has a high quality and can be used for all types of applications. At Origin = P (Pil-height measured – not geodetic measured), data is interpreted from mechanical measurement and only suitable for applications where low quality can be accepted. The data product has stretch distribution and connects to the railway network with reference to the immediately preceding node and the immediately preceding kilometre board with distances in metres to both the start and end position of the transition curve (=key points) in the direction of the track link. The object types Circular curve, Transition curve, Straight line and Rail cant together form the plane geometry and will create an overall geometry description for all track links in the Swedish railway network. For the three object types Circular Curve, Transition Curve and Straight Line there is the attribute Total Length of Object (m) which contains the length used to generate the lengths of the track links and which forms the basis of the linear reference system for railway - applies Link Length and Track Length.
Resources
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Description |
Link |
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http://geo-baninfo.trafikverket.se/MapService/wms.axd/BanInfo_1_4?layers=Overgangskurva |
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https://lastkajen.trafikverket.se/login |
Tags
- trafikverket
- nationell
- öppna-data