[[wiki-architecture]] · [[Architectural Concepts and History]] · [[ARCHITECTURE]] · [[000]] # Rankine's method Rankine's method or tangential angle method is an angular technique for laying out circular curves by a combination of chaining and angles at circumference, fully exploiting the theodolite and making a substantial improvement in accuracy and productivity over existing methods. This method requires access to only one road/path of communication to lay out a curve. Points on curve are calculated by their angular offset from the path of communication. Rankine's method is named for its discoverer William John Macquorn Rankine at an early stage of his career. He had been working on railways in Ireland, on the construction of the Dublin and Drogheda line. == Background == This method makes sure that any line drawn from the known tangent to curve is a chord of the curve by constraining the deflection angle of line. Since end points of chords lie on the curve this can be used to approximate the shape of actual curve. == Procedure == Let AB be a tangent line/path of communication or start of a curve, then successive points on the curve can be obtained by drawing an arbitrary line of length C i {\displaystyle C_{i}} from point A with an angle Δ i = ∑ j = 0 i δ j {\displaystyle \Delta _{i}=\sum _{j=0}^{i}\delta _{j}} δ i = C i × 180 2 π R {\displaystyle \delta _{i}={\frac {C_{i}\times 180}{2\pi R}}} where δ i {\displaystyle \delta _{i}} is deflection from nth chord in degrees. R is the radius of circular curve C i {\displaystyle C_{i}} is arbitrary length of chord == See also == Dublin and Drogheda Railway == References == - [[Professional Practice/Project Delivery Methods]] - [[Urban and Planning/Urban Design and Planning]] - [[Building Construction/Hill Architecture]] - [[Design/Building Typologies/Industrial Architecture]] - [[Urban and Planning/Transportation Planning]] - [[Professional Practice/Codes & Standards/National Building Code of India/Part 02 - Administration]] - [[Wiki-Architecture/Building Materials]] - [[Professional Practice/Codes & Standards/National Building Code of India/Part 05 - Building Materials]] - [[Professional Practice/Codes & Standards/National Building Code of India/Part 08 - Building Services/Section 5B - Escalators and Moving Walks]] - [[Interior Architecture/Renovation and Conservation/Restoration Techniques]]