Square Joints in Railway Track Waves

When rails are laid in a railway track, small gaps are left between the ends of adjoining rails to allow for the expansion of the rails when the temperature rises. Rail joints are provided to form a continuous rail path which are normally laid in standard lengths bolted together by fishplates. When two rail joints are exactly opposing each other, they are called square (side by side) joints. Manufacturers produce rails with different standard lengths. The inner line of rails in a curve is shorter than the outer line therefore, it would be complicated to have square joints by using only rails of standard length for both inner and outer rails in the curve. If some short rails were used in the inner line, it would be possible for all joints of rails to lie opposite each other in a precise manner. It is clear that equal rail lengths can easily create square joints along the straight portion of the track. In curves with larger radii, there is a substantial difference between inner and outer arcs of the cruve. Manufacturers producing different standard lengths also produce some short rails in two or three different lengths. This paper presents a simple method of finding the location of joints in the railway curve. Previous methods (used in European and American railways) use some short rails (3 or 4 short rails) with different lengths for the inner arc. In this method, short rails of one single length are used.