This line was originally designed as a " plateway " on the Outram system, but objections were raised to rails with upstanding ledges or flanges FIG.
Jessop thus produced what was virtually the flanged wheel of to-day, having the flanges inside the rails,.
Flat-bottomed rails are fastened to the sleepers by hookheaded spikes, the heads of which project over the flanges.
On all the accepted forms there are two or more flanges at the bottom, running lengthwise of the plate and crosswise of the rail; these are requisite to give proper stiffness, and further, as they are forced into the tie by the weight of passing traffic, they help to fix the plate securely in place.
The rail-failures mentioned above also drew renewed attention to the importance of the thermal treatment of the steel from the time of melting to the last passage through the rolling mill and to the necessity of the finishing temperature being sufficiently low if the product is to be fine grained, homogeneous and tough; and to permit of this requirement being met there was a tendency to increase the thickness of the metal in the web and flanges of the rails.
