Flat Footed Rails:
The rail sections having their foot rolled to flat are called flat-footed or Vignoles rails. This type of rail was invented by Charles Vignoles in 1836. It was initially thought that the flat-footed rails could be fixed directly to wooden sleepers and would eliminate chairs and keys required for the B.H.rails. But later on, it was observed that heavy train loads caused the foot of the rail to sink into the sleepers and making the spikes lose. To remove the defect, steel bearing plates were used in between flat footed rails and the wooden sleeper. These rails are most commonly used in India.
- F. rails have more strength and stiffness.
- No chairs are required for holding them in position.
- These rails require less number of fastenings.
- The maintenance cost of the track formed with F.F rails is less.
- The fittings get loosened more frequently.
- These rails are not easily removed and hence renewal of track becomes difficult.
- It is difficult to manufacture points and crossings using these rails.