Bullet-head rails are the standard form of rail used around the world. The rail has a wide base or foot relative to its narrow head. The UK introduced this type of rail, which was designed to be reusable. When the top of the rail had worn down, the rail was intended to be turned over. This proved impossible because the bottom of the rail would also wear down.
The flanged T rail is properly named due to its upside-down T shape. It is made by joining two rails together, and when sufficient metal is put into a rail joint, the joint becomes as strong as the entire rail length. The flanged T rail was manufactured as an all-iron rail and in the 1800s became the standard rail for all railways in the United States.
The Vignoles rail is the popular name of a flat-bottomed rail. Charles Vignoles, its creator, observed that steel rails set on stone blocks were wearing at a considerable rate and thus recommended a flat-bottomed rail. The Vignoles rail has a much wider base than most rails in use and is fastened with screws through the base of the rail.
The Barlow rail was invented as a cheap alternative to the conventional railway track. Barlow rails avoided the cost of sleepers and chairs altogether and are laid directly in the ballast, requiring no ancillary equipment. However, the rail itself is significantly heavier and more expensive than conventional rails. On curves, passing vehicles experience a crabbing effect, which pushes the rails apart.
