Bull Headed Rails: The rail section whose head dimensions are more than that of their foot is called bullheaded rails. In this type of rail, the head is made little thicker and stronger than the lower part by adding more metal to it. This rail s also require chairs for holding them in position.

bullhead rail (plural bullhead rails) (rail transport) A rail, most commonly used in the United Kingdom, with a head and foot nearly equal in cross-section, that is supported in cast iron chairs and secured by wedges or keys.