truck

…track, and a swiveling leading truck guided them into tight curves. On the Camden and Amboy Railroad, another pioneering line, the engineer John Jervis invented the T- cross-section rail that greatly cheapened and simplified the laying of track when combined with the wooden crosstie also first introduced in the United…

…arranged in two four-wheel swivel trucks, or bogies. The trucks resulted in smoother riding qualities and also spread the weight of heavy vehicles over more axles.