A loose end--"a snakehead" it was called--sometimes curled up and pierced through the floor of a car, causing a wreck.

The solid metal T-rail, now in universal use, was designed by Stevens and was first used on the Camden and Amboy Railroad, of which he was president and his brother Edwin treasurer and manager.

The swivel truck and the cow-catcher, the modern method of attaching rails to ties, the vestibule car, and many improvements in the locomotive were also first introduced on the Stevens road.
The Stevens brothers exerted their influence also on naval construction.
A double invention of Robert and Edwin, the forced draft, to augment steam power and save coal, and the air-tight fireroom, which they applied to their own vessels, was afterwards adopted by all navies.
Robert designed and projected an ironclad battleship, the first one in the world.

This vessel, called the Stevens Battery, was begun by authority of the Government in 1842; but, owing to changes in the design and inadequate appropriations by Congress, it was never launched.

It lay for many years in the basin at Hoboken an unfinished hulk.