America’s First Rail Locomotive
Col. John Stevens of Hoboken, N. J., had by 1825 long been intrigued with the idea of constructing a steam locomotive, having had considerable success with steam as a method of propulsion on water. In that year he constructed a small experimental 4-wheeled engine, the first rail locomotive to be built in this country. The unflanged wheels were kept on the flat rails by vertical bars that projected down from each corner of the locomotive. These were fitted on their lower ends with horizontal rollers bearing on the inside of the rails.
Equipped with a vertical water-tube boiler, and with its horizontal 1-cylinder power plant geared to a rack located between the two rails, it was built only for demonstration and experimentation. It was often run, however, on a small circular track laid out on the lower lawn of Stevens’ estate at Hoboken. This was the first steam railroad in America.
Figure 1.—Original boiler, now in National Museum, of experimental locomotive built in 1825 by Col. John Stevens.
Of this original locomotive only the boiler and safety valve remain. They are on exhibition at the National Museum (USNM 180029), where they were deposited in 1888 by the Stevens Institute of Technology. The boiler ([figure 1]) contains 20 wrought-iron tubes, each a little over 1 inch in outside diameter, set closely together in a circle and originally surrounding a circular grate, now missing. It is 4 feet high, including the headers, and 1 foot across, and was formerly enclosed by a jacket of thin sheet iron topped by a conical hood on which rested the smokestack.
Wood used as fuel was dropped onto the grate through a door in the hood, and water was put into the boiler through a pipe in the bottom header. Steam was taken from a 1-inch pipe in the top header. The boiler when new is reported to have sustained with safety a steam pressure of 550 pounds per square inch. The design of the boiler was patented by Stevens on April 11, 1803.
The safety valve ([figure 2]) is of simple design. It consists of a lever 10 inches long from which a 4-pound lead ball about 2½ inches in diameter is suspended. Beneath the lever, and about 1 inch in from the fulcrum, is a disk valve controlled by the weight of the ball, which hangs by a stirrup that can be moved to any of several notches, so that it can be set for different pressures at which the valve will open.
Figure 2.—Original safety valve of Stevens’ locomotive, now in National Museum.