ASME-Landmark:ALCOA 50,000-Ton Hydraulic Forging Press


The ALCOA 50,000-ton die-forging press is among the largest fabrication tools in the world. It was designed and built for the U.S. Air Force by the Mesta Machine Company of Pittsburgh, following the discovery a 30,000-ton press used by the Germans in World War II (and later acquired by the Soviet Union).

By 1950, a Heavy Press Program was organized to establish a self-sustaining industrial base for a press capable of producing large forgings and extrusions for the United States. While the Defense Department policy was then, as now, that contractors, provide their own plant, facilities, and equipment, an exception is warranted in the case of special facilities to produce goods for which there is no commercial market. Since there was no commercial requirement for presses of this size, the government undertook the sponsorship and support of the Heavy Press Program.

The 50,000-ton Mesta press was one of the first built under this program between 1952 and 1955. It has been dominant in commercial aircraft development as well as advanced military aircraft and aerospace programs, such as the 100-inch Hooker telescope at the Mount Wilson Observatory (landmark #66). The Aluminum Company of America is the operating contractor.

The principle of force multiplication that underlies the action of hydraulic presses was demonstrated in 1646 by Blaise Pascal of France. It was first incorporated into a useful industrial press by Joseph Bramah of England in 1796. See ASME website for more information