5-Million-Pound testing machine
The Technical Service Center’s iconic 5-million-pound testing machine continues to provide mission-critical support for Reclamation’s most complex and large-scale infrastructure projects. Its unique capabilities and exceptionally high load rating remain integral to the operation of Reclamation’s specialized facilities.
Since its installation, the machine has tested materials and components for high-profile projects and advanced research, including concrete samples for numerous Reclamation dams and water infrastructure projects across multiple agencies. Recent testing includes tensile tests of Hoover Dam intake tower gate stems, which allowed the Lower Colorado Basin to make informed, cost-saving decisions on replacement schedules. Critical components of the Shasta Dam Temperature Control Device hanger rods were also tested during a replacement contract, along with large-diameter concrete cores taken from the dam to assess structural viability for a potential dam raise.
Experts in the Concrete and Structural Laboratory, who operate the machine, have also coordinated testing of prestressed concrete beams, wire ropes, mine cribbing, 36-inch-diameter helical foundation piers, concrete formwork shoring towers, and aerospace components for NASA and Lockheed Martin.
More than just a machine, the testing system remains a cornerstone of structural evaluation for Reclamation and its partners, enabling design verification and engineering advances in civil, mining and aerospace fields for more than 75 years.
Constructed in 1948 by Baldwin Locomotive Works in Eddystone, Pennsylvania, the 5-million-pound universal testing machine is a monumental feat of engineering. Shipped to Denver on railroad flatcars, it was installed in Building 56 at the Denver Federal Center after extensive building modifications, including raising the ceiling and adding a traveling crane. A two-story excavation was required to construct a cork-insulated concrete foundation designed to support the machine’s 750,000-pound weight.
Installation took a full year. In July 1950, the machine was featured during an open house dedicating the Reclamation Engineering Center, drawing an estimated 40,000 visitors.
The machine stands 50 feet above the floor and extends 16 feet below it. It can apply loads of up to 5 million pounds on specimens as tall as 32 feet, in either compression or tension. Its largest component, the bedplate, is a 96,000-pound steel casting. The crosshead, which also weighs 96,000 pounds, houses the weighing capsule and moves along two precision screws, each 16 inches in diameter and 46 feet long. The foundation extends 25 feet beyond each end of the bedplate, allowing testing of specimens up to 50 feet in length.
The machine operates through three systems:
Loading system: A pump delivers oil to a 5-foot-diameter hydraulic cylinder, moving the crosshead downward to apply loads at up to 4.5 inches per minute.
Weighing system: Precision pressure transducers provide NIST-traceable calibrated load ranges from 6,000 to 5 million pounds, accurate to within 1%, and verified annually in accordance with ASTM standards.
Control system: Originally manual, the system was upgraded in 1999 to computerized controls for precise load application and data acquisition. In 2024, it was further modernized with updated hardware and software, allowing more customized system control.
Supporting equipment includes a full-load-rated floor pedestal measuring 6 feet by 6 feet that raises test specimens 30 inches off the floor, an elevator platform for maintenance and access to tall specimens, and a 15-ton traveling crane used to position heavy components.
