In 1954 the USACE purchased a pair of custom gearboxes for operating the downstream navigational lock miter gates. The miter gate gearbox drives were designed for a 20 horsepower input and a resultant output torque of over 270,000 foot pounds of output torque.

The original gearboxes, built by Willamette Iron and Steel, were still in service in 2012 when Premier Gear and Machine Works won the bid to replace them. The contract included requirements by the USACE to provide new shop drawings of the replacement gearboxes. The contract also required replacement gearbox designs to be analyzed to current AGMA standards and improvements to the lubrication system, including an automatic oil pump and control system, oil heater, and desiccant air breathers.

SCOPE OF WORK

Altman Browning and Company was contracted to fill the engineering requirements for the contract. The project tasks and deliverables included review of the existing as-built drawings, stress analysis of the shafts, bearings, and housing, and AGMA horsepower calculations for the replacement triple reduction spiral bevel, and helical gear sets. The project deliverables also included completing a 3-D CAD model of the gearbox and a full set of manufacturing drawings of the gears, shafts, and gearbox housing. During fabrication and installation we also provided inspection services and recommendations.

RESULTS

The gearboxes are in operation at the dam, providing the highly reliable service expected by the USACE and a source of pride for us.