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Nuttall Gear Custom Heavy-Duty Gear Drive for Moveable Bridge
The Arsenal (Government) bridge spans the Mississippi River connecting Davenport,
Iowa and Rock Island, Illinois. The bridge is positioned adjacent to Lock and Dam
No. 15 and the Rock Island Arsenal which is an active US Army facility located on a
946-acre island. Today, the arsenal manufactures gun mounts, artillery carriages
and other combat equipment.
Originally built in 1896, the Arsenal bridge was the first project engineered by world
famous bridge designer, Ralph Modjeski. The bridge features a swing section that
pivots 360 degrees allowing for passage of barge/boat river traffic (only one of two
like it in the world). The twin-deck bridge accommodates two rail lines on the top
level and road traffic on the lower level.
In 2011, the United States Army, Department of Defense completed an extensive
rehabilitation of the bridge. Nuttall Gear worked closely with Modjeski & Masters
engineers during the design/concept phase of the project to provide the custom gear
drive for the bridge’s 360 ft., 1,250 ton swing span. The unique Nuttall enclosed
reducer, which replaced original open gearsets, features a fabricated steel housing,
input rating of 30 HP @ 17.8 RPM, reduction ratio of 1.86:1 and output torque
rating of 295,000 in.lbs.
- Custom-designed enclosed
- 295,000 in.lb. torque
- 1.86:1 reduction ratio
- Fabricated steel housing
- One unit shipped