Seismic Dampers

Our dampers resist dynamic motion and remove energy from a structure during wind or seismic events, allowing it to withstand harsh input energy and reduce harmful deflections, forces and accelerations to structures and occupants.

Millennium Bridge - London
Millennium Bridge - London Control Dampers

37 special Dampers developed for NASA used for mitigation of lateral pedestrian vibrations.

Force range: 2250 – 4500 lbs.
Stroke capacity: +/-1.0 inch to +/- 11.0 inches. Effective damping to amplitudes less than .002 inches.
Design life: Greater than 60 years with no maintenance.

Port Mann - Canada
Port Mann Bridge - British Columbia, Canada Seismic Dampers

146 Fluid Viscous Dampers with various force and stroke capacity for seismic protection.

Output forces: Up to 790,000 lbs.
Stroke capacities up to: +/- 16.5 inches.

New cable-stayed bridge uses 146 Fluid Viscous Dampers in approach spans and at suspension span between piers and deck to dissipate seismic energy. This replacement bridge (replaces an aging, tied-arch bridge) boast a 470 meter main span, the second longest in the Western Hemisphere, and a 50 meter wide deck - the widest of any cable stayed bridge in the world.

Buddhist HQ - Taiwan
Buddhist HQ - Taipei, Taiwan Seismic Dampers

60 Fluid Viscous Dampers in diagonal bracing.

Force output: 220,000 lbs.
Stroke capacity: +/-3.0 inches.

San Bernardino Justice Center
San Bernardino Justice Center,
San Bernardino, California
Seismic Dampers

184 Seismic Dampers in diagonal bracing.

Output force: 450,000 lbs.
Stroke capacity: +/-5 inches.

Lock-Up Devices

Lock-up devices allow unrestricted motion when the bridge structure slowly expands and contracts thermally, yet locks the structural masses together under seismic or wind storm conditions.

Abernethy Bridge
Abernethy Bridge - Oregon City, Ore. Lock-up Devices

32 seismic Lock-Up Devices.

Output force: Varies up to 337,000 lbs.
Stroke capacity: Varies up to +/-6 inches.

LUD’s protect existing bridge from seismic activity and distribute forces while allowing free movement for thermal variations.

Seattle Central Light Rail
Seattle Elevated Light Rail, Seattle Lock-up Devices

84 seismic Shock Transmission Units for multiple sections of Seattle’s central link light rail.

Output force: Varies up to 650,000 lbs.
Stroke capacity: Varies up to +/- 6 inches.

New light rail line from Seattle through SEA-TAC International Airport utilizes shock transmission units to control seismic movement while allowing free thermal movement. Sections C755, C410, South 160th Loop and S440 South 200 Link all utilize these devices.

Taiwan High Speed Rail
Taiwan High Speed Rail - Taipei, Taiwan Lock-up Devices

34 seismic Lock-Up Devices.

Output force: 875,000 lbs.
Stroke capacity: +/-5.0 inches.

Dampers control elevated structure during train braking and seismic events.

William H Harsha Birdge
William H. Harsha Bridge - Maysville, Ky. Lock-up Devices

8 seismic Lock-Up Devices.

Output force: 300,000 Lbs.
Stroke capacity: +/-12 inches.

This new bridge, built in 2000, connecting Maysville, Ky. to Aberdeen, Ohio over the Ohio River utilizes lock-up devices to control earthquake movement and distribute forces while allowing free thermal movement.

Tuned Mass Dampers

Tall slender buildings require damping. Tuned mass dampers are a great option to provide this supplemental damping. Our tuned mass dampers control the response of a building’s mass and springs, reducing acceleration when subjected to high winds. Tuned mass dampers can also be used to reduce pedestrian induced vibrations in pedestrian bridges and long span floors as well as human induced vibrations in stadiums and theaters.

Park Avenue - NYC
432 Park Avenue - New York Fluid Dampers for TMD

16 long stroke Fluid Viscous Dampers for tuned mass dampers.

Damper force: 30,000 lbs.
Stroke capacity: +/-40 inches.
Damper power capacity: Greater than 4.0 HP.

Cumberland - Nashville, TN
Cumberland River Pedestrian Bridge - Nashville, Tenn. Tuned Mass Dampers

5 tuned mass damper systems for both vertical and lateral protection.

Tuned Mass: 7,600 lbs Lateral TMD.
5,700 lbs vertical TMD.

Park Hyatt - Chicago, IL
Park Hyatt - Chicago Fluid Dampers For TMD

4 special patented Fluid Viscous Dampers using technology developed for NASA for tuned mass dampers.

Output force: 9,800 lbs.
Stroke capacity: +/-20.0 inches

Infinite life dampers to control motion of 300 ton tuned mass damper at the top of a 67 story building in Chicago.

Rock Church
Rock Church - San Diego Tuned Mass Dampers

Twin Tuned Mass Dampers.

Tuned mass: 8,000 lbs vertical TMD.
Frequency: 3.6Hz.

TMD’s control vertical excitation due to crowd activity.