Tuned Mass Dampers

A&H Custom Machine is a world leader in the fabrication and installation of Tuned Mass Dampers.

rwdi logoWorking with world leaders in TMD design and engineering - our reputation for excellence in this area has led us to a variety of notable projects around the world including famous landmarks such as Taipei 101, Spire of Dublin, Las Vegas Control Tower, and the Royal Alexandra Interprovincial Bridge.

Why A&H Custom?

The A&H team has fabricated and installed TMDs worldwide on a variety of projects. We work from designs created by world leaders to achieve a common outcome – a functioning and unique custom damping solution for each project. At A&H we manufacture those designs to detailed specifications. Our installation team installs the TMDs on building sites and bridges worldwide working alongside project managers, general contractors and bridge contractors.

What is a tuned mass damper (TMD)?

A tuned mass damper (TMD) is a device mounted in large structures, such as tall buildings and long bridges, to reduce the amplitude of vibrations caused by environmental forces or otherwise. Tuned mass dampers are typically constructed of large steel bodies and mounted to move in an opposing direction to the oscillations of the structure.

It is important that the vibrations caused by wind loads on structures such as tall buildings and bridges be damped because it allows them to remain stable. Over the years tuned mass dampers in buildings and bridges have been responsible for keeping structures safe and reducing the amount of damage that harsh weather conditions can wreak on those structures.

Further vibrations can also come from man-made causes – such as cars or trucks passing over a bridge. By reducing the number of vibrations through TMDs, we help to reduce wear and tear on those structures which translates into less frequent, less costly maintenance and repairs.

What are tuned mass dampers made of?

Because they have a specific application, tuned mass dampers have a custom design and configuration. Regardless, however, there are three key components: a moving mass, a pendulum or springs and damping elements.

Working together, energy formed by the movement of the mass is dissipated in the form of heat.

What are the types of tuned mass dampers?

Although the two types of tuned mass dampers may feature slight differences in mechanics, both work to reduce vibrations found in a structure.

Horizontal tuned mass dampers: Typically located in narrow buildings, communication towers and spires, horizontal tuned mass dampers reduce horizontal and torsional excitations.

Vertical tuned mass dampers: Used to decline vertical vibrations, vertical tuned mass dampers are commonly found in bridges, floors and walkways.

How does a tuned mass damper work?

To stabilize against the motion created by harmonic vibration, a damper’s frequency is tuned to a specific structural frequency. Because the first vibrational mode of a structure contributes significantly to its dynamic response, a TMD is commonly tuned to the first natural frequency of the structure.

When the frequency is excited, the damper will vibrate out of phase with the structural motion and dissipate the energy created. Any vibrations experienced are less intense, which makes the structure more comfortable for occupants while also reducing material fatigue and other failures.

By implementing a frictional or hydraulic component in mass dampers, the mechanical kinetic energy can be converted into heat.

A TMD’s effectiveness depends on the accuracy of its tuning, its mass ratio and the extent of internal damping constructed into the TMD. If it’s too difficult or expensive to damp directly, a TMD can be used to add damping to a resonance, such as found in crankshaft torsional dampers.

Other methods of reducing vibration – such as adding stiffness or an immobile mass or changing the shape of the structure – are typically costly and aren’t as effective as required. 

Tuned mass damper applications

First used in 1909 to decrease the rolling motion experienced in ships and ship hull vibrations, TMDs are now most commonly found in buildings and bridges. 

Tuned mass damper in buildings/skyscrapers

Skyscrapers and tall buildings can move several feet in the wind. To reduce this effect and help maintain structural integrity, a TMD is used.

The world’s largest and heaviest tuned mass damper is located inside the Tapei 101 skyscraper in Taiwan. Capable of moving five feet in any direction, the TMD can decrease sway by up to 40 percent. Constructed out of 730 tonnes of suspended steel, the TMD can withstand Taiwan’s recurrent earthquake tremors and typhoon winds.

Tuned mass damper for bridges

Wind vibrations (vortex shedding), wave vibrations and earthquakes can result in unwanted movements and damage in a bridge. With the help of a TMD, bridges oscillate in the opposite direction to prevent these movements, making them safer for pedestrians and vehicles.

Our Commitment to Our Customers

At A&H Custom Machine, we have a global customer base. We’ve worked on many contracts for TMDs on massive projects including skyscrapers, airports, and bridges. We are honoured by the trust that our clients put in us. We take our responsibility to preserve the safety and structural integrity of their structural assets very seriously.  

We have been in business since 1986 and have always maintained the highest level of professionalism and expertise.  Furthermore, our shop technicians share over 150 years of experience in a variety of applications including Boring Mill Work, CNC Machining, Electrical Panels and Machine Assembly.

Our expert team has built and installed more tuned mass dampers for buildings than any other firm in the world. We are extremely proud of all the work we have completed to date and look forward to many more exciting projects in the future.

Contact A&H Custom

Seeing is believing. Let Our Work speak for itself.

taipei 101

Taipei 101, Taiwan


432 Park Avenue, NY City

432 Park Avenue, New York City, USA


Royal Alexandra Interprovincial Bridge

The Royal Alexandra Interprovincial Bridge, Canada


  •  Taipei 101 - Taipei, Taiwan
     660 Tonne Tower Tuned Mass Damper
     Two 4.5 Tonne Pinnacle Tuned Mass Dampers
  • 731 Lexington Avenue - New York, USA
     700 Tonne Tuned Mass Damper
  • Trump UN Tower - New York, USA
     600 Tonne Tuned Mass Damper
  • Spire of Dublin - Dublin, Ireland
     1250 kg TMD and 800 kg Tuned Mass Dampers
  • Sultanate of Oman - Muscat International Airport
     40 Tonne Tuned Mass Damper
     30 Tonne Torsional Tuned Mass Damper
  • Wichita Riverfront Pedestrian Bridges - Wichita, Kansas
    2500 kg Tuned Mass Damper
  • New Songdo City - Inchon, Korea
    Eight Tuned Liquid Column Dampers for Four Towers
  • Las Vegas Control Tower - Nevada, USA
    60 Tonne Tuned Mass Damper
  • The Royal Alexandra Interprovincial Bridge - Ottawa, Canada
    Eight 5 Tonne Tuned Mass Dampers
  • 432 Park Avenue - New York, USA
    Two Tower Tuned Mass Dampers, combined weight of 1370 Tonne