Pall Friction Dampers in News
a). Seismic Retrofit of Alaska Airline MTX Project in Seattle Wins ACEC Engineering Excellence Award 2010.

The maintenance and engineering building was built in 1965 and expanded in the 1990. It houses Alaska Airlines maintenance and operations information as well as partly storage. The braced frame steel building was upgraded to meet the Immediate Occupancy performance objective of ASCE 41. Engineers studied several schemes and chose and chose Pall friction dampers for retrofit. Installation of dampers in existing braces reduced the drifts and forces by more than 50%. As a major portion of seismic energy is dissipated by the friction dampers, the expensive and time consuming work of strengthening foundations was not required. Also, the conventional construction would have required replacement of existing braces with heavier braces. Reid Middleton, project structural engineers won prestigious 2010 ACEC Engineering Excellence Award, for using innovative structural design solution.

b). California Construction Link, June 2001 (McGraw-Hill Publication), Page 8-9. 
Moscone West Project, San Francisco.

The new convention center is located between the San Andreas and Hayward faults, which are approximately 12 miles in each direction. It is a US$186 million expansion of the 1.2 million-sq.-ft convention center. The use of 248 Pall Friction Dampers (slip load up to 500 kip) resulted in reducing story drifts to less than 1% compared to 2% without dampers.

"In the event of a major earthquake, 70-80 percent of the earthquake energy will be dissipated by friction dampers, leaving the building structure with little damage. The exterior wall system as well as all other systems of the structure will also experience lowered seismic movements and shock due to these systems and should therefore perform better," says Clonia Cautis with Gensler, architect of record. "We believe this system saved a couple of millions of dollars in initial construction costs and will save as much as tens of millions of dollars additionally in lowered repair costs in the event of a major earthquake," Cautis noted. " This gives a reasonable expectation that this building will be immediately occupiable after a major earthquake.

c). Engineering News Record, April 8, 2002 (McGraw Hill Publication), Page 18.

The article gives the story on Moscone West Convention Center and shows some pictures of installation of Pall Friction Dampers. Steel structure including installation of friction dampers was completed in January 2002. The new convention center opened in 2003.

The use of 248 Pall Friction Dampers of 300-500 Kip slip load reduced the building drift from 2% to 1%. City and County of San Francisco chose Pall Friction Dampers as it saved them US$2.25 million compared to alternate viscous dampers in open bidding. The cost of Pall Friction Dampers was about 30% the cost of viscous dampers.

Recent papers on Pall Friction Dampers, presented at the 8th US National Conference on Earthquake Engineering, San Francisco, April 2006.

a). The Use of Friction Dampers for the Seismic Retrofit of the Monterey County Government Center. Paper #951.

b). Friction Dampers for the Seismic Upgrade of A 14-Story Patient Tower with A 36=Foot Soft-Story. Paper #90.

Recent Projects


1. Hospital Valle de Lili, Colombia, Building #1. Seismic Retrofit.

2. Hotel Wilke-Bashford, San Francisco, CA, USA. Seismic Retrofit.

3. CHUS Hopitale Universite de Sherbrooke, Building #2, Quebec. Seismic Retrofit.

4. Hospital San Juan des Dios, Colombia, Building #1. Seismic Retrofit.

5. Ottawa Support Center, Ottawa, Canada. Seismic Retroft.

6. Canadian Space Agency HQ. Extension, Montreal. New construction.

7. Police Post, Longueuil. Seismic Retrofit.

8. Hospital Sante Mentale, Building #4, Quebec. Seismic Retrofit.

9. Sports Expert, Montreal, Quebec. Seismic Retrofit.


1. Boeing 737 MAX Project, Renton, WA, USA. Seismic Retrofit.

2. Canadian Embassy in Islamabad, Pakistan. Seismic Retrofit.

3. Hospital Valle de Lili, Building #2, Colombia. Seismic Retrofit.

4. Sir Banting Building, Ottawa, Canada. Seismic retrofit.

5. Hospital San Juan des Dios, Building #2, Colombia. Seismic Retrofit.

6. Carrefour Laval, Laval, Quebec. Seismic Retrofit.

7. Ecole Laruche, Magog, Quebec. Seismic Retrofit.

8. Sports Expert, Montreal, Quebec. Seismic Retrofit

9. Carre SINGER, St. Jean Sur Richlieau, Quebec. Seismic Retrofit.


1. EDATEL Telecommunication Building, Colombia. Seismic Retrofit.

2. USMQ Hospital Sante Mentale, Building #5, Quebec. Seismic Retrofit.

3. Jewish General Hospital, Montreal, Building #4, Quebec. Seismic Retrofit.

4. Hopitale Riviere-de-Loup, Quebec. New Construction.

5. CHUS, Hospital University of Sherbrooke, Building #3, Quebec. Seismic Retrofit.

6. Condominium Les Jardin Westmount, Westmount, Quebec. Seismic Retrofit.

7. Boeing SI Complex, Renton, WA. USA. New Mezzanine inside an existing building.