May 21, 1992

Mr. Curtis P. Parrish
Vice President of Finance
Wm. G. Knowles Construction Company
P.O. Box 385 - Route 3
North Chester, Illinois 62233

Dear Mr. Parrish:

This is in response to your April 16 letter requesting an interpretation of an Occupational Safety and Health Administration standard addressing the design of protective systems used in trenches.

You are correct that 29 CFR 1926.652(c), Option (2) allows support systems, shield systems and other protective systems to be designed using manufacturer's tabulated data without additional certification from a registered professional engineer (RPE). Tabulated Data by definition (§1926.650(b)) is required to be certified by a RPE and additional certification is not necessary.

If we can be of any further assistance please contact Mr. Roy Gurnham or Mr. Dale Cavanaugh of my staff in the Office of Construction and Maritime Compliance Assistance at (202) 523-8136.

Sincerely,



Patricia K. Clark, Director
Directorate of Compliance Programs