Roof bolt spacing
Series: Procedure instruction letter -- no. I12-V-08
Publisher: U.S. Department of Labor, Mine Safety and Health Adminstration
Published: 2012
Place of publication: Arlington, Va.]
Language: eng
Subjects: Mine safety; Equipment and supplies; Safety regulations; Mine roof bolting; Safety measures; Mine roof control
Notes: Title from subject line (viewed on July 1, 2013).

"Effective Date: 04/19/2012, Expiration Date: 03/31/2014."

"Reissue of PIL I10-V-04."