3-Bat Cupola Specs DQ1 2026-0355.pdf

This is a technical specifications document for the Colorado Inactive Mine Reclamation Program, specifically detailing bat cupola grating requirements for the PKAA Dream Canyon Project in Colorado. The specifications provide detailed engineering requirements for shaft grate modifications that incorporate an alternative bat cupola design. The cupola system is constructed using 2"x2"x¼" angle iron framing material, with specific grating specifications including 1¼"x3/16" bearing bars spaced at 1 3/16" on center, ¼" round cross rods spaced at 4" on center, and type WXA (19-4-53) grating material. The cupola shall extend a maximum of 6" above the shaft grating and must be welded to a framed opening. Cross rods are installed on the inside of the cross rod side, with every other bearing bar tack welded to the grate frame. The opening in the shaft grate must be framed with 2"x2"x¼" angle material, with the minimum cupola opening dimension specified at 24".

No information regarding pricing terms, contract duration, bid response dates, site visits, or bidder conferences is contained within this specifications document. The file serves solely as a technical attachment providing detailed dimensional and material specifications for the bat cupola construction, intended to guide contractors in the design and fabrication of the shaft grate modification component for the Dream Canyon Project reclamation work.