Where the height of the substructure and necessary placement of equipment does not permit a full six and one-half feet (6 1/2') vertical height above ground level, the maximum height available shall be used, but in no case shall it be less than four feet (4') above the ground level.
Beams of the substructure and pipe lines may be permitted horizontally across the passageway at ground level if an unobstructed vertical clearance of at least three feet (3') above such beams or pipe lines is maintained. Beams of the substructure or pipe lines shall not be permitted longitudinally within the two feet (2') width of the passageway.
Cal. Code Regs. Tit. 8, § 6577
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.