§ 503.12 Manholes; Barricades; Air Supply
   (a)   Barriers, barricades or standard guard railings shall be provided for guarding open manholes, hand holes, gratings or excavations. Visual warning devices shall at all times be provided for such barriers, barricades and guard railings. Such warning devices shall be visible to vehicular traffic at least two hundred (200) feet from such openings. Testing equipment shall be provided and a standard procedure established by the employer, contractor or person in charge to determine the presence of air contaminants or a deficiency of oxygen.
   Air contaminants or oxygen deficiency shall be controlled, minimized or purged by one (1) or more of the following methods:
      (1)   Removal at source by local exhaust ventilation;
      (2)   Removal by general ventilation;
      (3)   Removal by dilution ventilation; or
      (4)   Respiratory equipment furnished by the employer which provides protection equal to or greater than that approved by the U.S. Bureau of Mines, where there are air contaminants or where there is a deficiency of oxygen in the air. The air or oxygen supplied to a supplied air helmet shall be of the positive pressure type. The air supplied air helmets or other supplied air breathing apparatus shall be filtered.
   Ladders shall be provided for entering or leaving a manhole, vault or other similar underground area.
   The fixtures to which lamp sockets and plugs are attached will in all cases, be explosion-proof, vapor-proof, moisture-proof and dust-proof. All extension cords shall be made of heavy duty cord. All lamps shall be guarded.
   (b)   Where safety equipment is provided as outlined in subsection (a) hereof, it shall be the responsibility of the employee or employees working at or in the manhole to use that equipment.
   (c)   No person shall move or remove any barrier, barricades or standard guard railings, as provided in subsection (a) hereof, except where necessary to complete any work in and around such opening and only by persons authorized to work at the site of the opening.
   (d)   The employer, contractor or person in charge of work in and around any open manholes, hand holes, gratings or excavations, and their agents on the job, shall at the conclusion of work for that day, where feasible, replace any covering previously removed during the course of the work, or if not practicable, then by securely placing a temporary barrier across any such opening, and provide the visual warning devices required by subsection (a) hereof.
   (e)   However, the aforementioned provisions requiring the testing for air contaminants or oxygen shall not apply to any open hand holes, gratings or excavations that are less than five (5) feet in depth.
(Ord. No. 769-76. Passed 4-12-76, eff. 4-12-76)