§ 211.36. Temporarily located Class A magazines.

 (a)  Temporarily located Class A magazines shall be constructed as follows:

   (1)  Walls of No. 14 gauge metal. If the exterior walls and roof consist of sectional sheets, or the equivalent, of approximately No. 14 gauge metal securely fastened together, the walls and ceiling shall be lined with 5 inches of dry, white oak wood, and the metal floor shall be lined with a tight wood floor consisting of a minimum of 1 inch of tongued and grooved lumber, or the equivalent, securely cemented into position. The wood lining on the sides may be replaced with 5 inches of dry, clean sand, or with 4-inch thick solid concrete blocks or 4 inches of brick or weak cement mortar, provided that these alternate lining materials shall be faced on the inside of the magazine with not less than 3/4-inch thick, exterior grade plywood or the equivalent, and provided that the inside surface of the metal wall shall be lined with a minimum thickness of 1/2 inch of exterior grade plywood. These magazines shall be supported on secure foundations such as wood posts, brick piers equivalent cribbing of railroad ties, or the like. Reference should be made to §  211.35 (relating to permanently located magazines). If these magazines consist of modified over-the-road trailers, the tires need not be removed.

   (2)  Walls of 1/4-inch welded steel plate. If a magazine consists essentially of a welded steel box with a flat or sloping top, that is a roof, fabricated from 1/4-inch steel plate, it shall be lined on the sides and top with a minimum of 4 inches of dry white oak wood and the bottom shall be lined with a tight wood floor consisting of a minimum thickness of 1/2 inch of exterior grade plywood or the equivalent, securely cemented into position.

   (3)  Walls of 3/8-inch welded steel plate. If a magazine consists essentially of a welded steel box with a flat or sloping top, fabricated from 3/8-inch steel plate, it shall be lined on the sides and top with a minimum of 2 inches of dry white oak. The bottom shall be lined with a tight wood floor consisting of a minimum thickness of 1/2 inch of exterior grade plywood or the equivalent, securely cemented into position.

 (b)  The following applies to all temporarily located Class A magazines:

   (1)  The foundation shall be constructed according to the specifications set forth in §  211.35 or by securely mounted cribbing of railroad ties or the like.

   (2)  Buffer rails shall be installed in accordance with the specifications set forth in §  211.35, except that 1-inch by 1-inch nailing strips is permitted.

   (3)  Magazine doors shall comply with the specifications for doors set forth in §  211.35.

   (4)  The wood lining set forth in subsection (a) for the sidewalls of temporarily located Class A magazines may be replaced with 5 inches of dry, clean sand, with 4-inch thick solid concrete blocks, or with 4 inches of brick or weak cement mortar, provided these alternate lining materials shall be faced on the inside of the magazine with not less than 3/4-inch thick exterior grade plywood or the equivalent, and provided that the inside surface of the metal wall shall be lined with a minimum thickness of 1/2 inch of exterior grade plywood.

   (5)  Adequate ventilation shall be provided with suitable means to prevent ingress of sparks or burning embers, rain, snow, leaves or stray rifle bullets. If magazines of the types set forth in subsection (a)(2) and (3) exceed 10 feet in length, they shall be fabricated with two ventilators in the roof, and one ventilator on each side and on each end. The ventilation openings shall be placed in or near the ceiling and as close to floor level as is practicable.

   (6)  On trailer type magazines, there shall be a minimum of two ventilators on each side at the bottom as near floor level as possible, and there shall be a minimum of one ventilator on each end and on each side as near as possible to the top of the trailer.

   (7)  All nail heads shall be countersunk and filled. No metal may be exposed within the magazine in locations that might come in contact with explosives containers or explosive materials.

   This section cited in 25 Pa. Code §  211.37 (relating to Class B magazines).