New Hampshire Code of Administrative Rules
Saf - Department of Safety
Subtitle Saf-C - Commissioner, Department of Safety
Chapter Saf-C 5000 - DISPLAY FIREWORKS
Part Saf-C 5019 - DISPLAY MORTARS
Section Saf-C 5019.01 - Requirements for Single Fire Trenched and Reloadable Mortars

(a) Single fire and reloadable mortars shall be constructed of non-fragmentary steel, aluminum, or other material approved by the commissioner, of not less than 1/4 inch in thickness, and shall be capped at the base by a threaded or welded cap. Wood plug base ends shall not be permitted. Cast iron, stove pipe, corrugated culvert-clay, PVC, bamboo, and wood shall not be used to make mortars.

(b) Single fire mortars up to 10 inches in diameter shall be buried in a trench at least 18 inches apart to a depth of not less than 3/4 of their length. In no case shall the protrusion above ground exceed 8 inches. The trench shall be provided with a wooden base planking that shall be equivalent in width to the largest diameter mortar used. The portion of the mortar tube extending above ground shall be braced with 6" x 6" wooden timbers or their equivalent placed on both sides of the tubes and firmly secured together by wood or metal connecting straps. All remaining space between mortars shall be filled with firmly tamped rock-free sand or earth.

(c) For the purposes of paragraph (a) above, a material shall be approved by the commissioner if the licensee can demonstrate, through documentation provided by the manufacturer, that the material can withstand forces equal to or greater than the forces that non-fragmentary steel, aluminum, or other materials previously approved by the commissioner can withstand without displaying any fragmentation.