Sign 17 - 8-Inch Pouring Building

The most dangerous work of loading shells was carried out in the pouring and filling building. Here, small quantities of explosives, in total just a day’s worth, were delivered continuously. Cleaned, empty shells arrived by conveyor belt from the receiving building. Ammonium nitrate, a white crystalline solid stored in two separate buildings located just west of the carpenter shop, was crushed to a fine powder. Then it was transported to the kettle rooms where it was mixed with molten TNT in large vats. The kettle rooms were separated from other areas of the building by heavy fire-walls of brick, some of which still stand today.

The explosive mixture, known as amatol, was then sent to extruding machines or pouring buckets which workers used to fill each shell. Heavy concrete walls separated these filling machines from each other and outward-swinging doors were placed directly opposite workers’ stations in case of explosion. Safety chutes were placed in front of second story doors to also provide quick egress if needed. Ventilating systems kept the air free from noxious fumes and gases.

Filling the shell was not as easy as it sounds. Once the amatol was melted, the empty shell was filled about two-thirds full. As the mixture cooled, a crust formed which was immediately broken and a second filling took place. This two-step process prevented the formation of cavities within the explosive charge. Cavities were known to cause incomplete or entire failure of detonation. The hole for the booster was either drilled out or was created by plunging the booster into the shell filling before it cooled.

The pouring and filling building was the largest of the three buildings in the production line and had an irregular footprint. Of the four that were built, only one is accessible. The others are surrounded by swampy marshland. Visible today are 20-feet high brick walls, 5-feet high concrete piers, and concrete bunkers. One-foot high concrete foundation walls, 10 inches thick, define the perimeter. Most of the concrete floors appear to be intact.