Mare Island Naval Shipyard, Explosive "D" Loading Plant, Railroad Avenue near Palmer Avenue, Vallejo, Solano County, CA

Significance: Built in 1939, Building A187 is one of two remaining World War II-era projectile loading plants. The high explosive material known as Explosive "D" (Ammonium Picrate) would be received from Building A265 (Explosive "D" Shifting House) where the material would be shifted to remove foreign matter. The explosive would be loaded into trays and delivered to Building A187 where it would be carefully pressed into the Navy's large caliber projectiles, layer by layer, until filled. Building A187 is a contributing element of the Mare Island Historic District having fair historical integrity with approximately 60% of the original building existing.
Survey number: HABS CA-1543-AE
National Register of Historic Places NRIS Number: 75002103