Inside this dark building, located near the water in the Ammunition Depot of the former Mare Island Naval Shipyard, sits banks of battery charging stations. Sadly, there is little information published about most of the buildings in this section of the shipyard. I am not certain what the batteries were used for, but a number of signs point towards a forklift charging station and maintenance building.
Base facilities included a hospital, ammunition depot, paint and rubber testing laboratories, schools and four drydocks. During WWI and WWII, the shipyard constructed almost ninety vessels.