Air Fresh and Salt Water
Although this lid has no date, it is similar to other manhole covers in the Navy Yard that date to the start of World War II and marks the connections of three utilities needed in ship building. The salt water was part was for fire fighting.
The wide gutter grid design with a san-sarif text banner in the center was used extensively in the Brooklyn Navy Yard for various systems.
Special utilities for ship making
This cover was seen on 5th St., and several other identical ones are found across the Navy Yard. Similar ones with different sets of utilities are also found.