DESIGN:
The simple grid design was used for many underground access points with the actual utilities simply written out.
UTILITY:
SALT WATER lines were part of an older system to provide unlimited amounts of water from the East River in case of fire. The AIR was presumably high pressure air used for riveting and other work during ship repair and construction.
RANGE:
There are a number of covers with this style throughout the Navy Yard, and occasional uses UWS around the city.