In older installations, in which the basins were relatively small, the dock structure was built mainly of massive stonework, or in a few instances, heavy timber framing.
Stability calculations of the quay walls within an enclosed dock are important; in older installations such calculations may have been based on the continuing presence of water at the designed normal level, and in the event of a serious failure at the lock resulting in a considerable drop in the water level the stability of the quay walls could come into question.
Scale insulates water in older installations from direct contact with lead.
The show features a series of new paintings that record the design of these important symbols of American might, including older installations that hark back to more hopeful times, and others that take on a more paranoid, bunker-like aspect.
In some countries, different color codes apply to wires, especially in older installations.
Five of the paintings were previously known only from old installation photographs.
Among them is Sonya Blesofsky, a 32-year-old installation artist with a studio in her Williamsburg home.
Robert Kolb, a 33-year-old installation and service supervisor for Comcast's Xfinity television, phone and Internet service, has a one-year certification in network engineering.
It is a small, old installation with few recreational outlets in a neighborhood of Washington that is unwelcoming to patients' families.
By midyear, more than 10,000 people will be working at the 65-acre walled compound, which was acquired by the Navy in 1799 and is its oldest installation ashore.
