These vessels are cylinders, topped by shallow spherical or elliptical domes and incorporating a dome ring. Post tensioning tendon systems are installed separately for the wall and the dome.
The vertical wall tendons run from the tendon gallery below the base mat to the top of the dome ring. Dome tendons consist of three families located 120 degrees apart and anchored on opposite sides of the dome ring. Circumferential tendons are anchored at the buttresses.
These vessels are cylinders, topped by a hemispherical dome. This design eliminates
the need for a dome ring. The vertical and dome tendons are combined into an inverted "U" shape running vertically from the tendon gallery over the top of the dome and down the opposite wall to the tendon gallery below. Circumferential tendons are anchored at the buttresses.
The lower one third is a cylinder. Above, the vessel is shaped like a truncated cone with an open top, capped by a steel cover. Prestressing tendons run vertically from the tendon gallery and terminate either at a shelf located on the side of the cone or at the cone's top. Circumferential tendons encircle the cylinder and cone and are anchored at the buttresses.