Abstract: A sewage digester cap for use with a generally cylindrical tank, the cap held in place by a series of concrete anchors to ballast the cap on the digester. The anchors are suspended from the cap by a series of steel cables. The cap includes a liquid sealing skirt of a length to maintain the liquid seal in the presence of a high liquid level within the tank. The cap has removable anchors allowing the digester to be adjusted to accommodate different gas pressures inside the tank by using different ballast weights. The anchors remain submerged even when the maximum liquid level is reached allowing for increased gas storage with minimal pressure change. Additionally, the anchors provide a lower center of gravity for the cap which also reduces the tendency of the cap to tip in the wind or other atmospheric conditions. The cap is removable to allow for cleaning, maintenance and disassembly for relocation of the cap.

Abstract: A structural support member formed of a plurality of tubular members positioned to shape the structural support member in a desired form, e.g., an arched form. The positioned tubular members are permanently affixed to a base plate at one end and a nose plate at the other end, and the combination is layered by fiber-reinforced material to form the structural support member. Assembled plurality of structural support members can be interconnected to form a skeleton which can support a cover. Custom-sized structural support members are produced without the need for a mold. An additional embodiment utilizes an inflatable bladder as a mold around which the fiber-reinforced material is layered, the bladder then being deflated, removed, and reused. Custom-sized structural support members are thus produced in any shape desired and can also be assembled in group to form a skeleton which supports a cover.