Volume Twelve - Pre-Victorian to the Present Day - further aspects - Petroleum-Storage Installations at Avonmouth and at Cardiff [1890] . . . .

Storage Department

A line of 6-inch wrought-iron screw-jointed filling-pipes is laid from the dock to the tanks along the surface of the ground, and is fixed upon strong wooden carriages to keep it in position. At the dock end is a stand-pipe similar to an ordinary water-main stand-pipe, or suitable bends are provided, which can be readily connected with a flexible hose-pipe from the steamer. At the other end of this main filling-pipe a branch with screw valves is taken off to each tank.

The tanks are circular and constructed of boiler-plates riveted together with lap-joints as in an ordinary gas-holder, the large ones being 64 feet in diameter and 30 feet high, the smaller ones 47 feet in diameter and 26 feet high. The bottom is made of ⅜-inch plates, with 4 inches by 4 inches by ½-inch angle-irons.

The sides are formed of seven tiers of plates of uniform width, the first and second being ⅝-inch thick, the third and fourth ⅜-inch thick, the fifth 5/16-inch thick, and the sixth and seventh ¼-inch full.

The tops are of 1-inch plates, supported on angle-iron frames and principals (Fig.10). They rise 6 feet in the middle, forming a dome, and have four raised man-holes 24 inches in diameter, provided with hinged covers which can be locked.

The attachment of the side and bottom plating to the angle-iron at the base is by a double row of rivets, as is also the case with the vertical seams of the sides, but all other longitudinal seams are single-riveted.

The edges of the plates both in the bottom and in the sides are planed, and the work generally is equal to the best boiler work. All joints are made iron to iron, and caulked inside and out.

Each tank is provided with a disk or false bottom, 3/16-inch thick and 66 feet in diameter, which rests upon a bed of thin boards and sand, interposed between it and the foundation, in order that the tank may take an even bed (Fig. 14, Plate 7).

The smaller tanks, 47 feet in diameter, are made in the same manner, except that the thickness of the sides is slightly reduced.