THE WORLD’S GREATEST WATER-POWER.

Taranaki Herald, Volume LXI, Issue 144198, 15 September 1913, Page 6

THE WORLD’S GREATEST WATER-POWER.

There is nothing particularly spectacular about a dam only 50 feet high. A thread of foam leaping 1000 feet into the air, as in the Ycsemito, strikes tho popular imagination, but the Mississippi at Keokuk, penned behind a barrier over which a boy could almost throw a stone, eooms useful, perhaps, but not thrilling. And yet tho great Keokuk power plant, opened tho other day, is so huge that to evaluate it justly one must Imrn aside from ordinary precedents. The concentration of a ( third of a million horec-powcr in a single development, whoso power-house alone is more than a quarter of a mile long, requires unusual methods, and tho designers of the plant have had the daring, tho resourcefulness, and the capital back of them to employ those readily. Savs tho editor or tho Electrical Work (New York) in substance:— ‘•To begin with, the Keokuk development is by far tho mightiest lowlionet proposition over undertaken. Tho' Mississippi is not a precipitous stream, and it was sheer good fortune, tho result of a geological freak, that enabled even so modest a head as 32 feet to bo utilised without absolutely prohibitive expense. Tho first striking feature of tho plant, the single-runner colossal vertical-shaft turbino, is the direct consequence of tho low bead. Generally ono tries to get a fairly high generator speed bv using multiple runners. In this ease the largo output required very largo units to avoid outrageous complications, and the enormous volume of water to he dealt with for each unit forbade the complication of multiple runners on so low a head, bo gigantic aro tho turbines that the scroll chamber delivering tho water to tho runner is nearly 40” feet in diameter and is simplv moulded in concrete. Similar considerations apply to tho generator design, each being more than 31 feet in diameter. “The main transmission lino from tho Keokuk plant is operated at 110,000 volts to deliver energy to St. Louis, 144 miles distant. This lino presents no extraordinary features except thoso of magnitude. There are two circuits of 300,000-circ. mil cable carried on steel towers sot at a normal fijpan of SOO foot and provided with a .stool ground cable, us is now common, For tho care of tho lino a special telephone lino is erected at tho edge of tho right-of-way on its own poles, with telephone booths every four miles. Tho general supply of energy is just beginning to get under way, and the possibilities of tho situation havo as yet barely been touched. All told, -tho Keokuk enterprise is a huge one, with great output, high cost, and immense possibilities of industrial usefulness over a largo and prosperous territory,” ■ From a descriptive article in another part of tho same magazine, wo learn that the dam is nearly a mile long and creates a lake Co miles in area, "really improving river navigation. There is a lock, for vessels, as wide and high as any of thoso at X’anumu, a Government dry-dock—tho largest in fresh water—463 by 150 ft., and a driveway 30 ft. wide along tho top of tho dam. Dam, power-house, locks, and walls are one huge monolith of concrete over two miles from tip to tip. Tho receiving sub-station to' transform and distribute St. Louis’ share of tho current alone is tho largest in existence. Tho very cones of tho transformers weigh 30 tons a piece. To quote tho writer’s words: —

“No more description cau give an adequate conception of tho magnificent magnitude involved in tho work at Keokuk. Although there are other water-power plants whose future extensions will bring them within tho range of its horse-power capacity, these are chiefly high-head installations whose physical scale can hardly bp compared with tho Inigo hydraulic structures necessary to wrest 300,(XX) horse-power from tho 32-feet fall available in tho Des Moines Rapids.”