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Show i BRITAIN'S HUGE' TIDAL - POWER PROJECT , Since tho mechanical potency ot a bead ot water first was known, en- lneere hae gazed with covetous h vyvn upon the almost infinite cncrjjy p ot tho tides, and Bchcmca of all de- y, i- Krvcs of practicability have been pro- ', 08ed for the salvage of a modicum f f j of that wasted power for the work r 1 of civilization. Most ot these rather i' fanciful suggestions have been ua- f ble to survive the test of practical I mechanics and the whole idea has rc nialncd in the comfortable but un- f inogresslvo stage of a "development of the future." From this category however, It now appears to have I been sudenly removed, by the ah- ' nounceraent from no less authoritative authorita-tive a body than tho British ministry' ' I' f transport, of remarkably comprc-l benslve plans for an enormous tidal i power plant on tho estuary of the Ser 1 cm river, between England and h Wales. f The Severn project calls for a us-nblo us-nblo output of 50,000 hy, continuous- i . ly for ten hours a day, requiring the r Installation ot two complete plants, V with the stupendous total rating of more than 1,500,000 tip. It is tho aranrgement of these two separate , power plants for cooperative action that constitutes the ingenious fea- lure of the plan. . P Tho rirst work to be undertaken f would be the construction of reiti- I lorccd concrote dam extending latot- I nil)' from each shore as far as the fi central channel and then turning up I Hi ream along Us sides and terminat ing in a lock large enough to accommodate accom-modate any vesbel. In tho lateral part of this wall It is the Intention to hang automatic sluco gates, opening open-ing Inward when thctlle presses (igalnst them and then closing to proven tho escapo of the Impounded water. Built Into the parts of the' ft jff) dam paralleling the channel will be the power plant Itself, equipped with a si huge battery of vertical mlxed- J flow turbines, 10 feet In diamoter, A . tho channel serving as their tallrace. a These will have a working period of Huven hours, beginning with a 5-ft. i hcadsoon after the tide, begins to' ebb, reaching a maximum i$0-ft. head ' In three and a half or four hours, " tf Ith a possible drop of 10 ".ft. In one ., libur and'lhen dlmlssblng until there Is a flvio hour period of no Operation . nt all. ' - .: ' .:.- With ihls changing head ,the tur- '' bine-speed -would vary between 40 1 t)d -80 r. p. m. Direct current fi- 9 erators of separately excited typo 1 " 'type will be driven through) helical 1 " Keating at 300 to D00 r. p. jn. asd will develop a constant voltago ot 025, with a varying current output I controlled either automatically or oy nn attendant. The current will bo used to drive largo rotary converters-delivering converters-delivering alternating current at 330 olts, and this will be stepped up by transformers to 60,000 volts for transmission. Not less than 1,000,- 000 hp. will be tho maximum output of this plant. Ten miles fom this huge installation installa-tion Is tho proposed location of the secondary plant, of over 500,000 hp. maximum capacity. It Is on the bank of the river Wye. a Severn tributary, tri-butary, near Tlntem Abbey, and its main feature Is a concrete dam across a neighboring valley, forming a gigantic gi-gantic storage reservoir at a considerable consid-erable elevation above the river mouth. Between this artificial lake and the Wje, a tunnel of 10 feet diameter di-ameter Is to le driven through sol-1 id rock for more than a mllo. Tho plant equipment, as planned, consists 1 of a bank of 13,000 kw. alternating current motors, of a type operable al-m al-m as generators. Or these machines 00 per cent will be of tho Industlon type and the remaining 10 per cent synchronous. They will operate at 'a speed of 375 r. p. m. at 2,200 volts pressure. This enormous group of electrical .machines will nbsorb all the current ho primary plant generates In excess of the first 500,000 hp., which will bo distributed for Industrial puipos-oh. puipos-oh. Thus at tho peak of the tidal head, when the estuary plant Is producing pro-ducing 1,000,000 hp. or more, tho poweiful motor s of the secondary plant on the Wye will bo running to ,full capacity. Paul II. Woodruff in ,1'opular Mechaulcs Magazine. |