LOW LEVEL TUNNEL.

Inangahua Times, Volume II, Issue II, 5 April 1880, Page 2

LOW LEVEL TUNNEL.

(To THB EDITOR InaNGaHUA TIMRS.) Sib, — Acting on tbe invitation of %6mUM^ %tff^ i gestion of his letter in your Wednesday's issue, I beg leave to contribute my idea on the alUimportanfc tunnel question, .and while heartily concurring with the dj&fwn' of H " ttfafc tbe fixing of the starting points of the tunnel, as well as its courne in such a manner as will cut the crossing lodes at square angles," I must still differ with him as to tbe Mevatjotv of*4he^ tunnel, 4 'f Sfaa?e-«» ®W^' ilcim^fidsjthat If^e^n^ slraotecl "very much "lower " than tbe proposed 70 feet above the river bed. This, in my opinion, would he a great mistake, as it would, in consequence of tbe, .configuration of tbe ground, neces* iit.t, , m¥s9llnW tffl? §^in!p that a very low level would, perhaps, during heavy floods, subject tbe workings to tbe chances of damage, if not to tbe tunnel itself, at least to any outside ; vfarkf^wjiicji may have to be constructed j ih connection with tbe undertaking; but j tbe principal objection to a too low level would be the totnl loss of tbe drainage water, which could not then be utilised. It must be evident to ell practical men Jhaliiro Tilnnjjtfte fbpdy'Qjf %|tervlnd|* IbdglraenHn fbe country proposed 1 m b&" pierced, and that the tunnel, in addition to tbe generally accepted advantages it will confer, will also act as a gratuitous head-race, likely to carry a considerable and constant stream of water, which can be made a very valuable adjunct to the income of tbe company, as no doubt motive power will become in great demand in tbe vicinity of tbe entrance to the workings. To secure the advantages accruing from this source it will be neces* sary to open out at a sufficient height to allow pressure and room for turbines, for water wheels, crushing and other machinery, dams, reservoirs, etc., to be con* struc'pd in> con|fpnien| and ,f|fe:pl||ej^ an^l^ould^fbf'tlJsS ieaioAl 1 that 70 feet above river level would not he at all to bigb, but would, on the contrary, advocate an additional elevation of 20 or 30 feet, if it could be done without materially interfering with the work already planned, and the loss of a few yards-underfoot would be more than counterbalanced by tbe gains just enumerated. I am, sir, &c, SUTBO. Reefton, Ist April, 1880. j' ■■■''''[