BUILDING A DOCK.

Dominion, Volume 2, Issue 402, 11 January 1909, Page 6

BUILDING A DOCK.

,~ « — HOW THE CONCRETE IS TREATED. Passing along by Te Aro Railway Station it a late hour,, one's ear is hit by sounds of peculiar, quality—rattling, clanging, and unmusical, likea rain of lead falling on a roof of iron. It is, continuous, and calculated to disturb, the slumbers of any stray garrotter who should chance to.sleep, in the vicinity ' of the morguo. _ ' ' . " In the morning the noise still battles in onoco's attention, and following it, the inquirer finds that it proceeds from the con- . Crete mixer which has been erected to do the vrork of mixing concrete for tho dock works. A reporter who evinced a desire to understand the machinery was courteously shown over the,works. The building which contains tho plant is 1 a three-storied one, the *top story being devoted to the work of placing tho various sizes of shingle into their proper compartments.' For this purpose the shingle, which,comes from tho quarry ready screened into the various sizes, is carried up from the trucks in an elevator, which is much - liko a 'small bucket dredge. . As the buckets reach tho-top they deposit their load on an endless belt, which in turn drops it into the right compartment. 5. This endless belt is only a foot or so in width, and is quite flat, yet the gravel does not slip off, for tho same reason that/ water does not spill out of a bucket which is being swung round quickly. In all, there are sis compartments, fivo for . tho various grades of metal ranging from " 'arf a brick" to a pebbleVand ono for sand. Down on the first floor of.the building the mixing really Btarts. Under tho various bins a man pushes a truck containing six compartments, and each one of theso is filled in turn. Starting from the far end ho pushes his truck into position, and then pulls a slide,-when coarse shingle shoots down and fills one compartment. And so' on 'until the last division is filled with sand. This done tho truck is pnshed over tho i shoot down which the metal travels to the mixer. A look is taken to seo that'the-y;ater—.which has already been measured off into a small tank —is ready, and tho cement bags are close at hand to bo emptied with the other i ingredients for the pudding. All safe, and the bottom is taken from tho truck, the water 1 turned on and the huge-mixing "churn" starts to revolve. As the mixing is done the concrete is shot down into trucks, which are waiting in readiness to take it out on the staging. Theso trucks, which are hauled out by a small cable system, aro specially constructed for tho work of depositing the con- ■ creto into the huge boxes prepared for its reception. Theso boxes are very largo, being about 90ft. in length by 27ft. wide and 7ft.' deep. 'If the concrete had to drop through water for'any distance without any covering all the cement would bo sifted out, render- , ing its useless; so the N trucks have canvas coverings for the top, and aro thus lowered by-a derrick until near the bottom. When low enough the bottom \of tho truck, which is composed of two wings, is opened by means of a rope connected with the derrick, the concrete is deposited, and the truck is hauled I up again to be dispatched for another load. ' It is calculated that when working under ' good conditions almost 200 square yards of concrete can bo mixed in a day of eight hours. Tho work, which has just reached completion, after tho working of night shifts, is the laying of a sill for a small dock on the outside of tho larger construction.