THORNDON SEA WALL

Evening Post, Volume CIX, Issue 116, 20 May 1925, Page 5

THORNDON SEA WALL

EXCELLENT PROGRESS

NEARLY ACROSS THE BIGHT

The rapid progress in the construction of-'the. great Thorrido'n sea, wall across the Kaiwarra Bight will have been evident for the past year to "all whose daily journey s into arid but of town take 'them in that direction. Tlie wide staging, like a long jetty in itself; has crept up across the stretch of open water, until now it is, so to speak, within a. stone's throw of the Kaiwarra shore. Oh top. of it runs a travelling transporter with its load of fresh concrete to deposit in the boxes below the level of the water and form the wall Which the "staging bestrides, back and forward r'vms the transporter from the concrete mixer, which, at the Thorndon end, churns up the cement, gravel; and water into a rich, porridge, periodically shot into the bucket, of ah elevator, which drops it again into tlie bins of the transporter, as this.backs in under) rieath. Thus through..the day the work moves. .

,-. A visit *9 :.Wle.scene, of operations shows how. expeditio'usly the contractor, Mr.'.C. F.. Pulley,, is getting on with a big job, with.the aid of a. -\v ell-devised plant. The whole works like a machine* The gravel is brought in scows, from the Hutt Eiyer delta, and landed by an elevator in a great heap, into which, a steam shovel delves by ..the .yard and swings round to drop its., load in a round tower from which it shoots in measured Quantities down,into, the mixer along a, common channel into which cement by the bagfull is c&b to niake up the required proportions for the concrete.. The concrete itself, to anyone with an eye ior concrete ; , is excellent stuff. From the mixer it-is lifted up to be dropped into the transporter, which conveys it to" wliere it is wanted along the long line of wall. Some may be going into tlie foundation boxes, laid by divers on-'the Sea bottom, aii'd securely locked to the piles, so that it will stand immovable .to receive .their burden of concrete. Some,, again, may be going to fill up the regular gaps left .in the wall, the top step of which is sticking up like teeth above the water level.

Meanwhile, the staging is pushed forward with _ the pile-driver planting the jtpii'es ever in advance of the Wall, itself. The total length of. the sea wall ih a straight line across the bight is 2709 feet arid the., staging lias., already, advanced I ov'ftv 2600 feet, and the wall .beneath it nearly as far. The wall, itself will not run straight to nie'et the Kaiwarra shore, but will turn at tile distance mentioned aiid run parallel With the beach another 720 feet, making the total length of Wall sb'nie 3400 feet. This involves .a quantity of'concrete, ambuiitiisg tb 62,000 i cubic, yards. Of this anlbunt 37j000 1 yards' are ,'alr'ady ih place after about 17 n>bnt!)s"actual-w'o'rk; apart from thn time rrt<|uired for assembling and. constructing the, plant. • At any rate at which the concrete is beihg placed ih position— | some 3000 yards a month—aliother.year i should see the work approaching coiiii p'fotjon. at a r time "Well ih/a'dvuhce, 'of the original cbntta'ct pei'ibd. The wall lias reached now-what is appareiltly• .the dpfepest part of. tho bight neatly, .36 feet bi>lo\v low water. . The width p'f tlio wall at the.base is approximately 211 feet; arid it iiiounts tip in three step's to about high Wiite'r level, -gradually' tSpering ih ve'r; tieal cross-section. Tile, top port-ion; ii fourth 4tep, about fdur fetet above higliwatfer,,is Ihiil compared with the lh'assivo prpp'ortibh.i of. the lower strata; While the wall is. being constructed, the wbi'k '6f reclamation,, carried out by tli'e Harbour. Board rls'elf, is . prbceediit>' ii) such 'a^y/ay as hot tb interfere' with tttb pr'pgr'e'ss of the eontrael. Into a sort oi baSiii-, niad'e by the Prie'stinaii:dredger, spoil from the board's big dredge is puhiped aibiig large kieU pipes lying lind(iiv the- p'reSerit. reclafeied ..land. This spoil is a Sbi-t of iba bdzfe from .ttife bottom of. thS harbour; and; if aliqwe'd td spread, niight fdul the' inundations cjeaii; 'ed by the cbril'ractdr fbi- His sea wall. As it ft; the spoil,fldws ihtd the pi-ep'ared basin far, a>v'ay from where, the foundations bf the wall havE how Been exienaed, - I- ■

The- area ehcrb'sed by, the sea wkll is so lhrge^-bverVOßc'rel—that a^ the present rate of dfejibsit. it will take a. good many years to reclaihi;; but, if the Tawa Flat railway 'deviatibh is carried out, spoil frbni- thS tuhiiels under the hills might enable the reclainatibri to be accelerated. lii :lhy .'case.tlie tbtistructibh of the sea' wiilj will always . rank a§ a nbtablS a'chievbmeiit ih harbour bbnstrgstibh ahd a. inbdel of iiiithbd and organisation in tackling a big engineering job.