Land of Possibilities.

Auckland Star, Volume LIV, Issue 129, 1 June 1923, Page 9

Land of Possibilities.

HUGE INDUSTRY DESCRIBED.

Cement Works at Portland. WORKERS' MODEL COLONY. (By Our Special Commissioner.) XVL

WORKERS' MODEL COLONY.

(By Our Special Commissioner.)

XVI.

The cement making industry has reached very large proportions in the Xorth Auckland peninsula, and Wilsons Company ha? an output of Tj.OOO tons per annum. The works, which are the j lamest of the kind in the Southern Hemi- j sphere, are thoroughly up-to-date, and j compare favourably with anything of the i kind in the world. They arc situated at I Fortland. a few mile- from Whangarei. where the company have 2000 acres of land, containing large deposits of lime- j stone rock, lv fact, the area of the I proved workable limestone formation is ! no less than "50 acres in extent, and it has been estimated that there is'sufficient limestone on this property to sup- ' ply the requirements of the Dominion for 1000 years, if the rock were mined from above sea level only. Investiga- ' tions, however, have disclosed the fact • that the rock extends at least 200 feet below the level of the sea, so that some . idea may be gained of the enormous deposit in sight. The company was originated in ISSo. but the works at Portland were built by j American engineers and taken over in j 101 S. The property was then a barren- i looking wilderness, with perhaps a dozen cottages dotted aDout. To-day Portlard may be regarded as a workers' modern colony, containing more than eighty comfortable villas, mostly built of concrete. Electric light is installed throughout, and-a water system is now being . inaugurated, the supply heing taken I from Otaika from the Whangarei borough mains. The population of Portland has reached 602, half of this number being engaged at the company's works. A public school has a roll of 115 pupils, and . a teaching staff of three. Nobody who visits Portland can have other than good words to say for the way the company has provided for tbe welfare and com- | fort of the employees of the works and their families. There aro modern stores, a post office, boarding-house, bachelors' | barracks and a large ball in which, under | the direction of the Y.M.CA.., pictures are screened twice a week, on the unique basis oi 5/ per month for a family, or in the alternative 2/ per week. All profits are utilised for purposes connected with the welfare of the district. There are three buildings given over to the single men oi the town. In two of these htrfldings provision is made for 4S mcn — j -i in each; while eight men arc housed in t'ne third. Electric light is installed, and hot and cold water showers. Concrete tubs for washing clothes are also provided. A billiard-room containing two tables is -very much in use when work ceases for the day. Seven acres of land were recently set aside for a recreation reserve. This is now being "hroken in"' to grass, and when a permanent pasture is established it will be a valuable asset to the workers. Portland is not the only property of the company. Limestone Island, where the original works were established. although not in use now, is still regarded as a valuable asset, while, the company's works at "Warkworth are in full swing; at the present time. The company owns the "Wilsons collieries at Hikurangi, from which all requirements are drawn: an electric power station at the Wairua Fills, and its own steamships. The value o: the plant is estimated at approximately f.W0.000. The works at the present time are working to full capacity '75.000 tons per annum I. of which 1000 tans are consumed weekly by the local market Tbe works are four times tbe Sl zc of any other cement works in the Dominion, and constitute the largest cement making concern in the Southern Hemisphere. VISIT OF INSPECTION. I was a member of a large party that Paid a visit to the works on a recent occasion, and Mr. T. H. Wilson, tbe general manager, showed ils over the proPetty and explained all tbe processes of manufacture." The main features of the residential area were Brst of all outlined. »Ye then boarded trucks and were hauled ■•J locomotive along the company's line ot railway to a large quarry in the direction of Oakleigh. It wa? in thjs quarry that the largest explosive charge ever »M in Xew Zealand quarrying operations was recently fired. The drill holes _ ere visible in places on the face, and a 'air idea was conyeved of the weight M rock dislodged, which has been computed a 5 approximated 100,000 tons, j-team navvies were at work on the '?P. er a "d lower levels loading trucks with the rock, each shovel having a rapacity of two cubic yards. A Gilbert nn T- 5 Workin S ""'the upper level. ores being put i„ f or another"explosion. U the most recent mechanical methods ,' 6 ™ _*< tfa e works beinsr in every wav . P atl°r' d , ate - Ea " h ' la >- 45 ° tons <>" f ™« 1 * Peered "" »"•! on treat_ll\ th £ >' lpl 'l of cement is 230 tons per ■tin. Returning from the quarry tbe ftpfi !o!Wed xh < manufacture, from to th v ProCess of ""us!,in S the rock up reanV ' °"' ns of the finished product readbV° r .' !l 'P ment - S l '"ga were in . foisting the bags into ed irf m the event oi " hein g lQ adfflto vessels at the end of the wharf oW Z. a m " c lon S', built rio-ht out into <*ment X ,As mU(,,, a? 275 ° tons of in 1 , . o< "* n loadp ' 1 this wharf hh_T_ slll P mc nt. The trucks which 4rrv fi" 6 rr ' Ck from the q"arrv each hintw 6 - T ? n3 and are tipped'into a « that feeds the main crusher. There tie m n in f,IP ?dme locality for 'eb„7! P ' X ' n nf mi,> - "-bich has'also ~ * Wound mto f |„-. This coal comr;.--:, • , . . ' " : r:; ■•■-

to 100 tons per day. In addition, from 40 to 60 tons of white or agricultural lime from the company's works at Waro J Rocks. Hikurangi, is also listed amongst ;the daily arrivals. This lime is essential ,in the manufacture of cement, being j used in a proportion of roughly 12 per icent of the whole. ! After the first crushing the rock is I conveyed by a broad belt elevator to the secondary crushers. Here an elec-trically-driven crane hoists the proper quantity of Waro limestone to be added ,to the hydraulic lime rock. In the [secondary crushers the stone is ground Ito the size of marbles. It is then conveyed to two cylindrical rotary kilns. ' slightly declined, which revolve' slowly and arc heated internally. It then goes through a reducer and emerges as fine dust. Afterwards it i< placed in larger rotary kilns and on to huge furnaces. Coal powdered very line i< blown into these furnaces by powerful fans, the enormous heat of 2SOO degrees I Fahrenheit being generated. An electric pyrometer nearby registered 385 degrees centigrade in one furnace and 475 degrees centigrade in the other. Examining the "white heat" through blue glasses gives extraordinary results. The coal dust being pumped "in looks like a spray of gas in the upper chamber while the molten cement below can be seen rolling and dropping like globules of. mercury. It rolls down to a lower chamber and is cooled into "clinker,"' to be subsequently recrushed in puller mills, each with a capacity of 200 h.p. During the final pulverising pro- i cess about 3 per cent of gypsum is added to regulate the setting property of the cement. In the electric power bouse we were shown a wire no thicker than a lead j pencil carrying 22,400 volts from Wai- , nia Falls, seventeen miles distant. The I current is conveyed to reducers and broken down to 400 volts for reticula- j tion to Whangarei fl-nd Kflmo. A UNIQUE PROCESS. Mr. Wilson pointed out a site where ; preparatory work is being done for the ' establishment of a larger mill. The capacity of the existing mills i~ four tone per hour, while the now mills will deal with treble that quantity. There is a huge storage building with a capacity of 6000 tons, the bagging being done mechanically. This is a unique process. The bags are printed in a machine and then sewn at the tops with the exception of one corner. Through this opening in the bag a nozzle is inserted and the cement blown in. The supply is automatically cut off as the bags receive the correct weight. When filled the bags drop on to a travelling lied and are conveyed to trucks for store or shipment. Some idea of the modern methods of working may be gained when it is explained that 500 bags per hour can be filled in the manner described and as nui<ii a> 750 tons has been ( loaded in one day. . i In the company's laboratories the visitors were shown how the correct proportion of Waro white rock is calculated for addition to the hydraulic lime obtained from the Portland quarry. The fineness of the cement is standardised by passing samples through a remarkably fine mesh containing 40.000 holes to the square inch. Pondered coal, is also passed through the same sieve and 00 per cent of it goes through the mesh. It is necessary that this should be done in order to get the great temperature of 2SOO degrees Fahrenheit needed in the furnaces. An exnlanp.tion was made that after roasting hydraulic lime to all the properties of lime were lost. When the "clinker" was ground again cold, 86 per cent had to pass through the fine mesh a? a test of standardisation. Three per cent of gypsum was then ; added to give sotting properties. j A series of physical tests is carried out in the laboratories. Pats of cement j are made from every batch dailyThey are boiled, cooled, and tested I for strength and by this means the chemists are able to* tell in about six hours what the cement ■will be like in a | fortnight's time if left to set naturally. I There are a number of delicate balances in which specially made bricks, being at one point a cubic mcli, are inserted and by the addition of small weights, including shot, the crushing and breaking point, calculated at ton* to the inch, can be reckoned. There are many' other tests that check the quality ot the output and make sure that the manufactured article is up to the standard. A visit to Portland is most mstruc- j tive Visitors are impressed not only ! with the hugeness of the enterprise. but with the way in which a modern company cares for the welfare and happiness of it? numerous employees.