AN IMPORTANT INDUSTRY

Dominion, Volume 10, Issue 2986, 25 January 1917, Page 7

AN IMPORTANT INDUSTRY

NEW ZEALAND PORTLAND CEMENT "THE STUFF TO BUILD WITH' One of the most important industries of the north of Auckland district to be visited by the Parliamentary party, was the big modern works of the New Zealand Portland Cement Co., Ltd., at Limestone Island, Whangarol. As Wt<! world advances tho uses for cement liavo expanded. It was used away back' in the time of the Roman Neroa, but not for the thousand and one purposes to which this valuable product is now put to. Therefore good honest cement of proved quality is as good as gold to a growing communtty such as New Zealand, whilst tho demand for oement after tho war in shattered Europe will he immeasurable. It Stands to reason, then, that any country possessing deposits of liigh quality hydraulic rock must bo accounted fortunate, as it is not common to every land and cTipre. New ZcaTSiyl is blessed in many ways, and it is fortunate in the possession of valuable deposits of this rock, ready to the hand of man to pulverise arid manufacture into cement of the very highest quality. , An Island of Cement., One of the finest deposits is that at Limestone Island, in the picturesque Whangarei Harbour, where the New Zealand. Portland' Oement ' Company) Ltd., has ita works. _ This island, which is one of tlio sunniest spots in New Zealand, consists of about 98 acres, almost the whole of which is pure hydraulic rock of fine quality. Tho company, which owns the ■ freehold, started in a small way some twenty years ago, and the business has expanded gradually with tho growth of the Dominion, until at tho present time there is an impressive output of "Crown" cement, the quality of which is not only known and appreciated in New Zealand, but which has been realised arid profited by in Australia and throughout the ■ Southern Pacific. Cement is just as essential a building material to-day as bricks or timber and everywhere in T/nildii)j[s,' wharves, piers, bridges, towers, culverts, railway works, etc.,. the .reinforced concrete idea has been proved $0 be. that which makes for the greatest,'tensile strength and durability. To-day the demand, for "Crown" cement from the company's works is so great that several vessels, owned by tho company, are engaged exclusively in the trade between tlie works at Whangarei and Auckland. Unfortunately, in one way, tho works were practically totally destroyed by fire some two years ago. That necessitated rebuilding the wholo, of the works and installing a new plant in the mill. Advantage was taken of tho incident to bring everything right up to date, and to-day thero are no moro modern works of the kind in the wholo of Australasia than those at Limestone Island. Tho mill is operated for the most part by electric power generated by compound engines fed by large Babcock and Wilcox boilers, with a low pressure turbino fed By the exhaust steam from tho engines, which is recognised as tho most economical method of working. ' , At the Works. The visitors were shown over tno company's extensive works by tlio manager, Mr. F. T. Vickerman, and tho works manager; Mr. H. B. Washington, and were much impressed by the arrangeriient of the mill, the economical and compact lay-out (so essential where large quantities of material have to be handled), and tho comparative simplicity of- tho process of manufacture. The hydraulic rock, fresh from tho quarry, goes in at one end of the mill in large pieces, and is ground to a fine powder. It is then burned in' rotary furnaces at white beat to clinker, which, after seasoning, is, in turn, ground into the heavy fine brown-grey powder we know as tho cement of commerce. Tho ease and economy of effort with which the cement is bagged, taken from the. bins, dropped on to a conveyor, arid taken straight out to the ship's hold was fully demonstrated to those present. Two men were able to manipulate 450 bags of cement per hour. Those, who know that there is a hundredweight in each bag will realise what good work that is. . The operation is made possible because tho mill is built . alongside water deep enough to accommodate ocean-going steamers. That is a tremendous advantage to the company, and is being made the fullest use of. Who can say what the future holds for such works? Steel and cement will be the two chief building materials needed in the busy years ahead, and, lacking an output of steel —which, owing to .the enormous demands from Europe must be costly for many years to come —cement must be used in this country in everincreasing quantities. One only has 'to refer to the latest population figures to recognise that JS 7 ew Zealand's population is being rapidly augmented, and, as immigration has always occurred after a great war, it is held that the tide of population will set this way in the years to be. Universally Used. ■ "Crown cement" is standard cement. It has been used on some of tho finest and most enduring works in the Dominion. It is used on tho Auckland, Wellington, New Plymouth, Gisborn'e, Wairoa, Whangarei, and Suva harbour works, and by the New Zealand. Bailways, Public Works Department, Auckland, Wellington, and Christchurch City Councils, the Invercargill, Napier, Hastings, and Warigauui Borough Councils, and Rangitikei Road Board, the Fijian Government, etc. Tlie Henry S. Spackmann Engineering Co., of Philadelphia, who liavo a high reputation in the cement world, stated in their report: "The physical test made on this material ('Crown' Cement) shows it to be a high grado Portland cement, 'which satisfactorily conforms to the existing specifications. Its high percentago of fineness should make it an especially valuable cement. Its composition indicates that it is a properly proportioned, well-burned cement. 111 reporting on the three months tests they add: "Tho 1 sand tests show a very gratifying increase in strength, and you will notice there is a continued increase in both the neat and sand test under compression."