FOR BETTER ROADS

Evening Post, Volume CVIII, Issue 17, 21 January 1924, Page 4

FOR BETTER ROADS

RESTAR., LTD., PRODUCTS.

A GROWING NEW ZEALAND

INDUSTRY,

STEADILY INCREASING SALES.

Ten years ago Restar, Ltd., tar distillers, commenced operations on a small scale, but each of the branches at Wellington, Auckland, Wanganui and Uisborne now turns out several hundred thousand gallons each year, and each twelve months sees sales' records established. The total output of Restar, that is, of prepared tar apart from several biproduct preparations, including a disinfectant of excellent quality, benzol, tar paint, creosote, stains, weed killers, and insecticides, tar oils, etc., amounted last year to well over a million gallons. THEORY AND PRACTICE. The theory at the back of the Restar process is to reduce the raw tar to its elements by distillation, working right back to the pitch base, and then to put back just those component parts which are useful in macadam work and to keep apart those which are deleterious. That is not to say that the elements which are harmful in roadmaking are' valueless, for every coal-tar product is of value in one direction or another, and the greater- part of the acids, volatile oils and naphthalene thrown off from the stills in the working down to the pitch and other Restar components, go to the making of one or other of the by» product preparations'. Great heat is used under the pot. stills in which the main process is carried out, the oil-burning jets ensuring in the stills a temperature of between 900 and 1000 degrees Fahrenheit, while super-heated steam, at about 300 degrees or over, circulates round smaller stills in the preparation of the raw tar for the pot'stills or the completion of the process. It is plain that "home-made" boiling cannot achieve results such as. are obtainable with the special plant, for obviously such heat -cannot be generated in any but a special type of boiler, nor, of course, can the useful and the harmful components be separated in a rough-and-ready manner. Once, however, the Hestar process is completed, "homemade" boiling is ample " for actual macadam laying, whether the Restar used.be one of the heavy types particularly intended for road work or the lighter type for footpath and similar work. The reheating is merely a means to easier working. TESTS AND REPORTS. All Restar is prepared in accordance with the specifications, laid down by the British Road Board, spoken of amon" engineers as the "8.X.8.," and tests are regularly carried out by the company's chemists. Some little time ago samples of different batches of Kestar were sent to the Australian Gas Light Company, of Sydney, which has one of the finest laboratories for that class of work South of the Line, and in all cases the reports, which may be seen by engineers who are interested in tar macadam work, were 1 thoroughly satisfactory to the Restar management, and the remarks made by the chemists making the tests were highly complimentary to the growing New Zealand industry. AUCKLAND AND TARANAKI. "We put thhrough nearly half a million gallons for Auckland" last year " remarked Mr. J. F. Holloway, general 'manager of Restar, Ltd., to a "Post" representative, "and as the- Auckland Gas Works were unable to supply the full amount of raw tar required, a supplementary supply had to .be sent up from Wellington. The general policy of the Auckland City Council seems to be to go in for concrete roads in the heaviest traffic thoroughfares, but to lay down tar macadam in the secondary streets— that is, those which carry heavy traffic, though not of the tremendous weight of the main city streets, for instance, the streets of Remuera and Grey Lynn are being put down in tar macadam. Again, practically the whole of the tramway extension work in Auckland is being finished off with Restar macadam. The- real test of Restar is not in the Dominion record order for one year, but in the fact that each year sees a new record put up. An engineer is not going to come back to us if we sell him a 'dud.' " "Quarter of a million gallons of Restar go to Taranaki each year, and 90 per cent. _of the road binders used m that province have passed through our stills. One of the finest highways in the Dominion is a stretch of road between Manaia and Hawera, carrying perhaps the heaviest lorry traffic of any country road in New Zeaalnd, for over it runs the greater part of the dairy produce of the Kaupokonui and Riverdale districts. That road is in the Wainiate West County, where" nothing else but Restar is used, and the report of the chairman, Mr. T. M'Phillips, is that since tar sealing was adopted on the county roads rates have, owing to the saving in upkeep and repair, been reduced by onehalf. PREPARED TAR AND BITUMEN. "It is true that some local bodies are using bitumen as well as prepared tar, but in most cases the foundation is laid in tar macadam and the bitumen is used as a flush coat, and, to my mind, there is, except under special circumstances, nothing to be gained by laying a full bitumen road, though do not think that I have anything against bitumen; as a matter of fact, we sell a good deal of it ourselves. When a local body decides to go in for bitumen it usually purchases a deal of expensive plant and pays particular attention to the state o? the foundation on which the bitumen surface is to be laid, but occasionally an engineer in dealing with a tar macadam surface will pass over the foundation work rather lightly, with the result that the finished road will not be as good as it should be. No road binder will make a road of itself, tar, bitumen, or any other material, all that it will do is to hold the metal together ; and my contention is that, given the same amount of attention to foundation and preparation, a prepared tar, - such as Restar, will give results equal to those obtainable from imported bitumen, added to which are the facts that a prepared tar has a better penetrative value and is easier to handle. Tar can b». efficiently worked at a temperature of 220 degrees Fahrenheit, whereas, with ordinary grade bitumen a teniperatui-3 of as much as from 300 to 400 degrees is required for best results, and without special plant it is almost impossible to maintain such high ■working temperatures. There appears to my mind to be sound enough reason for the laying of the foundation course in tar macadam, with a top coating of bitumen, if bitumen is favoured as a running surface. When, of course, a local body is willing to lay out a large sum in plant and aims definitely at a bitumen road, then, perhaps, that is another matter, but I contend that under ordinary circumstances results that are just as good may be obtained by the use of a properly prepared tar. One of the finest advertisements for tar macadam roads is ii road at New Plymouth ; it was laid down, well laid, nearly forty years ago, nnd to.cjuy shows no aigne of disintegraLUo«, '—Published by. .wiangemeat.