PERFECT ROADBEDS.

King Country Chronicle, Volume V, Issue 407, 25 October 1911, Page 6

PERFECT ROADBEDS.

INTRODUCING A NEW SYSTEM

A special meeting of the Newmarket Borough Council was held last week to consider tenders in connection with the borough street improvement scheme, for which the ratepayers recently voted £30,000. The tender of the British Tar-road Company was accepted for the tarred macadam work, which is to be carried out, and also for tarring and sanding the footpaths of the borough. It has been decided that the council will undertake the foundation work in connection with the roads, and also the scarifying. The British Company's tender has been accepted for laying the final four inches of bituminous metal. The contract price is 2s per yard, and with the added cost of formatiun, which the council undertakes, will work out at a total cost of 3s 3d to 3s 6d per yard. The successful tender for the tarring and sanding of footpaths was at the rate of 3d per yard for one coating, or (id for two. The thoroughfares for which the contract was let include Carlton Gore road, Khyber Pass road, that part of Manukau road extending from the Royal George Hotel to the Parnell boundary, and the Remuera road to the railway bridge. The council further decided to at once call for alternative tenders for the reconstruction of the main road between Remuera road and Khyber Pass road, in compressed Lilhofeldt asphalt, jarrah wood blocks, or Neuchatel asphalt. Newmarket will be the first borough to introduce the bituminous metal system into New Zealand. The firm, which has been given the contract has operated very extensively and successfully in other parts of the world, claiming to have introduced a system which gives a metal bound macadam »road which is dustless, mudless, silent, durable and non-slipping. The mayor of Newmarket (Mr D. Teed), in discussing the matter with a Star representative the other morning, said that the question of what constituted the best method of establishing model thoroughfares in New Zealand wa3 still a matter giving municipal authorities serious trouble and consideration. Newmarket, in going thoroughly into the problem, had studied the methods of other places outside the Dominion. The use of tar as a factor in road construction had engaged th° attention of engineers only for the past six years. At first tar spraying was adopted, but it proved to be'only a palliative, and not a cure. In 190b", at the Paris Congress of Engineers, it was recognised that to be effective the metal would have to be incorporated with the tar. Subsequent operations proved that this method lacked durability simply because the tar used was to a certain degree soluble in water, and this was fatal to good results. The new system which is to be adoptsd by the British Company in Newmarket is entirely different to the old, as it was found that in order to get durability, not only was it necessary to use tar from which the more volatile and soluble matters had been extracted, but a bituminous substance would have to be added to give it plasticity. This compound, when boiled, had to be added to the metal. So that instead of making roads of ordinary tar and cold metal, with dust, etc., inter-mixed, the material was prepared in a machine which heats and cleans the metal, and mixes it with a compound containing 40 per cent, of distilled tar and Trinidad Lake asphalt. At the congress held in London last November, added the Mayor, this system was unanimously adopted, and so satisfied were the engineers with its durability that practically every country in Britain had adopted it in laying down their main highways. The cost in the first place was not expensive., and maintenance was not a big item. For instance, in Cheshire, before adopting this shcenie, the cost of keeping up the main roads totalled £76,000 per year. Now it had been reduced to £19,000 per year. The streets in Newmarket to be formed, scarified, and treated in this way will only cost from 3s 3d to 3s 6d per yard, which Mr Teed says is no more than it has cost to follow the old scheme of throwing scoria on the roads. A start is to be made immediately after Christmas, and when the contract is completed the Mayor is convinced that Newmarket will be the least dusty and best roaded borough in New Zealand.