MAIN SOUTH ROAD

Evening Star, Issue 21835, 26 September 1934, Page 14

MAIN SOUTH ROAD

GOOD METAL DR NOT? ALLEGATIONS REFUTED Our issue of Saturday last contained an article dealing with the class of stone used for the construction of the HenleyMilton section of the Main South road. The article stated that the stono used had been obtained from Clarendon quarries Numbers 1 and 2, and suggested that the stone used was quite unsuitable for the purpose of road-making. Since the publication of that article reliable information has been supplied to us which makes it clear that the statements therein made were unfounded and contrary to fact. Photographs of the Clarendon quarries accompanied the article, which did not give a fair indication of the stone faces because of the fact that they were taken at a distance. The views now shown give a better representation of the Clarendon quarries.ft is regretted that the article was published on such misleading information. Copies of reports by Dr P. Marshall (petrologist to the Main Highways Board) have been submitted to us, from which the following facts and opinions have been extracted : No. 1 Quarry.—French co-efficient 16.7. Remarks: A very fine grained basalt with much magnetite and no olivine. No pore space. Abrasion and toughness extremely good for a volcanic rock. No. 2 Quarry.—French co-efficient 17.5. Remarks: An extremely good stone. Fine grained. Heavy and unusual toughness and hardness. The Public Works Engineer at Dunedin (Mr T. M. Ball) assures us that the stone from both Clarendon quarries has, after test, been found to comply in every way with the requirements of the Main Highways Baord. Mr Ball further states: — “The quality of the metal is beyond question, and has been specially commented on by the board’s petrologist as being amongst the hardest s to lie obtainable in the district, the French coefficient of wear ranging from 17 to 19, whereas the specifications called for not less than 10. This more moderate requirement was specially designed to enable stone to be obtained from other

sources if obtainable at a reasonable price.” The statement in our previous article that examination of the bins showed that material suitable for garden soil had been included in the output delivered in the highway we believe to bo entirely without foundation, and an unwarranted reflection on the contractors.

From the report of experts and the contractors, we now think that taxpayers need have no fear that the material from the Clarendon quarries, which has been placed on the foundation of the Heiiloy-Milton of tiie Main South road to carry the bituminous surfacing is other than suitable and durable.