ELECTRICAL INDUSTRY

New Zealand Herald, Volume LXXII, Issue 22108, 14 May 1935, Page 5

ELECTRICAL INDUSTRY

DEVELOPMENTS OVERSEAS ADVANCES IN TRANSMISSION REPORT TO AUCKLAND BOARD Various aspects of the development of tho electrical industry overseas were reviewed by Mr. R. H. Bartley, general manager of the Auckland ElectricPower Board, in a report submitted to the board yesterday. Mr. Bartley recently returned from a trip to England, the United States and the Continent, and his report was the second of a series he is preparing to put before the board. The transmission of electric power had made a verj r rapid advance, Mr. Bartley said. A great deal of time and money had been spent on the insulator design and general research work, with the result that the insulator of to-day was a very reliable and efficient part of the transmission system. Voltages had crept up and up until 230,000 volts was now looked upon as a standard in the United States, in Canada and on the Continent. In England there had been no necessity to standardise on sucii high voltages as the transmission distances were much shorter. Line Protection and Repairs "These very high voltages aro carried on overhead lines, using for the greater part steel towers similar in construction to those us;ed in N6tV. Zealand." Mr. Bartley said. "The same applies to the 132,000-volt lines in England, although it is not uncommon for these voltages to be transmitted by underground cables where special instances and circumstances demand it. With these high voltages and important transmission lines, line protection is - a very vital factor and this has been developed to a very high state of proficiency." An interesting point was that even with such high voltages a vast amount of repair work and adjustment to these lines was carried out by the use of special appliances, without in any way disconnecting the line or interrupting the service. It was not an uncommon thing to find a whole section of insulators replaced with new ones, and the line kept in service during tho whole period. Distribution Systems Distribution overseas followed very much the same lines as had been adopted in New Zealand, and rural g distribution was almost exactly simi- % lar, wooden poles and, in some places, \ steel and concrete poles being üßed to support the overhead lines. As far as he could gather timber seemed to predominate, with sterel or steel-fab-ricated poles a very close second, and concrete in a very few instances, al-y though he observed that -in certain parts of Australia concrete was most generally used. This might seem peculiar on account of Australia being the home of hard timber, but the reason for the adoption of concrete poles was the ravages made on hardwood, and on timbers generally used for poles, by the white ant. This pest would honeycomb the pole < in a very 6hort time and its destruction could not be observed externally, the result being that there was always a danger of a timber pole giving tray without warning. The Opening-up of Roads "I made a special point of inquiring in the United States, Canada and England concerning the practice adopted in opening-up roads and footpaths for the laying Of cables and other publio services, with a view to improving, if possible, the system adopted by us in Auckland," Mr. Bartley added. "1 find that in each instance notice to carry out this sort of work must be served on the city authorities and a prescribed number of days allowed before the work is commenced. The city authorities endeavour to co-ordinate the various notifications and. by this method prevent a considerable amount of duplication and unnecessary work. "I gather, however, from the opinion# of those concerned that the arrangement still leaves much to be desired, and it results in duplication no doubt due to emergency requirements and other causes which necessitate the opening up of roads. It is still questionable, in my opinion, whether any better method can be devised other than that adopted by us. and we sire certainly no worse off, according to tho observations I have been able to make, than our friends overseas."