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Hokitika Guardian, 7 August 1925, Page 3

Concrete telegraph poles have been m use in some parts of New Zealand folio years, and of late months a good deal of interest in this type of structure has been manifested by the various electric power boards scattered through the country. However, m spile of an inclination on the part of some boards to adopt this type of pole, the opinion of most engineers is decidedly against it (states the Auckland “Herald”). Even in the course of erecting the poles, cracks and defects have been known to develop, while numerous hair-cracks occur attei the poles arc in position, due to the lateral stress. These hair-cracks absorb moisture, which lends to corrode the steel reinforcement, subsequently causing the strips of the concrete to disintegrate and break oil. To prevent this corrosion, it. has been found necessary in Auckland to repaint the poles with concrete and plaster up the defects. If one pole is called upon to hear a sudden stress, such as might occur through the wires being struck by a falling tree, it is not only likely to break, hut is bound to cause damage to a large number ot other poles further along the line. In contrast to this possibility. Hie case is mentioned of an ironbark pole, which, mootin' sudden strain of this kind, iK-nt over at, an angle and tore itself completely out of the ground without breaking.