TESTING TIMBER

Wanganui Chronicle, Volume LXXXII, Issue 19477, 21 December 1925, Page 16

TESTING TIMBER

FOR ELECTRIC POWER POLES For some time past Mr N. G. McLeod, engineer to the Thames Valley Power Board, has been conducting experiments with a view to testing the durability of certain timbers under varying conditions. Poles for electric power lines are at present, obtained from Australia, and the demand keeps on increasing, and with the diminishing supplies it is necessary for Power Boards to look well ahead. The Thames Valley Power Board in carrying out its experiments is endeavouring to learn whether New Zeal'and-grown timber is durable enough if treated properly for their purposes. The poles were obtained from the State Forestry Department plantations, Rotorua, and’ are all Australian specimens of eucalypti. The poles have been sunk sft in the ground and 9ft apart, and have been in the ground nine months. No perceptible change is expected for at least five years, and the tests will probably not*be completed in 20 years. The first line of poles were of stringy hark. Before being placed in the ground they were charred and dipper in hot creosote. Six different specimens were treated in this manner. With the next line tests are being made with the object of determining the relative durability of the top, middle and lower portions of a tree. These polos have received no treatment at all. The third lot of poles have been given one coat of hot preservative. The varieties of eucalypti include muelliriana, oblique, onata. risdoni and eugcniodcs. The land on which the tests are being made has been placed at the disposal of the Thames Valley Power Board by Mr F. M. Strange, Mangaiti.