Timber for Mining Purposes.

Cromwell Argus, Volume 2, Issue 92, 15 August 1871, Page 6

Timber for Mining Purposes.

A question has lately been raised aC Ballarat as to the safety of split timber as compared with round timber used for cappieces in mining claims. Some experiments were made by Mr Seijeant, legal manager of the Band and Albion Consols Company, with the following result, as given by the Australasian of June 17 : " The tests on Saturday were—No. 1 split, 19|in., broke at 6 tons 6 cwt. ; No. 2, round, 21£ in., broke at pressure of 5 tons 9 cwt.; No. 3, round, 23in,, broke at 7 tons 8 cwt. The test was a most crucial one, because, instead of the weight or power being distributed equally the cap experimented upon, as would be the case if it was sustaining dirt, the whole force of the hydraulic ram was applied to about ten inches of the centre of it, The timber experimented upon was, so far as the round pieces went, the very best and heaviest in the yard, and in this respect had the advantage of the split, that the inferior pieces of the split timber seemed to be much superior to the inferior pieces of the round. There was no attempt made to distinguish the varieties of timber; and the relative strengths of gums, stringybark, peppermint, or messmate, and whether the pieces tried all belonged to one variety or not, did not transpire. Given, timber for timber, of equal quality and equal girth, the experiments do not show much advantage either for split or round in so far as actual resisting power goes ; but there were two very noticeable features in connection with the test which require notice. When the round timber reached its maximum strain it broke across the grain of the wood, and about half-way through, with a loud report; and as the water was let out of the ram, the timber showed it had little or no spring left in it, whereas the split piece gave several slight cracks as intimation of its going, and when it did succumb the fracture was one of longitudinal splinters, also about half way through the body of the wood ; in this respect especially the split timber appeared to be far safer than the round, as it would not only give more warning of its going, but would go more slowly than the round when it could no longer support the weight abova it. The next feature was that these sjnlit caps will, if placed with the wide or sap side to the weight to be supported, carry a heavier weight than if placed with with the sap side down, and the same peculiarity also is observable in them as between the round and split caps. If the heart side of the timber he placed next to the power exerted to break it, the sap side breaks with a sharp report across the grain of the wood ; while if the sap side be placed next the power, the heart side splinters off into longitudinal strips, and shows a greater tenacity after it is broken."