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Lyttelton Times, Volume LI, Issue 5577, 7 January 1879, Page 4

The railway bridge over the Bangitata is a puzzle to the general public. It appears to have been constructed with a complex object, which, on the principle of killing two birds with one stone, is much to be commended in bridges as in other things. It would, however, be more satisfactory if one could understand this complexity somewhat better. But in the absence of any official, .list there is nothing for it but guesswork. The primary object of the bridge is, of course, to carry the railway trains over the Bangitata. That is obvious to the meanest capacity. It is different with the other objects which were present to the view of the designer of this unfortunate structure. To reach them we must embark on a wide sea of conjecture, To judge by the results, one object of this bridge seems to have been to find ceaseless repairing work for the railway department. From this point of view the structure becomes a kind of machine for the production of perpetual motion. . A flood unsettles one portion; the workmen begin to drive piles; the papers are filled with paragraphs; the bridge is put right. Another flood comes, down drops another portion; more paragraphs and more workmen; and so the thing goes on in endless fashion. The department mends and the department hopes it will be the last time; the department mends again and the department hopes again; and so on da capo without prospect of ever coming to a stop. If this is not perpetual motion, it is something very near it. Another object of the designer of this bridge was perhaps to have something always new, something to remain in its first youth, something to remind him of the ever - green forests of his adopted country. If so, he has succeeded. It is certain that there will never be any rotten timbers in this bridge. It may be termed the recurring bridge pf Canterbury. A fourth object suggests itself, viz., to build a bridge for the sole purpose of carrying its supports. In other places the supports carry the bridges, or at all events go a long way in that direction, but we are at the Antipodes, and therefore most build bridges with piers banging to them. It shows the power of mind over matter. The idea is therefore grand, but the experiments have net yet proved quite satisfactory. When success crowns the efforts of the engineers, the Legislature will pass an Act for placing carta before horses. Which, of these objects is the true one it is impossible to say. The only thing certain is, that the bridge jus always getting wrecked. One reason assigned is that the piles were not driven deep enough into the bed of the stream, because the piles were found unable to penetrate the great boulders which obstructed their passage to the necessary depths. ” The monkey hammered the piles at one end, the boulders ground them away at the other; the piles were left between two stools, and the first flood: washed them away.” This is a theory* put forth to account for the constant breaking down of the bridge. It it is true, then we need only ask tho railway engineers how many thousands of piles they must drive by way of repairs before they satisfy themselves that wood is not, by several degrees, as hard as rock. There is talk of a Commission in some quarters to enquire into all these matters. Tho best Commission would be a commission to somebody to build a new bridge on a different principle. We want less experiment and more durability.