THE HELENSVILLE COLLAPSE.

New Zealand Times, Volume XXXIII, Issue 5352, 23 May 1878, Page 3

THE HELENSVILLE COLLAPSE.

An 'engineering disaster, nearly as bad as the collapse of the Brunner bridge, was ro< ported in opr telegrams from 'Auckland the other day’~aa having, occurred at the Helensville terminus! w.Tho -/Star furnishes the following full account of the accident’:— I'Engineers and workmen- connected with the filling-in behind the breastwork of the new railway' wharf and, 1 terminus at Stewart’s Elat, have been' astonished, after a week’s depositing ol stulf, to see ,tho apparently immovable array. Of largo piles and massive woodwork, against which the earth waii being fhfown, gradually’' break up and g}vo V/ay. ■fhe partial wreck visible is of so astounding a character, ’that 'it' requires Ho bo seen to bo properly 1 understood or believed. <‘ In order to form some idea, of the appearance jof things, imagine l a long row of nearly 700 feet’ of-pilaa driven "along tho edge of the Kaipara,river. On the land side of the piles, tho "tide Hows ovcr.somo .hundred feet more or

less of mud, and into this mud two other tiers of piles have been driven. From the principal row in front substantial beams or ties are fastened, and in order to form a substantial terminus, the engineer’s idea was to fill up the spaces between the outer piles and terra firma with earth, and the following is a statement of the timber used The breastwork will show how effects have been miscalculated. Ttie outer piles are 3D feet long, each 12 x 12, at the commencement of the breastwork (the place Where it is in partial ruin). They are driven clown into the mud a distance of 23 feet. The two inner rows of piles are, each, pile from 12 to 20 inches diameter, driven in 20 feet (also burst away). The ties or braces, two to each pile, are 35 feet in length, 12 x 6 (these arc broken in two or torn off). The sheet piles, 5-inch stuff, are gone out of place with the rest. Only some 100 feet of space has had earth thrown in, and a portion of this extent of breastwork, with its formidable looking timbers, is forced four feet or five feet out towards the river by one week’s filling in, and as above-mentioned presents a moat pitiable sight (for the engineer who fathered the scheme). This portion was considered most secure, as the piles are driven in ■so much deeper than any other part of the 680 feet, in the centre of which they are driven oniy 15 feet, thus offering less resistance. The prodigious strain to which the whole would be subjected must be enormous, if true that it will take 30,000 yards of .earth to fill the whole space ; only 100 tons have done the present mischief. The fact that 200,000 ft. of totara, all heart, has been used in Ibis structure will render future notion of interest to the public. Mr. Heart, tho inspector, has been a terror to timber merchants, behaving throughout been exceedingly strict in passing timber—on one occasion condemning 15 out of 20 piles. This proves the yielding of the structure not to be attributed to inferior materials. A Wellington engineer is said to have planned it. By coming to Helensville at the present juncture lie will see the huge timbers gaping with rents, and split asunder —a scene desolate in the extrema (from such an engineer’s point of view), while the two pile-driving machines stand erect upon tho structure, in silent condemnation of the enormous blunder perpetrated. Further operations are stayed pending instructions from the Engineer-in-Cluef. It is likely that the remainder of the breastwork will be strengthened by means of fresh piles and extra land ties. A few men are at work with wheelbarrows, wheeling out the earth which has already been thrown in, in order to prepare the way for remodelling tho damaged section. Mr. Brets, foreman, was the first to observe the -shifting -of the timber, and acquainted the inspector, who at once waited ou the resident engineer, the result being that work was stopped at this important place, and upwards of twenty men discharged. It is understood that Auckland engineers disapproved from the first of the plan of carrying out this work, but Wellington brains had the preference.