WESTERN WHARF COLLAPSE.

Auckland Star, Volume LV, Issue 283, 28 November 1924, Page 7

WESTERN WHARF COLLAPSE.

MOVEMENT IN THE MOUND. DISCUSSION ON THE DIRECTION .MR. HAMER RE-EXAMINED. The principal feature of yesterday* inquiry into the collapse of the western wharf was the questioning of the engi necr to the Auckland Harbour Board (Mr. \V. 11. Hamer) as to the direction in which the rubble mound (built alongside the wharf) would tend to move, and in this he and the. commissioners expressed different opinions. Mr. Haiuer was recalled, and in the early part of the examination reference was made to a letter which he had written from Philadelphia to the board in reference to the wharf. In this it was suggested that it' piles were driven the stone hank should be put in and the piles allowed to adjust themselves to the conditions. Asked whether he anticipated some difficulty, witness replied that he had had a previous experience of a pile canting, and he thought it wise to take the precaution he suggested. Mr. Williams: X°u did not feel an . T discomfort that there would be any outward movement of the etonc when it settled ?—Distinctly not. I felt that there would be only vertical settlement. After drawing attention to the triangular shape of the mound with the long side running to sea, Mr. Willinms contended that in the event of any movement the centre of mass must go outward. Mr. Hamer: I looked to no forward movement of any kind. Mr. Williams: We have evidence of that forward movement now. .Mr. Hamer: Wo have evidence of the top of the mound hulg ing out and in places coming in con tart with the piles. I have looked 01 the rubble mound as a separate entity I insisted on the wall being made 01 loose rubble. I wanted it to have al the time possible to settle. Mr. Williams: The reason we art pressing this is because. It thaT actior is not taking place, then the rubblf mound is npt a menace, but if such action is taking place, then the mound is a menace?—Of course, Mr. Williams we are talking of conditions after the event. I have not considered we would have any lateral pressure in this mole or mound of any kind whatever. It was for that reason that I stressed in my letter from America that we ought to bench the ground and pet it as nearly vertical as possible. Here you have got a great, big, deep mattress of stone bedding itself together. Yes (observed Mr. Williams), but it is not like a mass of concrete in a fixed position. It is a flexible thing which must move. —Again, after the event (replied witness), it is possible that that might be so, but I doubt it very much, and I doubt if you could find evidence of it in any part of the wall which stands to-day. Mr. Furkert*: You admit the pressure here moved the Avail?—l admit that there is a bulge in the wall. Mr. Furkert: You would not have expected the bottom to have moved in against the piles if the mound were not moving?— There was settlement. Mr. Furkert: Settlement would not harm at all. TT you admit this mass of stone get 3 smaller, then the centre of mass must move outward? —1 looked upon it as a solid mass settling down vertically. Mr. Williams: It is a universal experience that there must be a move ment of the centre of mass. Mr. Hamer: What amount of movement would you assess. Mr. Williams: I would not like to assess it. If 1 were set an examination paper on the question 1 do not think I could give an if.-urate answer. Mr. Hamer: 1 don't think you could. Mr. Furkert: But it would be very considerable. Witness went on to say that in hi* many years' experience of stone walls he did not know of any creeping forward. Mr. Williams: Was it not important that you should have detected any slight movement in the banks you observed? —No. Mr. Williams: It would have been going on though, but in most cases it would not matter. Mr. Furkert: The only point is that in this case something of a riyid nature was attached to it and made the movement apparent. The board's engineer then remarked that in his early experience he had contemplated putting in gravity walls, but they were out of the question on account of the expense. When he was able at economic cost, he put in agravity wall. The inquiry then adjourned until this morning, when a round of inspection of various works and wharves was made.