NEW BRIGHTON BRIDGE.

Press, Volume LXV, Issue 19690, 6 August 1929, Page 10

NEW BRIGHTON BRIDGE.

CITY ENGINEER'S SCHEME.

borough not in favour

The New Brighton Borough Coun-i cil declined to consider the erection j of a four span bridge over the Avon j instead of a three span one when the suggestion from the City Engineer (Mr A. R. Galbraithj came before it at last night's meeting. The City Council's letter, embodying the proposal, claimed the following advantages for it:— (1) The original width of waterway would be reverted to at the minimum cost. . . (2) Proper provision for a regatta course would be made, because two central spans of 30 feet clearance would permit of two eight-oared, or other ix>ats, racing abreast. (S) The elimination of the proposed embankment over the silt bank on the southern side would materially assist in the prevention of silt accumulation. (4) The river and bridge would have a considerably better appearance. "I think we had better just receive the letter," commented the Mayor (Mr J. H. Shaw). "The question is settled so far as this Council is concerned and we do not. I think, desire to reopen the matter." This course was adopted. Mr H. F. Toogooi, consulting! engineer, asked, by letter, that the replies of the local bodies contributing to the bridge concerning the clearance be expedited. The Mayor explained that the Tramway Board was the only body concerned which had not leplied, and it was considering the matter. The City Council had not replied officially, but the Council knew its opinion. The Harbour Board appeared to be in passive agreement It was resolved to reply to Mr Toogood in these terms.

HARBOUR ENGINEER'S OPINION.

The Engineer to the Lyttelton Harbour Board, Mr P. W. Fryer, submitted to yesterday's meeting of the Board the following observations on the plans for the New Brighton bridge:— "I have examined the outline plan of the above-mentioned bridge, forwarded by the New Brighton Borough Council. This proposal provides for a bridge of three spans, having a total length of 74 feet between centres of end piers. When this matter was last submitted to the Board in February, 1923, alternative designs were put forward for bridges 94 feet and 74 feet long respectively. The Board's Engineer then expressed the opinion that the longer of the two should be erected, and I am in agreement with that opinion. The length of the present bridge is 128 feet. "The proposal now under notice provides the same water space as the shorter of the two previous proposals, and therefore shows a very considerable reduction in width as compared with that of the present bridge. Apparently, the designer had in mind the fact that the width of the river at this point is already constricted by a mud bank on the west side. This bank, however, is covered at high tide, and there would therefore be a further constriction of the effective water space at that level. I would expect that the proposed reduction in width would encourage the further deposit of silt on the banks in the dead water immediately above and below the bridge, andso further reduce the effective water space at high tide. This might slightly affect the escape of flood water from above the bridge. The scour in the middle of the stream and against the banks on which it impinges at bends above and below the bridge would probably be slightly increased. However, as these effects would not adversely affect the depth of the navigable channel, they are, I presume, matters for consideration more by other parties concerned than by this Board, which I understand is mainly interested from the point of view of protection of rights of navigation. "The present bridge has a clearance of three feet three inches above H.W.0.5.T., and the plans under consideration indicate that it is proposed to increase this to five feet three inches. "As the proposal has been given considerable publicity, it seems fair to assume that the absence of objections indicates that the latter clearance is satisfactory to present users of the river for navigation purposes." The report was received.