SOUNDING AT LYTTELTON

Press, Volume LXXXIII, Issue 25304, 2 October 1947, Page 3

SOUNDING AT LYTTELTON

PURCHASE OF ECHO APPARATUS

REPORT TO HARBOUR BOARD

A recommendation that recording hydrographic survey echo sounding apparatus be installed in the launch Ruanine, put forward by the Lyttelton Harbour Board’s resident engineer (Mr A. J. Charman) and the harbourmaster (Captain A. E. Chrisp). was adopted at a meeting of the board yesterday. In a report to the board, the two officers said they were of the opinion that some improved method of sounding was necessary, and that the hydrographic echo sounder was the apparatus to provide that improvement. If it was installed in a suitable launch, all sounding in the dredged channel, turning basin, and open parts of the inne • harbour, together with most of the sounding round the wharves, could be done more quickly. While it was not claimed that the echo method was more accurate than the hand lead system in moderate depths, the advantage of speed enabled work to be completed during a brief spell of fine weather, the report con-, tinued. A closer examination of the sea bed was made, and a better coverage provided by the echo methqd of sounding. It had been proposed that any future pilot launch should be,fitted with echo sounding apparatus. The officers recommended that the apparatus be installed in the Ruahine, and that if a pilot launch was obtained, certain equipment, such as built-in oscillator tanks, be installed so that the recording apparatus could be used in either launch, as the Ruahine was more suitable for sounding in confined spaces. The estimated cost of one complete set of apparatus was £906, and the cost of additional equipment to make possible the use of the Ruahine or a large pilot launch was estimated to be £lOO. Commenting on the report. Mr R. E. Cairns said it was time they had something of that type. It was badly w<&ited at the port. He moved that authority to obtain the apparatus be given. “I am certain it would be a wonderful addition to the equipment of the port,” said the chairman (Mr W. S. Mac Gibbon). Mr F. W. Freeman: It is only 10 years overdue. The Rangatira had it when it first came out. The report was then adopted.