WARNINGS OF FLOODS

Press, Volume XC, Issue 27302, 19 March 1954, Page 12

WARNINGS OF FLOODS

DEVICES SUGGESTED TO DEPARTMENT (New Zealand Press Association) WELLINGTON, March 18. Two "promising ideas” for devices which eauld warn trains nearing the Tangaiwai bridge that the river was in dangerous flood, were today outlined to the Tangiwai Board of Inquiry by the Railways Department’s chief engineer (Mr A. H. Murison). The proposals were: (1) A light suspension bridge with an arm or arms hanging from it. If the river rose above a certain level the water would flap a hinged portion of the arm or arms, and so set ofi an Alarm. (2) A photo-electric beam between the two banks of the river in a gorge upstream from the bridge. If the ray was obstructed by water which had risen high, an alarm would be set off. Mr Murison said that, though he had used the word fantastic to describe some of the suggestions made by 92 persons who had written to the department, the principles underlying these were generally fairly sound.” Mr Murison said the simplest suggestion offered consisted of a solid concrete block at a predetermined level in the stream. On the top of the block it was suggested a log of wood be placed. When that, or even the block, carried away, a contact would be broken and a warning given. Mr Boys; Has consideration been given to a suggestion from a number of people who regard it as within the bounds of possibility that diverse channels and dams could be erected dose to the bottom of the main boulder fan that comes down the mountain, so that excess water could be diverted into that wasteland area to the east of the river? fir Murison: I have given no conWCOTtum to that. Murison said that other suggejans envisaged warnings modelled cn the ordinary type of flood gauge.

but that would not be an efficient warning for a lahar, he said, as it would choke up the gauge and make it inefficient ;