REMOVAL OF CLAY FROM RIVER

Press, Volume LXXXVIII, Issue 26868, 22 October 1952, Page 3

REMOVAL OF CLAY FROM RIVER

SUGGESTED USE OF SPECIAL BOAT

To remove clay from the Heathcote river, it had been suggested that a river sweeper, similar to that used in both the Avon and Heathcote rivers some years ago, might be used to push the accumulated silt downstream into a previously prepared silt trap, from which it could be removed by dragline, said the engineer (Mr E. F. Scott) in a report to a meeting of the Christchurch Drainage Board last evening. Investigation had show that it was unlikely that there would be regular and continuous use for a sweeper, but there were still quite a number of places where such a machine could at times be used, he said.

For a sweeper of the size proposed, the machine required would be a diesel-driven high-pressure pump drawing river water from the upstream end of a pontoon, and discharging it through two nozzles on to the bed of the river at the opposite end of the pontoon, Mr Scott said. The unit would cost up to £l5OO when installed. Before an order was placed, it was proposed to make trials with a jetting pump or trailer pump unit. On Mr Scott’s recommendation, the board decided to buy a pontoon at a cost of £425 as a first step towards making trials. Mr Scott said that quotations had been obtained for a pontoon which had been specially designed so that, if necessary, it could b- used with the Estuary dredge or, with another similar pontoon, could be used to carry a dragline.