NEARLY 1000 TONS SMASHED FROM BREAKWATER

Grey River Argus, 3 June 1948, Page 4

NEARLY 1000 TONS SMASHED FROM BREAKWATER

Damage on South Side of Grey Harbour Although heavy rain and pounding seas ot the last three weeks did little damage inland, a serious consequence was observed yesterday at the entrance to the Greymouth harbour. The Board, when it inspected harbour works, found that for a distance of 2t> feet from the end of the southern breakwater the sea had under-, mined the workings, and these had fallen down. Only about three* feet of the work remains on the river side of the breakwater. This is being endangered toy the further undermining action of the sea. The portion of the construction which has suosided was completed in recent years. It appears rnat this heavy concrete woik, placed on top or the lime stone blocks which had been tipped into the water around the original breastwork, has not had a sutriciently strong foundation to withstand the action of the seas, the limestone material having possibly proven unequal to the needs or the structure. Partly due to the solution of the rocks by the sea water, and partly due to incessant sea pounding and undermining, the works have weakened and finally collapsed. It was estimated by the Harbour Board Engineer, Mr D. 3. Kennedy, yesterday, rhat about 600 tons of rock and concrete is involved in one slip at the end of . the breakwater. Around this he proposes to erect temporary boxing and to fill the subsidence with concrete, thus consolidating the ; mass of broken rock, which might otherwise be driven into the river mouth, thus narrowing the entrance still further. Inside the breakwater, about fifteen feet from the end of the subsidence, there has taken place a slip ot the limestone rocks supporting tne breastwork. This was caused by solution and battering. The material has slipped down to join the present apron at the harbour mouth. Other large rocks in the same vicinity are expected to crumble soon, and this has been put in hand by the engineer. Repairs are at present being carried out.. Referring to this matter in his monthly report, Mr Kennedy said that ho more limestone should be used on the works. He stated that a strong and heavy head was required now that no immediate extensions were necessary. It was proposed to fill bags of cement and wall off a section for placing mass concrete. The engineer added that only concrete and granite should be used on the rocks.