MISHAP TO DREDGE

Grey River Argus, 14 March 1940, Page 12

MISHAP TO DREDGE

REPORTS, TO HARBOUR BOARD. The following report on the recent mishap to the dredge Mawhera. was presented to the Greymouth Harbour Board last evening by Captain H. Moar (Harbourmaster): I have to report the accident to S.D. Mawhera, the circumstances of which are as follows: — < Wednesday, 6th., 8.30 a.m.: Left lagoon and came up river and took 4 trucks bunker coal, thence to north side of river to lift dredge mooring chains which had been left there previous to flood. This proved a very difficult task as the chains were covered with shingle to a depth of 6 feet. However, at 2 p.m. this job was completed and owing to the urgency of more soundings being taken before .the deep loaded vessels sailed on the following tide, I decided to sound the bar and lower reaches of the river. After sounding the bar, out and in, I continued the soundings right up to the wharf on the white beacon line. I then allowed the dredge to drop slowly clown on another line of soundings and every ! thing was working smoothly when the stern of the dredge suddenly I grounded on some obstruction about half way down the lower reaches and about 100 feet away from _ north training wall. The current in the • river, about four knots, caught the ! starboard bow and swung her head on to the training wall, although I endeavoured to manoeuvre her off, all without avail, and she remained fast until 4.45 p.m., when she slipped off the obstruction and we came back to the lagoon wharf. The fore peak was sounded when on the north training wall and water was entering ; very fast. When we arrived at : the wharf it was decided to enlist the ■ service of the Fire Brigade Pump to « endeavour to reduce the water, and i if possible to locate damage, but the fire pump could not cope with the ’ inrush of water. It was then decided to put the vessel on the hard >in lagoon. The damage was then j surveyed and repairs were started at ’ once. One plate was pierced apparently by a sharp rock. Fortun- ’ ately, spring tides were making act! ’ this assisted greatly in regard to the position of dredge. ’ Sunday, 10th., 7 a.m.: All repairs 3 completed and at 10.30 a.m. came through bridge and made fast in the usual berth. Only one dredging day was lost through the mishap owing to weather conditions.

I might add that if a suitable vessel had been available the Dredge would never be used for sounding under the above conditions. The Engineer (Mr. . D. S. Kennedy),- reported:— The actual mishap has been fully reported on by the Harbourmaster and needs no comment from the writer in regard to the various causes leading up to it. The repairs, however, coming as they do under my jurisdiction, were placed in hand immediately, and I am glad to be able to report that our second major job concerning, the Board’s floating plant in the short space of six to s6ven months, was carried out to a successful conclusion in spite of many handicaps due to the short time available for working at low water and lack of suitable dockyard gear. It will be realised that the work was really a dry dock job under a difficult part of the hull. The whole of the staff immediately concerned worked long hours often under trying conditions, with the result that the dredge is now ready for commission again. I would also like to place on record the help offered by the Public Works Department, but not required, and that readily given by the N.Z.R. Workshops, the Fire Brigade and the Dispatch Foundry. .. Briefly the repairs carried out were as follows: The keel strake plate under the fore peak tank was badly holed and the floor plate and lug angles were buckled. The entire damaged portion was cut away with the gas and a new plate electrically welded from the inside and tack welded on the outside. Owing to the tides, the latter work was considerably hampered. A new floor has now been built in with electric welding and also the necessary cleat angles. The whole of the work while at present satisfactory to the Inspector of Machinery and Surveyor of Ships, may need further attention when the next dry docking and sur-

vey is made, as it will be realised by members that the headroom outside was strictly limited and the work was necessarily hurried on to finish each .portion of the repair as well as possible under the prevailingconditions of tide and entry of water to the small coffer dam built round the bow of the vessel.

In regard to the rock or obstruction that was the cause of the accident, I hope to bring before the April meeting of the Board a report on the condition of the half tide training wall in the lower reaches of the river, the serious shoaling adjacent thereto . during the recent flood and the consequent dredging now being undertaken. This report will also be coupled with the damage to the North Tip Head by the recent heavy seas, the placing of the concrete block and proposals to deal generally with making good the damage. These works appear more or less interdependent and as my information is not yet complete, I have been unable to prepare the necessary report in time for the present meeting. The Chairman, Mr. W. Clayton, said that the dredge was working again and it was hoped that the berthages would be cleared by next week. He paid a tribute to the work of the staff, particularly Mr. Leitch, mechanical engineer, for the expeditious manner in which the work had been carried out. Mr. P. J. McLean seconded the motion, which was carried.