AN ELECTRICAL STORM

Dominion, Volume 9, Issue 2620, 16 November 1915, Page 7

AN ELECTRICAL STORM

AFFECTS SHIP'S COMPASS THE MAPOURIKA MISHAP

The grounding of the U.S.S. Co.'s Mapounka, off Clay roiiifc, when the vessel was on the way from Picton to Nelson, in. the early hours of Saturday, November 6, was the subject of a Magisterial inquiry yesterday.** Mr. W. G. Riddell, S.M., presided, antl the nautical assessors were Captain Felix Black, coastal pilot, of Wellington, and Captain W. J. Grey, retired master mariner, of Wellington. The Collector of Customs (Mr. E. R. Brabnzon), with Captain C. G. Smith, Marine Superintendent, appeared for the Marine Department, and Mr. E. H. Kirkcaldio appeared for Captain Oaroy, master of tlio Mapounka.

Robert Pnterson, Superintendent Engineer for tlio Union Company, gave evidence as to the nature of the dam-

age to the Mapourika. The stern, below the 10ft. level, was bent, and some of tlio plates were bulged, in addition to other small damages. Temporary repairs ho estimated to cost about £50, and permanent repairs about £250. To Mr. Kirkoaldie witness said that the ship had been Tunning with the temporary Tepairs, and the buoyancy and structure of the ship, wero not endangered. William John Carey, master of. the Mapounka, gave details' of the voyage after the ship left Picton on November 6.' At Jackson's' Head, tbe tides were setting against them, and the weather was a bit dirty. Ho set a course and passed Motungarititi Island about a mile and a. quarter off. At midnight the weather was getting dirtier, with occasional' rain, flashes of lightning, and very' heavy thunder. He could see about 'two miles. The course lie set was half a point off the usual course, and should have'put him a mile off Clay Point. He l looked in the compass'when he altered the course, to' see that the man had it; and a little later on he told the second mate to see that the man was steering right. About halfway between Harding Point and Clay Point the 6econd mate said he could see Clay Point. Witness 'thought ho could see it too. A littlo later land was reported on the port bow. He had Tung "stand by" in case the weather got heavier. Shortly after land was seen dead ahead—the extreme point of day Point. He rang "full astern, hard aport," but before the ship could be stopped the land was" struck. He called the passengers, and got the\boats ready, but when it was reported that the vessel was making ho water he went slow astern, and the ship' came off. He then steered for Nelson.. He was unable to

account for the accident, unless the conditions of the weather had affected the compass.' : ' « A .Peculiar Blue Light. To Mr. Kirkcaldie he said that they had no difficulty in picking up all the points down to Harding Point. Tho difficult part had been passed. He had been oh the run fivo or sis years, as mate and master. He ■ estimated that they passed Harding_ Point by _ threequarters of a mile. The Mapourika was only. going about ten knots on the night in question. The usual speed was about lli knots. She must have gone at lesuat a mile out of tho course, according to the time between Hardin" and Cl&yffoints. He had never noticed any "set" there. - The wind was nor'west, two points on the starboard bow. He wa» confident the course set by him was being steered. There, wats considerable lightning and heavy thunder; 6uch as he bad never before experienced on the New Zealand coast. There was -a peculiar light near the mast. He was going to pass a remark on it, when the second mate said that it looked as if the ,masthead light had.

fused. It" was;a blue 60rt of light. He looked upi and saw tho headmast light was all right. The light' ho saw tf&s much higher. The Mapourika made no water going from Clay Point to Nelson. The vessel was then brought on to 'Well-

ington, without repairs being necessary at Nelson. t Permanent repairs had not yet, been made, and the ship was now used as a storeship in the harbour. Joseph Henry Claydon, chief /officer of the Mapourika, said that he was relieved at five or six minutes after midnight (about half an hour before the mishap). The night wais then very dark, but clear. Before he went off he had seen Harding Point. He estimated that they would paSB it by a mile. The wheel was relieved at midnight, and witness stood and 1 saw that the new man took up the right course, west-nor'-west.

To Mr.t Kirkcaldie, witness said that ho had experienced many \ electrical storms at'sea, hut none of more severity than tlfat of the night-of the mishap. It would be correct to say that the night was peculiar. James H. Miller, second officer of the vessel, gave similar evidence to that of the previous witnesses. On tho night of the mishap they steered half a point more to sea than they usually did. He could only ascribe the mishap to a deviation of the compass, through an unknown cause. -

To Mr. Kirkoaldie: He had one© known the compass to swing about sight points during an electrical storm in the South Atlantic. He was sure that some electrical disturbance was the cause of their touching Clay Point.

John Finlayson, A.B. on the Mapouvika, who was steering at the time tlio Ik; at struck, said that ho kept tlio course sot. bj the officer The compass seemed to jump about more than usual on that night.-. Simon Smith, look-out on the vessel, said that he pickod up what_ appeared to be Clay Point, after clearing Harding Point. The boat seemed to bo clearing the land. Immediately before she struck he reported land on the port how. He waited a minute, or half a minute,, so as to be suro before ho reported. Due to Electrical Storm.. Before calling evidence, Mr. Kirkoaidie said that the. defonco he intended to make was that there was a disturbance of the compass, caused by the electrical storm. He quoted cases in which the compass had been affected by storms. ; There could, ho said, be temporary magnetic disturbances, which might be subsequently rectified. Ernest Marsden, Professor of Physics at Viotoria University College, gave evidence that he had had special opportunities of studying the effect of 'electrical disturbances on land. He had studied the actual and supjwsed course taken before -tho M.apourika struck Clay Point. There , was a difference of 11 points, and this error must have beon in the compass if she was_ steered i as stated, and there was no wind or tide. Ho had made somo investigations 011 Ins own behalf.' and had got in touch" with Christchurch. They came to the conclusion that tho storm was rather bigger than a usual magnetic storm. Ho put the trouble down to the fact that tho high iron mast of the ship was possibly collecting electricity from tho clouds. Before hoing conducted to earth that would have an effect on the ship. 'Hie jumping of, the compaßS and the blue light at tho mast were consistent, with the theory advanced, and indicated a magnetic disturbance to the compass. It would not be necessary for tho ship to'ibo struck by lightning for the oompass to disturbed. Witness agreed that the disturbanco might be vers' temporary. He could see that it would have to have ]asted_ about fivo minutes to explain the deviation, unless there was induced magnetism caused, Captain A. Gifford, teacher of navigation, recounted instances whore the compass of shins had boeu altered by electrical 6 toncfc ' I

Offioers Exonerated. After consideration the Court delivered the following findings:— "Tho Court finds that the damage done to the s.s. Mapourika. on the occasion of her stranding at Clay Point on November 6, 1915, was material, but not in the opinion of the Courf serious within the meaning 4 of Section 238 of the Shipping and Seaman Act,--1908. The cause of the stranding of the Mapoitrika at Clay Point on November 6, 1915. was due to the state of the weather, which prevented the master, second officor, and look-out from obtaining a. proper view of the point, and an electrical _ atmospheric disturbance then in operation, which affected tho compass to sucli an extent as to make it temporarily inaccurate for steering purposes. "In the opinion of the Court the stranding of and material damage to the ship was not caused by or contributed to by the wrongful act of the master, William John Carey, or tho second officer, James Hino Miller.''