FAULTY CABLE QUESTION AT FIRE INQUIRY

Grey River Argus, 8 April 1948, Page 3

FAULTY CABLE QUESTION AT FIRE INQUIRY

Testing Engineer Denies Cause Was Electrical P.A. CHRISTCHURCH, April 7 The joint in the electric cable which yesterday was described by the Crown as amateurish, was stripped of its covering insulation tape neforc the Commission of inquiry into Ballantyne’s fire, by Stewart Maxton Nicol, testing engineer to the State Hydro Electric Department this morning. Nicol said that traces of corrosion indicated that the solder used on the joint had been Mr E. S. Bowie said he was watching the interests of Thompson and Doreen, electrical contractors, in regard to the installation of the eiectrn. cable, and he notified his intention o. calling witnesses on their behalf Mr G. G. G. Watson (for the Crown, said that an undertaking had been given that Thompson and Doreen aim some of their workmen would be caned. . . Points regarding the joint were explained in detail before it was unwrapped. while, after that had been completed, half of the covering of a properly-insulated joint was removed vzitn explanatory comment by Nicol. After the rubber covering had been removed from a properly insulated joint, Nicol said that here, again, there was unmistakable evidence of insufficient heat haying been employed in the work on it. In reply to Mr Lascelles (Christchurch City Council), Nicol said that the repairs discovered couid possimj have been done without disconnecting mains. The work showed some knowledge, but little skill. He told Mr R. P. Twyneham (five underwriters) that he had .not modified his opinion that the cause of hry was not electrical nor would the additional finds cause him to modify it. Re-examined by Mr Young, he (witness! said that the absence of tinning on one part of tlie rubber insulatea joint was significant. Only han m second joint appeared to have been tinned, and that half was a continuation of the conductor. The signiiwa,. fact of this, in his opinion, said Nicol, was that, for some reason, and in some way, the tinning had been removed, because tinning was originally applied by the maker of the conduc tor. He explained that, if it came mtc contact, with the earth at an eaiih potential allowing of the passing oi fault current, it would cause the tinning to disappear. He had thus concluded that part the conductor could have come into contact, 'yn* 1 some other metal. Nicol said that, electrically, this.was a most unpoifan. discovery

RISK OF LOOSE CONNECTIONS. In reply to the Chairman. Sir Harold Johnston, Nicol said: “One of the most common causes of electrical fires—not. that they are common —might be described as loose connections, particularly associated with switchboards.” . Sir Harold: “Can you conceive of any circumstances which would pet'* mif of an electrical breakdown of cable sufficient. to cause fire which would, at the same time, permit power to pass for an appreciable period ?—“No.” . Eric Edward James, assistant District Electrical Engineer of the State Hydro in Christchurch, agreed with Mr. Nicol’s findings. He said that, where there was any shadow ol doubt that a fire might Jiave been caused by electricity, the State Hydro Electric 'Department should, automatically, take charge of the investigat'on before any parts were touched, or before the interested parties interfered with the installation. "I think it is fantastic myself,’ said witness, when asked by Mr. W. R. Lascelles (for the City Council) for his opinion on the theory of Mr. Salvesen, of the cable causing the fire. Sir Harold Johnson: “I am inclined to think that you take the duties of inspectors rather lightly. What can they see, and what not?” “An inspector does not inspect material before it is installed. An inspector can only go round and put on certai' 1 prescribed electrical tests. They have to have special Qualifications.” Sir Harold: ”f thought you took lather a defeatist attitude of their duty?” ”1 did not intend to, but I have some sympathy for them as, however conscientious they may be, there are still parts of the installation which inspectors cannot see without stripping the installations. They must, rely, to a certain extent, on the integrity of the contractors.” Detective Sergeant George Walter Alty, who investigated the cause of the’ fire for the police, said that it had been suggested to him that the electrical cable should be examined by an electrical engineer. He had no power to authorise removal or to prevent removal. The suggestion was made by Mr. A. E. Smith. Secretary of the Underwriters’ Association. Mr. Smith later told witness that Mr. Salvesen would be the engineer, and that the police would be given a copy of the report. Removal of the cable was begun on the afternoon of November 20. When later he was asked to direct who should inspect the cable, he said that he had no authority to do so, but he considered that the State HydroElectric Department had the best facilities. To Mr Lascelles, witness said that he assured that Mr Salvesen was acting for the Underwriters. The Commission adjourned until to-morrow.