SUPREME COURT.

Poverty Bay Herald, Volume XLIV, Issue 14340, 3 July 1917, Page 6

SUPREME COURT.

NIVEN AND CO. V. POVERTY BAY FARMERS' MEAT CO. _ Charles McCarthy was continuing his evidence at the Supreme Court this afternoon. He stated that m Taihape the excess pressure was not as great as Longburn, and there was little difference between Longburn and Gisborne. (The aim of all engineers was to get pressureequal between inside cylinder and inside of discharge pipe. If the differj ence was 3 or 51bs there was something {wrong. The machine at Taihape was i working at an excess of between one and two lbs. When they had such an excess as at Poverty Bay (between 10 and 27 ibs) there was a shock on the stem of the valve and this excess pressure was due to want of clearance. Nivens did not take indicator cards off any of these machines. Witness produced Williams on refrigerating machinery," also Redwood on the same subject, Journal ..f of American Rerfigerating Engineers. Witness said it all come back to the , question of clearance, and thid was ( demonstrated by the experience at Tainape, where the compressor was now working all right. His Honor enquired whether the delay m payment was due to these valves. Mr Myers said there were various contracts and disputes. Mr Skerrett suggested waiting for the correspondence, remarking that that question did not then come m. Witness detailed his various visits to the Poverty Bay works, stating the compressor was never working at its full capacity. There was plenty of gas engine power if the valves had been all right. In Feh.rnary, 1916, he cerified to a payment of £1800 for machinery. It was then °. n ,^ le i°^» *>ut not erected. Up to the time it. broke down it had never had a proper run at full working conditions. Its total running from start to smash was 967hrs or five weeks and four days (of 24 hours) on a "light load." Witness had been consulting engineer m connection with all three works mentioned. The rhythm or noise of these machines was a rattle— -a tremendous rattle. >f anything he thought Taihape was a little less noisy. The question of rhythm applied to motor cars and high-class machinery, but did not apply to compressors. With the latest valve put ; n at Longburn one could hardly hear any sound at all. It was the hitting of the stop that caused this rattle. He gave instructions for a Stern to be kept ?s a standby. Witness arranged that the parts of the damaged machine should be sealed up, and the broken parts Kent under lock and key. He had seen tops 1 break, leaving the springs intact. , Two of those of the present machine 'vere like that. Witness would not have anything to do with the machine with repaired bed plate and similar valves — not after the past experience. Apart from loss of life nearly £1000 worth of ammonia m the system would be dissipated m the event of the cover breaking. That I would bo dead loss. In th© event of putting m another make of compressor they would have to take up the old foundations and put m new ones, costing £250, and cost of dismantling present machine £30. The Crossley engine had to have the shaft reduced to connect. With another type of compressor they would' want a new crank shaft for a low .speed machine coating about £250, He j did not know of an English high-speed {compressor of 36 tons, but there were several American. During the 1915-16 season the Stern compressor was going • at full capacity. To Mr Skerrett : As a consulting eng: ineer he was acquainted with the science of refrigerating and there was a scientific method of determining the sufficiency „f clearance. That method was the most \ certain. The only method of determining that was by the indicator cards. Having got the cards one was governed by the record of pressures. And what about the velocity ? — You do not bother about velocity. • By what scientific process do you determine the sufficiency of the clearance? :— A^ell, if it is not sufficient you make lit a little larger. I Counsel repeated his question. — Wit-.-'ness replied that was all counsel would get out of him. ■ • 1 , i Is not the scientific method to ascertain the velocity with which the gas passes through? — Asa practical engineer I tell you I do not bother with velocity i Is it not a scientific truth that there is a relation of 'area of clearance to the velocity of gas to pass through a given point? — There is not a definite formula for ammonia gas. , Counsel demanded whether as a consulting engineer this was not so. Witness ultimately agreed that there was. ) Mr Skerrett proceeded to request witness to check the calculations of Mr A. S. Mitchell. — Witness said that he was not going to work them out, and he did : not think there was anyone m the room who could. j Mr Skerrett : You come here to tell the jury that there is an insufficient clearance. I want to put you to the scientific test, which you admit there is. Witness: Put me to the practical test. Mr Skerrett: The practical test is a mere guess. Asked regarding the calculations, witness said Mr A. S. Mitchell's calculations were nearer than Mr A. C. Mitchell (Nivens). j Mr Skerrett proceeded to put the proposition to the witness, remarking : I have never seen such a scientific engineer. Witness : Wait a minute. I will show you where you are all wrong.! j Mr Skerrett : Don't start prophesying, or you will find you have fallen m the soup. i Witness : I think you are on the wrong track. (Proceeding.)