GEARED TURBINE PROPULSION.

Otago Witness, Issue 3148, 15 July 1914, Page 74

GEARED TURBINE PROPULSION.

THE MAHENO’S SPEED TRIALS. During her lay-up at Port Chalmers for the past two or three months the Union. Company's stearrfSr Maheno has undergone a very extensive overhaul, both inside and outside, the most important item in her new equipment being the substitution of the latest type of geared turbines for those of the earlier typo with which the vessel was originally fitted. From a marine engineering point of view the skill and labour involved in removing the old turoines, which operated three propeller shafts, and replacing them with the geaVed turbines, operating two shafts, constitutes the most important job of rts kind yet undertaken in the Australasian colonics. Owing to her central propeller being discarded, hr r port and starboard shaft bearings had to be increased proportionally in size, _and this necessitated idle re-boring of the stern tubes by means of speciallybuilt machinery. Another big item was the difference in size of the old and new bedplates for the engines, important and extensive structural alterations being found necessary to accommodate the new turbines. The handling of the heavy machinery alone represented a very important and delicate task, which was greatly facilitated by the use 'of the Harbour Board’s electric luffing crane, which dealt with the 12-ton lifts with the utmost case and precision, with the result that the Maheno was ready on Friday to give her machinery a trial test. Shortly after 11 a.m. the Maheno left Port Chalmers under the command of Captain King, with whom Pilot M‘Dougall was associated on the bridge, and steamed down the harbour for the purpose of undergoing steam and speed trials, which were carried out over a measured distance along shore outside the Hoads. The weather was perfect, and the sea was calm as a pond, the * conditions being ideal for the occasion. A man get the visitors on board were: Messrs John Roberts, C.M.G.. C. Holdsworth (managing director), 0. R. Ritchie, C. W. Rattray, D A. Aiken (general manager TJ.S.S. Company), William Belcher, James Roberts, Q. Holdsworth, E. Fisk (Marconi wireless representative), E. Roberts, C.E., J. M Chntock (British Corporation), W. Crawford-and J Williamson (Government Inspectors of Machinery), and several others. IN THE ENGINE-ROOM. Mr Smart (superintendent engineer) and Mr Dunsford (representative for Sir Charles Parsons), assisted by Chief Engineer James Eas re and ins staff, superintended the workin<r of the turbinck- and auxiliaries. Owing to” the fact that the new turbines occupy less space than those they have superseded, the engine-room is much more roomy than it was previously, and the temperature below was slirpns.ngly low, the engine-room being described by one .of the staff as being as cool as a cucumber.” All _that could be seen were two largo enclosed machines lepreseriting the geared turbines, from which protruded the driving shafts, running at an approximate 'speed of 250 revolutions per minute; whilst at various points of vantage a number of the engineers, with notebooks and pencils, were bushy engaged in scrutinising closely the various steam gauges, vacuum gauges, speed indicators, etc., and notin <r carefully the various revolutions of the shafts at the different progressive speed trials-over the measured mile. The Maheno made four double runs over the measured mile, starting with a speed of about 11 knots. This speed was gradually increased at each stage, the vessel being run twice over each course, in order to secure a correct mean average speed over the same distance. The second run was at a, speed of about 13 knots, the third registered 15 knots, and in the final run the engines were tested to within a trifle of their full capacity, propelling the vessel ~at a speed of 17.C9 knots per hour. This works out at the rate of 3mm 30 3-ssec per knot, which is equal to 6080 ft, or roughly one mile and an eighth. The figures showing the coal consumption were not available, but we understand tnat the trials showed a very substantial reduction in the amount consumed, as compared with the coal consumption under her old turbines. The running of the machinery from start to finish afforded the greatest satisfaction to those in charge, and it is no exaggeration to say that the installation ofthe new equipment reflects the highest credit upon Mr Smart and his staff, a very pleasing feature of the work being the freedom of vibration usually associated with high speeds at st*a. At the present moment the Maheno looks as spick and span as though she had just left the builder’s hands, and the Union Company is deserving of warm praise for its enterprise in adopting the most up-to-date propelling machinery available in order to keep abreast of modern passenger requirements; and, in view of the heavy °cxnenditure involved —about £30,000, —it is extremely gratifying' to all concerned that yesterday’s trials proved so successful. To Port Chalmers belongs the credit of having carried cut a most important feat in marine engineering. The geared turbine system of marine populsion is said by some experts to be destined to work a complete revolution in the near future. It is only about four years ago since the steamer Vespasian was first equipped with engines of that type. Meanwhile the Channel packet steamers Normania and Hamptonia, the cargo steamer Cairnroes (which recently visited this port), and a few otfier modern liners have been fitted out with them, and to this small list must now be added the ned Funnel liner Maheno. INTERNAL DECORATIONS.

Internally the Maheno has undergone a transformation. The first class smoke room has been picked out with a charming combination of pale blue, light salmon, and cream in flat tonee, contrasting well with the richly polished mahogany Handling and the dark moquette upholstering of the lounges. The special features of the decorations’ in the social hall are the harmony of tones in cool greys, and the effect is subdued and restful, being produced by monochrome effects in broad masses of colour, as opposed to the more ornate style of decoration which prevailed a few yearn ago. The vestibule leading from the social hail to the music room and the dining saloon embodies a happy idea in the form of a deep frieze depicting ancient Phoenician war galleys, worked out in a cool grey effect, with a sunset background. Coming to the dining saloon, one is struck with the pleasing effect obtained by the decorations in their choice of pale peacock, blues, russet browns, and ivory white, these tints being specially chosen to produce broad and harmonious effects with daylight or when artificially lighted, the upholstery and curtains being of corrcsDonding richness and beauty of tone. The

whole jet the interior decorative work has been encrusted to Messrs Wren and Co., the various colour schemes being worked out by Mr S. H. Osborn, whb was given a free hand to carry out this important branch of the work, which cannot fail to please the eye of all lovers of harmonious.effects in colour. Every stateroom on the Maheno has been renovated, repainted, and re-furnished. The second' saloon accommodation has been renovated and re-furnished in keeping with' the other parts of the vessel, a feature of the second class accommodation being the cosy sitting rooms for the ladies on one side of the main deck and for the gentlemen on the starboard side. A special messroom has been set -apart for the ohfldrcn in the second class division, which, is vwy comfortably fitted up throughput. The Maheno will go into commission next week, being.scheduled to leave Wellington on the 10th inst. for Sydney. Her next trip to the Commonwealth will be watched with keen interest by a very large section of the travelling public, as well- as the shipping experts, many of whom regard her firpt voyage as, an important epoch in New Zealand shipping.