UNION COMPANY'S TURBINE STEAMER.

Poverty Bay Herald, Volume XXXI, Issue 10140, 29 August 1904, Page 1

UNION COMPANY'S TURBINE STEAMER.

MARINE ENGINEERING PROBLEMS

At the smoke concert at Dunedin last week, at which the New Zealand 1 Institute of Marine Engineers honored Mr A. Burl-, the Chairman (Mr James Mills), m the course of his address, referred to the vast changes m the development of shipbuilding during the past 20 or 30 years. He said : The engine has developed from the ordinary condenser first to. compound, then to triple and quadruple expansion. At the present moment we are on the eve of a very great transition m the shape of the turbine, so that engineers, however perfect their qualifications may be at the moment, must always be prepared to brush themselves up and keep themselves abreast of the times. There is no doubt the turbine has come to stay — at all events as a substitute for the reciprocating engine m vessels of liigh speed. Many shipowncrs»are recognising this and adopting the new method of propulsion. Others hold back, not because they question the great advantages of the turbine, but because they say it is still m its infancy and that before many years are over vast improvements may be expected; and they prefer to wait until they can avail themselves of the new invention m its most highlydeveloped and perfected form. The coml>any which I represent had to consider this position very seriously. We asked! ourselves the question, Is il advisable to adopt the turbine m its present stage, or should we wait until further developments have taken place? With us it was a question which demanded an immediate answer, as it was absolutely necessary that- 'we should' go on building' every year to supply the growing requirements of our various trades, and! replace older vessels which were becoming obsolete. After carefully weighing the pros and cons, we decided that, as the turbine m its present stage offered undoubted advantages over the older method of propulsion, we could not do otherwise than adopt it for any new vessels of high speed' which we might order. As a result of this decision, we have just had built a fast, shallow-draught steamer for the ferry service between Melbourne and Launceston. She is called the Loongana, and I expect to hear m the course of a few days the result of her trial trips, and of her departure for line colony. She is designed to attain 18 knots on a draught of lift 6in to 12ft, for the navigation of the shallow parts of the Tamar river. She is fitted with the turbine,, which is specially adapted for vessels of this class, owing to the absence of vibration. This is an advantage which will commend 1 itself to those of you who have had the opportunity of travelling m the Oldl Country m such steamers fitted with twin-screw engines of the ordinary type. Such vessel's when m a seaway are almost impossible to live m, so great is the vibration. This is partly due to the action, of the engines, and partly to. the light construction of the vessel, necessary to secure moderate draught. The Loongana is a vessel of 2500 tons, and will' develop something over 5000 horse-power to maintain her contract speed. My New Zealand friends will have an opportunity of making acquaintance withi the turbine m about 12 months, as we have let a contract for the building of a steamer for the intercolonial trade to be propelled by the new method. She is to be of the Manuka type, but larger and! faster, The Manuka's gross tonnage is 4500, and her contract speed at sea (loaded) is 14£ knots, for which she requires to use from 4000 to 4500 horse power. The new ship is somewhat larger, and is intended to maintain 16 knots loaded, for which she will ordinarily require something over 6000 horse power; of course, she will be capable of steaming 17 -when m ordinary light condition. If you will note these figures m your mind, you will have an idea what it means to increase the speed of a ship. As I have said, the new turbine is to steam 16 knots, as against the Manuka's 14, which means an advance of 12£ per cent; but to secure this extra 12j per cent she requires fully 50 per cent more power, so that, as far as additional speed is concerned, it will bo seen that the power required and, therefore, the cost of running are out of all proportion to the extra speed to be obtained. And it must also be remembered! that owing to so large a portion of the ship being taken up by boilers the space available for passengers and. cargo is considerably curtailed. I mention all this to enforce the point which I wish to impress upon you— that is, that there is great room for study on the part of engineers, and a great future before them Further, let me say that, while many improvements will no doubt be effected from time to time m the turbine, I am personally inclined to think that the greatest improvements are to be expected m connection with propellers. As you are aware, the propellers of a turbine ship are small, arid attain a much greater number of revolutions - than m the' case of an ordinary twin-sore w vessel. The revolutions of the latter are usually from 100 to 110 per minute, Avhereas m a turbine of the Loongana class they reach SQP per minute ; while m the case of Atlantic liners the revolutions will probably be 250 per. minute. This extra propeller speed introduces new difficulties which have yet to be thought out by engineers. Then, again, we have. 'the ever present question of the best type of boilers. So far, the mercantile marine has adhered to what is known as the .Scotch cylindrical boiler, but the advocates of the watertube boiler are very clamorous, and' claim great advantages for their system of heating— advantages m the shape of economy m space and consumption of coal. Some shipowners ,pin their faith to them, and the Admiralty have used them largely, but are still making exhaustive tests ; so that this type of boiler will eventually supercede the ordinaiy form of cylindrical boiler. Another question m connection with engineering is that of oil fuel, which represents a very important departure. It has been proved beyond a doubt that oil as fuel presents many advantages over coal. _ In the first ' place, you avoidl the loss of time caused 1 m ordinary steamers by the cleaning of fires every four hours. Then again, the firing is done mechanically by means of a spray, so that there are no stokers or trimmers required I—an1 — an enormous advantage! This may ultimately become a pressing question, though meantime it is not of interest to this colony, seeing that we can get coal at- a reasonable price, whereas oil is difficult to obtain. The question is being debated whether m any case the world's supply of oil will be equal to the demand which would be made m the event of the general adoption of oil' fuel by the mercantile marine.