SHIP PROPULSION

Dominion, Volume 22, Issue 76, 22 December 1928, Page 10

SHIP PROPULSION

MARINE ENGINEERING PROGRESS REVOLUTION AT SEA DEVELOPMENTS IN NEW ZEALAND TRADE .1 A good deal of the story of the revolution, which is taking place in the methods of marine propulsion, is told in the many interesting developments in New Zealand shipping this year. Situated as it is at the antipodes of the world’s markets involving the transport of its exports of butter, cheese, frozen meat, wool, and other primary products, across nearly 12,000 miles of oceap, the Dominion is vitally dependent upon its shipping services. It is therefore a matter for pride ami satisfaction that the shipping lines which carry ou the trade of the Dominion are in the van of progress in shipbuilding and marine engineering. Remarkable Development. This year has seen the advent In the New Zealand trade of the Shaw, Svill aud Albion Company’s four new liners Zealandie, Coptic, Taranaki, aud Karamea, which rank as the highestpowered motor-driveu cargo ships in the world, and have, with two exceptions, the greatest refrigerated cargo capacity. The Commonwealth and Dominion Line has increased its fine fleet of cargo carriers by the addition, of five fast Diesel-engined ships—Port Huon, Port Gisborne. Port Fremantle. Port Alma, and Port Fairy. The NeW Zealand Shipping Company is adding three remarkable ships to its fleet—the 18.000-ton motor passenger liners Rangitlki, Rungitata, and Rangitane

—which will be the largest ships in the New Zealand-London trade. They are expected to develop a speed of over 15 knots, and the sumptuous appointments of their passenger accommodation will be in advance of anything’ yet seen in the service. Other remarkable developments this year in the direst trade between New Zealand and England include the alterations to the propelling machinery of the Shaw, Snvill and Albion liners Tamaroa and Mataroa, which on a greatly reduced fuel consumption have increased their speeds by knots, reducing the time of the passage by several days. The next few weeks will witness the introduction into the New Zealand trade of an “all-electric” ship, the oil-tanker Brunswick, which is propelled by an electric motor taking power from Diesel-engine driven generators. Shipowners’ Wide Choice. Notwithstanding the great development in the Diesel oil engine as a prime mover at sea. the age of steam Is by no means at an end, and leading shipowners are maintaining a very open mind in regard to systems of ship propulsion, There are those who consider that the Diesel marine engine will reach the “peak” of its development and employment during the next few years. Certain it is that the marine steam turbine with reduction gearing and high pressure boilers and superheated steam are making a great bid for supremacy in the matters of lower capital cost and efficiency and economy in operation. It has been said that the lot of the shipowner and his technical advisers has never been so embarrassing as at the present time, insofar as the question of the. choice of propelling machinery is concerned. Never before have marine engineers offered such wonderful value for money in respect of the fuel economy of the different prime movers.

Pulverised Coal. Side by side with the important developments taking place in marine steam engines and boilers, is that connected with the use of pulverised coal in place of oil. The New Zealand Shipping Company’s large cargo steamer Hororata, which leaves London this week for New Zealand, has had some of her boilers adapted for, the use of pulverised coal, an experiment which will be watched with great interest in the shipping world.

Exhaust Turbine Development. Yet another important development in marine engineering in which the Do minion is interested is the fitting of reciprocating-engine ships with Bauerwach exhaust turbines. The new system is the joint creation of two eminent German engineers, Drs, Bauer' and Wach, although the former has given Sir Charles Parsons the credit for the original conception of the idea, It consists in a turbine driven by the exhaust steam from the reciprocating engine, and connected to the propeller-shaft by double-reduction gearing. The system has now established itself as a very sound means of improving the economy of the marine reciprocating engine. Not the least important advantage of the system is the ease with which it can be fitted to existing ships. In two years, over 150 ships have been fitted in Germany with Bauer-Wach exhaust turbines, and British owners of recipro-cating-engined ships are now hastening to equip them similarly. New Zealand Traders Fitted. To the Commonwealth and Dominion Line belongs the credit of introducing the Bauer-Wach turbine Into New Zealand trading ships. The Port Hardy, 8705 tons, a twin-screw steamer built in 1923, was recently fitted with a set to each reciprocating engine, resulting in increased speed and a marked economy in fuel consumption. The Port Hardy, which is now loading at New Zealand ports for London, has proved so successful that the C. and D. Line is applying the system to a number of its reciprocating-engined ships. Speaking at the launch of the motorship Port Alma a few months ago, Mr. Robert Corry, a director of the C. and I). Line, said they did not intend to build any more ships at present, but they were sending eight or nine of their steamers to Wallseud-on-Tyne to have BauerWach turbines fitted. The ships will be the Port Auckland, Port Brisbane, Port Campbell, Port Darwin. Port Denison, Port Nicholson, Port Wellington, and probably the Port Melbourne and Port Sydney. It is understood that the New Zealand Shipping Company have decided to have Bauer-Wach exhaust turbines fitted to its steamers Rotorua, Remuera, and Ruabine. A cable message yesterday announced that the P. and O. Branch Line steamers Buradiue. Balranald, Ballarat, Barrabooi. and Bendigo, all of 13,000 tons, are to be converted to burn oil. and will have Bauer-Wach turbines fitted. The Clan Line is also having seven of its steamers similarly fitted.