TO-DAY’S CARGO SHIP.

Otago Daily Times, Issue 21266, 21 February 1931, Page 10

TO-DAY’S CARGO SHIP.

EFFICIENCY AND ECONOMY. MOTOR VESSEL OTAIO. The New Zealand Shipping Company’s new motor vessel Otaio, which is at present in port at Dunedin on her maiden voyage from Liverpool, is one of the outstanding cargo ships of 1930, and an excellent example of what can be achieved nowadays by the ship designer and builder. One of her most striking features is the general excellence of the accommodation provided for the officers and crew, which is a long way in advance of what prevailed in the old days. The captain, chief officer, chief engineer, and second engineer all have their own private bathrooms. The junior officers and engineers as well ns the crew also have their own bathrooms. The officers have a special smoking room, and also a veranda lounge to themselves, and similar facilities are provided for the engineers. The latter « also have a changing room and a lavatory in the engine room, so that they can divest themselves of their working clothes and have a “ clean up ” before entering their quarters. The idea underlying this excellent accommodation is that it tends to foster a spirit of esprit de corps, of responsibility, and of loyalty throughout the ship, which results in attracting the best type of man to the company, and thus promotes the highest possible measure of efficiency in the fleet. Built by Messrs Vickers-Armstrong, Ltd., at Barrow-in-Furness, to designs prepared by Messrs Esplen, Son, and Swainston, of London, the principal particulars of the Otaio (says the Journal of Commerce, Liverpool) may be summarised thus:—

Dimensions: 470 ft by 67ft by 40ft (490 ft overall)-; tons (dead weight) 11,300. Draft: 31ft *6in; holds, five, with 472,000 cubic feet refrigerated capacity. Screws: Two. Auxiliaries all electric, with 900 kw Diesel electric load. Machinery; Doxford two-cycle o.p. four-cylinder 27.5 m by 82.5 m combined. Service speed about 15£ knots. Total power about 900 b.h.p at 115 r.p.m. The Otaio is thus one of the most powerful cargo vessels afloat. Service: United Kingdom to New Zealand, via Panama. With her large hatches 40ft by 20ft and her 50 tons cargo derrick she is able to accommodate almost any cargo that may be offered. The vessel was built for the refrigerated and general trade between the United Kingdom and New Zealand, the space for refrigerated cargo being 439,324 cubic feet, which means that the ship can carry 150,000 carcasses of mutton. In addition to this there is 275,032 cubic feet of space for general cargo. The refrigerating machinery consists of two quadruple compressor vertical enclosed type CO2 refrigerating machines, one machine being capable of maintaining the required temperature throughout tiie insulated spaces. Each machine is driven by a variable speed t electric motor of 165 b.h.p. directly coupled to the crankshaft without intervention of any gearing in order to ensure quiet running. The motion work is totally enclosed, and arranged with forced lubrication. There are four circular cast iron condensers, containing nests of copper coils, and four circular built steel evaporators containing nest of steel coils, the evaporators being arranged in an insulated room The capacity of each of the two compressor sets is rated as 84 tons ice melting, the total thus being 168 tons for the two machines. The electricity supply is an important consideration in such a ship. It is provided by Euston and Hornsby three-cylinder four-cycle Diesels, the total electric load being some 900 kw. Each of the two main Doxford Diesels

exhausts into a Clarkson silencer boiler; each unit is 0 feet in diameter and 11 feet 6 inches high, with 570 square feet of heating surface. They are fitted with a combustion chamber 0 feet 7 inches high for use with with two oil burners of the Todd low-pressure air type, two burners being fitted to each boiler. The cooling of the Doxford Diesels is carried out by fresh water, as is usual in the Doxford engines, this being another necessity which is catered for by a waste heat boiler installation. The steam from the boilers goes through a Beiliss and Marcom reciprocating generator set rated for 160 kw output The exhaust steam from the ,turbine is passed out at 51b pressure, and half the quantity is used for accommodation heating, the remainder being used for evaporating about 20 tons of distilled water per day, which may be used in connection with the cooling of the engines.