SHORTAGE OF TONNAGE

Otago Daily Times, Issue 17038, 23 June 1917, Page 7

SHORTAGE OF TONNAGE

ADVANTAGE OF AUXILIARY VESSELS. A NEW INDUSTRY FOR NEW ZEALAND. A shortage of tonnage at the present f 111 ?, 0 ,. should give an impetus to tho shipbuilding industry in New Zealand. Tho question is whnt is the right type of vessel to build, and the one that would prove tho most economical and serviceable? The experience of the American people with auxiliary ships should be a good guide, as there is no doubt that these vessels have proved a soimd investment. The last two years have witnessed scores of large auxiliary vessels _ trading in all parts of the world, and with present rates of freight most of these vessels have paid for themselves in a single, voyage. 'On tho Pacific, coast of America great activity prevails in the construction of wooden auxiliary ships, and quite a number of yards are turning out a complete standard ship in less than three months. At tho present time over 80 auxiliaries are on tho stocks, and they are •° r J? avo crude oil engines installed. , The advantage of the auxiliary vessel is fU j 7l u en E\™es of a moderate power installed there is no encroachment on cargo space, and yet thesa vessels make a fair Present practice is to build vessels oi 1000 to 2500 tons with twin screw engines of 100 horse-power and 250 horsepower. With these .engines an average speed at between six and seven knots per hour is maintained under power. It will be apparent with this speed alone quite good voyages result, and a time-table is maintained. The idea in tho first place was to use the power when becalmed, but so satisfactory have these engines been that now usual to rim them during the whole voyage. With sails set and a' fair some very good runs are obtained. ino machinery is installed in the back part of the vessel, where it would not be convenient to store cargo, and it only requires a very 6mall space indeed. The engineering staff consists of one engineer an two unskilled assistants, and one man san.5 an . do all the work there is to be don© during his watch. Thus, the fireman trouble is instantly settled. There are no boilers, and_ the heavy expenses usual with steam engines _ and boilers are done away with. An engineer has only to watch his engines turning round, as while there is fuel oil and lubricating oil on board the engines automatically feed themselves. The type of engine used in auxiliary vessels is the hot bulb semi-Diesel. These engines in practice have _ proved their worth, chiefly because of_ their simplicity and low working cost. Their solid construction gives them a . .5 ! ife ? n .d great wearing qualities, and their simplicity enables unskilled men to operate them successfully after a few days' tuition. The engines work on the two stroke principle and are designed to operate without valves of any kind. The piston is arranged to open and close ports in the cylinder at the end of its stroke. This arrangement dispenses, with gear wheels, cams, levers, and a lot' of other noisy gear, which, while liable to breakdown, is costly to replace. The arrangement for feeding the fuel to the engine is interesting. The mechanism is extremely simple, and at the same time "positive. A small plunger pump picks up the fuel oil from the supply tanks and forces the fuel directly into the cylinder. This pump is controlled by the governor by altering tho stroke of fuel pumps, thereby adjusting combustion to suit the load. Tho injection of the .fuel is further timed to take place at a certain period in the cycle. By so timing, the fuel different grades of oil can be used, which is important, as the quantity of fuel oil varies in different parts of the world. During a part of the cycle compressed air is admitted into the cylinder, which thoroughly scavenges it, and gives pure air for the next combustion. Tho ignition is effected by the heat of compression and a small red hot ball. This system dispenses with all electrical equipment and is absolutely positive.

The. Commonwealth Government is at last giving tho shipbuilding industry an opportunity, and very shortly there' will be a number of wooden vessels in course of construction, to be fitted with oil engines. Quite recently an auxiliary four-masted schooner arrived in Sydney, from Portland. This vessel carried three million feet of timber for A-ustralian ports. Fitted with twin-screw crude oil engines developing 240 h.p. each, this vessel made the splendid run_ to Sydney in 37 days. A regular auxiliary service is now to be maintained between America and Australia. The performance of this vessel is an example of the reliability of the oil engine, and its value as an auxiliary power, and its coming has gently set the ball in motion, and it now remains for some enterprising people to givo it the push.

' In Australasia there are capable shipbuilders, and. with careful handling, there should be little difficulty with labour.' There seems to bo an excellent opportunity at tho present time to establish the shipbuilding industry. After the difficulties of commencing have been overcome, and it has become firmly established, there is no reason why th'*s industry should not be a paying one. At any rate, ships must be had, and, as they cannot be obtained from abroad, a beginning mieht bo made now. The New Zealand Government would do well to watch 'both the Commonwealth and New ■ South Wales Governments in shipbuilding. Two wooden vessels are i\ist being completed for them for fish-carryincr on a large scale and for passenger and lighthouse service. Both vessels are being fitted with these engines.