THE TUG KOPUTAI.

Otago Witness, Issue 1323, 7 April 1877, Page 11

THE TUG KOPUTAI.

The Eoputai made her first trial as a tug boat on Tuesday, but under circumstances which militited against a striking display on her pirt of rapidity of action, but for power and downright effectiveness, the demonstration made by the new tug yesterday was not to be mistaken. _ She is fully up to the work she was built for, and we have no he itation in pronouncing hei a decided success. The start made yesterday was really made before the Koputai was absolutely ready. Her steam starting g»ar was not quite as it should have been, and hence the use of hand levers was necessitated, but by ths time a steam cock or two have been fixed, she will be all right in this particular, and very much more easily handled than she was on Tuesday. Then ajrain, excepting the short spin of last Saturday, the Koputai's machinery was untried out here, aii'i, like all new gear, worked stiffly, whilst the inclination to prime, common enough with n-jw boilers, prohibited am thing approaching full steam baing turned on. Gentle action from first to last waa adopted, and her.ee the comparatively slow time male by the tuir going out. We have been waiting f»r this trial trip of the Koputai to say a few words atiout her build, niichinery, etc. She is a full lined boat, very full forward above water, but fairly lined underneath, with a fair rise of floor and delivery. She hid to be substantially built to sustain the strain and weight of the mass of machinery she carries, and no better descriptive designation can be applied to her than " a box of machinery." The Messrs Wingite, her builders, certainly did their duty by the contract, for both engines and bailer are perfect of their kind, that kind being exactly suitable for the purpose of towing. Her engines are compound, and, as in the case of the Bteamor Iron Age, the cylinders are placed cue on each side in a semi-horizontal position abaft of tho main shaft. The high-pressure cyliuder on the starboard side is 33in. diameter, and the low-pressure oue on the portside is 52in. diameter. Huge piston and connecting rods attach them to tho ponderous cranks of the main shaft— a piece of solid iron 12in. through. The air and circulating pumps, and surface condenser, and every other portion of the machinery, are constructed upon the best principles, and in all minor details a completeness is manifested indicative of thorough workmanship and libeialitv. The Koputai's wheels are 15ft. diameter, and the floats, fixed on the feathering principle, are 7ft. by 3ft., and thus take a great grip of the water. The boiler— a marine maltl

tubular— is 14ft. diameter by 12ft long, and is fired from three urnaces.

The Kopotai hanselled hercareeron Tuesday by towing out the ship Marlborough, and if we say she made light work of the job, we shall <?o her no more than justice. Tlib ship, a 1200 tonner, was fastened to about half an hour after noon, and plucked away from the pier. Some ten minutes then elapsed ere she was properly straightened, for the tide being strong flood both vessels sheered a little : the tug had to stop in order that tho tow line which had fouled tho dolphin htiiker might be cleared. A fair start was then cft\vte>l from abreast the barque Southern Cross anchored «ff C.irey's Bay ; but until the tuvc and her tow were clear of the shipping much below half speed was maintained. The piessure of steam at this time was 541b5., and vacuum 25 inches. After the barque Loch Dee w:is pissed Mr Donald, the engineer let the tuif out a little, and the revolutions of the engines wei\s iucrcise't to i!S, about half-speed. They were subsequently increased to 30, and once to as high as 36, but as the boiler then discovered priming inclinations, the revolutions were gradually reduced to 30 again. Thus, reckoning 41 revolutions as full-speed, only about three-quarter speed wai attained at any time, whilst below it was the average. At ihi3 rate, and steaming against the las; quarter of the flood tide, the Koputai passed the Tinwru lightship in 50mins., and after having eased a few minutes to pick up the pilot boat, cros&ed the bar in Ihour Gniins. Tvve.ve minutes after she opened Cape Saunders. The time made wa3 not so bad by any means, and will be easily improved upon as the tug works into good order. The pressure of steam ranged between 481b. and 541b. , 701b beiDgfullpre3sure, and the number of revolutions from 2S to 3G, or an average of about 30. The rate of speed attained was six miles an hour, according to measurements made on board the Marlborough. Having eiven the latter a good offing, the tug cast off and returned to Port, the run from the bar to the Old Jetty being made in 55 minutes, against a strong ebb tide. Tne Koputai w.s then taken down to the Carey's Bay dolphin to ba swung for the adjustment of her compasses. On Wednesday she left for Lyttelton, with the ship Canterbury in tow. The towing power of the tug Koputai hai ro n demonstrated in a very gratify in<? manner by her la'-e performance iv towing tho shin Canterbury to Ly-tel-ton. _ We gave the Koputai 30 hour* to accomplish the ai.-iUnco, which, in round numbers, may be :,9t down at 200 mile 3. To do tVis in 36 hours with a 1300-ton ship behind her, would bo a most creditable performance; but the Koputai excelled it by five hours, for, according to the telegraphic advices received yesterday by Mr James Mills, the managing director of the Union Company, with which the tug is ma measure incorporated, she arrived at Lytteltorfat 9 p.m. on Thursday ; and as she left Port Chalmers at 2 p.m. on the preceding day, she niaue the run up in 31 hours. This gives an average speed of six knots and a half per hour nearly- excellent work indeed in a sea-way.