POWDERED COAL

Nelson Evening Mail, Volume LXIII, 18 July 1929, Page 8

POWDERED COAL

ECONOMIES ON LONG VOYAGE AN INTERESTING EXPERIMENT Unusual interest attaches to the present, visit of the New Zealand Shipping Company's steamer Hororata on account of her semi convorsioii to tlm use of pulverised coal- The vessel berthed at Queen’s Wharf,' Auckland, las! week, gays tile ‘‘Herald”, on Lite completion of her second voyage from England under the, new fuelling conditions. Of the world's maritime tonnage, only eight vessels tiro til present using powdered coal. The Ilororatu. is one of them. Although still in the experimental sttigc, the new fuel lias already demonstrated its commercial advantages and ti great future for it is prophesised by shipbuilding authorities. The results ,achieved on the. llororata are being carefully watched and tabulated by the engineering stall, and will be the subject of searching investigation by experts’ on the vessel’s return to England. The intention of the owners to convert all six boilers on the steamer to the use of the new fuel was prevented bv unforeseen circumstances on the vessel’s last trip Homo, With the result that three boilers' are still being fired by ordinary coal. It is expected that complete conversion will be effected upon the return of the vessel to London. UNIFORMITY IN STEAM PRESSURE Owing to an abnormal amount of rough Wegthcr enciVuniered on the voyage out add tlic fact that only three boilers arc boiiig .steamed on powdered coal, the economics obtainable from the use of the new fuel were not as fully obvious ns might be desirable. .For these reasons the, consumption of coal was not materially reduced, averaging 95 tons a day, and the speed was maintained at only a fair average of 12.69 knots a day. The great advantage of uniformity in steam pressure was fully demonstrated, however, in the ease of the three boilers under observation. The actual saving in steam and eonsumption of coal under the new system is counter-balanced at present by the fact that most of the steam saved is required to drive the crushers and sifters employed on board to pulverise the coal. It is maintained that if this special machinery were driven electrically the economies in coal consumption would be very noticeable!' The economies in labour are also off-set bv difficulties occasioned by the combined use of the two fuels. The Horofata’s usual staff .of liremcn mimbers If], but, it, was found necessary to replace three firemen, whoso services' ware dispensed with when tlm Scmi-coiiversioif was effected, by l.lircc extra 'greasers. When complete conversion is achieved substantial reductions in the boiler-rOom staff will lie practicable. COMPLAINT REGARDING DUST The new fuel is not, .viewed with much favour by the enginerbom and boilcrYoom stuffs ail the Uororata. ' While admitting' its advantage over' ordinary coal from the economic standpoint, they eonipla’in of a fine dust which seems at present to be inseparable from the pul’.vcnsiiig process. At the stage when ’tins fuel is firc'cl it has the consistency of crumbled' chalk, very find and soft, and quantities at all times pervade tlm air of the boiler-room. Blackened faces are unavoidable after even a brief visit to the lower regions of the big ship. The conversion ill England of the remaining three boilers to pulverised coal will occupy about three months, during wliieli the'vessel will have to be laid up.