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Reduce Lake Vessels’ Fuel Bill-III A Study of the Influence of Boilers, Main Machinery and Auxiliaries on Earnings of Great Lakes Cargo Vessels has often been said that no ad- vance has been made in_ this direction in 40 years and it is very nearly true. Indeed, judging from general results, the movement has been retrograde, but this is not so much the fault of engine design as of other features which have been touched upon. To all intents and purposes the triple engine stands to- day as when it made its entree in 1888. Improvements in design and performance which have demonstrat- ed themselves in other lines of en- gineering have made no impression afloat. Even devices well known and proven 50 years ago as contributing to economy have been discarded. Above all things simplicity and re- liability have been watchwords and, as words go, they have done pretty well, but they are a synonym for back- wardness and inertia. Therefore we have stuck to the plain multicylinder engine with positive valve gear with all its crudities and inefficiencies, de- ceiving ourselves with the idea that we were thereby insuring dependa- bility by continuing to use something that is found almost nowhere on earth outside of a ship’s engine room, while day by day, year in and year out, the things which go to improve efficiency and economy and which we tell ourselves are not dependable, go on performing their functions with even fewer troubles and_ interrup- tions than the dependable apparatus we have tied ourselves up to. if RESPECT of main engines it This is no fault of an engine builder —he has always known of these things and has been ready and will- ing and able at any time to put them into practice but he can only give the owner what the latter wants and is willing to pay for, and the re- sponsibility for the dead-end at which marine engineering has been stand- ing for these many years lies square- _ly at the owner’s door. For example, over 50 years ago, the Corliss engine was in use in a lake ship. To be sure it was a single- cylinder engine, but of fair size as engines went in those days, and the introduction of the compound engine ‘at about that time (in 1872 to be This is Part lil of Mr.. Penton’s article, Part IV will appear in an early issue. 88 By Henry Penton exact) with its immediate great economies pushed the other to one side, but the old Corliss was a won- der of economy in its day and con- tinued to be good for many years until the ship burned in the Detroit river in the eighties. Over 50 years ago the Cromwell line on the Atlantic coast used poppet valves and releasing gear in large single-cylinder engines, larger than anything of the kind ever used in lake practice, and obtained a fuel econ- omy, according to published reports, ‘that compares favorably with almost any of our modern triple ships in spite of the comparatively low steam pressure employed at that time, reach- ing a reported consumption of 1.33 pounds per indicated horsepower per hour. : The New York & Mexico Mail S. S. Co. used Corliss releasing gear in engines of similar type and size in its ships about the same time. In both cases the engines made about the same revolutions as are customary with modern engines but very much higher piston speed because of their longer stroke. Both designs were purely American and no record has been found of their appearance else- where until lately. The fuel economy question in Europe being more press- ing than with us has led to the reintroduction of the poppet valve gear in a number of recent instances with the resultant improvement which was to be expected. The compound engine as it came to us, and in its extended form of the triple engine, represented sim- plicity and cheapness of construc- tion in the most extreme degree. The same features account for its re- tention now. No builder attempts to deny that the ordinary engine is an inefficient agent but so long as _ his customer is content with cheapness and mediocrity there is no reason why he should shoulder any burden or responsibility without adequate compensation. During the late war, in an effort to extend the steaming radius of the ships turned out by the lake yards and which by reason of their com- paratively small size suffered severely in loss of cargo deadweight due to bunkers, authority was granted to equip one of the ships under con- MARINE REVIEW—April, 1927 ~ This tract with an engine with a better type of valve gear than ordinarily fitted. The engine was not designed for the purpose, but one of the standard engines was modified by the substitution of poppet valves and a modern gear. Due to delays of one sort and another the improved en- gine did not go on trial until some time after hostilities had ceased and the results were no longer matters of moment. However, careful com- parisons were made as between the engine with the poppet valve gear and one of the standard type in a sister ship built at the same time and in the same yard and shops, even to the extent of running both ships over the same courses in the same sort of weather and in exactly the same trim and with the same identi- cal crews in the engine rooms. Space does not permit of presenting more than the outstanding features but the full report of the trials was pub- lished at the time. The fuel in both cases was oil which made accurate measurement easy by means of care- fully calibrated measuring tanks. The difference in fuel per indicated horse- power per hour was 18 per cent but the overall difference was much greater by reason of the fact that to get the same revolutions and speed the older type of engine had to de- velop so much more horsepower that the figures in favor of the poppet valve engine were about 29 per cent. additional power appeared to be due to friction losses since there seemed no other way of accounting for it. The instruments were the same in both cases and applied at the same points and checked by alternate observers. It is hardly probable that all the losses were in the older form of valves and gear, extravagant as we know them to be in that respect, and there undoubtedly was much bet- ter workmanship put on the _ substi- tute engine, but the observations ful- filled most completely and _ perfectly the expectations of all concerned. The ship went to sea and made _ several voyages to Europe and on one occa- sion returning in ballast fought a succession of westerly gales during which time the engines raced con- tinuously for days on end but with- out the slightest difficulty attending their operation. Her voyage reports