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Reduce Fuel Bill (Continued from page 34) to add the complications and expense of so-called improvements of which the real value is either debatable or minus. Improvement in Construction There is opportunity, however, for the builder to contribute something in the way of better workmanship than has been the rule for some years. Especially will this be true if types of engines employing other than the erude valves and valve-gear of cur- rent use are adopted. There is no doubt either that much can be ac- complished by better foundry control and denser and harder mixtures for cylinders, pistons, valves, and cylin- der and valve-chest covers, in fact all those parts exposed to steam of varying temperature. This is par- ticularly true as regards the high- pressure end. It has been abundantly proven that the softer and more open the iron the more rapid the rate of condensation, or heat exchange, and if the surfaces are machined the condition is aggravated. Its probable effect on the difference in performance of identical ships has been already touched upon. The suggestion does not necessarily involve higher material costs; it might even be the reverse, although it might slightly affect ma- chine tool time. There remains the question of speed which is so old and so well under- stood and has been so often and so thoroughly proven that one rather wonders how it persists. Perhaps it will be with us always, partly be- cause the subject is attractive, partly because of the facility with which it lends itself to specious arguments and partly because there are actually trades and routes where it is advan- tageous or even necessary. Moving bulk cargoes over short routes such as the Great Lakes and at low rates offering no premium for quick de- livery cannot possibly, over a period of time such as a navigation season, show other than a penalty for speed. The time and distance are too short and the rates too low. Occasions do occur where a little extra speed may advance a ship’s turn or perhaps avoid a delay and this is the principal ar- gument urged, but over a period of time, working with other ships and under the same port conditions the faster ship cannot possibly gain more than the actual hours cut off the running time and everything must work out exactly and at all times to do even that. The difference in run- ning time is easily calculated and 48 . justifying the means. summed up over a period must ac- complish delivery of sufficient addi- tional cargo to at least liquidate the costs of the higher speed over the whole period. If it did no more than that it would still be a net loss by reason of added wear and tear. But it can’t be done. It is of interest to note that the speed question seems to be recurrent. When the steel bulk freighter made its entree in the late eighties speed was apparently considered as among its most important characteristics and for a time in fact it dominated the others. An examination of the ma- rine publications of about that time will disclose that there strong rivalry as to speed records. However, even in those days of low fuel costs it became apparent that speed was costly and practically all of those vessels underwent modifica- tions which resulted in speed reduc- tions. In some cases. ships .were lengthened; in others the engine and boiler powers were reduced and in still others both measures were adopted, the end always, however, Run at Economical Speed There is for every ship, as every shipbuilder knows even if others do not, a best and most economical speed. This speed for our ships has actually been determined by conditions into which speed did not enter, that is to say the necessity for giving the ship sufficient power to make an able ship, or in other words to take care of herself in bad weather and make her handy in maneuvering. This pow- ering has been the result of long ex- perimentation; some of it very costly. It has gone to both extremes and the acceptance of what appeared to give the necessary qualities naturally pro- duced and fixed the rate of speed which is normal to that ship. It does not mean that the speed possible is the most economical but it means that since the powering is fixed by other con- ditions the most economical speed is that which is obtainable with the given ship at the lowest cost. Driv- ing the ship beyond that speed im- mediately reduces earnings. It just happens also that for our ships the needful power about corresponds with that for best efficiency, using the word in its technical sense. On very long voyages there is opportunity for a slight increase in speed produced in the lower cost brackets to add earnings, but as the power cost in- creases rather faster than the cube of the speed it ought to be readily apparent that between the added pow- er costs on the one hand and reduced MARINE REVIEW—May, 1927 existed a- cargo deadweight on the other the possibility of increased earnings soon disappears. There is, however, a sort of twilight zone in which lie possibili- ties of better speed without increase of power through fining the lines but only at the cost of reduced dead- weight. The zone is bounded by very narrow limits and can only be accur- ately determined either by model basin tests or extremely careful ob- servation of actual ships. Naturally the latter method is exceedingly costly and practically out of reach, involving construction and operation of the com- plete ship and careful separation of propulsion costs from all other factors. E. B. Sadtler’s Proposal Analyzed An example of the misleading argu- ments frequently encountered and which owe their origin generally to lack of accurate knowledge of ac- tual conditions is found in the sug- gestions of E. B. Sadtler in the No- vember MARINE REVIEW. Mr. Sadtler (who should not be confounded with Dr. Sadler) cites a specific ship for which he assumes an average speed of 12 miles (we may ignore the knots, since nautical miles are not employed in lake navigation) per hour for a round trip distance of 1650 miles and a voyage period of seven days. The distance corresponds with the Duluth-Ashtabula mileage and the period is fair enough. Now let us consider the figures used in support of his suggestions. He says if the speed is increased one mile per hour the voyage period will be reduced to six days. Since the re- duction in voyage period due to high- er speed cannot exceed the reduction in hours under way, it will be ap- parent that the running time © is shortened 10% hours, not 24 as claimed, and this moreover provided the whole distance can be negotiated at the speeds indicated which is far from the fact, since, as everyone familiar with the trade knows, at least 400 miles of the total are subject to shoal water and controlled navigation impediments. Abundant evidence, not hearsay nor general statements, is at hand dem- onstrating that good-weather time for able 12-mile ships on the voyage indicated is 144 hours, or six days. This running time would then be shortened to 5.56 days and the voyage period to 6.56 days and the number of gained trips in the 210-day season assumed would be exactly two and not five as claimed. It can under no circumstances be anything different unless changes occur elsewhere than in speed. If now the deadweight is reduced