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April, 1919 matters, including. threads, etc., but I am certain their deliberations have never penetrated into marine engine practice, for the variety of fittings and diversity of flange diameters in the engine room is truly bewildering. In’ this respect there would be a great gain in standardizing on proportions of flange diameter to bore, and pitch and number of bolts, etc. Much Hinges on Uniformity It is of more importance than a first thought would be deemed neces- sary, that the manipulations of marine engines. should be more uniform. En- gineers come and go—particularly juniors—and mistakes are liable to be made with the variation of present design ‘and practice. Without refer- ring to those differences it is sug- gested that in a standardized type of engine: All starting platforms should be on the starboard side; all propellers right-handed; all link motions at the front for ahead position; all reversing wheels to work right-handed for ahead —left for astern; all main stop valves in particular, and check valves in gen- eral, including tank and bilge valves, right-handed, viz., right-handed to open—left-handed to shut; all engine telegraph dials to face athwartships, viz., the handle, or reply, to be ahead- ways for ahead, and asternways for astern. With a new standardized type of ma- rine engine it seems to me that economy in lubrication is deserving of attention At present the sizes of engines we are commenting upon consume an average of 21% to 3% gallons of engine oil per day. If solid lubricant, in screw-down spring cups, could be fitted to main shafting, rocking and weigh shafts, eccentric rod and drag link ends and pump links, eccentric straps, etc., it would greatly reduce oil used and wasted, and solve the greasing question. As to piping arrangements, there seems to be no symmetry or design, nor any provision for an additional supply; or indeed for the required capacity of steam and exhaust areas of auxiliaries if all are working to- gether. A simpler arrangement can be made when junction pieces are introduced for the distribution of the steam services and connections from exhausts brought to a cast iron junc- tion box, thereby simplifying the con- trol to atmosphere, condenser, or to the low pressure chest. It also per- mits of suitable drainage at all times. It seems a pity that there are not similar ideas as to the strength of boiler scantlings between the classifi- cation societies and the board of trade. One wonders why, at this stage of marine engine and boiler practice, the board of trade should consider that some parts—particularly boiler shells—require, under the rules, such additional thicknesses. The only explanation to the ordinary mind is that their rules require revision in the light of modern improvement of material and workmanship, for if 1 3/16 inches is good enough for a given working pressure for a first- class cargo steamer carrying, say, a crew of 75, why should a small passen- ger ship, carrying perhaps a total on her certificate of 50 persons, and hav- ing a similar size boiler and working pressure require a 13-inch steel plate? I am not giving exact figures, but the difference is an approximation to that named. Where this anomaly comes in to the detriment of the cargo steamer—particularly of the shelter decker or ’tween deck steamer —is when a temporary certificate is required for the carrying of labor emigrants, coolies, troops or similar human freight. For such conditions the working -pressure, calculated on the scantling, suffers a quite serious reduction, as also for the _ British Corp. calculations for crankshafts, etc. If, on the other hand, the machinery is specified to pass board of trade rules, the extra expense and the addi- tional weight to be carried is quite a considerable item. For the main boilers of standardized vessels the chief point that appears to me essen- tial is that furnaces and tubes should be standardized into certain groups of sizes. For instance, based on a working pressure of 180 pounds. Furnace Sizes Vary Greatly Furnaces might be standardized on certain diameters, as 38, 40, 42, 44 inches, etc., with lengths to correspond to an agreed practice, and the back ends—preferably of the withdrawal type for easy renewal, as now general practice. The important thing is that a maker could stock ready—or ready to complete to templates—a minimum of standard sizes. Then the difficulty of getting flues for new or renewal requirements would save time. Neither would the make of a furnace matter— particularly of the ribbed or corru- gated type—matter if the ends were THE MARINE REVIEW 181 to a standard fitting. As things are at present, the furnaces are to every conceivable length and fraction of diameter. On this head one might draw attention to the objection to large diameter in furnaces. When these get up to 48 inches diameter the tendency to distortion and sag- ging is very marked, particularly on long voyages. With furnaces not ex- ceeding 44 inches diameter this ten- dency is greatly reduced. There is rarely any trouble with flues of, say, 42 inches diameter. It is a moot ques- tion whether four furnaces of small diameter are not much better than three of large diameter, notwithstand- - ing the usually accepted objection on the score of firing, or of single or conjoined combustion chambers. The fact remains that there is a very large amount of furnace renewal, and that not on account of age, nor often due to actual neglect. Parts Should Be Labeled All important and heavy parts of | a marine engine should have the weight of each item cast or stamped on them, so that lifts and overhauls may be attended with the minimum of risk. The boiler should be stamped with its shipping weight and _ total gallons of water to the level of half- glass. All rods and journals should be stamped with the original outside diameter of the wearing part. Each chamber and _ cylinder should be stamped at their respective ends with the original bore. Piston and _ slide valves should be stamped on their top edges with the travel, lap, and leads respectively. All glands should be stamped with the size of packing re- quired for each gland, and, better still, with the depth also. A propeller shaft should be lettered on its inside end as to whether the brass liner is continuous or in two portions. All auxiliary machinery should bear the | maker’s name, number and size. All valves should be _ properly brass- labeled to indicate their function. Finally, if some such standardization and allowances for maintenance could be arrived at by a joint committee of both technical and practical men it would simplify the whole question of specification detail, and secure to the superintendent—on his owner’s behalf—those extras and allowances - against wear and tear that the prac- tical man feels justified by experience in providing .for—on the present basis of specification—more particularly with some firms than with others. Me eae etn ae eee AS