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6 MARINE REVIEW. eee eee pe PS te AA LN TE ITE TT a EE EE LE I TEE TT TT a ae TL TT AT ET aaa Eats apa a ESTAS? GE EIT SSE SS TORE RIG oie saa Report of Experimental Trip, /MADE UPON SCREW STEAMER E. P. WILBUR TO THE BUILDERS, THE GLOBE IRON WORKS COMPANY, CLEVELAND, O., [BY GEO. C. SHEPARD.| In the practice of ship-building upon these waters, designers, owing to the shallow rivers and limited dockage, can not borrow directly from the practice on the coast, but must depend upon their own origitiality wherewith to get out vessels to accommo- date the peculiar conditions existing, and with the advent of steel in construction, finer lines and the use of high expansive engines, it has become desirable to obtain comprehensive results of actual performances, from these, coefficients by which these perfor- mances may be compared with those of vessels considered to be good practice upon deep water. Acting on this line we left Buf- falo September 16th, 1889, upon the Lehigh Valley Transporta- tion Company’s steamer E. P. Wilbur, prepared to take such observations and make such trials as the regular running of the vessel would permit. The weather, though not severe, was such as to keep the ship pitching some during nearly all of the out-bound trip; this made testing impossible at times, but on the return trip the weather was more propitious for our work. Going up, the ves- sel was loaded with only a few hundred tons of package freight and 231 tons fuel, plus the water ballast usually carried under these conditions, of some seven or eight hundred tons, and drew 5 feet 2 inches forward and 13 feet aft. This gave good water for her wheel but presented considerable surface at the bow for the action of the wind. From Chicago to Buffalo the Wilbur carried a miscellaneous load of grain and package freight which load gave her a draft of 15 feet 6 inches aft and 15 feet 2 inches forward. This vessel was built for the package freight, grain and flour trade between Buffalo and Chicago and was designed to carry big loads with despatch, hence has fair lines. She is built with ‘Steel frames covered with soft steel sheathing and is in every way a stiffstaunch craft, while the arrangement of masts and _ cabins is such as to present a very attractive appearance. Dimensions of ship: 290 feet, 2 inches keel. 306 feet, 6 inches over all. 25 feet, 6 inches depth of hold. 40 feet molded beam. Mean draft of water, 9 feet, 1 inch, 15 feet, 4 inches. Displacement, net tons, 2,410, 4,300. Immersed midship section, 354 square feet, 603 square feet. Co-efficient of fineness, .731, .773. Co-efficient of water lines, .750 .786. The engines, well toward amidships, are of the ordinary triple expansion type, with high pressure cylinder forward and | low pressure cylinder aft, all connected by belts in cylinder cast- ings. The action of the steam in the system is centrolled by single “D” valves actuated by eccentrics directly through the Stephenson link. These links are shifted by a small engine, whose cross-head is connected directly to the. reverse shaft. ‘The points of cut-off in the cylinders are fixed by notches in a small quadrant, these notches engaging lugs on crosshead of reverse engine, thereby fixing the position of the links. The crank shaft is built up of three pieces bolted together at angles of 120 de- grees from each other and the crank of low pressure engine leads, followed by that of middle pressure and lastly by that of high pressureengine. ‘The shaft is 12 inches in diameter and 12 inches in the bearings and the thrust is taken on three collars presenting a surface of 603 square inches. The condensing apparatus consists of a large jet condenser and an air pump, both bolted to port trames of engines. The air pump gets its motion from the cross-head of middle engine. To extensions on either side of air pump cross-head are attached two 3% inch feed pumps, onc bilge and one cooler pump; be- sides these pumps and auxiliary to engine is a small pony pump for general use and a larger duplex pump tor emptving ballast tanks. Dimensions of engines : Cylinders, 24 inches, 38 inches and 61 inches diameter, by 42 inches stroke. Clearances per cent. or piston displacement: H. P., 09; M. P., .078: L. P., .057; Air pump, 24 inches diameter by 21 inches stroke. Weight of engine and shafting, 140.35 tons. The boilers, three in number, are placed forward of the en- | gine fore and aft, ina line across the hold of vessel. They are of the Scotch pattern with three of the Fox corrugated flues in each boiler. Inspectors allowed 164 pounds steam. Dimensions of boilers : i diameter by 12 feet long. perkates se inthes dianréter with grates 6 feet long. Total water heating surface, 5574 square feet. Total grate surface, 162 square feet. Ratio, 34.4. - Weight, (empty), 116.21 tons. — Boilers are provided with horizontal steam drum. The wheel is sectional of cast iron after the style of a Grif- fiths, and as originally laid out the buckets were built with a pitch of 16 feet, but when this vessel came out her wheel had 17 feet pitch. Later, when the engineer fitted her out last spring he still further increased the pitch by moving the flange of the blade around 5-16 inch giving her a uniform pitch of ‘18.07 feet ; diameter 14 feet, with 60 square feet of bucket surface. The gases from the three boilers were discharged through one up-take, 7 feet in diameter and 45 feet high from top of grates, and at a point about 20 feet above grates, put in a pyro- ineter and also draft gauge. Preparatory to this experimental trip encased thermometers were inserted, one in injection pipe and one in hot well; graduated scales were attached to water glasses to read heights thereof. Then the readings of revolution counter, steam and vacuum gauges, thermometers and water glasses were taken every hour by the engineer on watch and thence copied upon printed form by first engineer. On deck, took readings hourly of taffrail log, pyrometer, thermometers, wind, barometer and course. For distances traveled, relied en- tirely upon ship’s log which had been corrected by frequent com- parison to measured distances upon courses. Many of the read- ings taken are not needed in the present instance so have taken those presenting the greatest diversity and combined extracts of the two logs to form one as found in the following table: | | | | lowe | } | | | er | Notel Resister!| BEV: | Steam! Pyro- | Log | Miles | App. No.) Time. of | peer! Per | a leaim) Lyre | wind. | Read-| Per. | Slip. | ‘Engine Reading Min. Gauge. meter. | | “ing. | Hour s | iy on ee Co | 1 |11.50Pa 16 ee FOES Ne LIES eee fo. % | Left) Buffalo (Light. |............ Os 73 | 10 | 4.00pm 18|Thr’tle) 194,360 | 79.1 158 BHO Se: | 289.4 14.04 | 133 11 | 6.00pw18} ** | 204,020 80.5 155 | 610 | Abeam.| 314.3 14.33 | .129 12 | 7.00pm 18} 2d 208,690 77.8 1 620 | Ahead. | 326 13.46} .154 13 | 8.00pm 18| 2d | 213,290 76.6 140 565 | Ahead. | 337.7 13.46 | .141 14 | 9.00pm 18} 2d ; 217,900 | 76.8 85 ea Bee eee | Abeam. | 35 14.15 | .099 18 |10.00A" 19} 2d 278,790 | 77. 155 0 | Ahead. | 507.3 14.04 | .185 19 |11.00am 19} 3a | 283,695 81.7 145 620. |L., Ahead} 520.8 15.54 70 20 |12.00m. 19) 8d | 288,520 | 80.4 135 625 | Ahead. | 683.8 14,97 | .089 28 | 2.50PM 21} 2d estas (3 !31) al ase ois 5 HOitl CMCakOr cr heels. ess. 36 | 3.00pm 22) 24 | 111,450) 73. 143 | 580 | None. | 2755 | 12.54 | .160 37 | 4.00PM 22} 2d | 15,770) 72. 138 640 | None. | 286.5 | 12.66 | .140 38 | 5.00PM 22) 2d i 120,680: RL, 135 590 | Ahead. | 297.5 12.66 | .128 43 | 9,00aM 23) 2d 193,040 | 77. 158 OBO re as | 480.8 13.81 | .123 44 10.004 M 23 2d 197,420 ) 13. |e Tee CU ae eR re | 492.1 13. 129 45 | 9.00PM 23) 3d Po SSO TOU I ccesqentcehre” EO fe OO ficoeet s Beer: | eecee ees Ae 46 |10.00PM 23) 3d 14 SEU SER: | cutie ke 4S 2h O60 t ANCA A EDR. brian eee 47 | 11.00pM 23 3d 246,080 U1.7 140, 660 | Ahead. | 174 13.92 | .124 48 |12.00eM 23! 3d ) 250,7 77.8 G0 Sea ee ers te 'L. Ahead» 29.6 14.04 | 118 5O | 9.00AM 24 |. seeees 292,310 | 798 | 150 | 660 (L, Ahead) 1348 | 13.58 | 1167 51 |10.00aM 24)............) (296,900 | 76.5 | 150 | 650} 2 | 145.5 | 1846 | .139 52 11.00AmM 24 aiiadaas Sa 301,500 76.6 150) | 665 None. |. 158.3 13.58 | .182 54] 1.00PM 241 ........... | 810,870 | 79.5 1 a a | eR See | 182.4 VA2T | 122 | | | i i In the preceding table are different speeds made by the ves- sel in miles per hour, also the revolutions of the engine per min- ute for the same hour, and now to get a graphic representation of the relation of these elements in their difterent magnitudes, have plotted them on the following plate (No. I) using the miles per hour speed of vessel, for abcissae and the revolutions per minute for ordinates. Since increasing the draft of water changes the relation between revolutions and speed, have taken points of different drafts with different origins. At all times there was more or less wind and sea to retard motion and other- wise affect the vessel and wheel, and points plotted from data taken under these conditions without eliminating the effect of disturbing influences will not closely, follow any law or forma curve. The curves that have been drawn are but the approxi- mate, theoretical curves that might have been drawn had the conditions been perfect. They represent the loci of the mean relation between speed and revolutions. [ro BE CONTINUED.] The above is the first of a series ot the most complete report of a tri ever made on a lake steamer. articles which will give ple expansion marine engine as camer. Four sets of indicator cards, taken under very different conditions are among the illustrations. Steamship and engine builders and mechanical engineers will be interested. Send $r for ten issues, which will include the article complete. A docetg ee ee ae