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June, 1914 THE MARINE REVIEW a 217 dicate at what stage, if any, the steam loses all "superheat" and returns to the "saturated" state. The table on page 216, which is ap- proximately reliable, gives the average results obtained, although the higher temperature taken by the pyrometers of the ordinary "D" valve for the may, as before mentioned, be lower M. P. engine, fitting of suitable piston- than was actually the case. rod metallic packing, -- steel-neck It will be seen that superheat is bushes instead of brass, and additional shown in the steam chest of the first some modification was made to the smoke-boxes to allow. of the super- heater headers being fitted. The al- terations to the engines consisted, in addition to the usual general overhaul, of fitting a balanced flat valve in place Port Lincoln, but fitted for carrying frozen cargo, and not fitted for emi- grants. Before dealing with the tabulated sults of the performances of the steamers under consideration, some description of the data available, and the basis on which the deductions have been drawn, is essential for the purpose of arriving at their value, not only to engineers, but also to ship- three engines, and almost in the low- Bae oe . - incoln pressure, while at times a few degrees S. S. Port Augusta. and Port : Macquarie, of superheat are reported to have Triple expansion. Quadruple been actually registered there. The ae ' expansion. : : it Wit With ers a about: H. a 73. per cent; : 2 : saturated superheated _ superheated ; : er cent: 3h verage of consecutive voyages. steam. steam, steam. M, 2 P oi P. 2, 70 per Port Augusta, London to Adelaide, via the Cape.. 7 So omer cont; k, P;,-70. per. ces. Port Lincoln Ph Port Macquarie, London to Mel- : boutne, calling "at the *Caness 2: <8 oi se ea 6 The co eosin from which these data Days on voyage 8-689 Wes Sole FSP REE OMe SANE Ocoee aso ts 46 days 10 49 days 12 41 days 1 were obtained belong to W. Milburn hrs. 46 min. hrs. 2 min, hr. 35 min. 6 66. --of--London--stk oar khoale Days "under: Steam: 4.06 2 se 7 he ae eS days 2 ce ' rs. 38 min. rs. 1 min. rs. 43 min, are due to: Mr. Milburn' for his per- Hone ida in pounds per square inch........ gh fee ee mission to place the results before Draught (mean) leaving Legdom,.....- 60a 40. 24 ft. 934 in. 24 ft. 5% in. 24 ft. 1034 in. se sinstitution... The,,Port. Augusta Cot aused ten aM paponece | yaa | Pe6ONs |" Gaeages was built and engined by Hawthorn Less deductions for raising steam, banked fires, : : i ee 7 : winches, galley fires, crew's bogies, and Leslie & Co.,-in 1906; the boilers were condensing fresh | Mile arses 34 15.0 61.88 fitted with superheaters and the meces- Co#ls used for main boilers for supplying! sieam on | sary alterations made to the engines, ee gear oo plectrit ant iaccc eee: os 1,710 1,545.45 SOVSAT j : ess deduction for Port Augusta steering gear SEs by the North-Eastern Marine and 'electric' light at 1 ton: per. day. <.+..... 46 AOS ee cree Engineering Co., Ltd., of Wallsend- Less deduction for Port Lincoln and Port Mac- T 4 ' quarie, including also steam cooking process on-T'yne, in May, 1911, when the boil- -and boilers and previsiog refrigerator ma- r : Chine at 2 tons: per "day...%..- Oisicie wie bias oie ae Re SRR Sn ere 81.9 and eres were five years old. Coals used for main engines and auxiliaries (cir- The Port Lincoln and Port Macquarie ' ee pump, feed pump, evaporator, and fan) 1,664 1,495.95 2,191.27 : : Oal= Per cday vic. ect. wine sug eee ees ete 36.65 tons 32.1 tons 56 tons were built by Hawthorn, Leslie & Co. Coal per indicated horsepower, in pounds per hour 1.6 1.4 1.29 and engined by the North-Eastern Quality of coal as indicated by loss reported on ee 3 ij Voyare © Cashes,. etc) 2. ea ee: 14 percent 13 percent 16.4 per cent Marine Engineering Co., Ltd. of Indicated AGreePOWEL ea ie ee 2,102 2,005.4 4,027 Wallsend, in 1912. The boilers were designed for working the engines un- der saturated steam requirements, but fitted with superheaters. The Port Albany was also built by Hawthorn, Leslie & Co. and engined by the North-Eastern Marine Engineering Co., but the boilers were designed for and fitted with superheaters. lagging to cylinders, etc. A gravita- owners. tion filter was installed, and after- the wards enlarged and improved until its efficiency was satisfactory. The Port freights, and, to do so, the cost of Lincoln and Port Macquarie are du- running involves a heavy expenditure plicate vessels in every respect; they for fuel, either coal or oil; the ordin- have no auxiliary boiler, so that all ary means of ascertaining such ex- demands for steam are supplied by penditure on the fuel account is by calculating the tons of fuel used per Mercantile steamers are for commercial purpose of carrying passengers and cargo at remunerative Port day. ; Port Port Mac- Port : Particulars, Augusta. Lincoln. que: nee The data for this purpose are ob- no. ee pee pels in. ae 42 Sie tained "Prom the' yoyaee Wostea et Depth, molded ee oe 28 ft. 7 in. 31 ft.10% in. 31 ft. 10% in. 31 ft. 10¥% in. the engineers' log book, which latter Coss: tonnage). Ser en ee 4,063 7,236 7,236 7,206 i 1 ilable for th ificati PAU WCRS oo). fa) oii cee 7,226 9,254 nee ae is also available fo e verification Gun Ee tee tae ee os daple bts pe egeiad ee of the daily averages as set forth in ee ee a 74 in, 81% in. 81% in, 81%in. the abstract sheet. These data, when cu Dan whyageni 0s. oak ee Ae 4100 a in0 covering a number of consecutive voy- Boilers, ie Two Four gos ee ages, assume a value, and in general oO : pes ; iz indri- yli = : : t NS Lena aE am A GG Kae Ce ope aa single cal, single practice are accepted as a fair basis : ended ended ended ae of comparison, so that, with a known Total heating surface.......:....... 5,720 11,600 11,6 , se f £ 1 d Total grate surface................. 137 240 240 260 consumption of tons of coal per day, Total superheat 'surface. 0... 2,390 4,000 4,000 4,320 ti in bunkers required for Working pressure =... 0.53024, .00045 180 220 220 220 the quantity b q eaioae diam, of boiler. tube, plain: . 2% in. 24 in. ae en a definite number of steaming days €rnal diameter of boil t 2% in. 4 in. 4 1n. : ae nternal diameter of pe ie Peaitea he i ng ais 13 mm. 15 mm. can be ascertained. The amount of ee ee ee Howden Howden Howden Howde coal required for loading and dis- 2 In the case of the Port Augusta no alteration was made to the boilers, the grate surface or any of the sat- urated steam connections, the only change or addition being in the case of pipes or connections coming in con- tact with the superheated steam, and the main boilers; these are increased above the usual requirements of aux- iliaries owing to the vessels being fitted up for emigrants, which neces- sitates additional galleys, pantries, re- frigerator machine, and electric light. The Port Albany is a duplicate of the charging cargo and other purposes is estimated separately according to the conditions and circumstances of the voyage. The tabulated results are therefore not compiled upon data, such as are available in a laboratory, on the "test"