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19022] MARINE REVIEW. | ae covery, but there was also a Leyland liner of 8,000 tons, a Hamburg & River Plate liner of 4,000 tons, and a cargo boat of 2,300 tons for Canada, besides other craft. The output of the yards on the Dee (Aberdeen) 'was thirty vessels of 6,435 tons as compared with thirty-two. vessels of 6,905 tons in 1900. Practically the whole of this output was in the form of steam fishing vessels (trawlers) and all, with two or three exceptions, for local owners. There were also constructed at the yard of John Duthie & Sons, Montrose (to the south of the Dee), ten trawlers aggregating about 1,800 tons. . STATISTICS OF MARINE ENGINE CONSTRUCTION. The total indicated horse power of marine engines constructed in the world in 1901 is estimated at 2,246,630, of which 1,476,818 I.H.P. was in the United Kingdom, and 769,813 I.H.P. in other countries. Of this the Clyde proportion was 483,605 I.H.P., being nearly one-fifth of the output of the world and nearly one-third of that of the United Kingdom. | But no individual engineer on the Clyde turned out as much as Richard- son, Westgarth & Co. of Hartlepool, whose record was 106,000 I.H.P. The following shows the output on the Clyde of marine engines: THe. Brown. a Cor CU lvdepank. coco! ov oe ees Gg a ns 61,000 Poirheld 4, Gove... ova ei ek ee 57,200 Denny & Co, Diimbparion <4. ee a 30,650 London <Glassaw S. & FE. Co. Govan... 2. 28,300 Dunsmute. 66 JACKSotn. ci cies cs oe cs eee ee 24,700 RowWath @.00.05 aes. ce in a ee ee 19,280 Beardmore & (0. Gowan... 6). Saco 18,800 Hienderson, & Co. Partick. 0 ich ke ek ee 18,450 Kineaid @ Co. Greenock... c. . .18,250 Stephtn Ww SONS, Linthouse.. 6... os ee 18,100 Rankin & Blackmore... <: 0 25 ea 16,300 scott .& Co. Greenock. oor) aa 15,010 "Barclay Curie & Co, Whiteinch.23...4...... 5. 11,900 Ross (& Duneat oe yrs ee eee 10,615 Clyde's. Eo Oo. Por Glasgow. ...0 0 a 10,600 Gard Ce. Greenock... ee 9,300 SHNONS G00. er eee eee Se 9,205 Bow, NVitlachian G70. os 0 a ee pice ue ae Weve A Ditiverwoed. .. sec. kee ss oe 7,680 Bor CET Tio i ee ee ee 7,150 Lobmtz @- Co. Reniew...9..). a ee * op Del OU Blefiitnie & Mersuson Paisley. 1.0... ee . 6,150 Daniop & Co,, Port Glaseow..... bean a ee 4,100 McKie & baxter Govan, ..0. 2) 4,400 FiGgison ee On - 4,050 Camppblr SW @alGetWOOG. .. 0... a ee 2,365 Ay Rodger a COL Nrovdte. i oe a ee 2,000 Pisher, O00 ee 800 Orier Semis. ee ... 3,500. 433,605 This total compares with some previous years as under: 1.HiP. rEeP 1000 ee HOO 36° TY TAGE 295,620 1800 Os ES 478,603 NOON a 256,545 © S08 OC ea 510,815 LOO2 322,564 BOTS Oe ee, 373,195 TOO 308,886 106.2, eo ee 426,759 TEQ0F ee 363,807 B96 FL 363,490 In 1900 the largest engine output in the world was that of the North Eastern Engineering Co., Wallsend-on-Tyne, with 81,910 I.H.P., while John Brown & Co., Ltd., Clydebank, came second with 70,000 I.H.P. It should be noted that engines are often made on the Clyde for vessels whose hulls are constructed elsewhere. The year 1902 opens with orders already booked by Scotch ship builders to the extent of 430,000 tons, which is pretty well distributed but not evenly, and so it will be that in the early months of the year many of the yards will begin to present an empty appearance, unless there is a new inflow of orders. In the meantime contracting is at a standstill, so large is the over-supply of ocean tonnage, and so depressed are the freight markets.. Of course the established lines and mail carriers have to keep up the efficiency of their fleets, no matter how traffic and freights fall off, and they will have'to build anew as they have to do every year. But they are holding off meanwhile in the expectation of buying cheaper later on. Among the work on hand is an Ocean company liner and two Pacific company mail liners at the Fairfield yard; four British India liners at Inglis's yard; three large liners at Henderson's yard; Furness-Withy and Australian liners at the Clydebank yard; two large sailers for the Anglo-American Oil Co. at Rodgers' yard; two Peninsular & Oriental steamers and two Pacific Mail liners at Caird's yard; a 12,000-ton oil tank steamer for the Anglo-American Oil Co., two big cargo tramps and a British India liner at Scott's yard. These are only a few typical instances among the many items. The admiralty contracts under the last naval program have yet to 'be placed and it is tolerably certain that a large por- tion of them will come to the Clyde. Then the Cunard company and some of the big lines will have to build this year. For "cargo tramps" the demand for the present is "off." THE SUBJECT OF RUDDERS. The all important subject of ship-steering was under consideration at a recent meeting of our Institution of Engineers & Shipbuilders. Much light was thrown upon it by Mr. J. F. King, who, in the course of a paper on rudders described the types of rudder commonly in use in normal merchant vessels. He said it might have been expected that the gradual evolution of the tramp steamer, and the accumulated experience of hun- dreds of vessels of varying types would have produced a generally similar and presumably best form of rudder for each type, but really the most striking feature is the extraordinary diversity of opinion shown in the forms of rudder fitted in vessels of practically the same type. In order to ascertain the effect of rudder forms on steering, some experiments were recently made in the famous experimental tank at Messrs. Denny's works at Dumbarton. The different rudder blades were slipped into a circular stock. It was found that there was no steering value in the stock itself. A rudder of ordinary full form was found to have exactly the same turning force as a rectangular rudder of the same depth and area. The _Tectangular shape, however, possessed the practical advantage of showing a reduction in the twisting moment and corresponding area of stock on account of the center of gravity of the rudder plane being nearer to the center of the stock. Experiments with triangular rudders, one set having the bases and the other the apices of the water-line, showed that the series with the broad part at the water-line gave about 20 per cent. greater steering efficiency, and those with the broad part at the bottom of the stock about 8 per cent. less efficiency per foot of area than the square rudder. Mr, King suggests that the superiority of the former is due probably to the increase in wave-making resistance from the rudder blade towards the surface of the water, and to the form of the vessel causing acceleration of the stream lines towards the load line. As these simple forms practically embrace the extremes to be found in the curvilinear - shapes, experiments were also made with rectangular and triangular rud- ders of different breadths. It was found that the value of each type varied directly as the breadth of the rudder. As the model used was that of a vessel of comparatively full form, having a co-efficient of .76 at the load line, it might be concluded that generally the best form of rudder for a merchant vessel would be one very wide at the load line and narrow at the bottom, but, it is contended that apart from the fact that a rudder of © this form would require a large stock and more powerful working gear on account of its great breadth, it is probable that the action of the propeller accelerates the movement of water past all parts of the blade, and such a rudder would be useless when the vessel was in ballast trim. These experiments and considerations suggest that a square rudder is the © most satisfactory form to adopt, as representing a large surface at the load line at all conditions of trim, and requiring the smallest stock and working gear in proportion to efficient area. Mr. King does not find sufficient reason, beyond fondness for curves, for the common practice of extending the rudder blade high above the load line, as he thinks the extra area can have little or no steering value, while it exposes unneces- sary surface to shocks from seas, and adds unnecessary weight. With regard to the proportion which the area of the rudder should bear to the. size of vessel it is generally believed that a narrow rudder which could be rapidly set to a large angle without undue loss of speed, if it had enough area, steers as well as, and perhaps better than, a broad rudder. The minimum for modern sailing vessels and for coasting or other steamers which require to maneuver under their own steam at slow speeds in narrow waters is computed at about 1.4 sq. ft. per 100 sq. ft. of middle line plane. STEAMER BRANDON FOR THE OLD DOMINION STEAMSHIP CO. OF NEW YORK. : Building by the Harlan & Hollingsworth Co., Wilmington, Del. REMARKABLE RECORD FOR PUNCTUALITY. The American line steamship Philadelphia was reported at Fire Island at 1 o'clock in the morning on Saturday last. This is the fifth arrival of this steamer since Oct. 19, and during these winter months the Philadel- phia has made a remarkable record for punctuality. Her sailing times from Cherbourg have varied between 5 p. m. and 5:30 p. m. on a Saturday and her arrivals at Fire Island between 1 a. m. and 5:30 a. -m. on Saturday. This is a remarkable showing considering the fact that these five sailings were made during the winter months and in view of the voyages of other steamers.