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Steam Turbine (Continued from Page 38) logous to the overhead shafting of a machine shop. On considering the characteristic duties of the various pumps in re- spect of their output and the head against which they discharge, it will be seen that for the majority of them a rotary drive from the main engine cannot be suitable at all speeds of the ship, since a constant head of dis- charge is required whatever the speed and direction of the main en- gine. This is the case with the con- densate and feed pumps, the forced lubrication pump and the bilge and sanitary pumps. At first glance it might appear that the circulating pump and the fans were suitable for driving in this manner, because in these units both the required head of discharge and the required quantity diminish in such a way that a speed reduced in proportion to the speed of the main evgine is sufficient to maintain them. But in the case of the circulating pump there is the difficulty when re- versing that if this pump were driven from the main engine the vacuum would fall off and stopping power be lost at the moment when the engine came to rest, to avoid which it would be necessary to bring the ballast pump into operation when maneuver- ing or preparing to maneuver; while in the case of the forced draught fans independent regulation is of considerable value for maintaining the correct proportion of combustion air. From these considerations it appears that a simple system in which the above auxiliaries are driven from the main engines under all conditions is hardly practicable. For all maneuvering conditions these auxiliaries must be independently driven. A system however in which for the sake of economy of overall voyage consumption the auxiliaries were driven from the main engine at full speed ahead, and_= stand-by auxiliaries provided for other condi- tions, would both add to the initial cast and be cumbersome in opera- tion. Combined Arrangement Used The solution of this problem em- ployed in conjunction with the Simplex unit is a combined arrange- ment of certain of the auxiliaries in a group unit, driven by the main en- gine at full power and by a separate ergine when maneuvering. The cir- culating pump, condensate pump, forced lubrication pump, bilge and sanitary pump are driven in this raanner, by a chain drive and fric- tion clutch from the main engine at full power, and through another fric- tion clutch from the auxiliary engine under all other conditions. The feed pump and forced draught fans are not included in the system, but for 40 the sake of independence of control are separate steam driven and motor driven units. Such an auxiliary unit has been designed and manufactured by Drys- dale & Co. to work in conjunction with the main unit described above. In conclusion the author desires to express his thanks to the Parsons Marine Steam Turbine Co. for facili- ties in connection with the experi- ments described, to his colleagues at Turbinia works, to Mr. Johnson, of the Canadian Pacific Steamships Lid., and to Drysdale & Co. Chicago, Foreign Trade (Continued from Page 25) at gone, O17, Some coke also is shipped from East Chicago, total exports last year from there and Chicago being 53,757 tons, against 29,457 tons in 1933. A variety of products from Chicago’s meat packing plants move to foreign ports via the Great Lakes. Exports of pork in barrels last year were valued at $320,640, compared with $223,024 in 1933. Other meat prod- ucts shipped last year included beef and hog casings, beef extract, hams, bellies and bacon as well as such by- products as animal hair, green salted hides, cattle hoofs and waste. Newsprint paper comprises’ the leading import by water at Chicago, and practically all of this commodity consumed by the Chicago press is de- livered by lake vessels from Cana- dian mills. Two of Chicago’s lead- ing daily papers are located on the river-front which facilitates the un- louding of paper from vessels to printing plants by eliminating an in- termediate handling. Last year im- ports of newsprint paper amounted to $5,405,503, or nearly 43 per cent of total foreign goods received. Grains ranked second in impor- tance among imports, being valued last year at $38,849,753. These in- cluded feed wheat, rye, oats and screenings. Next in order came food products at $1,140,044, being made up principally of fish, sugar, fruit and vegetables. Receipts of flaxseed totaled $603,898. Metals and ores to the value of $481,389 were imported last year. These were largely spie- geleisen, ferrosilicon and pig iron. Cargoes also are shipped directly to Chicago after being transferred from ocean vessels at New Orleans to barges using the Mississippi river and the new Illinois waterway. These barges generally unload at the Inland Waterways Corp. terminal on the Chicago river at Western avenue and Twenty-ninth street. Various ter- minals are used for discharging car- gees received via Lake Michigan, the principal ones on the lake-front be- ing the Navy pier and two other piers at the mouth of the _ river. MARINE REvinw—March, 1935 Shipbuilding (Continued from Page 34) exch and upwards, 16 were sent down the ways in 1934, as against only 4 in 1933. A marked increase was shown last year in the building of ships fitted with steam turbines, these vessels avgregating 169,967 gross tons, com- pared with 19,090 tons in 1933. Leunchings of ships fitted with a combination of reciprocating engines ard turbines, during 1934, totaled $37,740 tons, as against 11,358 tons in 1933. Launchings of vessels built on the Isberwood system of longitudinal framing, last year aggregated 71,381 gross tons, as compared with 46,351 tons in 1938. The largest vessel launched in the world last year was the QUEEN Mary, built in Great Britain and Ireland. Numerous changes occurred in the ship production ranking during last year. The lead in the volume of ton- nage launched was retained by Great Britain and Ireland, who have held it continuously since they displaced the United States in 1921; and Ja- pan is again in second place. In 1933, Japan launched 58,000 gross tons less than Great Britain and Ire- land, but last year the gap was wid- ened to 307,000 tons. The United States, which stood tenth in 1933, has advanced to eighth. The contrast in the volume of tonnage launched by the various countries during the last two years is shown as follows: 1934 1933 Great Britain and Ireland.. 459,877 133,115 sje LOB4 20 74,290 73,733 42,195 61,729 34,016 49,542 60,860 46,905 35,899 MG Beye sesh scien siices Sune vancocensaeanasekans 26,638 16,560 Mmited: States: viccecscissccccsearss 24,625 10,771 INGE W EY scias stevescaievncsvaciassotcsasace 18,857 9,718 SOUT red eee oe ound ees 18,358 18,044 Ua Way of= vaste ey ee eactis aie ene inne 15,950 34,073 Great Britain and Ireland last year made a marked increase in their pro- portion of the world’s launchings of merchant tonnage. As against only 27 per cent of the total construction in 1933, their share advanced to 47.5 rer cent in 1934. In the same pe- riod the figure for the United States gained slightly, going from 2 per cent to 21% per cent. The Cunard White Star Ltd., and associated lines carried a_ total of 153,000 transatlantic passengers dur- ing 1934 which was an increase of 51,000 passengers over 1933. Coal Handling and Marine Machinery Incorporated 92 Liberty Street Tel. BArclay 7-7964 NEW YORK CITY