September i6, 1909J 



NA TURE 



345 



passed through the whole length of the Welland Canal in 

 1907, about 75 per cent, moved eastwards, and more than 

 62 per cent, of the 2,100,000 tons which passed through 

 the St. Lawrence canals moved in the Same direction. 



Shipping on the Great Lakes. 



Canadian shipping and shipbuilding on the Lakes have 

 made considerable progress in recent years, although they 

 do not rival those of the United States. According to 

 authoritative statements there were not twenty Canadian 

 steamers engaged in the transport of grain fifteen years 

 ago ; only three of these were steel-built, and the largest 

 carried only go, 000 bushels. The total carrying capacity 

 of Canadian grain-carriers at the present time has been 

 estimated at ten million bushels, and the capital invested 

 in the fleet is said to be about three millions sterling. 

 Between the harvest and the close of navigation in winter 

 it is estimated that no fewer than si.xty million bushels of 

 grain can be moved from port to port in Canadian 

 steamers. 



Many special engineering features have been introduced 

 into the strtijEtures and equipment of these Lake grain- 

 carriers. They are really huge steel barges of full' form, 

 of uniform cross-section for a considerable portion of their 

 length ; and they possess enormous cargo capacity, 

 moderate engine power and speed, with structures of a 

 simple nature which can be largely standardised and made 

 to resemble bridge-construction rather than ordinary ship- 

 building. They can be built in a short time, the largest 

 vessels occupying about four months in construction. In 

 this way the cost of construction is cheapened, but the 

 rates for labour and materials prevailing in the Lake ship- 

 yards are so high relatively to British costs that at present 

 these grain-carriers are said to cost about 40 per cent, 

 more {per ton dead weight carried) than the cost of 

 ordinary " tr.mip " steamers built in Great Britain. Their 

 holds and hatchways are arranged so as to facilitate the 

 rapid shipment and discharge of cargoes. At their ports 

 of call special mechanical appliances are provided for deal- 

 ing with cargoes, most of which consist of grain, ore, or 

 coal. 



In the design and construction of these cargo-handling 

 appliances the inechanical engineer has displayed great 

 ijigenuity, and the results obtained in rate of shipment 

 and discharge of cargoes of grain, ore, and coal are re- 

 markable. Cases are on record where vessels carrying 

 7000 tons dead weight have been loaded in four hours and 

 discharged in ten hours ; more than 5000 tons of ore have 

 been discharged in about four hours. The draught of 

 water of the steamers must be kept within moderate limits 

 and the breadths of the locks are moderate, so that increase 

 in carrying power must be chiefly obtained by increase in 

 length ; consequently, as individual cargoes are increased, 

 a greater number of lifting appliances can be brought to 

 bear simultaneously, and the rate of loading or discharge 

 can be maintained or accelerated. 



The season of navigation extends over only seven or 

 eight months in the year; consequently, " quick despatch " 

 is essential to success. A large vessel of this class, has 

 the following approximate dimensions : — Length, about 

 600 feet; breadth, 58 to 60 feet; depth, 32 feet; draught 

 Of water, 19 to 193 feet when carrying 10,000 to 11,000 

 tons of cargo ; corresponding displacement, 16,000 tons. 

 The engines of such a ship develop about 2000 horse-power, 

 and drive her at eleven to twelve statute miles per hour 

 in fair weather. The large size and moderate speed result 

 in very economical conditions of working, and the frefght 

 rates are exceedingly low. From oflficial returns it appears 

 that for these dead-weight cargoes the freight per ton 

 mile across the Lakes is from 004 to 005 of a penny per 

 ton mile, the corresponding railwav rate being about ten 

 times that amount. The multiplication of this type of 

 vessel on the great Lakes is a proof that it satisfactorily 

 fulfils the conditions of service. Similar vessels would not 

 be well adapted for ocean work, which demands greater 

 structural strength, different proportions, and a more liberal 

 equipment ; but shipbuilders generally may benefit from a 

 study of the Lake steamers. 



The greater portion of the traffic on the Lakes passes 

 through the " Soo " canals. The vovages are compara- 

 tively short, the average lenith of the trip being about 

 NO. 2081, VOL. 81] 



S40 miles. Consequently, individual vessels make several 

 passages during the season when navigation is open, and 

 the total number of passages as well as the total aggregate 

 tonnage of the ships reaches very high figures. In the 

 season of 1907, for example, when the canals were open 

 less than 240 days, 20,440 vessels (counting as a vessel 

 each passage), with an aggregate registered tonnage ex- 

 ceeding 44 million tons, passed through the United States 

 and Canadian canals at the Soo. The aggregate freight 

 tonnage carried exceeded 58 million tons ; the weight of 

 coal approached iij million tons; the iron ore carried 

 weighed 39,600,000 tons ; and the grain transported 

 amounted to 136 million bushels. The conditions of the 

 Suez Canal are, of course, entirely different, as vessels 

 passing through are engaged on long voyages, and in- 

 dividual ships make few passages in the year. On the 

 other hand, Suez Canal traffic proceeds uninterruptedly 

 throughout the year, while the Soo canals are closed during 

 the winter months. Subject to these differences in work- 

 ing conditions, it may be of interest to state that in 1907 

 4267 vessels of 14,728,000 tons passed through the Suez 

 Canal, and paid transit dues which amounted ta 

 4,460,000/. ; whereas the passage of the " Soo " canals was 

 free. 



The St. Lawrence Ship Channel. 

 Closely allied with the waterway from Montreal to Lake 

 Superior is the improvement of the channel of the St. 

 Lawrence from Montreal to Quebec and beyond towards 

 the sea. From the Straits of Belleisle to Montreal the 

 distance is 986 miles ; from Quebec to Montreal it is 160 

 miles. Formerly the minimum depth of water between 

 Quebec and Montreal prevented the passage of vessels 

 drawing more than 10 to 12 feet during the greater part 

 of the season of navigation. In 1826 the question of 

 deepening the river channel was raised ; in 1844 the work 

 was begun, but was abandoned three years later; in 1851 

 it was resumed, and has since been continued. In 1869 

 the minimum depth of the channel at low water was in- 

 creased to 20 feet, in 18S2 it was 25 feet ; in 1888 27i feet 

 for 108 miles from Montreal to a point within tidal in- 

 fluence. A channel having a minimum width of 450 feet, 

 and 550 to 750 feet wide at the bends, with a minimum 

 depth of 30 feet, was coinpleted in 1906 from Montreal to 

 tide water at Batiscan. Certain work remains to be done 

 between this point and Quebec in order to complete the 

 project adopted in 1889 and amended in 1906, but it is 

 anticipated this will be finished in about four years. Below 

 Quebec the channel is 1000 feet wide. When once dredged 

 it is stated that the channel remains permanent. .Accidents 

 in the channel are few. The Superintending Engineer in 

 Ms Report of July, 1908, indicates the magnitude of the 

 work done by comparisons with the Suez and Panama 

 Canals, the figures standing as follow : — 



Suez Canal . 



Minimum Minimum E'^timated 



T englh depth breadth excavation 



Miles Feet Feet Cubic yards 



. 100 ,.. 29J 100 (bottom) — 



Panama Canal 49 ••• 41 { 500 (mrx'.)|^°'°°°'°°° 



St. Lawrence Channel. 220'... 30 {,0^ (m.ix.)/^°'°°°'°°° 



In 1844 the largest vessels navigating the St. Lawrence 

 to Montreal were of 500 tons ; now the Virginian and 

 Victorian of the Allan Line (12,000 tons), and the Laurcntic 

 and Megantic of the White Star Line (15,000 tons), pro- 

 ceed to that port, and have made the passage from Quebec 

 in less than ten hours. Ordinarily, this passage occupies 

 eleven to twelve hours, the return passage being made in 

 nine to ten hours. 



In the execution of these great works a specially de- 

 signed dredging plant, including several types,, has been 

 employed, and works about seven months in the year ; and 

 the rock dredging and blasting in the section below Quebec 

 has involved great difficulty. The total amount of rock 

 to be removed amounted to 1,700.000 cubic yards, extend- 

 ing over nearly three miles, and the whole bottom was 

 covered with huge boulders, some of which were 30 to 

 40 tons in weight. These great masses had to be lifted 

 before blasting and dredging was done. During the fiscal 



1 Leneth of channel requiring improvement demands dredging and exca- 

 vation over a length of about 70 miles. 



