Engineering Wonders of the World
Volume III

172 ENGINEERING WONDERS OF THE WORLD. THE TWIN LOCKS, THE WEITZEL AND POE, ON THE ST. mary’s falls canal. carrying capacity of the fleet transporting ore from the vicinity of Lake Superior. It is estimated that the trips of these vessels through the locks number 25,000 a year. These “ twin ” locks, the Poe and Weitzel, are named after two able generals detailed from the War Department to make recom- mendations and supervise plans to suit the unprecedented commercial growth—a task in which they were ably assisted by the eminent engineer, Alfred Noble. The appropriations made for the Sault Ste. Marie Canal and improvements total $2,405,000. The length of th© canal is 7,000 feet, and the least width—at the movable dam where the swing span or International Bridge is built—is 108 feet. The water averages about 16 feet in depth. Plans are now on foot by the United States Government to double the present width at the narrowest place, thereby relieving the present dangerous strong current that occurs when the locks are filled. This will also enable two or more locks to be filled at the same time. This Sault Ste. Marie Canal is among the largest and finest engineering achievements in the United States, and will rank as first among its canals until the final completion of the Erie. Traffic demanded a canal to connect Lake Michigan with the Mississippi River. Hence the Illinois and Michigan Canal, named after the State traversed and the lake in question. The first link in this is the Chicago Drain- age Canal—or, as it is sometimes called, the Sanitary and Ship Canal—which cost about $50,000,000. This canal can, if need be, carry the volume of a large river. Its use is twofold: first, as its name implies, it deals with the sewage of Chicago, a city of 2,500,000 persons ; second, it is used largely for navigation between Lake Michigan and the Mississippi River. It is 34 miles long, Chicago Drainage Canal.