Engineering Wonders of the World
Volume III

TRANSPORTATION CANALS OF THE UNITED STATES. 171 Increasing com- merce made yet an- other lock necessary. So the Poe Lock, with a chamber 800 feet long and 100 feet wide, and a depth of about 19 feet at low-water, was built to reinforce the Weitzel. These locks were confidently expected to handle the com- merce of Lake Su- perior, but at times are congested to an The boats had grown in size, and the locks were not cap- able of handling them. The canal was at that time under state control, and it soon became evident that for the full development of the inter- ests involved the wisest move would be to transfer it to the General Government. The transfer was effected on June 9, 1881, since which time no tolls have been collected. In 1870 th© rapid increase in commerce and in the carry- ing capacity of the boats brought about the construc- tion of the Weitzel Lock, which was completed in 1881. A “ WHALEBACK ” STEAMER ENTERING THE LOWER END OF THE POE LOCK ON THE ST. MARY’S FALLS CANAL, BETWEEN LAKES SUPERIOR AND HURON. THE WEITZEL LOCK ON THE ST. MARY’S FALLS CANAL; HIGH WATER. The Weitzel and Poe Locks. It is 500 feet long, 80 feet wide in 'the chamber, and has about 14 feet of water over the sills at low-water. The walls are of limestone, and contain 34,207 cubic yards of masonry. Water is admitted into the lock through culverts under the floor. exasperating degree. Boats have reached a size that renders the present lockage facilities almost useless. Many of them now have a capacity of 8,000 tons, and at the present time there are some thirty-two of these 8,000-ton boats plying on the Lakes. This adds 20 per cent., or 338,000 tons, for a single trip, to the