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. 26 THE Marine REVIEW CONSULTING BOARD OF ENGINEERS, ISTHMIAN CANAI, COMMISSION. Reading from left to right. Seated-- Joseph Ripley, Henry Hunter, British representative; M. Guerard, French representative; J. W. Welker, Nether- lands; Alfred Noble, Gen. George W. Davis, Chairman; William Barclay Parsons. Reading left to right. Standing--Capt. Oakes, U.S. A., Secretary; Gen. Henry L. Abbott, Herr Engen Tincauger, German representative; M. Quellennec, French constructor of Suez canal; Isham Randolph, Chicago; Frederick B. Stearns and William H. Burr. e DULUTH AERIAL FERRY BRIDGE Norton Mattocks in The American Manufacturer. The Duluth ship canal, through which passes annually the same commercial tonnage that is carried through the famous Suez canal, was cut across Minnesota Point by the city of Duluth in 1871 and pile and timber cribs to hold its banks were constructed the following year. This canal was later adopted by the United States government which in 1901 widened it fram 240 ft. to at least a width of 300 ft. and constructed substantial and permanent piers of crib work and concrete. The opening of the canal converted Minnesota Point into an island and the city accepted the responsibility of providing the inhabitants with adequate communication with the main land. Until 1897, a rowboat ferry was maintained, but as the popula- tion of the point steadily increased and it became popular for summer homes, a steam ferry for transportation of passengers and freight across the canal was substituted in that year for the rowboats and has been in use ever since. The aerial bridge scheme came about through the im- perative necessity of better communication with the point at a less cost than was being paid for the steam ferry service. A tunnel was proposed but was abandoned on account of its prohibitory cost. A draw bridge, a lift bridge, a roller bridge were proposed in turn but all failed to secure the necessary approval of the United States war [Copyrighted, 1905, by National Press Association. department, whose requirements demanded a method of transportation which in no way would impede the traffic through the canal. The suspended car transfer bridge at Rouen, France, was brought, in 1899, to the attention of the city'.engineer, who prepared a plan, adapting a general scheme of the conditions at the Duluth ship canal. The idea was received favorably by the United States war department and the people of Duluth: A bond issue for the amount of the. estimated cost: of the structure ($100,000) was sanctioned by the state legislature and a general specification and contract were prepared and 'let for the erection of the structure in 190T. The concrete piers to sustain the bridge structure were built under the original contract and the work then was abandoned by the contracting company. After various delays, a contract finally was entered into in February, 1904, with the Modern Steel Structural Co., of Waukesha, Wis., for a riveted truss on riveted steel tower; the ferry car to be supported by an inverted steel tower, in accord- ance with designs made by the structural company's engineer, C. A. P. Turner, and submitted to the city engineer for approval. The work was erected and com- pleted during the winter of 1904-5. In the foundations of the bridge; there are 730 tons of concrete. In the eight piers, which extend below the water: level of the lake, there are 24 anchor bolts, two inches in diameter, fastened by means of large washers