THE MEMPHIS BRIDGE

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THE MEMPHIS BRIDGE.

i.

PRELIMINARY NARRATIVE.

The construction of a bridge at Memphis has been a matter of pro-fessional interest among American engineers for many years. In 1867the bridge across the Missouri River at Kansas City, the first bridgeacross that river and the bridge whose construction led to the building ofthe railroad of whose system the Memphis Bridge now forms a part,was begun. At this time a bridge at Memphis was talked of as one ofthe works of the future. Like other works which were considered far inthe future, the difficulties of the problem were overestimated: the depthof the river was overstated and other conditions were considered muchmore difficult than they really were. At that time, however, the con-struction of a bridge at Memphis would have been a matter of greatexpense, and the changes which finally rendered the building of thisbridge a comparatively simple affair represent the advances which bridgeengineering has made in twenty years.

The Kansas City Bridge was begun in 1867 and opened in 1869.The Memphis Bridge was begun in 1888 and was opened for traffic in1892. The Act of Congress under which the Kansas City Bridge wasbuilt was approved July 25th, 1866; the Act of Congress under whichthe Memphis Bridge was built was approved April 24th, 1888. Thetwo bridges were really about twenty-two years apart.

The first definite action looking to the construction of a bridge atMemphis was the passage by Congress of an Act approved February26th, 1885, conferring on two corporations the right to construct andmaintain a bridge across the Mississippi River from or near Memphis inthe State of Tennessee to or near the town of Hopefield in the State ofArkansas.

The physical requirements of this charter were favorable, and thepeople who obtained it hoped that it would prove a profitable enterprise.As it is of interest to compare this charter with the one subsequentlygranted to your company it is printed in Appendix B.

Some months after the granting of this charter Mr. Simon Stevens ofNew York, who represented the parties holding the charter, called at myoffice in New York to consult me in regard to the construction of abridge under its provisions, and at that time I made some crude estimatesand prepared some crude plans. The plan which at that time seemed tome the best contemplated crossing the river with two long spans havinga double pier on a single foundation in the middle of the river. Thisplan, however, was prepared without surveys, the data being obtainedfrom some old maps. When actual surveys were made, the width of theriver was found to be materially greater than these maps showed and theplan became impracticable. The matter was one which interested megreatly from the start, and I also thought that if a bridge was to be builtthere it should be in the interest of the Kansas City, Ft. Scott & Mem-phis System of railroads.

On the 15th of January, 1886, I called upon you in Kansas City andwe had our first conversation in relation to this bridge. It is from thisdate that the connection of your system with the scheme really began. Ileft Kansas City that night and reached Memphis on the afternoon of thefollowing day. The river was full of ice and it was difficult to go about;but I made a short trip on the transfer-boat Charles Merriam and climbedup the bluff on the Memphis side of the river. On this day I se-lected the location for a bridge, this location being fixed by the top of arude staircase on the Memphis side and by a log cabin in the bottom-landon the Arkansas side. I never had occasion to alter this location and thebridge was built upon it.

Nothing definite was done for several months thereafter, but towardsthe end of the year you authorized me to make an examination of thesite and a report on the cost of a bridge on this location. On the 23d ofNovember, 1886, I again visited Memphis, taking with me Mr. E. Dur-yea, Jr., as my assistant, to make borings in the river. Mr. Duryea con-tinued at Memphis till the spring of 1887 and during this time a carefulset of borings were made. These borings gave results more favorablethan I had expected, as they showed that a layer of hard clay was to befound entirely across the Mississippi River at depths within the limits towhich foundations could be sunk by practical methods.

The results of these borings and examinations were embodied in a

report dated February 15th, 1887, which I addressed to you and which Ihave thought best to attach to this report as Appendix E. This reportcontemplated crossing the river with three equal independent spans ofabout 660 feet each, which the charter of 1885 permitted, and whichafter a careful examination seemed to me the best arrangement. It alsoconsidered a 1300 feet span of cantilever construction.

The charter of 1885 was found to be unsatisfactory, in various par-ticular's, to the interests which you represent, and in the winter of 1886-87 a bill was introduced in Congress granting another charter to a cor-poration in your interest. This bill did not pass.

During the following season another bill was introduced which be-came a law: this is the Act under which your bridge has been con-structed ; it was approved April 24th, 1888 and is given in Appendix C.

This Act fixed the minimum length of the channel span at 700 feetor 150 feet more than the length of clear spans specified in the previousAct. A more serious difference, however, was that it fixed the heightabove high water at 75 feet instead of 65. The Act also required thatprovision should be, made for highway traffic. I was at that time inquarantine at San Francisco, but plan,s were prepared by. my partner, Mr.E. L. Corthell, and submitted to the Secretary of War for approval.

The Act provided that the Secretary of War should order three en-gineer officers from the Engineer Bureau to examine by actual inspectionthe location where the bridge was to be built and report what should bethe length of the main-channel span and of other spans. A board wasappointed consisting of Col. W. E. Merrill, Major O. H. Ernst, and Cap-tain D. C. Kingman. It met at Memphis in May, 1888. On the 25thday of that month I arrived at Memphis; Mr. Corthell was already there.We met the board and explained the situation while various gentlemenrepresenting the steamboat interests were also present.

The full proceedings of this board and the action of the Secretary ofWar are given in Appendix WW 22 of the Report of the Chief of En-gineers, U. S. Army, for 1888 (pp. 2514-2525). The board did notagree in their report, the two junior officers recommending a minimumchannel span 1000 feet long, while the senior officer, whose professionalstanding made his opinion of unusual weight, considered 700 feet in theclear enough. The board was unanimous in locating the channel spannext to the Tennessee shore and this location was accepted.

The findings of this board were overruled by the Secretary of War,who decided that if a clear width of 730 feet, at all stages of water,could be provided under the channel span it would be enough, and who