By Don Heinrich Tolzmann
Special to NKyTribune
The formal opening of the John A. Roebling Bridge took place on New Year’s Day in 1867. Shortly thereafter, Roebling’s report on its construction was published in the annual report of the Covington & Cincinnati Bridge Company. A briefer report was also published that year by E.F. Farrington, an assistant of Roebling. Almost two years before that, an article on the bridge’s construction, likely the first published report on the topic, appeared in “American Railway Times” (4 February 1865) under the title “The Cincinnati Bridge.” I obtained a copy from the Roebling Collection at the Rensselaer Polytechnic Institute. It reads as follows:
“It is not generally known that in 1856, under the direction of John A. Roebling, a large Suspension Bridge over the Ohio River was commenced, designed to form a permanent highway between the city of Cincinnati on the north side and the city of Covington on the south side. The extreme low water of the season enabled the engineer to complete the extensive foundations for the erection of the two towers, which are located at the edge of low water, at a distance of 1057 feet from the centre to centre. The area of each of these foundations covers 9600 superficial feet, being 120 ft. x 80 ft. wide. This will convey some idea of the magnitude of this work. Great difficulty was experienced in the Cincinnati foundation on account of the enormous influx of water, which collected from the springs and wells of the surrounding but rather distant hills.
The extreme difference between high and low water in the spring flood of 1832 rose up to 62 ft. 6 inches, which is the level of Front Street on the Cincinnati side. Near the mouth of the Cumberland the same flood rose to 74 feet, which is the greatest known rise in the valley of the Ohio. With such an extreme variation, the task of constructing a bridge that shall answer all purposes of travel, and at the same time not interfere with the free and unobstructed navigation of the river, would appear to present insurmountable difficulties.
The general subject of bridging our navigable watercourses, has on various occasions been very ably discussed before the Supreme Court of the United States. That court has by its decisions very nearly reversed its former views. No longer is the unobstructed and free navigation of our rivers insisted upon, but the court has shown a disposition to make very large allowances for the necessities of land transportation. Indeed, the ever-increasing interests of land communication appear now to be considered paramount, and to such an extent, that even objectionable draws and narrow spans are submitted to.
The plan of the Cincinnati Bridge, as adopted in 1856 and approved by the charter of the States of Ohio and Kentucky, presents one middle or principal span of 1057 feet from centre to centre, leaving a clear-water-way of 1000 feet at the lowest level stage. This leaves two side spans of 281 ft. each, from the centre of tower to the face of anchor abutment. This makes the whole distance between the two abutments 1619 feet, offering a clear space of 1519 feet for the river flow. The general proportions of the work were therefore not a matter of choice, but governed by legislation. The abutments form also the anchorages for the cables, and extend on the Cincinnati side 104 ft. from the wharf to Water Street. This street is to be covered over on an iron truss bridge, and the descending grade continued to Front Street, where the level of high water is reached. The landing on the Covington side is about the same distance, but its level is 10 ft. higher.
The original height of the principal span at the centre was fixed at 120 ft. above low water, but afterwards reduced to 100 ft. This reduction was granted in justice to the great interests of communication which this great thoroughfare involves.
The Cincinnati Bridge is destined to become one of the greatest highways on this continent. The Kentucky Central Railway once completed to the Tennessee line, and the extensive system of southern railways will connect, to seek outlets to the North and North-West. Louisville is one of these points already established; Cincinnati will be the next, and there will be most ample commercial supply for the wants of both.
The heights of towers when completed, will be 105 feet above the bridge floor, and 195 feet above low water. The mass of both in the aggregate amounts to 30,000 perches; they are well proportioned and will produce an imposing architectural effect. To secure so large a span against the extreme violence of a hurricane, heavy proportions of masonry were considered necessary. It is only in extreme cases, that the whole strength of such a work will be brought into play; a strength which to a superficial observer may appear a useless waste of material.
The floor of the bridge will be 36 feet wide, divided into two outside walks and a double track roadway in the centre. The weight will be suspended by two wire cables of 12 inches in diameter each, assisted by a system of wire rope stays, which will nearly double the supporting strength, and greatly add to the inherent stiffness of the structure. The rigidity of floor will be further increased by two lines of trusses, each 10 feet high, located between the roadway and sidewalks and extending from abutment to abutment. With exception of two courses of oak planking all the supporting parts and framing of the floor will be of wrought iron, so put together that all parts will contribute to stiffness.
As remarked before, the foundations of the towers were laid in 1856. In the following year the masonry of both was carried forward to a height of 42 feet on the Cincinnati side and 73 feet on the Kentucky side. But in consequence of the financial disasters of that year, operations were suspended, and remained so until 1863, when the work was resumed with a view towards final completion. It is now expected that the bridge will be opened for travel in the winter of 1866. In magnificent proportions, solidity and strength, the work will have no rival.”
For further information on the bridge’s construction, see E.F. Farrington’s 1867 report that has been republished as: “The John A. Roebling Suspension Bridge: A Full and Complete Description, with Dimensions and Details of Construction,” by E.F. Farrington, edited by Don Heinrich Tolzmann, with a Foreword by Paul A. Tenkotte (2016).
Don Heinrich Tolzmann, PhD is Historian for the Roebling Bridge Society and author and editor of several books on the Roebling Bridge, as well as the region’s German heritage.
Paul A. Tenkotte, PhD is editor of the “Our Rich History” weekly series and Professor of History at Northern Kentucky University (NKU). To browse more than ten years of past columns, click here. Tenkotte also serves as Director of the ORVILLE Project (Ohio River Valley Innovation Library and Learning Engagement). For more information see orvillelearning.org. He can be contacted at tenkottep@nku.edu .