1851 Great Exhibition: Official Catalogue: Class VII.: Charles Vignoles
105. VIGNOLES, CHARLES, 4 Trafalgar Square — Designer.
Model of the wrought-iron bar-chain suspension bridge at Kieff, now erecting across the river Dnieper, by command of H. I. M. the Emperor of Russia. Its length is about half an English mile, and breadth 52A English feet. The area of the roadway is 140,000 superficial feet.
The bridge of which this is a model is the largest work of the kind hitherto executed; the chains on the right, or Kieff side of the Dnieper, are moored in an isolated abutment, built in the river, at a sufficient distance from the shore to allow vessels to pass. This is effected by a drawbridge, 521 feet broad, spanning an opening of 50 feet. The supports are hollow beams of wrought iron, about 130 feet long; the drawbridge revolves in one leaf, and centres like a railway turn-table; the counterpoise required is very small. The whole weight of the drawbridge is about 150 tons.
The four principal suspension spans are each of 440 English feet. Each chain extends over the five river piers and through the two abutments, and is more than half an English mile long.
The platforms are suspended from the chains by wrought-iron rods of 2 inches diameter. The roadway is made peculiarly stiff, to resist the various strains to which it is liable.
The total quantity of iron employed in constructing the bridge, including the machinery used, is 3,500 English tons (3 millions of French kilogrammes, 78,000 German centnars). The whole was manufactured in England; the chains by Fox and Henderson, Birmingham.
Sixteen vessels were employed in transporting the iron from Liverpool to the port of Odessa, whence it was conveyed on bullock-carts to Kieff, a distance of 400 English miles.
The channel of the river Dnieper at the bridge is about 35 feet deep in summer, but the spring floods increase the depth to 50, and sometimes to 55 feet.
Eight coffer-dams were required for getting in the 1 foundations, and 10 steam-engines were employed on the works, two being of 50-horse power each.
The foundations are on piling and concrete; the piers and abutments are brick, faced with granite. About 1,000 tons (English) of granite ashlar are inserted in each abutment as an extra mass, for the mooring plates of the chains to bear upon.
The granite was brought across a country destitute of hard roads, from a distance of nearly 100 English miles.
The hydraulic cement employed is prepared artificially, according to the system pointed out by the celebrated French engineer, Vicat.
Cost of the bridge about £400,000 sterling. Time of building will have been about five years; but from the climate and other circumstances not more than 100 working days in each year could be calculated on for the principal and more difficult parts of the work.
The whole of the piers and abutments will be brought to the level of the roadway in the course of the present summer (1851); two of the river piers will also be carried to their full height; and the bridge will be completely finished in the autumn of 1852.
Every part of the model is in exact proportion to the original bridge. The scale is 1 inch to 8 feet.
The two views in chromolithography, which illustrate this bridge, are from drawings executed on the spot.
[Suspension bridges of iron were introduced about the year 1741, at which date one of 70 feet span was thrown over the river Tees. Scamozzi, "Del Idea Archi," published 1615, conveys some notion of these structures, but Bernouilli first explained their true principles. The Union bridge over the Tweed, 449 feet span, constructed by Capt. Sir S. Brown, in 1820, was the first large bar chain bridge erected in Britain. The Newhaven and Brighton suspension piers were also erected by the same engineer. The great bridge by Telford across the Menai Straits is 570 feet span; it was commenced in May, 1819, and completed in December, 1825. The Hammersmith bridge, 422 feet span, by Tierney Clark, was completed in 1824. The Montrose bridge, by Rendel, 412 feet span, was erected in 1829; and the Hungerford bridge over the Thames, 6761 feet span, by Brunel, was built in 1844. The wire-rope bridge of Freiburg is 820 feet span. The roadways of suspension bridges must not merely be hung from the chains, but be rendered stiff to resist the undulatory motion caused by the wind. See Minutes of Proceedings of the Institution of Civil Engineers, Feb. 16, 1841, on this subject.— S. C.]