Jumna Bridge (Delhi)
Jumna Bridge at Delhi for the East Indian Railway. Also known as Lohe-ka-Pul
Length of 2,640 feet in twelve spans, each of 202.5 ft.[1]
1862 Large Iron Bridge for India.
There in course of construction in Manchester a very large iron railway and carriage way bridge combined, intended to span the Jumna, near Delhi. It is to consist of twelve spans, each girder being 216ft. long, which, with the thickness of the eleven piers upon which it is to rest, give a total length of over half a mile. The first span of this malleable iron lattice bridge is now completed. The metals for the East India Railway Company are laid along the top, and the roadway along the bottom, the latter having clear height of 16ft. The bridge is from designs by A. M. Rendel, Esq., C.E., London, and is being constructed Messrs. Ormerod, Grierson, and Co.'s, of the St. George's Ironworks, Hulme, Manchester. One unusual feature of tho structure is that all rivet holes are drilled, instead of being punched. The bridge, great strength, has a light and airy appearance.'[2]
1862 'LARGE IRON RAILWAY BRIDGE FOR INDIA.
There is in course of construction, in Manchester, an iron railway and carriage-way bridge combined, of such dimensions and character as to render the structure worthy of illustration. Messrs. Ormerod, Grierson, and Co., of the St. George’s Ironworks, Hulme, in that city, have just completed the first of a series of twelve spans which are to constitute an iron lattice bridge over the River Jumna, near Delhi.
The bridge is for the East India Railway Company, and is from designs by A. M. Rendel, Esq., C.E., London.
It is constructed as to answer the double purpose of railway and an ordinary road, the railway being along the top and the roadway beneath it. Each girder is 216 ft. long, and this gives a clear span of 205 ft. between the piers, of which there will be eleven. The twelve spans will therefore form a structure having a total length of over half a mile.
Confining attention a single span, as representing the main features of the entire bridge, it may be described as consisting of two principal girders with two tops, and two bottoms formed of 3/8in, plates, each top and bottom being united by diagonal lattice-bars, so to form one main girder, which is united to a similar one transversely by means of strong cross girders. Between the upper side of the lower roadway and the underside of the railway there is clear height of 16ft., and the total breadth of the bridge at its centre is 18ft. It has a slight rise towards the middle, being constructed with a camber of 5in. The four girders which thus stretch along the four angles of the bridge and form its support (when united by the lattice-bars) resemble in each case a sort of continuous trough, the upper pair being inverted. The bottoms of these troughs commence with one thickness of three-eighths plate, but increase towards the centre to three thicknesses. The sides of the trough are 1ft. 9in. deep (and 2ft. 3in. apart), each side being composed of two half-inch plates, riveted together, and, instead of being joined to the bottom plates in the usual way, with angle iron, they are flanched or bent to a curve of 4in. radius, thus forming their own attachment. This method of construction has added materially to the appearance of the bridge without detracting from its strength.
The breadth of the upper section of the girder is 3ft. 5in., while the lower increases from 3ft. 5in. the ends, to 4ft. at the centre. The cross girders for supporting the metals of the railway are firmly fixed below the upper section of the main girders. They are 4ft. 6in. apart, and there are forty-six in each span. The lattices are placed at an angle of 45 deg., and the tension-bars are riveted to the outside of the top an bottom troughs. At the ends of the girders the bars are flat, 1in. thick and 5in. broad, but they are substituted by channel iron of a lighter section as they approach the centre. The compression-bars are formed of two angle irons riveted to the inner sides of the trough, and cross-braced by light channel bars. The whole is surmounted by light and elegant handrail, formed with wrought-iron standard of a curvilinear outline, connected together by iron tubes.
In a structure of such magnitude it was, of course, requisite to provide for the variation from expansion and contraction, and this object appears to be effectually secured. The extremity of each girder is firmly fixed to a casting, the underside of which is concave, and rests so as to move freely upon a corresponding casting, with a convex upper surface, made to accurately fit the concavity above. This casting has a flat planed under-surface, resting upon five iron rollers, arranged in strong wrought-iron frame, and has- perfect freedom of motion over a bedplate secured to the masonry. By this arrangement the span is at liberty to undergo deflection, and yet to press with equal weight upon all the rollers. It has only been deemed necessary, however, to place the rollers at one end of each span. It is an unusual feature in this structure that none of the rivet holes are punched. Multiple drilling-machines, five in number, were constructed specially. The largest receives upon its table a plate 13 feet long and 4 feet broad, and in the course of seven minutes’ drills four rows of holes, making together 160. The pressure upon the drills is maintained by two hydraulic rams acting upon the underside of the table. We understand that the Messrs. Cochrane, of the Woodside Ironworks, Dudley, were the first who applied this ponderous machinery to bridge-building, and to them Messrs. Ormerod, Grierson, and Co., were indebted for much valuable information while engaged in their construction. The holes made in this manner, besides being more accurate than when punched, leave the iron much stronger, and its fibre uninjured.
The first span has been completely riveted up in the works, and loaded with nearly 450 tons of pig iron. The deflections were carefully noted, but the details would not be of general interest, and it may be sufficient to state that the result of the test was even more favourable than was anticipated. The iron has been supplied by the Shelton Bar Iron Company, near Stoke, and was required to bear a tensile strain of 21 tons to the inch of section. The breaking-strain is estimated at from 2500 to 3000 tons, equally distributed, which leaves ample margin beyond any weight to which it will be subjected.
The bridge, notwithstanding its great strength, has a light and airy appearance. The open lattice-work relieves it from the dull and heavy aspect inseparable from tubular structures; and when a dozen such spans as that now completed stretch across the Jumna, we can scarcely think otherwise than that the railway company will regard the bridge sent from Manchester as alike creditable to their engineer, as its designer, and the firm who were intrusted with its construction.'[3]
1866/7 Opened for traffic.