Battersea Bridge
1771 The first Battersea Bridge was a toll bridge commissioned by John, Earl Spencer, who had recently acquired the rights to operate the ferry. Although a stone bridge was planned, difficulties in raising investment meant that a cheaper wooden bridge was built instead. Designed by Henry Holland, it was initially opened to pedestrians in November 1771, and to vehicle traffic in 1772.
1885 The old bridge was demolished and replaced with the existing bridge, designed by Sir Joseph Bazalgette and Edward Bazalgette. Some sources name John Mowlem and Co as the contactors, other sources identify Williams, Son, and Wallington (see below). Mowlem did have the contract for demolishing the old bridge[1]
1886 'A CONTRACTOR'S MISTAKE. This morning the Metropolitan Board of Works decided to receive the tender of a different contractor than the one previously arranged with for the construction of the Battersea New Bridge. The circumstances were peculiar. Mr. G. B. Godfrey had sent in the lowest tender, which had been accepted by the Board; but subsequently Mr. Godfrey wrote to say he had tendered a less sum than he now found he could undertake the work for, and he therefore offered another price, still below all that of the other contractors who tendered. This fresh offer was submitted to the Works and General Purposes Committee, on whose recommendation the Board this morning decided not to entertain Mr. Godfrey’s suggestion for an increase in the amount of his tender, but to accept the next lowest tender, that of Messrs. Williams, Son, and Wallington, amounting to £143.000.'[2]
1886 'THE CONSTRUCTION OF BATTERSEA BRIDGE. The Works Committee recommended—“That Mr. G. B. Godfrey be informed that the board are not prepared to entertain his suggestion for an increase in the amount of his tender for the Battersea New Bridge; and also recommending that the next lowest tender — namely, that of Messrs. Williams, Son, and Wallington, amounting to £143,000 be accepted, subject to the same conditions as were attached to the acceptance of Mr. Godfrey’s tender.’ Sir Joseph Bazalgette said Messrs. Williams, Son, and Wallington were prepared to carry out the work for the sum mentioned in their tender —.£143,000. On the motion of Mr. Fowler, the recommendation adopted.'[3]
The following information is condensed from an 1895 Engineering article[4]:
The work fell within the province of the Metropolitan Board of Works, and a design was prepared by Sir Joseph Bazalgette, and executed by Williams and Wallington. It is an arched bridge of five spans; the width between parapets being 40ft., divided into a 24-ft. roadway and two side-walks of 8 ft. each. Two tracks or tramlines were placed in the roadway. The width of the central span is 163 ft.; of the two adjacent ones, 140 ft. ; and the two land spans are 113 ft. 6 in. wide. The rise in the centres above springing is 18 ft., 13 ft., and 8 ft. 6 in. respectively. The foundation for each of the piers consists of a block of concrete 75 ft. by 36 ft. and about 17 ft. deep, the surface of the concrete being 18 ft. below Ordnance datum. The concrete is enclosed within a rectangle of sheeting piles 14 in. square, and driven well into the clay below the concrete, the enclosed space being cleared down to a sufficiently good material to afford proper foundation. On the concrete blocks the brickwork of the piers was commenced. Above the footings the piers are granite-faced in courses 2 ft. deep and from 3 ft. to 3 ft. 9 in. deep. The top of the pier is finished with a course of granite, and the spaces between the iron skewbacks that meet over the centre of the pier are also filled with granite and a brickwork hearting. Above the skew-back level the piers are carried up with brick walls faced at the ends with granite, the size being 10 ft. by 4 ft. 6 in. Below the level of the skewbacks the piers are finished with rounded ends. The abutments are constructed in a way similar to the piers, and the granite-faced brick walls are backed by masses of concrete. The spaces between the piers are spanned by a series of cast-iron ribs, seven to each opening ; they were cast in five lengths making together a segmental arch 5 ft. 6 in. deep ; the various sections are fastened together by bolts passing through flanges at the ends. The two outer pairs of ribs are placed 3 ft. apart, and the others are 5 ft. 9 in. apart. The ribs are braced together transversely by light diagonal bracing at 15 points in each span, the depth of this bracing corresponding to that of the ribs. At short intervals, vertical members are taken from the back of the ribs to beneath the roadway, where they are connected by the top member of the spandril framing, A complete system of horizontal and transverse framing is introduced between these spandril fillings, and the foundation of the roadway consists of wrought iron bent plates connected to the upper part of the spandrils. The footway on each side is carried on cantilevers bolted to the outer girder, and supporting similar floor-plates. Beneath, the cantilevers are concealed by cast-iron casings. ...'
The following is condensed from The Engineer, 25 July 1890 [5]:-
'The ironwork of the bridge has been constructed and
erected by the Phoenix Foundry Company, Derby, and the
granite for the piers and abutments has all been supplied by
the Kit Hill Granite Company, Gunnislake. We understand
that every stone has gone into its place without any alteration, .... The arches of the bridge consist of 175 cast iron girders, .... The segmental girders weigh from eight to
ten tons each, and the whole of these were cast by the
Phoenix Foundry Co. without a single misshap. The metal
from which they were made, procured from the Stanton
Furnaces, Derbyshire, was of extraordinary strength; bars,
2in. by 1in. by 3ft. 6in., standing a transverse strain of 34 cwt. before fracture, and bars 1in. diameter standing as
much as fourteen tons tensile strain. The whole of those
girders were tooled on their abutting faces, and drilled for
their bolt holes at one setting by special machinery designed
here for the purpose, a clearance of 1/50 in. only being allowed
in the bolt holes.
Very ingenious machines were likewise designed and constructed for the drilling of the holes in the stiffeners to attach the wrought iron bracings. Three tools driven by endless
chains, each drilling six holes, worked simultaneously, so
that some 5460 1 1/4in. holes were thus drilled quickly
through 1 3/4in. metal. A multiple drilling machine - Wilson
and Robins' patent - on the same principle, is now
working on an overhead railway contract, Liverpool, which
drills 200 holes in ten minutes. Upon the facias of the
bridge are large apertures, in which very fine ornamental
spandrils and shields are inserted. Underneath the facia is
fixed an ornamental coving or cantilever arrangement, a
composite structure of pressed steel and wrought iron. This,
from Sir Joseph Bazalgette's design, is, we believe, unique,
Battersea being the only bridge so ornamented. At the top
of the facia is a massive and imposing cornice, which forms
an elegant parapet, of a Moorish-Arabesque design. This
parapet consists of a series of ornamental panels, clustered
columns, and massive handrails, the whole constructed of
cast iron, so tooled that scarcely a joint can be perceived,
thus having a very pleasing effect. The iron and steel work
used in tho structure - upwards of 3000 tons - was carried out
by the Phoenix Foundry Company, Derby, under the supervision of the County Council engineers. ...
Aspects of Design and Construction
In 1886, at an early stage in the project, The Engineer ran a series of articles on the design of the bridge, reproducing many of the drawings and details of the stringent specifications. Considerable accuracy was demanded for the structure, and the requirements concerning the provision of the decorative wrought and cast iron work were onerous. In fact the degree of decoration was relatively restrained, but the required standard of accuracy was very high, in order to avoid unsightly discontinuity where components joined, for example. It was specified that rivets on visible surfaces had to be countersunk. Examples are just visible in Fig. 10.
Each cast iron arch rib was assembled from five segments. The drawings (see Fig.2 ) indicate that there is a curved pivot where the end of the arch rib contacts the iron casting at the springing (the springing being the junction between the rib and the pier or abutment). This pivot aimed to ensure that each arched rib would be free from any initial bending strain at the springing. The specification required that 'After the supports of all the arch ribs of a span have been removed so that all the ribs take their own weight, levels are to be taken to ascertain that all ribs occupy their intended position, and any not doing so are to be blocked up again at the supports, and one or more of the segments in such ribs taken out and altered. After all the arched ribs in a span have been ascertained to occupy their correct positions, the steel taper packings shown are to be finally finished off exactly to the required thickness and placed in position between the face of the skewback and the end of the arched rib, the bolt holes drilled through them, and turned bolts inserted.' It will be noted that the curved pivots were only effective during construction, and were not provided to accommodate expansion in service.
Away from the crown of the arch, the roadway is supported by an increasingly complex framework assembled from wrought iron sections. The pavement is supported by wrought iron framework cantilevered from the outer arch ribs.
The road material is supported by numerous wrought iron plates riveted together, visible in Fig. 13. As can be seen, they are dished, but for the central span they also have slight curvature to correspond with the hump of this span. The pavement material is also placed on dished plates, which are supported on the wrought iron framework outboard of the outer arch ribs.
Decorative Coving: A distinctive and intriguing feature of the bridge is the decorative coving with radial 'ribs', outboard of the outer arch ribs (see Fig. 14).
Remarkably, pressed steel was the specified material. The 1886 specification required that 'The plates for the coving to be of mild steel 1/4 in. thick, and of such a quality that they can be turned out to the required curves and to the exact form shown on drawing.' Pressed steel is a surprising choice, but the relatively poor performance in corrosive conditions may not have been well-appreciated at that date.
In cross section, the profile comprises alternating flat and dished surfaces. The depth of the dishing increases with distance from the bottom to the top (see the three sections at the top of Fig 5). These sections, and also a section shown in the middle of Fig. 4, show sharp corners at the transition between the curved and flat parts of the pressings. Sharp corners are also evident in the actual coving (Figs 14 & 15). It is difficult to see how (or why) sharp external corners could be produced in 1/4" thick steel by presswork.
The 1886 Specification drawings show that the coving comprises a series of individual pressings which each have two channels, and that these pressings abut neatly against their neighbours. The pressings are shown to be riveted to curved angle iron bars, and joined to each other via a backing plate using numerous countersunk rivets. Joint lines are just visible in the photographs at the top of the coving, but not elsewhere, and the presence of countersunk rivets is certainly not apparent. An area having a different form of construction can be seen at the top of the coving in Fig. 15. Perhaps some replacement has been carried out here. This area is at the lowest part of the arch, presumably vulnerable to corrosion by brackish water.
Evidently money was no object, as production and installation of the coving, without any discontinuity at the joints, would have been immensely challenging. The arc length of the hundreds of individual pressings changes progressively from the springing to the crown of the arch. This is because the height of the coving progressively reduces from the springing to the crown of the arch.
In fact the design shown in the 1886 drawings did not survive contact with reality. Construction as drawn would have been impracticable and staggeringly expensive. From a practical point of view, the required sharp external corners could not be produced by pressing, while the presumed aim of having tens of thousands of countersunk rivets and numerous joints which would be practically invisible, would be too much to ask.
In fact, no evidence can be seen, in the photographs, of long radial joints or of countersunk rivets on the 'ribs', and it is clear that the design was changed. There is evidence of radial and horizontal joint lines, and possibly rivet heads, in the small 'arched' parts at the top of the coving, but not elsewhere. In fact the solution was extremely ingenious, albeit still difficult and no doubt shockingly expensive. The dished parts are individual iron castings. The are held in place, and the joints between them covered, by curved T-iron bars. The ribs of the T-iron bars were punched with rectangulat slots, which accommodated loose-fitting rectangular bars each provided with two screws to clamp upon lugs cast on the dished iron castings. Ingenious and practicable, but still highly challenging and expensive. We do not know the names of any of those directly involved in undertaking this impressive work.
The 'secrets'of construction of the coving have occasionally been revealed when vessels have collided with the bridge. Fortunately, thanks to the London Metropolitan Archives, we can see photographs of the damage. A 1918 example here [6] shows components of the coving, and also indicates the brittle nature of the cast iron ribs. Another point of interest is the decorative spandrel casting, showing that great effort has been made to minimise thickness and therefore weight.
See Also
Sources of Information
- ↑ South London Press - Saturday 19 July 1890
- ↑ Echo (London) - Friday 21 May 1886
- ↑ South London Press - Saturday 22 May 1886
- ↑ Engineering 1895/04/19
- ↑ The Engineer 1890/07/25
- ↑ [1] Record No. 234268, Battersea Bridge: close up of damage, 1918. The London Picture Archive, owned and managed by London Metropolitan Archives on behalf of the City of London Corporation