Suspension Bridge, Broughton
NEW BRIDGE AT PENDLETON - The foundation of a suspension bridge was laid on Friday week a little below the Broughton Ford in Pendleton to communicate across the river Irwell between the townships of Broughton and Pendleton. The Guardian also noted that the ford had been little used in recent years in consequence of risks from shifting sands. [Manchester Guardian Saturday 29 October 1825 Page 2]
Broughton Suspension Bridge was an iron chain suspension bridge built in 1825-1826 to span the River Irwell between Broughton and Pendleton. Opened in the same year as the Menai Suspension Bridge, it was among the first such structures in Europe. With a span of 144 feet, it was built by John FitzGerald to link his estates and coal mines at Pendleton with the Adelphi and Lower Broughton districts and was sited close to the old ford across the river. The design has been tentatively attributed to Commander Samuel Brown RN, though others suggest that it was built by Thomas Cheek Hewes, a Manchester millwright and textile machinery manufacturer.
Although failing to name the engineer, a detailed description of the bridge as at September 1832, appeared in “A Memoir on Suspension Bridges” by Charles Stewart Drewery, dedicated to Commander Samuel Brown RN. as follows:
The span is 145 feet, 6 inches and the deflection 12 feet six inches. The platform is 143 feet 3 inches long, and 18 feet 3 inches wide, and is supported by four chains, two on each side of the bridge, formed of round rods 2 inches diameter, and 4 feet 6 inches long, united by open coupling links of iron, one inch square, and bolt pins 2 inches diameter. The vertical suspending rods are round iron, one inch diameter, and they spread out at the top into a fork, connected by a bolt pin 7/8th inch diameter, to a plate, which is interposed between each pair of the links of the chains, and is secured to them by the coupling bolts. The main chains are supported by four cast iron suspension frames, viz. one at each end of the bridge for each pair of chains. They are made of plates bolted together with 5/8th inch screw bolts, at intervals of about 18 inches; the frames stand on a base of about 5 feet square, and thence rise up pyramidally. The chains are attached at the points of suspension in the way described for Mr. Brunel's bridges; viz. they are connected by a pin to the lower ends of a pair of vertical links, the upper ends of which are supported by a fixed pin in the upper part of the cast-iron suspension frame. Hence the points of suspension are movable, to accommodate themselves to the expansion or contraction of the chains.
The Broughton Bridge was broken down on the 12th April, 1831, by a party of soldiers marching A over it in step. Sixty men are said to have been on the platform at the time the accident occurred, their line extending nearly the whole length of the bridge. The failure was in one of the coupling-bolts that held the ends of the back stays to their fastenings. The last link of each chain was bolted to an iron strap about 3£ inches broad, by a bolt 2 inches diameter; and it was one of these bolts that was unable to resist the violent effect of the vibration produced by the march of the men. The bolt is said to have been of bad iron, the fracture presenting a granular and crystalline appearance like cast iron. The bridge was quickly repaired, and is now in the state described above. This accident shows the imminent danger to a suspension bridge from bodies of troops marching in step. For although the bolt which broke, was not as strong as in prudence it ought to have been, still it was strong enough to have resisted a much greater weight in dead load than it had to bear. The weight of the bridge itself is about 43 tons; and the weight of the men on it, if at rest, was about (60 x 180) = 4-8 tons; in all say 48 tons. The tension for a deflection of 1 in 11.64 is about 1.55. Therefore, the utmost strain the holding bolts could have had to endure, had the bridge been loaded with 60 men at rest, would have been (48 x 1.55=) 74.4 tons, or 37.2 tons for each bolt. Now the length of the holding bolts between their bearings was about 3-75 inches, and their diameter 2 inches, and each if of good iron would have borne * The author is not aware of the exact weight of the bridge. The above of 43 tons is computed from data communicated to him by an engineer who had examined and measured it before being crippled, 68.75 tons. Whence it must be inferred that the shocks, and the vibration given to the bridge by the simultaneous stepping of the men, must have produced an extra strain of about 30 tons beyond that of the mere load, in order to break the holding bolt.
A holding bolt of the dimensions above stated ought not, however, in prudence, to have been exposed at any time to a strain of more than 18 tons, had it been perfectly sound in the beginning; for under that strain it would be, if not actually deflected, at least on the very verge of deflection, and if so strained frequently, and for any length of time, the iron would probably become, by degrees, permanently injured. The holding bolts of the Broughton Bridge were, in fact, of such proportions that they would be perpetually exposed, in the common traffic of the bridge, to more than the strain they were capable of undergoing for a short time only, without receiving injury. They ought to have been about 3.5 inches diameter to have borne as much as the chains would bear. “A Memoir on Suspension Bridges” by Charles Stewart Drewery]
As a result of this collapse, the British Army issued an order that troops should "break step" when crossing a weak bridge. Though rebuilt and strengthened, the bridge was subsequently propped with temporary piles whenever crowds were expected, particularly for the Manchester races.
For many years, foot passengers and vehicles crossing this old bridge had to pay toll, but it became unremunerative when the Wallness and Cromwell bridges were opened as free highways. In 1898 the suspension bridge was offered to the Corporation but declined owing to the cost of repairs or replacement.
There is a proposal on foot to either reopen reconstruct the old Gerald Road Suspension Bridge, which spans the river Irwell in the Lower Broughton district of Salford. This bridge was built seventy years ago by Mr. Fitzgerald, who owned considerable land in the locality, with the object of developing the traffic from the collieries in Whit Lane, Pendleton, into the Adelphi and Lower Broughton districts. A small toll was charged from foot passengers and vehicles for using the bridge, and it proved a very popular route. The opening, however, of Cromwell Road and Wallness Road bridges by the Salford Corporation as free highways caused the bridge to become unremunerative. The result was that it got into a dilapidated state, and was eventually closed. About eight years ago the owner of the bridge offered it to the Corporation on the condition that it should be reconstructed as might be preferred, but the offer was declined by the municipal authorities. Nothing further has been done in the matter, and the old bridges still remains closed. People who reside in the Whit Lane district and desire to get to Lower Broughton have either to use the Cromwell Road or Wallness Road bridge, and it is contended that if the Gerald Road bridge was opened the distance at present to be traversed would be shortened by 430 yards and 530 yards respectively. Councillor A Stringfellow, one of the representatives of Charlestown ward, who is taking an active interest in the matter, has brought the question before the notice of the Building and Bridges Committee of the Salford Corporation. [Manchester Guardian 1 October 1906 page 4]
By 1907 the suspension bridge was in a dilapidated state and closed to all traffic. [Corbett]. Finally, in 1924 the suspension bridge was replaced by a footbridge (qv) designed by the Borough Engineer re-using the original abutments.
Foundation stone laid 23 October 1825
Reference Manchester Courier Saturday 29 October 1825 Page 4 - Local Intelligence
Reference Manchester Guardian Saturday 29 October 1825 Page 2
Reference Manchester Guardian 16 April 1831 page 3 – fall of suspension bridge
Reference Observer 18 April 1831 page 3
Reference Observer 25 April 1831 page 3
Reference A Memoir on Suspension Bridges” by Charles Stewart Drewery, 1832
Reference Manchester Guardian 1 October 1906 page 4
Reference J Corbett: The River Irwell page 64
