Norfolk Suspension Bridge
at Shoreham-by-Sea
NO LONGER EXTANT.
This impressive chain-type suspension bridge was one of several bridges crossing the River Adur in Shoreham. Named after the Duke of Norfolk, who provided the finance.
1833 Bridge opened. Designed by William Tierney Clark.
W. Ranger of Brighton undertook the excavation and masonry work.[1]
The two piers were each topped by a Coade stone statue - one of a horse, one of a lion.
Three tiers of chains (eye bars) on each side, each 8ft 10 1/2" long, 1 1/8" thick, width 6 1/4", increasing to 8 3/4" at eyes. Cast iron platform cross bearers were 1" thick I-section, 14" deep at middle, 10" where vertical suspension rods are fixed to them, and 6" at the ends. Oak plank deck.[2]
1921 'NORFOLK BRIDGE. How the Structure Has Been Strengthened. An Interesting Official Test. For the last six years the picturesque Norfolk Bridge, which carries the main Worthing and Brighton rod over the River Adur at Shoreham, has been closed to heavy vehicular traffic, owing to its unsafe condition. .... In view of the financial conditions resulting from the War and the urgent necessity of economy in all public expenditure, and also the difficulty in obtaining tenders, it was ultimately decided to postpone the building of a new bridge for the present, but to carry out instead a temporary scheme for strengthening the existing structure, at an estimated cost of about £5,000. This has since been carried out by a well-known London firm of contractors, and apparently with complete success.
What Has Been Accomplished
The weight of the Bridge and its traffic now rests, not on the suspension chains and ironwork, but on a substantial and carefully designed understructure of well-seasoned timber resting on piles and concrete foundations; it would be possible to remove the whole of the upper structure without imperilling the carrying capacity of the Bridge. Exhaustive tests were made on Friday, under the supervision of the County Surveyor (Mr. H. M. Bowen) end the Consulting Engineer (Mr. Howard Humphrey, jun.), ....'[3]
1922 'NEW SUSSEX BRIDGE STRENGTH AND APPEARANCE.
The problem of bridges in relation to motor trattic is discussed by a correspondent of "The Times," who gives some interesting particulars of the scheme for replacing the Norfolk suspension bridge at Shoreham.
This bridge was built from the designs of Mr. Tierney Clark, one of Telford’s ablest pupils, who combined engineering skill with great architectural ability. Mr. Tierney Clark subsequently built the great Danube bridge linking up the towns of Buda and Pest. The Norfolk bridge has central span of 280ft. 6in., and two side spans each of 160ft. The dip of the chains in the centre is 23ft. 9in. The piers and abutments are built of brickwork faced with stone. The whole of the weight is carried on pile foundations. The main suspension chains are composed of two tiers of iron links on each side of the roadway, and are carried over the piers on rollers fixed in cast-iron frames. The flooring of the bridge is carried bv 1 1/4in. square suspension rods spaced 4ft. 10in. apart, which support cast-iron cross girders, on which oak planking is laid longitudinally, with an overflow of lighter oak planks for portion of the width: above this comes the road metalling. The pathways are of oak planks.
An analysis of the stresses the bridge showed that the existing cast-iron cross girders were already over-stressed by the dead weight alone which they were carrying. One, in fact, had already failed. The stresses in the suspension chain links and rods were lso much too high.
When replacement of the bridge being contemplated, the first suggestion, in order to preserve as much as possible this well-known landmark, was a design for stiffened suspension bridge. It was, however, eventually agreed have some form of lattice girder bridge as the best combination of strength and appearance. This will necessitate the building of a new central pier, similar in external appearance to the existing ones, and the dismantling of the existing towers. Alterations will also have made to the present abutments in order to allow of sufficient pathway clearance at the end of the main girders. The clear roadwav will 18ft. The new roadway will consist of an asphalt surface laid on concrete which, in turn, will act as filling on3/8in. buckled steel plates. The new bridge will be of sufficient strength to carry loads far in excess of the present maximum legal loading — this being a condition imposed by the recent Ministry of Transport regulation.'[4]
By 1923 the suspension bridge had been demolished, replaced by bowstring girder road bridge having four spans. This in turn was replaced by the present concrete bridge in 1987.
See here [5] for an account of the several bridges, with excellent illustrations.
Note: The famous Széchenyi Chain Bridge in Budapest, built in 1849, was similar to the Norfolk Suspension Bridge.