A remarkable group of bridges in or near Newcastle carries the traffic across the River Tyne. The most recent of these is the largest single-arch bridge in Great Britain
FIVE BRIDGES span the River Tyne at Newcastle within a reach of less than a mile. The new Tyne Bridge in the foreground had a clear span of 531 feet and was opened in 1928. Behind it are the Swing Bridge, the High Level Bridge, King Edward Bridge, and Redheugh Bridge. King Edward Bridge is a railway bridge; the High Level Bridge is for road and rail; the others are road bridges.
THE City of Newcastle-upon-Tyne has long been famous for the pits that have linked its name with coal and mining. Newcastle is justifiably proud also of the wonderful series of bridges that join the city to Gateshead on the other side of the river. There are five of these bridges, carrying road and rail across the Tyne. At Newcastle the main line of the London and North-Eastern Railway crosses the River Tyne on its way to Scotland. The volume of traffic between Newcastle and Gateshead can be gauged from the fact that the five bridges, one of them a double-decker, are all crowded into a distance of less than one mile.
Taken in order from east to west, the bridges are: Tyne Bridge (10.7 miles from the river mouth), the Swing Bridge (10.75 miles), the High Level Bridge (10.8 miles), King Edward Bridge (11.3 miles) and Redheugh Bridge (11.4 miles from the mouth of the river). Set in the heart of a vast industrial district, these bridges are of enormous importance and are fitting descendants of a lineage that goes back long before the City of Newcastle was built.
The Swing Bridge is movable on an artificial island in the river so that shipping can pass freely on either side when necessary. The clearance of this bridge above high water is only 14 ft. 3 in., compared with the 82 feet of the lowest of its neighbours, and for centuries the approaches to the bridge on this site were steep on both banks. It is said that the Duke of Cumberland, on his way north during the rising of 1745, arrived at the top of the southern bank one winter’s evening and looked down upon the crossing far below — then the historic Mediaeval Bridge. He told his staff in forceful language that he had no intention of being taken “down there at this time of night”. But we must look back much earlier than 1745 for the earliest forbears of the Swing Bridge that spans the Tyne to-day. There has been a bridge on this site since Roman times. The first of them all, the Pons Aelii, is said to have been built by the Emperor Hadrian about A.D. 120 in connexion with the Roman Wall, that famous fortification which extended across the country for 74 miles from Wallsend, on the Tyne, to Bowness, on the Solway.
The Roman bridge comprised a series of stone pillars carrying a level roadway of timber. For more than a thousand years this bridge served as a highway across the Tyne, but in 1248 a mighty fire swept the town of Newcastle and the wonderful old bridge, which had been repaired and renewed from time to time, was destroyed.
After considerable delay the building of the Mediaeval Bridge was begun. This bridge was built of stone and comprised twelve pointed arches, of which three were closed at the sides and used as cellars. Many houses, shops and a chapel were built on the bridge, and in the centre stood a tower which was used as a prison by the Corporation of Newcastle.
For five hundred years this graceful bridge, with its roadway only 15 feet wide and its picturesque buildings, stood above the river, but in the winter of 1771 there occurred one of the greatest floods in British history. Early in the morning on Sunday, November 17, 1771, the age-old central arch was swept away, to be followed soon afterwards by two more arches and their timber houses. Many lives were lost, but one house floated for miles, carrying a cat and a dog to safety. All the Tyne bridges then in existence were destroyed by the flood, with the single exception of that at Corbridge, about eighteen miles above Newcastle. This bridge was built in 1674 and it still stands.
After the destruction of the Mediaeval Bridge, work on a new bridge was begun in July 1773. This bridge, opened in 1781, was also of stone and comprised nine round arches with a total length of 550 feet. The width of the bridge was 21 ft. 6 in., and in 1810 this was increased by 12 feet.
In 1850 control of the river was taken over by the Tyne Improvement Commission and vast dredging schemes were inaugurated to improve the waterway. It was realized that a stone arch bridge offered a serious obstruction to river traffic, and in 1874-75, after years of careful planning for future development, demolition of the old structure was carried out. A temporary wooden bridge was built for use until the completion of the swing bridge, which was opened for pedestrian and road traffic in June 1876.
On Site of Ancient Crossing
The Swing Bridge has a huge central steel span, 280 feet long and weighing 1,450 tons, which revolves about its centre on a circle of rollers. This swinging span rests on a pier built over a series of cast-iron cylinders sunk in the river bed and filled with concrete. The granite piers for the fixed spans were built in a similar way. The total length of the bridge is 540 feet and the length of the longest fixed span is 102 feet. The carriageway of the bridge is 22 feet wide and it has two footpaths 7 ft. 9 in. Wide.
The height of the roadway above high water is only 16 feet, but the headroom for ships on either side of the central pier, when the bridge is swung, is limited only by the height of the High Level Bridge, 82 feet above high water, ordinary spring tides. Despite the size and weight of the great swinging span, the time taken to turn it is only one and a half minutes. Thus on the site chosen —it is said — by Hadrian is found a structure of which the Emperor could not have dreamed — a bridge that carries swifter chariots than he could have imagined and permits the passage of great steamers to seas unknown to those who manned the galleys of ancient Rome.
THE SWING BRIDGE OPEN to allow the passage of shipping. This photograph was taken on November 20, 1927, and shows the state of progress reached in the building of the new Tyne Bridge, which was opened on October 10, 1928. The Swing Bridge, opened in 1876, is hydraulically operated. The swing span is 280 feet long and weighs 1,450 tons.
The Swing Bridge, however, is not the oldest of the five Newcastle bridges now standing. That honour falls to the High Level Bridge, completed in August 1849 and opened by Queen Victoria in the following month. This remarkable double-decker bridge carries road and railway and has a most interesting association with British railway development.
For hundreds of years the low-level bridge had served Newcastle and Gateshead, but early in the nineteenth century a plan was put forward for a road bridge at a higher level to obviate the descent and the ascent of the steep banks of the river. This plan was supplemented in 1825 by Telford, who suggested a bridge on the present site. It was not until 1843, however, that circumstances enabled John Hodgson Hinde, in association with George Hudson, the famous “railway king”, to form the High Level Bridge Company.
The consulting engineer was George Stephenson, and the year 1844 saw the completion of the railway from the south as far as Gateshead. The bridge proposal was incorporated in the railway promoters’ bill authorizing them to carry their line north into Scotland. The bill was passed in 1845, just a century after Cumberland’s contemplation of the steep-set bridge of stone.
With the passing of the Bill the need for a railway bridge had become so pressing that a temporary high-level structure was made in wood, to serve for twelve months.
The building of the main bridge, under the direction of Robert Stephenson and T. E. Harrison, was pushed on as fast as possible. The bridge is 1,350 feet long, and comprises six main spans of 125 feet each, and subsidiary spans on either bank.
The spans consist of cast-iron ribs which are prevented from spreading by huge chains hidden by fascia work. The feet of the ribs rest on tall piers built on piles driven into the river bed. Mounted at intervals on the cast-iron ribs is a series of cast-iron pillars that carry the railway. The track was originally carried on cast-iron cross girders which joined the tops of pillars on opposite sides of the bridge. As a measure of precaution, however, these cast-iron girders have been supplemented by steel joists.
The cast-iron side pillars are extended downwards below the arch ribs to form an artistic colonnade. The lower portions of the pillars contain suspension rods that hold the roadway below the railway track. The roadway is 18 ft. 7 in. wide, and there are two footpaths.
For Road and Railway
Originally the roadway of the bridge was carried on wooden beams, but upon the introduction of tramway cars the wood was replaced by steel joists and the suspension rods were strengthened. The height of the railway track is 112 feet and the clearance above high water is 82 feet.
It serves as an interesting commentary on British engineering of the last century to note that this magnificent bridge, built to carry locomotives of only 50 tons, is capable to-day of carrying railway giants weighing more than twice as much. After the building of the High Level Bridge, and a few years before the opening of the Swing Bridge, the ever-growing requirements of traffic between Newcastle and Gateshead called for yet another Tyne crossing by road. An Act was passed by Parliament in 1867 authorizing the building of Redheugh Bridge, first opened for traffic in 1871. This bridge originally cost £54,000, and it was rebuilt thirty years later.
HALF-ARCHES were built out from either bank of the Tyne until they met in midstream to form the complete arch of the Tyne Bridge. The half-arches were anchored back, at first to the ends of the shore spans, later to anchorages farther back along the shore spans. Each halfarch carried a30-tons electric crane for the purpose of handling the steelwork.
The original bridge had two central spans, each about 250 feet long, and two side spans of over 160 feet. These spans were composed of iron girders, of which the bottom components were in the form of troughs; the upper members were of tubular section. The three lofty piers supporting the spans were built on massive cylinders sunk into the river bed to meet gravel at a depth of 60 feet below high-water level. The cylinders, four to each pier, were 12 feet in diameter at the base, decreasing to 8 feet at low-water level. Above each pier were built iron towers 64 feet above the roadway, from the tops of which suspension rods sloped downwards to give additional support to the girders.
In the rebuilt bridge the four original cylinders under each pier were replaced by four steel cylinders, 8 feet in diameter. These cylinders were taken, by the use of compressed air, to a greater depth than those formerly used. To-day the steel cylinders, arranged outside those they replace, rest on shale at a depth of 65 feet below high-water level. The towers supporting the span trusses incline inwards from the piers, and they are not extended above the roadway as in the original bridge.
An important feature of this reconstruction was the necessity for imposing the least possible traffic delay, and special measures were taken, apart from the special arrangement of the cylinders. The new steel trusses were placed 4½ feet east of the bridge girders and the new platform was built slightly above that already in existence. Finally the whole of the new steelwork was moved and lowered on to the new towers with the minimum of interference with the heavy road traffic. During the reconstruction of the main bridge the original arched approaches were converted into steel spans.
Redheugh Bridge was reopened for traffic in 1901 after an interruption of only a few weeks. It now occupies the original site and the levels and spans are the same. The roadway of Redheugh Bridge is 20 feet wide and is flanked by two footpaths 7 feet wide. The roadway is over 91 feet above high water level, leaving a clearance for ships of 85 ft. 6 in. The total length of the bridge is 1,366 feet.
Standing less than two hundred yards east of Redheugh Bridge is King Edward Bridge, a fine steel structure carrying four railway tracks. The length of this bridge is 2,180 feet, and there are two centre spans, each 300 feet long, made of lattice girders 28 feet deep. The centre spans are flanked by two other spans, also of lattice girder construction.
On the south side of King Edward Bridge the design of the girderwork was modified to allow the tracks, which diverge, to be laid in ballast on a floor of steel troughing instead of on timber beams as in the other spans. The piers were sunk by the use of caissons and were all taken down to the solid rock 69 feet below high-water level. A point of interest in connexion with the excavation work for this bridge is that originally it was intended to build arched approaches. Excavations for the foundations, however, revealed the existence of old mine workings below the river bed and the arches had to be abandoned in favour of additional steel spans at the shore ends of the bridge. There is clearance for ships up to 83 feet above high-water level. The bridge was opened by King Edward VII on July 10, 1906. There remained the great post-war problem of the enormously increased motor traffic throughout the British Isles. The Great North Road, in particular, confined between Newcastle and Gateshead to the High Level Bridge and to the Swing Bridge — closing for every passing ship — called for a clear sweep on its way to Scotland. Yet another crossing was projected to carry the ceaseless stream of cars across the Tyne, and to-day the people of Gateshead and Newcastle point with pride to the largest single-arch bridge in Great Britain, the magnificent Tyne Bridge, to which lead the once broken ends of the Great North Road.
The Tyne Bridge, with its approaches that carry the road over streets and houses, has a total length of 1,254 feet. The giant arch spans 531 feet in a single stretch of the finest steel. The roadway, suspended from the arch, provides a head clearance of 84 feet for shipping, and the top of the great arch towers 200 feet above the water.
The bridge roadway is connected to the Great North Road at the southern end by earth-filled abutments between concrete retaining walls and at the northern end by a steel viaduct. The width of the roadway is 38 feet, with 9-feet footways on either side. Under these footways are enclosed ducts carrying two water mains and two gas mains, all 2 feet in diameter. The roadway carries two sets of tramway tracks and the bridge is designed to carry, in addition to the Ministry of Transport test load, a vehicle carrying a load of 100 tons on four wheels.
Rising to a height of 200 feet above the river, the single-arch span of the Tyne Bridge at Newcastle is the largest in Great Britain. The approach spans carry the road over the streets and houses, giving the bridge a total length of 1,254 feet. The roadway is 38 feet wide and there are 9-feet footways on either side. The great steel arch has a span of 531 feet. The Tyne Bridge was opened by His Majesty King George V on October 10, 1928.
The total cost of the Tyne Bridge amounted to £1,299,568. Of this sum £18,645 was accounted for by the tramway system, £33,574 by lifts, and £458,829 by the acquisition of land and property. The bridge itself, apart from these considerations, cost £788,520.
The Tyne Bridge contains 8,000 tons of steel, of which 2,400 tons are in the arched trusses, 1,600 tons in the deck and the remainder in the approaches and towers.
The bridge was designed by Mott, Hay and Anderson, associated with R. Burns Dick, as architect, and W. J. Steele, City Engineer of Newcastle-upon-Tyne. The contractors and builders of the bridge were Dorman Long and Company, Ltd., This firm was responsible also for the Birchenough Bridge and for Sydney Harbour Bridge, both of which are single-arch bridges. It is not surprising that all three bridges should show similarities in design, although the Tyne arch, large as it is, is small by comparison with the giant spans of Africa and Australia that are counted among the largest bridges in the world.
The foundations that carry the steel arch of the Tyne Bridge are of special interest. It was found necessary to use four heavy caissons to take the load, and they were sunk down to the solid rock deep below the bed of the river. The caissons are rectangular, measuring 84 ft. 6 in. long by 28 feet wide. Each caisson weighs 90 tons.
The sinking of these caissons was carried out by excavation with the aid of compressed air. The caissons were finally filled in with concrete and surmounted by concrete piers holding the heavy granite skewbacks on which rest the arch bearings. Each caisson, with its pier, contains 7,000 cubic yards, or 10,400 tons of concrete up to the level of the bearings.
These bearings are of massive construction, with forged steel saddles that carry the 12-in. diameter bearing pins of the arch. At either end of the arch the abutments are extended above ground level in the form of pylons or towers 100 feet wide along the river front and 75 feet deep. These towers are built on two concrete foundation piers flanking the bearing caissons, which are also bridged by a floor of heavily reinforced concrete.
Lifts for Passengers
On either side of the bridge roadway the towers are built up to a height of 35 feet above deck level, and at these points the deck is carried on steel girders, 60 feet long. These girders are not carried by the tower walls, but rest on steel columns carried down in the walls to the foundation piers below. The handsome pylons supplement the imposing appearance of the bridge; but appearance does not give place to utility, and the towers have been equipped with floors for use as warehouses, with provision for goods lifts. In addition, the abutments contain stairways linking the low-level quaysides with the roadway, and on the Newcastle side two passenger lifts have been installed.
At the Newcastle end of the bridge there are three approach spans with a total length of 423 feet. The Gateshead approaches comprise two spans totalling 199 feet. The spans are supported on steel columns, some of which are 75 feet high. These columns are octagonal in section, with a diameter of 5 feet, and are composed of steel joists and plates filled in with concrete. The foundations for the columns consist of cast-iron cylinders, with a diameter of 22 ft. 6 in.; the cylinders are sunk deep into the soil and filled with concrete.
NEWCASTLE-UPON-TYNE IN 1864, when the original of this illustration was drawn, had two bridges, the High Level Bridge, opened in 1849, and Tyne Bridge, which was demolished in 1874-75 to make way for the Swing Bridge. Opened in 1781, the Tyne Bridge was of stone, comprising nine round arches with a total length of 550 feet. The High Level Bridge is a remarkable double-decked structure, 1,350 feet long, carrying a road and railway tracks. The bridge has a clearance of 82 feet above high water.
The building of these approach spans was a fine example of engineering practice. The spans were first built on the masonry abutments at the inshore ends of the bridge approaches on either bank. The tops of the columns were then fitted with rollers and a false “nose-piece” 20 feet long was built on the end of each leading span.
When all was ready the hundreds of tons of steelwork were rolled forward to meet the abutments prepared for the great arch. As many as 2,000 tons of steel were on the move at the same time on the Newcastle side and this gigantic task was carried out by hand.
With forty men allocated to four winches the spans slid slowly into position, the false nose-pieces were removed and the river ends of the spans were left supported on temporary steel columns.
The main arch of the Tyne Bridge consists of two trusses 45 feet apart, each comprising two crescent-shaped ribs connected together by a single system of webs. The arch rises 180 feet above the bearings and the distance between the ribs at the centre of the arch is 20 ft. 3 in. The roadway cuts longitudinally through the arch at a height of 93 ft. 9 in. above high-water level and is carried on a series of cross girders.
The procedure adopted in building the arch was the same as that later used in the construction of the Birchenough Bridge and of Sydney Harbour Bridge. The half-arches were built out from the abutments simultaneously and during construction they were anchored back by steel cables until they were finally joined at the crown of the completed arch. A special clause in the bridge contract provided that no material whatever was to be hoisted from the river, which had to be kept clear for traffic. Special permission was later granted for the raising from barges of the three centre cross girders for the roadway.
70-feet Steel Masts
The whole of the remaining steelwork, however, was handled from the river banks, or from the half-arches as they grew out over the water. The lowest members of the arch were erected by the use of a temporary steel cradle assembled first on the Gateshead and then on the Newcastle side of the site.
The half-arches, each carrying a 30-tons electric crane, were first anchored back to the ends of their respective shore spans. Then, as the work proceeded and the strain on the cables became greater, temporary steel masts 70 feet high were built on the shore spans.
Cables were then attached higher up the arch ribs and carried over the tops of the masts to anchorages farther back along the shore spans. Close to these anchorages were placed long hydraulic jacks with which it was possible to vary the tension on the cables. These jacks were used in the lowering of the half-arches, before their final joining to form an integral structure resting on the bearings on either side of the river.
The steel building material was handled by 20-tons derrick cranes, with jibs 115 feet long, and mounted adjacent to the abutments. The long jibs picked the material from railway wagons on the quayside and dumped it on to bogies running on a track along the bridge cross girders. The bogies were operated by cables and hand winches and from them the steel components were finally lifted by the 30-tons arch cranes and moved across to the erectors.
The building of the bridge involved the excavation of 40,000 cubic yards of material and the placing of 12,000 cubic yards of filling, 41,000 cubic yards of concrete and 90,000 cubic feet of granite ashlar (hewn) facing.
The Tyne Bridge, the fifth and greatest of the river crossings at Newcastle, was opened by His Majesty King George V on October 10, 1928.
THE STEEL ARCH of the Tyne Bridge has a clear span of 531 feet, and the approach spans give the bridge a total length of 1,254 feet. The too of the arch is 200 feet above the river and the roadway provides a headway of 84 feet above high water. The Swing Bridge is in the foreground.
