G. M. DAVID OBE FREng INFRASTRUCTURE CHAIRMAN, AERIAL FACILITIES LTD T ern unn ev e S l

he estuary of got up by the Great the river Western Railway TSevern had consulting engineer always been an John Fowler. The obstacle to trade plan was for a new between South railway entitled the Wales and the west Great Western of England which Railway and South was overcome to Wales Direct Railway some degree by which would be double shipping arrangements: a track mixed gauge of forty very good trade built up miles in length from Wootton between Bristol, Gloucester Bassett to Chepstow crossing and the South Wales ports, the Severn estuary at Aldbury Sands although it should be remembered that via a bridge or viaduct not less than 2.5 Cardiff was only a village in 1830 and Brunel miles long and 100 feet above high Barry and Penarth were only hamlets. A Brunel had been very active in getting water. very heavy trade existed, however, the broad gauge into South Wales and The addition of standard gauge rails between Cardigan, Milford, his tubular bridge at Chepstow was between Didcot and Wootton Bassett Carmarthen, Burry-Port, Swansea, evidently a practice run for his great and between Chepstow and Cardiff Briton Ferry and Bristol: the Severn Saltash bridge. But by the time the was to be arranged with the Great Trows did a brisk trade up the Severn railway had reached Swansea in 1850, Western Railway. This plan was called and Wye estuaries far above what is Brunel had already embarked on other ‘Fowler’s Line’ and duly authorised by now considered as navigable water. A major projects such as his ships: the Parliament in 1865. ferry service was installed by the Great Great Eastern was beginning to occupy Western Railway between New his every waking moment. Passage on the Bristol side and The construction of the Saltash Charles Richardson Portskewett on the Chepstow side, bridge in the early stages involved A separate project called the South where piers were built and railway Brunel a great deal and it is noted in Wales Junction Railway by a much less access was provided. Passengers many of the biographical records of his well-known engineer, Charles disembarked from the trains at the pier life that large numbers of cigars and Richardson, was for a tunnel beneath and took the paddle steamer across amounts of brandy added to the many the Severn between Pilning and Rogiet. the estuary to a corresponding rail arduous days of twelve hours in the However, the board of the Great service on the other side. saddle were material contributions to his Western Railway and its advisers did With the rapid development of the failing health. There were many ideas he not favour Richardson’s plan and it was railways and the discovery of extensive had envisaged and discussed with never put forward to be authorised by coal fields in South Wales between others which eventually were carried out Parliament. The company was 1830 and 1850, the need for links by his friends and colleagues in the dissolved in 1870. between South Wales and England industry. A good example of one of Charles Richardson, however, did became an engineering pipedream for these is the Severn Tunnel which is first not give up easily and deposited a Bill many of the shrewdest visionaries of noted in the records of the Great for the 1872 session of Parliament ‘To ingenia the industrial revolution. Western Railway as a bridge proposal authorise the construction of the 17 INFRASTRUCTURE

Severn Tunnel Railway and other and the estimated cost was £750,000.’ 400 yards wide and 80 feet deep, purposes in connection therewith’. The proprietors adopted the scheme called the Shoots, through which the Since Brunel was now dead it as proposed and it was duly sanctioned strong current of the river runs at low seemed strategically useful to by Parliament and work began at water; and next about half a mile of Richardson to engage Brunel’s old Sudbrook on the shaft in March 1873. more half-tide exposed rocks, called critic, Sir John Hawkshaw, as Owing to the funnel-like shape of the the Lady Bench. consulting engineer. He was now Severn estuary, the tides are the The railway was designed to pass successful in getting the Great Western highest in Europe, spring tides rising at under the Shoots at a level of 50 feet directors to adopt the scheme and they the mouth of the Wye to 50 feet above below the rock bottom and from this, its reported to the shareholders in low water. At the site chosen by lowest point, to rise in each direction at February 1872 ‘That the railway Richardson for the tunnel the estuary is a uniform gradient of 1 in 100. The total proposed be constructed and that the 2.25 miles wide. Of this distance, the length of the tunnel was to be 7,942 authority of this Bill extended from first mile and a half from the yards or just over 4.5 miles, a little more Pilning station on the Bristol and South Gloucestershire side consists of a level than half under the river, about three- West section to a point on the South of rough rocks, known as the English quarters of the remainder being under Wales Railway near Portskewett. The Stones, which are uncovered at half the land on the Monmouthshire side, length of the line is about eight miles tide; then comes a deep channel about where the mouth is on the north side of the South Wales line. Figure 1: Map of 1887 showing the completed tunnel ingenia

18 INFRASTRUCTURE

March 1873 – August 1877 Company’s men. These pumps easily 1877, with whom Hawkshaw had been disposed of all the water met with in associated in the extension of the East The first thing to be done was to the workings, none of which came from London Railway under London Docks. explore the strata that would be met in the river. Walker renewed his former offer with the excavation of the tunnel and for this certain modifications; his figure of purpose it was decided to sink a shaft £948,959 was accepted and the works at Sudbrook as near as possible to the The Great Spring halts work were handed over to him on 18 west bank and drive a heading from it The work went on steadily until the December 1879. under the river, the shaft to be 15 feet middle of October 1879, by which time His description of the scene he in diameter and about 200 feet deep the original heading from the Old Shaft found is as follows: and the heading to rise gradually from had been driven nearly two miles under Nothing could be more desolate its bottom, so as eventually to drain the the river and was within 130 yards of than the appearance of the works at tunnel at is lowest point. A dozen Norris’s westward heading from the Sea this time. There were near the main cottages and an office having been Wall Shaft, while other headings had shaft only six cottages and a small erected near by and a temporary been made in each direction form the office, the necessary boiler-houses railway laid to Portskewett Station, Marsh and Hill Shafts and also at a and engine-houses, a small work was started on 18 March 1873 by higher level than the original one, from carpenter’s shop, a fitter’s shop, a men employed by the Company under the Old Shaft (see Figure 2). In this last blacksmith’s shop and two low Richardson and his assistants. heading men working westward some buildings or sheds, used as cottages With so small a provision progress 300 yards away from the river on 16 also. The tramway which had been was necessarily slow and in August October suddenly tapped a large spring originally laid to Portskewett Station 1877, after four and a half years’ work, of fresh water, which poured in in such had been pulled up and in lieu of it all that had been done consisted of the volume that it utterly overpowered the another tramway had been laid sinking and lining of the shaft, pumps and within twenty-four hours all following (on the surface of the afterwards known as the Old Shaft, and the workings connected with the Old ground) the centre line of the tunnel the driving of about 1,600 yards of a Shaft were full up to the river level. itself from the Old Shaft to the Marsh seven-feet square heading under the Fortunately the men were able to Pit and joining the Great Western river. A second shaft had been escape by a cross-heading into the Iron Railway a mile west of Portskewett commenced in which it was intended to Shaft, so no lives were lost. Station at Caldicot Pyll. The engines fix the permanent pumps to drain the By the irony of circumstances it of the main shaft stood idle, the tunnel but this was only about half sunk happened that the Severn Bridge at boilers were out of steam, most of and was unlined. Save for a short length Sharpness was opened next day and at the men who had been employed of coal shale, the heading passed the luncheon Sir Daniel Gooch, unaware had left in search of other work and through hard Pennant sandstone, all of of what had happened, invited the the water in the shaft was standing which had to be drilled and blasted. company present to visit the tunnel in up to the level of high water in the At this date the Directors advertised about six weeks and walk through the Severn. for tenders for the whole work. Three heading under the river, which would The pumping engines at Sea Wall, were received and rejected. They then then be completed, at the same time Marsh and Hill Pits were still at work, made two small contracts: one with warning them that it might be rather wet! as the working of those pits had Oliver Norris of New Passage, to sink a been in the hands of Mr Norris and shaft on the Gloucestershire side, Mr Brotherhood; but no work was afterwards known as the Sea Wall Shaft T. A. Walker and Sir John being done below, orders having and drive headings east and west from Hawkshaw been given to these gentlemen to it; and another with Rowland Determined to proceed in spite of this suspend their operations. Brotherhead to sink two shafts on the melancholy discouragement after nearly The pumps were able to keep the Hill Monmouthshire side, some distance seven years’ work, the Directors asked Pit dry, but were not sufficiently west of Sudbrook and drive headings Sir John Hawkshaw to take charge of powerful to drain either of the dipping each way from them. These were the works and carry them on as he headings from the Marsh or Sea Wall named Marsh Shaft and Hill Shaft thought best. Sir John agreed on Shafts, while the main shaft and respectively. Pumps were established in condition they would engage a heading were full of water. all these four shafts and also in the contractor for the whole in whom he Hawkshaw decided to lower the permanent shaft at Sudbrook, known had confidence and on their tunnel under the Shoots 15 feet, from its lining as the Iron Shaft, as soon acceptance sent for T. A. Walker, one of maintaining the gradient eastward at 1 ingenia as it had been completed by the the three who had made tenders in in 100, 15 feet below the former level 19 INFRASTRUCTURE

throughout and making the westward flood door in the long heading under go and close the door for £10,000. gradient 1 in 90 instead of 1 in 100, so the river, 340 yards from the shaft, Lambert then borrowed the apparatus as to run out into the old levels on the Lambert went down to grope his way from him and after some practice with it Monmouthshire side. This, of course, under water, in total darkness, over the under water, succeeded in reaching entailed deepening all the shafts and debris in the heading, which he had and closing the door. the construction of a new drain from never seen, past overturned skips, As soon as he had mastered the the new bottom under the Shoots to beams, tools and lumps of rock for the water, Walker began work underground the pumping shaft and made the work 340 yards. Though two other divers with great energy, his first step being to much more difficult for the contractor came down to pass his air-hose build a strong wall in the westward as it converted the bottom heading forward, it floated so hard against the heading from the Old Shaft to imprison already driven into a top heading. rough roof that he was unable to drag it the Great Spring. This was Some larger pumps and engines along farther than 270 yards and after accomplished early in January and the having been ordered, four new shafts some vain efforts had to return. The water from the spring entirely shut out were commenced, one at Sudbrook, journey was still more perilous as the from the works. He had already made one at Sea Wall and two at a point 26 hose on which his life depended, curled considerable progress in providing chains west of the Sudbrook Shafts up in kinks and coils about the timber dwellings for the men at Sudbrook and and beyond where the Great Spring and other obstacles and he had to find, founding what soon became a small had broken in, in the hope of pumping gather up and carry all these coils, town, with its mission room, school, all the water from it there and so which were constantly slipping from his hospital and post office, besides a large keeping the rest of the work dry. grasp. brickyard and the engine houses and Owing to the time taken in the About this time Walker had heard of other buildings of the tunnel works. delivery and fixing of the new pumps, a new apparatus for diving without an At the Sea Wall Shaft on the other the failure of the measures taken to air-pipe by means of a knapsack of side of the river, the brick arch of the shut off the Great Spring effectively and compressed air, which Fleuss, its tunnel itself had been begun in a chapter of accidents, the works were inventor, was exhibiting at the December and the bricklayers were at not clear of water till 7 December 1880. Westminster Aquarium. He accordingly work when, one day towards the end of telegraphed to Fleuss to come and try if April, water suddenly burst in from the he could do the work. Fleuss arrived full roof, putting them to flight and soon Diver assists with the of confidence and went down with flooding that bit of the tunnel. To drainage work Lambert to the mouth of the heading Walker’s dismay it was found to be salt ingenia In the course of the pumping but when he found the sort of place he and therefore from the river. Above, at operations a diver named Lambert was expected to go into for nearly a low water, was a pool near the shore performed a very brave act well worth quarter of a mile, his heart failed him called the Salmon Pool, only about 3 recording. It being necessary to close a and he came up, saying he would not feet deep, so a number of men were 20 INFRASTRUCTURE

Figure 2: Sectional view of tunnel on 18 October 1879 when the Great Spring broke in. This is a cross- section looking south (west is on the right, east on the left).

sent to join hands and walk through the lying Marsh Shaft. At the bottom of this 7,942 yards to 7,666, the cutting at the pool to find the hole. Soon one of them shaft about a quarter of a mile of tunnel west end being lengthened 276 yards found it, suddenly disappeared, and was had been completed and eighty-three to provide material for making sidings at pulled up by his neighbours. The hole men were at work in it. As the water the new station near Rogiet, afterwards was then stopped with clay and loose rose they retreated up the gradient to named Severn Tunnel Junction. sand in bags and later made secure with the scaffolding at the west end. Above, The whole of the tunnel, except cement concrete. Fortunately the long help was got from Sudbrook, whence rather less than 300 yards where the heading under the river had not yet been some men waded to the shaft and Great Spring had been shut in by two completed or it would of course have managed to form an emergency dam head-walls and the cuttings were now been flooded throughout. The two around it. In spite of all that could be fully at work. The largest possible headings were joined up on 26 done, the water rose in the tunnel to number of men – at one time 3,628 – September 1881, opening the way within eight feet of the crown of the was employed and all the plant and under the river between the Sea Wall arch. At last the men were rescued by machinery that could be used, including and Sudbrook Shafts and enabling means of a small boat lowered down several more pumping engines, was on through ventilation to be established by the shaft. The tidal wave flooded the the ground. means of a Guibal fan at Sudbrook, in cutting at the west end of the tunnel, place of compressed air. fortunately not yet connected with it and also the fields on the The Great Spring is tamed Gloucestershire side. So on the In order to deal with the Great Spring, The Great Spring halts work morning of 18 October 1883 the works Hawkshaw determined to drive a side again were in a worse state than they had heading parallel with the line of the Steady progress was made with the been since 1880. tunnel from the Old Shaft at Sudbrook tunnel and the long cuttings at either Lambert was once more engaged to to intercept the spring. The water end until 10 October 1883 when the close a door shutting off the Great having been allowed to run into the old Great Spring again burst in in much Spring which he succeeded in doing on heading and so to the pumps, this side greater volume than before, drowning 30 October and a few days later all the heading was pushed forward till it the works at Sudbrook and under the works were free of water. reached a large open fissure in the river. Two days later the largest pump at By the end of the year 2.25 miles of strata which had formed the channel for the shafts 26 chains west of Sudbrook full sized tunnel had been completed the underground stream. Then by broke and in a few hours those and rapid progress was being made diverting it into the side heading, the detached works were also full of water. with the remainder and also with the tunnel was left for the time almost Then on the night of 17 October came open cuttings at each end. perfectly dry. Finally in 1886 a new large a tidal wave, inundating the lowlands Early in 1884 it was decided to shaft was sunk at the side of the tunnel west of this and pouring into the low reduce the length of the tunnel from and six big pumps fixed in it and so the ingenia 21 INFRASTRUCTURE

Great Spring was permanently mastered. The last three Cornish beam engines remained at work until replaced by electrically worked pumps on 6 November 1961. At the end of 1884 the whole of the tunnel was completed, except about 200 yards just west of Sudbrook, and 500 yards of invert under the Shoots, where connections remained to be made with the drains. On 18 April 1885 the last length of brickwork in the tunnel was finished. Altogether 76,400,000 bricks were used in the construction of the tunnel and bridges. Much work still remained to be done in the long open cuttings, especially on Figure 3: Photograph of Sudbrook pumping engines in 1970 shortly before the Gloucestershire side. These their demolition cuttings are protected from any such inundation by a tidal wave as occurred Portskewett Piers ceased and the through train each way, by no means in October 1883 by high banks. The railways to the Piers were closed. fast, was established in July 1887. At western one was finished first and the The permanent way consisted of the eastern end of this loop a large yard permanent way having been laid there steel bridge rails, 68 lb to the yard on of sorting and marshalling sidings on and through the tunnel, a special train longitudinal timbers in the tunnel and both sides of the main line (Bristol, East with Sir Daniel and Lady Gooch and a elsewhere of 86 lb bullhead rails in 43 lb Depot) was laid out. The construction party of friends was able to make the chairs on cross-sleepers. of shunting necks for those on the Up first journey from Severn Tunnel The total cost of the new line was side involved the demolition of Brunel’s Junction through the tunnel into the £1,806,248. No. 1 Tunnel, 326 yards long and the cutting on the Gloucestershire side and To provide for the heavy traffic widening of the resulting cutting. This back on 5 September 1885. expected on the opening of the new was safely completed in March 1889 On 9 January 1886 an experimental route to South Wales, the single line of without interrupting the traffic and early coal train ran from Aberdare to the old Bristol and South Wales Union in the following year the new yard was Southampton, through the tunnel, Railway, between the junction of the brought into use. Meanwhile it had resulting, as the Directors proudly Avonmouth Branch at Narroways Hill already been found necessary to reported in February, ‘in coal which had near Stapleton Road Station and the quadruple the South Wales line from been raised at the Colliery in the new Severn Tunnel Railway at Pilning the north end of the loop, through morning being delivered at the Port in was doubled, a separate Up line being Lawrence Hill and Stapleton Road the evening of the same day’. made between Pilning and Patchway Stations, to the junction of the The opening for traffic was delayed with a uniform gradient of 1 in 100 and Avonmouth Branch at Narroways Hill for the completion of the new pumping a tunnel exactly a mile long – Patchway and this was finished in November arrangements at Sudbrook already – Narroways Hill opened 1 September 1891. mentioned and the installation of a large 1886 and Pilning – Patchway 27 May Thus was completed the great link Guibal fan, 40 feet in diameter and 12 1887. The old line has 1.25 miles of 1 between the South Wales coal field and feet wide to ventilate the tunnel. This in 68 and tunnels of 1,246 and 62 its markets to the east and it is worth fan was completed and set to work on yards. noting that since the 19th century all 31 August and on 1 September 1886 At Bristol a short loop was the engineering proposals for crossing the line was opened for goods traffic. constructed between Dr Day’s Bridge the Severn estuary have been by bridge Colonel Rich having made his Junction (named after a local medical rather than tunnel and when one looks inspection on 17 November and benefactor) and North Somerset at the history of the difficulties reported favourably to the Board of (formerly Feeder Bridge) Junction to encountered by the builders of the ingenia Trade, passenger trains began to run enable trains to run direct to and from Severn Tunnel it is not surprising that between Bristol and Cardiff on 1 the east, making the distance between engineers have preferred to be above December 1886, whereupon the ferry Paddington and South Wales 15 miles the waters of the Severn rather than service between New Passage and less than by the old Gloucester route. A beneath it. 22