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.