Thomas Andrew Walker

“ At another point where the tunnel had been perfectly dry, while the mining was done, the lifting of almost the last stone out of the invert set free an immense body of water which no pumps underground could cope with. At another point the water boiled up from a hole 18 feet in depth under the invert with such force that stones, the size of a man’s fist, dropped into the water would descend about 10 feet, and then begin to flutter like a leaf in the wind, and be thrown out again by the water. ”

“ I can say that, in a long experience on public works, I have never known a resident engineer more cautious or painstaking, more anxious to protect the interests of the Company, and at the same time pleasant to transact business with. ”

“ Their discontent first showed itself by their jeering at the men who took their meals with them up the long heading, asking them why they did not get tin hats made to carry their dinners in; and then by assaulting in the darkness, or when they could meet with them alone, men I had brought from a tunnel I had just finished at Dover.
At last, on Saturday the 21st May, a notice appeared, written in chalk, at the top of the main shaft: ‘I hope the ———— bond will break, and kill any man that goes down to work.’
The men gathered round the pit, but refused to go below. ”

“ One such experience as the Severn Tunnel, with its ever-varying and strangely contorted strata, and the dangers from floods above and floods below, has been sufficient for me. One sub-aqueous tunnel is quite enough for a lifetime.
Since these pages were commenced, I have had a great pressure of work upon me. Not only have I had to carry on such large works as the Barry Dock and Railways, and the Preston Dock, but I have also been called upon to visit South America to start the work of the Government Docks at Buenos Ayres, and at home to begin the construction of the Manchester Ship Canal. ”

“ A good driving-road had been made from the shaft to the nearest public road, near the ‘Black Rock Hotel,’ and encouragement had been given to the various tradesmen in Chepstow and Caldicot; and from this time to the completion of the works the men were as well supplied with all the necessaries of life as if they had lived in an old town; tradesmen and farmers’ carts of all descriptions calling at all the houses nearly every day. ”

“ By an ingenious contrivance the speed of the six engines is regulated by two cataracts, which, although allowing each engine to perform the same number of strokes per minute, so regulates them that no two engines make their stroke at the same moment, this insures uniform pressure of steam, and an even discharge of water into the culverts. ”

“ The Severn, as a river, may be said to end at Gloucester, at the point where the turnpike-road is carried, by Telford’s famous bridge of only 150 feet span, over it, for almost directly below it opens into a tidal estuary, which spreads out till, at the point where the tunnel passes under it, it is 21⁄4 miles wide. The tides in the Severn estuary are known to be the highest in England or in Europe. They are only surpassed in height by the tides which run Description of the Severnup the Kennebecasis River at the head of the Bay of Fundy, in New Brunswick. ”

“ When the arch is entirely bricked in a ‘break-up length,’ what is known as a ‘running length’ is commenced at one end of it. For this the top heading has been already driven, as before described, and then the bars are placed in the same manner as in the break-up length, propped with back props, and then with props upon sills; but, as one end of the bars rests upon the brickwork of the finished length, there is only one face to timber down. The face of each break-up and running length requires to be carefully timbered, and if the ground is loose, polled ”

“ A heading is a small tunnel, and if timbered at all, it is timbered quite differently from the tunnel itself.
A heading 7 feet square is quite large enough for working skips or small trolleys. If it is decided to get ordinary tip-waggons into the works, the heading must be at least 9 feet square.
If the ground is in rock, only occasional timbers may be required to support the roof when stones in the top are loose, or sound, when struck, what the miners call ‘drummy.’ The top in that case may require ‘head-trees,’ which are timbers across the line of the heading, and polling-boards. ”

“ The great rise of this tide is caused by the funnel-like shape of the estuary. The tide running round the South of Ireland, and becoming imprisoned between South Wales and the Cornish and Devonshire coasts, as the width of the channel is continually decreasing, mounts up to a great height, till it reaches, at the mouth of the Wye, a height at spring-tides, of 50 feet above low water. ”

“ It would be wrong for anyone reading this account to blame the men for cowardice. I am sure that a finer body of men could not be found in England. They were men who had had a thoroughly hard Progress of the work—1882. of training, and accustomed as they were to work in dangerous positions, and knowing every time they went below that each man took his life in his hand, they still went cheerfully to their work, and were no doubt as brave as Englishmen always are. ”

“ The bucket-pump is simply the ordinary lift-pump used all over the country, with a bottom valve fixed as near as possible down to the level from which the water is to be pumped, and with large rods running down the centre of the pump attached to the bucket-valve which works up and down the length called the working barrel, the bucket-valve opening as the pump-rods descend, and allowing the water to pass to the upper side of the bucket ”

“ We cleared this heading out and descended to the farthest point to which it had been driven, which was 864 feet from the centre of the Old Pit. We found that in order to drain the heading several bore-holes had been put down from this heading into the long heading, and, as soon as we had secured the timbering through the coal-shale, we broke up a shaft from the long heading at the extreme end of the upper one to give the men a second means of escape, should any further accident occur. ”

“ The only difficulty about the operation was that the shields must be lowered by signals received from divers, who must be down the shaft at the level of the headings, and that the struts must be fixed and wedged up also by divers at the same level.
The depth of water from the shield to the surface being about 140 feet, the pressure upon the divers was so great that very few men were able to bear it at all, and no man could do work requiring great physical exertion under that pressure. ”

“ The greatest number of men at work at one time was 3,628.
In almost all parts of the tunnel the men, when at work, had to wear either waterproof clothing or flannels. These clothes were provided by me, and large rooms were erected at each pit-top where the men could change their clothes, and at each room there was a man on duty day and night to see to the safety of the men’s own clothes, and to superintend the drying of the wet garments.
The average amount per week earned by the miners, taking into account all lost time, was £1 18s., and by the labourers £1 7s. ”

“ In a heading being driven at any distance from the shaft, though there may be but five or six men in the heading, the heat becomes very great, and, of course, a constant supply of fresh air is required for the men themselves. ”

“ As soon as the 9-ft. barrel was completely bricked, in the middle of this year, a number of shafts were sunk to a depth of 20 feet, from which to put in the permanent drain required by the alteration of gradient. This when finished was to be a 5-ft. barrel.
The ground in which the drain was constructed was principally hard Pennant rock, but for a short distance it passed through the coal-shale. No great quantity of water was met with, and for the first 1,000 feet this was easily disposed of by hand-pumps. ”

“ When the heading is driven, and a number of break-ups commenced along it, the great difficulty will be to take out the requisite number of skips of rock or other material filled from the lengths and the heading-face, and to take in the empty skips to be loaded, and to carry to the bricklayers the bricks and cement which they require; while at the same time there will constantly be timbers to be taken in to the miners. ”

“ The point chosen for commencing the works of the Severn Tunnel is within about 100 yards of this Roman camp, on the north side of it.
To the south of the camp the inroads of the sea have made marked progress during the last century.
More than 2 miles from the shore is a small island, known as ‘The Denny,’ on which it is reported that, within a hundred years, a fox, followed from the mainland, was killed. It is still possible, at low water of the spring-tides, to walk to the Denny and return in the same tide, but the journey is not unattended with danger. ”

“ By altering the old engine-house, where the 41-inch engine had originally stood, and strengthening the ‘bob-wall,’ which carried the beam, a house was provided for one of the 70-inch engines. A house for one 60-inch engine at 5 miles 4 chains was built of brickwork, and for the other 60-inch and 70-inch engines two new houses were built of stone and brick. ”

“ On the Gloucestershire side, at Sea-wall Shaft, one 29-inch plunger and one 29-inch bucket, 9-foot stroke, each raising 258 gallons per stroke; steam cylinders 41 inches diameter, 10-foot stroke; beam engines, horsepower per stroke from water lifted 7·66 each pump; ordinary strokes per minute average 51⁄2, maximum plunger 10, bucket 12; lift 98 feet. These pumps take water from cutting and a length of tunnel; as a rule, one only works at a time. ”

“ It was nearly an hour’s work for men to go up, pushing trollies with timber, from the shaft to where the fall had taken place. I therefore arranged for a few men to go in, taking timber with them and food, so that they might remain at the end of the heading for the whole shift of ten hours. ”

“ When this was completed, the pumps were started again, and the clay was found to have effectually stopped the water.
At each end of the lengths of brickwork, where the water had broken in, a 6-ft. length of tunnel was immediately commenced, 4 feet thick; the ordinary work being only 2 feet 3 inches. These lengths were taken out as rapidly as possible, and brickwork in cement built in them, thus forming, in the chases which had been cut, a ring of brickwork nearly double the ordinary thickness to stop the water from travelling along the back of the work. ”

“ Not the slightest hitch has occurred in the working, and the speed of the trains has often been as much as a mile a minute. The ventilation has been perfect, and the relief to the traffic between South Wales and the South-West of England has been very sensibly felt. No doubt this traffic—with the accommodation afforded by the Tunnel—will be greatly increased.
A considerable amount of the Severn Tunnel traffic for the south of England passes over the main line between Bath and Bristol, and thence on to the Salisbury line, which joins the main line at Bathampton. ”