Sheffield Flood
The Inquest
«ReturnThe inquest was opened before the Coroner, J. Webster, and his deputy W. W. Woodhead, on Saturday, March 12, at the Sheffield Union House.
Members of the Jury included: Mr. Henry Pawson, foreman, Mr. Thomas Prideaux, Mr. J. B. Fordham, Mr. J. Walker, Mr. C. J. Porter, Mr. Henry Pearce, Mr. T. Appleyard, Mr. John Howson. Mr. John Bland, Mr. R. Booth, Mr. S. Dawson, Mr. F. W. Colley, Mr. T. Cole, Mr. F. J. Mercer, Mr. Edward Bennett, and Mr. William Marples. The Town Clerk. J. Yeomans, Esq. was also present to watch the inquiry.
The Coroner, in opening the inquest, said he should proceed to identify a few of the bodies, in order to facilitate their burial, after which he would suggest that the inquest should be adjourned for a week or ten days, so that he and the Chief Constable might have an opportunity of investigating the matter, and of consulting with the Secretary of State, so that he might send down a competent person to examine the present condition of the reservoir at Bradfield.
The inquest on the bodies of Thomas Elston and others was resumed at the Town-hall on the 23rd of March..
The coroner (Mr. John Webster) conducted the Inquiry. Among those present were Mr. Robert Rawlinson, C.E., and Mr. Nathaniel Beardmore,C.E., from the Home-office; M. Mille, member of the Legion of Honour, and engineer of bridges and roads to the French Government; Mr.Robert W. Mylne, C.E., F.R.S., of London; Mr. W. Lindley, C.E. (London), engineer of the Hamburg Sewage and Water Works; Colonel Ford, of York; Mr. Perronet Thompson, barrister, instructed by Messrs. A. Smith and Sons, solicitors to the Water Company; and Mr. William Smith, chairman of the Water Company.
The CORONER, in opening the proceedings, said the jury were to inquire how Thomas Elston and others came to their deaths on the 12th inst. He proposed only to direct their attention to the death of Elston. Separate inquisitions could afterwards be made with regard to the other deceased without any particular inquiry. Having read the evidence taken on the previous occasion, the Coroner added that the course he proposed to take was to examine the engineer of the company first, in order to get as far as possible a history of the embankment. If Mr. Leather could not give all the information deemed necessary, he (the Coroner) would examine Mr. Gunson, the resident engineer, Mr. Craven, the contractor, and such other witnesses as might be necessary. If their evidence was not satisfactory, he would call Mr. Rawlinson, the Government Inspector, and one or two other witnesses who had been engaged in examining the reservoir, who would give their opinions upon the cause of the disaster. That would be the most direct way of getting at what they wished. He hoped to be able to conclude the inquest that day, but if the witnesses were not all examined by half past 5 he would adjourn the proceedings for the day.
Mr. John Towlerton Leather, Leeds, civil engineer said, 'I am the consulting engineer of the Sheffield Waterworks Company. I was consulted by the company when they applied to Parliament for powers to make Bradfield Reservoir. I prepared the plans for its construction. That would be in the year 1858. I examined the country generally before depositing the plans, to see if the water could be obtained. The contract for the Bradfield reservoir was let, I think, in 1858, Originally the embankment was set out lower down the valley than where it was executed. That first embankment was never commenced, because it was found, on trial holes being sunk, that there had been a disturbance in the strata. I then altered my plans for the embankment to be where it is now. I examined the ground before we commenced making the embankment, and found it to be on the outcrop of the coal measures, and at the commencement of the millstone grit. The strata consist first of soil, then clay, then stone, then shale, with a gannister formation and a little coal in the centre of the valley. I had to deal with soil, clay, stone and shale in the embankment. The only spring I ever saw in the valley was one on the site of the reservoir, a little above the embankment. The first thing in forming the embankment is to sink the puddle trench in the centre of the base. The original plans provide for a puddle bank about 10ft below the surface. In sinking a trench we did not find a good foundation at that depth. It was not sufficiently water tight. It was therefore necessary to sink it until we got to a water tight foundation. We sank to a depth varying from 10 to 60ft. and then got a water tight foundation. A good deal of water came into the puddle trench during the working. We got rid of it by pumping. I do not remember what powers the contractor had to pump the water. I came to see the trench, I think twice. I came when I was wanted. I walked over the bottom of the trench when it was finished, and I knew it was water tight. I was not aware that in wet weather the quantity of water in the trench was so great that they could not pump it down. I saw the puddle trench in 1861, and in 1863 I saw the puddle wall. I did not see the puddling in the trench in its progress - at all events not at the lowest point. I did not see the whole of the puddle, but what I did see was well put in, and the work was good. The water was not cut off altogether from the trench. The trench simply divided the watercourses. The water came into the trench so long as it was open. The bottom of the trench was impervious, but the sides were pervious. The water was not got rid of, but blocked out by the puddle, as is usual. When, therefore, the puddle wall got to a certain height there would be water against it on the upper side. The water that would get through the rock to the puddle wall would not have a tendency to injure it. The object of a puddle wall is to keep out water, and therefore water is always against it in a reservoir. The water rises against the puddle wall, but does nor percolate through it. The water was not let off by any natural means; if it had, the puddle wall would not be perfect. As the puddle wall was being constructed, the water rose with it, and was carried away. The embankment across the valley is 418 yards long. It is 500ft wide at the base and 12ft at the top. The inner slope is two and a half to one, the outer slope the same. The greatest height is 95ft high, it will be 16ft wide at the base. There is 60ft of puddle below the surface, making the total depth of the puddle wall 155ft. The reservoir would contain a little over 114,000,000 cubic feet of water. The surface area of water was about 75 acres. The area of the gathering ground is about 43,000 acres. We got the material for making the embankment from the inside of the reservoir, and in doing so laid bare the rocks. In some places we got a good deal of stone. The embankment is made of stone, clay, shale and earth. I cannot say how the material was put in. Mr. Gunson was not my servant. He was the resident engineer. He had the superintendence of the works, and occasionally consulted me. He could not deviate from my plans. There are two 18 inch pipes from the inside to the outside of the reservoir underneath the embankment. The pipes are about 500ft. long, made up of lengths of 9ft. There would be 55 or 56 lengths, They are joined with sockets and lead in the ordinary way. They are laid in a trench 9ft below the surface of the ground. They are wrapped round with clay puddle to the thickness of I think, 18 inches, the trench then being filled in. The pipes are laid obliquely, not diagonally, across the embankment in a straight line. The valves are at the lower end of the pipe outside the embankment. If one of the pipes were to burst in the centre it would be difficult to repair it. It would have to be reached by excavations. An instance of that kind occurred in the great dam at Crookes. The pipes were originally of wood. I removed them by excavating, and substituted iron pipes. That would be 30 years ago. The breaking of one of those pipes would most likely cause serious damage to the embankment. The embankment might possibly fall before we could find out the damage; I can't tell what might happen. I never knew an instance of that. The pipes were made of double the usual strength. I should think there could not be an unequal pressure upon the pipes from the embankment. Being laid in the solid ground, the weight above could do no harm, unless it was a crushing pressure. There would not be an unequal pressure upon the pipes so as to raise them at any of the joints or cause them to leak. We can insure a sufficient equality of material along the whole length of the pipes for all practical purposes. The Water Company have other dams constructed on the same principle which have been in operation a great number of years. Possibly water from the sources blocked up in filling the puddle trench might get into the pipe trench. If it did it would show itself. If water got in below the puddle trench it might be dangerous; if above, it would not. It would show itself by percolating to the lower end. Water-mains in streets do not often give way under external pressure. I never knew one break or yield at the joint from external pressure.'
Mr. Rawlinson, - Is it not a common thing for a new line of mains to have blemished joints and leak?
Mr. Leather, - The pipes of the company are severely tested before they are put down.
Mr. Rawlinson, - I saw the testing apparatus, but nevertheless the question is a proper one. My experience is that they do give way.
Mr. Leather, - My experience on the contrary is, that they scarcely ever do give way.
Examination of Mr. Leather by the Coroner resumed. - I never heard of a pipe giving way on account of water creeping along the pipe trench. I do not know there was such a case in Birmingham. It would not have been better to have made a culvert for the pipes. Laying them in a trench is better, because in my judgement it is a more simple operation and more secure. In case of accident a culvert would give readier access for repair, but with much greater liability to accident. I can hardly tell the pressure of water on the valve when the reservoir is full; I am not prepared with the necessary calculations.
Mr. Rawlinson, after a calculation, said the pressure of water on each valve would be from 4 to 5 tons, when the reservoir was full.
Mr. Leather's examination resumed, - When the water is flowing freely through the pipes they are not likely to sustain much injury. The opening of the valve would not have a tendency to wrench the joints of the pipes. The pressure lessens as the valve is opened.
The CORONER - It took half an hour to open one of those valves on the night of the inundation, and there was a shaking and straining of the pipe during the opening not felt before or after. That is the reason why I ask the question. What I mean is, would there not be a greater pressure upon the valve when the water was in motion?
Mr. Leather. - No. There would be greater disturbance in the way of noise in opening the valve, but the pressure would diminish as the valve opened. The pipes would run off 10,000 cubic feet of water per minute. Every inch that the water lowered would diminish the water the pressure upon the embankment. At this rate, 190 hours, or about nine days, would be required to let off the whole of the water, supposing there was no addition. I have not hitherto thought it necessary to have had more complete control over the water. I did all I thought necessary to provide against danger. I know of no means of providing against danger except the pipes and bye-wash. There is a drain all round the Redmires dam, but that is for another purpose altogether.
The CORONER. - Ought you not, as a practical engineer, to minimise the danger as much as possible in making these large reservoirs? There has been no attempt to minimise the danger here, and there is no use in having an engineer unless he does that. You have had the management of these dams. You have placed a great embankment there, and collected an immense body of water behind it. But even though there was a suspicion that the embankment might give way, you have taken no means of taking the water any other direction, so as to avoid its coming down in one body upon the people of Sheffield. I ask you, is it not desirable in such cases that some means should be taken of lessening the danger?
Mr. Leather.- I cannot conceive any other way than that adopted.
The CORONER.- There was not the slightest arrangement made for doing away with the danger; that is what I complain of. Why, it would have taken eight days to have run off the water in the dam through the pipes, if there had been no influx. The influx of water was so enormous that it would have taken three weeks to run off the water by the pipes. I saw a large cutting near; could not that have been made available Mr. Leather?
Mr. Leather.- No; a cutting should be at the bottom of the embankment of a reservoir to relieve it under such circumstances, and I know of no means of having such a cutting.
The CORONER.- Could you not have drawn away any water that reached the puddle without the puddle being injured - drawn away from the outside, I mean?
Mr. Leather.- Yes; I do not know that anything of that sort has been done.
The CORONER.- It was no part of your plan to drain the puddle trench? - No; except during the working.
I mean afterwards? - No; I do not suppose any would get there afterwards.
I am supposing it has. The puddle trench could not be so drained as to prevent water getting there? - Any water that might get there would naturally percolate through the embankment on the lower side. It would get away without doing any injury.
The CORONER.- I am told that water was seen coming from the bottom of the embankment sometimes; that might be the reason?- It might be said that would be the natural result if any water did get into the embankment. Would there not be a greater weight upon the escape pipes in the centre of the embankment than at the edges of it? The pressure would be greater. The embankment was 90ft high in the centre. If this weight pressed the pipes down at the centre through the puddle it would not necessarily disjoint the pipes.
Mr. Rawlinson called the attention of the witness to a report published by the Society of Civil Engineers, in which it was stated that pipes laid under an entrenchment occasionally broke from the pressure upon them not being equal; and mentioning an instance at Melbourne, where the fracture had to be repaired by inserting a line of boiler plating inside. The pipes in this case were excellent castings, and had borne a very severe pressure, both externally and internally, but by the weight of the embankment were flattened and distorted, more in the centre than at the sides, because the pressure was unequal. There was, therefore, a possibility of pipes subjected to an unequal pressure being injured.
Mr. Leather replied that the pipes in the case cited by Mr. Rawlinson were laid in the embankment, not in a trough. Those of the Bradfield reservoir were, however, laid in a trench under the embankment. The cases, therefore, were quite different.
The Coroner.- But though the trough was made in the natural ground, the pipes themselves were laid in an ground, which might offer more resistance in one part than another.
Mr. Leather.- There were 18in. of puddle round them, but they would adjust themselves in the puddle.
By the Jury.- How do you determine the strength of the embankment?- It was ten times that of the pressure against it. I cannot tell how much water would run into the reservoir in 24 hours on a wet day. The pipes had not been examined since the flood. But there was no leakage through or about the pipes before the accident, and as there was a full flow of water through the pipes when the valves were opened, it is fair to presume there was no leakage.
Mr. Leather, examined by Mr. Perronet Thompson.- I have been the consulting engineer of the company in respect of all reservoirs. I have not previously had an accident, though some of the reservoirs are of greater extent than the Bradfield reservoir. The embankment of the upper dam at Redmires is much larger.The plans and sections for this and the reservoirs that have stood for years are precisely the same in principle, and there is a great similarity in situation and materials of some of them. I used all the means known to me as a practical engineer in the construction of these dams for insuring the security of the work. So far as my observation went, the quality of the work was good throughout. The fact of the puddle trench being sunk to the depth of 60 ft, although the plans required only 10ft, is an illustration of the care exercised in providing for the safety of the dam. The specification provided for the trench being made deeper than 10ft if necessary. The weight of the water is measured by the depth, and not the quantity of the water on the superficial area. One-fourth the water might have given quite as great a pressure if the depth had been the same. I have not an instance in my experience of pipes carried under the embankment having given way. If the valves of the pipes had in this instance been unable to sustain the weight of water, the only result would have been that the water would have run away; no damage would have resulted. I have taken all reasonable means to provide against danger. The object of an embankment is to confine the water, and the business of an engineer is to make his embankment sufficient to resist the pressure of the water against it, not to provide any other means of letting the water off on the supposition that the embankment is not strong enough. This embankment was sufficient. The puddle wall is the real security of the water. The only object of the embankment is to support the puddle wall, not itself to keep out the water. It is not, therefore, specially important that the earth of the embankment itself should be such as will keep out water. This puddle wall was 60ft deep. The pressure of water in the pipes at Sheffield is much greater than in those at Bradfield.
By The CORONER.- If an embankment is to support a puddle wall, and the embankment is insufficiently strong, the puddle bank will, of course, fall. I have examined the embankment since the flood, and think it was properly made. Under the lower side there was a footing of stone, to prevent the embankment slipping.
By the Jury.- The pipes would be carried through the puddle trench if not through the embankment. They would find that proper precautions had been taken against any settling there, by which it was not likely that the pipes would be broken.
By The Coroner.- I really do not know the cause of the embankment bursting. I have very great difficulty, indeed, in forming any opinion worth relying upon. I can form conjectures, and so can anyone else, but they are not worth much. There is a possibility of a landslip under the seat of the embankment having produced it. I do not believe the embankment itself has slipped, but the stratification beneath it may have slipped.
Mr. Rawlinson.- You mean that you do not think the embankment was the first to slip?- That is the more correct way to put it.
By The CORONER.- A fracture of the pipes has been suggested. If the pipes had been broken that might have caused it; but we have no indication of any such breakage. I hazard the conjecture that there has been a landslip beneath the embankment, because we know they do take place; because a landslip taken place in this valley below the dam. I am speaking of a slip under the embankment, not under the puddle bank. I do not ascribe the bursting of the reservoir to unsound principles of engineering or to bad workmanship.
By Mr. Rawlinson.- A blow would not cause equal injury with a crack in the pipe, if such took place. I do not know the maximum volume of water, but it has been carefully recorded. My view of the way in which a landslip might take place is that the water naturally percolates into the strata would get between the face of the rock and the bed of clay resting upon it, and cause the superincumbent mass to slip off. The water through the fissures would be cut off by the puddle drain. I have not examined the reservoir since the flood, because I believe if the rock would allow the water to percolate such water would be cut off by the puddle trench.
The CORONER.- If the percolating water was not stopped by the puddle, but went through the rocks at a lower level than the bottom of the puddle trench, would it not have had the effect of washing down the embankment on the low side of the puddlebank?- The probability is that it would find its way to a spring lower down the valley. I have not seen the embankment of the Rivington Water Works at Liverpool. I am not aware that the reservoir bottom there was quarried the same as ours, and that subsequently a large quantity of water found its way below the stratification of the puddlebank, and leaked out a considerable distance below the embankment. I am not aware that any special arrangements were made to prevent the water creeping alongside the two outlet pipes by putting collars around them. I am not aware that one of the Birmingham reservoirs 6 or 7 years ago was destroyed by the water creeping along the cast iron pipe and blowing a hole through the embankment like a tunnel. I should think in any such case it would be detected by a previous leakage. I am not aware that a considerable body of water was issuing under the side wall below the embankment before the bursting of the embankment. I do not know how long a pipe such as the outlet pipes would last. Everything will come to destruction sooner or later. I do not know how far the two pipes were placed apart.
John Gunson.- I am the acting engineer for the Sheffield Water Works Company, and have had the construction of the Bradfield reservoir from the plans of Mr. Leather. The embankment was made in the usual way, but it was found necessary to dig the puddle trench deeper than we originally intended, the reason being that there was so much water. We went to a depth of 60ft. There was a very large flow of water, which was pumped out by two engines, one of them working a 12" and a 13" pipe. The other pumped two 12" pipes. Together they would be about 20 horse power, and they were kept constantly working for nearly two years. This shows that a large body of water comes through the rocks to the puddle. We got rid of the water by pumping it out. The water originally came out of the reservoir, about 100 yards north of the embankment. It was caused by a fault or throw of the rock, and came from the top of the hills, perhaps miles away. When we got the puddle trench in, that was an effectual barrier, and the water from that spring was thrown back into the reservoir. The puddle trench was cut and worked in the ordinary way. When we got above the level of the spring, the consequence was of course that the water had to make its way back again. The trench laid for the pipes was 9ft or 10ft wide, and perhaps the depth was equal to the width, but ran up considerably less. The pipes were laid in puddle, at a distance from each other of 2ft 6". The depth of the puddle above and below the pipes was 18". It was the same kind of puddle wall - the best. The trench was filled up with the best material, thin layers of gravel, and very solid. We put in the materials of the embankment in layers or tips. There were barrows used, three wheeled carts, two wheeled carts, and waggons. We did not take the material for the embankment indiscriminately from the banks of the reservoir, and tip it on the embankment. First, 24,000 cubic yards entirely of stone was placed on the outward slope of the bank, the stone forming an embankment itself up to within 50ft. of the top of the embankment. The object was to prevent the embankment slipping on the surface it was placed on; and to get that done effectually we paid 3d. per yard additional for the work. The next process was to lay the material that the finer sort came up to the puddle wall. The work was somewhat similar to that which is going on at present at the Agden reservoir.
( Plans showing the course of the pipes were given to the jury for inspection) Great precautions were taken in laying the pipes in the puddle trench. The puddle trench was 40ft. or 50ft. below where the pipes went. The pipe trench was about 9ft below the surface. About a couple of lengths of pipe went through the puddle trench proper. My fear was, if nothing was provided, the puddle in the puddle trench being deeper than in the pipe trench, it might sink; and so we made a special arrangement for the protection of the pipes, by an extension of the width of the puddle wall. This was done to the extent of something like 100ft. on either side. The pipes were laid in good strong shale, not compressible with pressure. No water could possibly creep along the pipes.There were no collars put upon the pipes to prevent the water creeping along - the sockets of the pipes themselves formed collars, and they were very strong ones. The lines of pipes were 2ft 6" apart.
The court at this stage adjourned for half an hour.
Mr. Gunson recalled and examined by the CORONER.- The parliamentary plans are not here, only the working ones. The former can be given to Mr. Rawlinson. The plans carried out were not precisely the same as the Parliamentary ones. We discovered that the ground where we first intended to put the embankment was faulty;- there had been what we call a landslip. I should say that landslip was some hundred years old. I did not observe it first. After I discovered it would not be safe I saw Mr. Leather, and he gave directions that it should be made where it is. We had not begun work at the first embankment, but the contracts were let. The rainfall of that district from 1859 was as follows:- 1859, 46.055", 1860, 44.280, 1861, 37.940, 1862, 40.060, 1863, 40.700. The smallest flow of water in the summer is half a cubic foot per second for each thousand acres of the watershed, and the maximum 150 cubic feet per second per thousand acres. The gauge was placed in the Rivelin valley before we went to Parliament, and when we got the act I had it reconstructed. It was 18ft high. The heaviest flood we have had occurred in August 1856. The overflow was 60", and it took away the gauge. The gauge was kept at Redmire's, about 1,200ft. above the level of the sea. On the south side of the dam we have an artificial cutting. That was to divert the stream during the construction of the reservoir, and we used it till about a year ago. The embankment was finished before then, with the exception of where the weiring is at the south end, which is not finished yet. Some of the materials got out of the cutting might be brought into the embankment, others washed away. In August 1856 we had 9" of rain - the largest quantity in any month. It would take 14 or 15" to fill the reservoir, so no flood could materially affect it. When we bared the rocks we had no apprehension that mischief could arise; and I was perfectly satisfied that no water coming from the rocks could injure the embankment, because we sunk the puddle trench far down into the rock below any excavations in the reservoir. It was put down into measures quite impervious to water. The water was seen coming out of the rocks where the reservoir has been, flows into the river. It is possible it might drain into the embankment, but it would be stopped by our puddle. It was not at all a hazardous proceeding to bare those rocks. We might have got material elsewhere to make the embankment if we had bought 100 acres of land for the purpose. There was about 400,000 cubic yards in the embankment. We should not have required 100 acres if the material was anything like. I cannot say how many acres of rock were bared; 8 or 10, I should guess. We did not find all the material for the embankment in the baring of the rock.
Mr. Rawlinson asked if it was not a mistake that they had laid bare so much of the rock, because the larger portion of the bottom of the reservoir was covered with an impervious shale.
Witness said there was very little which they had bared which was not rock in some form or other, though parts might be covered by shale.
Examination continued.- Some of the puddle was got close to the embankment - some brought from nearly a mile above. We first let water into the reservoir last June, and the water rose in the dam in two days upwards of 50ft. The pipes were then closed. Some water came out of the rocks and got behind the embankment. The water coming into the reservoir by the flood was quite thick. The water from the rocks was clear as any crystal, but strongly impregnated with iron and sulphur. That water came from the rocks, but could not come out the reservoir. Witness was confident that no part of the water came through the puddle wall. When there were 50ft. of water in the reservoir, many of those rocks visible now were not visible. We are making the Agden reservoir on the same principle, except that the puddle trench is not below the outlet-pipe trench in the solid rock.
By the Jury.- The excavations were not made to any great depth. I thought the embankment, perfect up to the time of its giving way. Had no reason to think that the Agden work would not be perfect. If a pipe were fractured it would be difficult to reach it, but not impossible. It would have been better to provide in the original plan for getting at a fracture, if we had assumed there would be a fracture, but we did not.
The CORONER said the engineers ought to have assumed there would be danger and provide against it. There would, he was afraid, be another disaster in the Agden reservoir.
Examination resumed.- I visited the dam 3 or 4 times a week, and sometimes oftener. I generally went on a stormy day. I was there the day before the flood and also on that day. I went on stormy days to see the effect of the wind on the water. On the day of the flood I went because I had seen Admiral Fitzroy's prediction of a gale. I had also noticed that the wind would be blowing down the valley. I think the wind would not have had any effect on the embankment. I have seen the wind and waves ten times worse at Redmires. I did not observe the least sinking of the embankment, though I was watching it all afternoon. I stood so that I could see the water level all the way across the embankment, and should have seen any sinking if there had been any. I did not cross the embankment that day, because of the spray. I saw nothing of the crack that was seen afterwards. I could not have saved the embankment if I had seen the crack - at least I think not.Opening the pipes would not have had any good effect;for that was done. I have no idea what caused the crack. When I first saw it, a little after 8 o'clock in the evening, I thought the action of the wind and waves, which had been playing against it all the afternoon, might have loosened the material of which the inner slope at the top of the embankment was made, so as to withdraw to some extent the support of the puddle wall, which would thus lean forwards and cause a crack in the embankment. I had gone home that afternoon without doing anything, being perfectly convinced that all was safe. There is a rumour that you had said, during the day, something about the embankment giving way. Is that so? - No. I never said such a thing, and never expected it would burst. After returning home, I received a message from Bradfield that I and Mr. Craven were to go up, Mr. Hammerton having observed a crack in passing over the embankment after the men had gone. When I got there the valves of the out pipes had been opened, and the water was running freely through them. I did not notice the slightest escape of water through the pipe trench.
By Mr. Rawlinson.- There were pipes at the end of the valves to carry out the water coming through the pipes. I believe all those pipes are there yet. To have the pipes for a thorough examination would take from 6 to 12 months, because on the outer side of the puddle gutter the embankment is yet perfect, and there is a great deal of puddle on the other side. To expose the whole length of the pipes would probably cost 2,000 sterling. On reaching the embankment, after being sent for on the night of the flood, I found our foreman, Mr. Craven's partner, and the workmen waiting for me with lanterns. I examined the crack, which was 10 or 12ft from the top of the embankment measuring down the slope. I could just get my fingers edgeways into the crack, which was longitudinally on the embankment. I cannot say the length. It was where the breach is. The water was not coming over the top. I came to the conclusion that I had found a satisfactory explanation in the theory I have explained. I came to the conclusion that, if we could get the water a few feet down, we could so far relieve the pressure as to put a stop to the danger. I ordered the men to blow away the upper stones of the by-wash, intending to make a broad opening for that purpose. I thought it was merely a surface crack, and by getting water below the surface of the level should do away with all danger.
By Mr. Rawlinson.- I intended to make an opening 60ft. long in the by-wash. There was a drop in the by-wash which would have let all the water of that breadth goes off. We were not able to make the breach in the by-wash. I heard the shot go off after the embankment had burst. The water lowered rapidly in the meantime, though I did not see how much.
Mr. Gunson explained that he never apprehended any danger until he saw the water dashing over the embankment, and that he thereupon sent persons to warn the nearest residents. He had no time to warn anybody lower down.
(BY THE ELECTRIC AND INTERNATIONAL TELEGRAPH)
Before the jury separated, Mr. Rawlinson, Government Inspector, said that some calculations had been prepared with regard to the flood. The total fall from the dam head to Owlerton was 450ft. or 72ft per mile. The velocity between those points of the flood was 18 miles per hour, showing that the water passed at the rate of 26 and a half ft per second. The average area of the cross sections of the flood between the same points was 3,780 feet, showing that 40,170 cubic feet of water passed per second. At this rate the reservoir would empty itself in 47 minutes; the weight of water was 3,250,000 tons. After the dam broke, a Derby horse could not have carried the warning down the valley in time to be of service.
The inquest was then adjourned until Thursday. continued »
