The Sun.
London, England, 1864-03-24 00:00:00

THE SUN, LONDON, THURSDAY EVENING, MARCH 24, 1864.

made a culvert for the pipes. Laying them in a trench is
better, because in my judgment it is a more simple opera-
tion 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 four to five 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 sus-
tain 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—lt took half an hour to open one of these
valves on the night cf the inundation, and there was a
shcking and straining Jf the pipe during the opening not
felt before or after. That is the reason why I ask the ques-
tion. What I mean is, would there not be a greater pressure
upon the valve when be water was in motion ?
Mr. Leather—No. There would be greater disturbancs
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 pressure upon the
embankment. At this rate, 190 hours, or about nine days,
would be required to let off the whole of the water, suppos-
ing there was no addit on. I have not hitherto thought it
necesssry to have had more complete control over the water.
I did all that 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 Red-
mires dam, but that is for another purpose altogether.
The Coroner—Ought you not, as a practical engineer, to
minimise the danger at 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 wss a suspicion that the embankment
might give way, youhave taken no means of taking the
water any ether directon, so as to avoid its coming down
in one body upon the ?eople of Sheffield. I ask you is it
not desirable in such cases that some means should be taken
of lessening the danger ?
Mr. Leather—l caniot 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 com-
plain 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. Loather ?
Mr. Leather—No ; a cutting should be at the bottom of
the embankment of a reservoir to relieve it under such cir-
cumstances, and I know of no means of having such a
cutting.
The Coroner—Could you net 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 nut know that anything of that
sort has been done.

The Coroner—lt was no part of your plan to drain the
puddle trench ?--No, except during the working.
I mean afterwards ?--No; I do nut suppose any would
get there afterwards.
lam supposing it has. The puddle trench could not be
so drained as to prevent water getting there ?—Any water
that might get there wculd naturally percolate through the
embankment on the lowr side. It would get away with-
out doing any injury.
The Coroner—l am told that water was seen coming
from the bottom of ,he 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 ;rester. The embankment was 901 t.
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 eallec the attention of the witness to a re.•
port published by the a)ciety of Civil Engineers, in which
it was stated that pipes aid under an entrenchment occa-
sionally broke from the )ressure upon them not being equal;
and mentioning an instence at Melbourne, where the frac-
ture had to be repaired ty inserting a line of boiler plating
inside. The pipes in Ws case were excellent castings, and
had borne a very severe pressure, both externally and in-
ternally, but ny the weght of the embankment were flat-
tened and distorted, mo e in the centre than at the sides,
because the pressure ws unequal. There was, therefore, a
possibility of pipes suVeted to an unequal prossure being
injured.

Mr. Leather replied tlat 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 pips themselves were laid in an arti-
ficial ground, which miztat offer more resistance in one part
than another.
Mr. Leather—There were ISin. of puddle round them,
but they would adjust themselves in the puddle.
By the Jury—llow do you determine the strength of the
embankment ? It was 10 times that of the pressure against
it. I cannot tell how touch water would run into the reser-
voir in 21 hours on a wet day. The pipes had not been
examined since the flod. But as there was Ho leakage
through or about the ppcs before the accident, and as there
was a full flow of water through the pipes when the valves
were opened, it is fair ;o presume there was no leakage. I
' have seen the valve work under half the full pressure.
Mr. Leather, examned by Mr. Perronet Thompson-1

have been the consulting engineer of the company in reaped,
of all their reservoirs. I have not previously had an aeci•
dent, though some of the reservoirs are of greater exten
than the Bradfield reservoir. The embankment of the upper
dam at Redmires is isuch larger. The plans and sections
for this and the reservoirs that have stood for years are pre-
cisely the same in pricciple, and there is a great similarity
in situation and materials of some of them. I used all the
means known to me is a practical engineer in the construc-
tion of these dams fo• insuring the security of the work. So
far as my observation went, the quality of the work was
good throughout. The fact of the public trench being sunk
to the depth of 60 feet, although the plans required only 10
feet, 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 10 feet if necessary. The
weight of the water is measured by the depth, and not the
quantity of the water on the superficia: 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 em-
bankment 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
mean 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 60 feet deep. The pressure of water in the pipes at
Sheffield is much greater than in those at Bradfield.
By the Coroner—lf an embankment is to support a pud-
dle wall, and the embankment is sufficiently strong, the
puddle bank will, of course, fall. I have examined the em •
bankment since the flood, and think it was properly made.
Under the lower side there was a footing of stone, to pre-
vent 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 brut
conjectures, and so can anybody else, but they are not worth
much. There is a possibility of a landslip under the seat
of the embankment having produced it. Ido not believe
the embankment itself has slipped, but the stratifiettion
beneath it may have slipped•
Mr. Rawlinson—You mean that you do net thick the
embankment was the firs: to slip ?—That is the more cor-
rect way of putting it.
By the Coroner—A fracture of the pipes has heel sug-
gested. If the pipes had 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 leneath
the embankment, because we know they do take place; be-
cause a land slip taken place in this valley below the dam.
I am speaking of a slip under the embankment, n)t under
the puddle bank. I do not ascribe the bursting of tae reser-
voir to unsound principles of engineering or to tad work-

manship.
By Mr. Rawlinson—A blow would not cause c(pal injury
with a crack in the pipe, if such took place. I donot know
the maximum volume of water, but it has beer carefully
recorded. My view of the way in which a landslip might
take place is that the water that naturally percolates into
the strata would get between the face of the rok and the
bed of clay resting upon it, an- cause the supeincumbe,nt
mass to slip off. The water through the fissure would be
cut off by the pud lie drain. I have not ex.tnited the bare
stratification on the by-wash side of the reservoir since the
flood, because I believe if the rock would allowthe water to
percolate such water would be cut off by the piddle trench.
The Coroner—lf the percolating water was not stopped
by the puddle, but went through the rocks ata lower level
than the bottom of the puddle trench, woule it not have
had the effect of washing down the embankrent on the low
side of the puddlebank ? The probability isthat it would
find its way to a spring lower down the valid'. I have not
seen the embankment of the Rivington Witer Works at
Liverpool, lem pot aware that the renrYir bottom there