Improvements in and relating to Sewer and like Manholes.
Year: 1897

page_text: Date of Application, 26th Nov., 1897-Accepted, 29th Jan., 1898
COMPLETE SPECIFICATION.
Improvements in and relating to Sewer and like Manholes.
I, HENRY EDWARD STILGOE, of Castle Knoll, Dover, in the County of Kent,
Civil Engineer, Associate Member of the Institution of Civil Engineers, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:
1
Considerable difficulty is frequently experienced in laying sewers owing to
the pressure of subsoil water in the trench in which the pipes are being laid, and
it is often necessary to keep pumps continually at work in order to prevent the
water washing away or disturbing the cement &c. used in the construction of the
manhole inverts or bottoms.
Iron pipes having turned and bored spigots and sockets and requiring no joint-
ing material such as cement, are now used in cases where subsoil water is met
with, but the manhole inverts or bottoms have hitherto been constructed of bricks
set in cement, or of other materials requiring the use of cement to make the struc-
ture watertight.
Now the object of this invention is to so construct such inverts or bottoms as
to avoid the necessity of pumping, and, for this purpose, the inverts or bottoms
are cast or otherwise formed in one or more pieces adapted to be readily connected
to the adjoining sewer pipes so as to form a water tight chamber extending
upwardly to above the level of the subsoil water; the construction of the parts
is such that they may, after the pipes have been laid, be lowered into place in the
trench or hole. The subsoil water will flow away through the sewer pipes and
through the invert or bottom (unless it is constructed at the top end of a sewer
and without an inlet) and the pipes and invert or bottom can then be rapidly bolted
up, or the joints otherwise made.
Referring to the accompanying illustrative drawings;
Fig. 1 shows a longitudinal vertical section of a sewer manhole according to
this invention.
Fig. 2 a horizontal section on the line ab Fig. 1; and Fig. 3 a transverse
vertical section.
The manhole bottom or invert 1 is, in the example illustrated, of iron, cast in
one piece and is of such a height that its upper edge, which is preferably flanged
as shown, extends above the level of the subsoil water.
The invert or bottom piece is formed at its ends with openings 2 which have
outwardly extending faced rings round them; the bottom portion of the invert
is formed with depressions or pockets 3 at each end, from the extremities of which
spring part flanges 4, as shown. The sewer pipes, 5, 5 are of metal formed with
flanged ends 5 and with depressions or pockets 6 which are similar to those in
the invert or bottom piece 1 but are of somewhat greater length. The object of the
depressions or pockets 3 and 6 is to make the part flanges practically speaking
project inwardly and thus enable all the connecting bolts 7 to be passed through
the bolt holes and tightened up more easily by a person standing within the

page_text: invert and with less likelihood of the person getting wet than would otherwise
be the case. It will he understood that in constructing a manhole at the top
end of a sewer when the manhole bottom is lowered into place, the subsoil
water which had previously been flowing away through the sewer will immediately
commence to rise, and great difficulty would be experienced in screwing up the
bolts, and in making the joint if this had to be done from the outside; in such
cases the pockets are particularly valuable as they enable the bolting up to be
done from inside. The pockets 3 and 6 are, after the bolting up is completed,
filled in with suitable material S such as cement so as to prevent sewage and other
matter accumulating in them. The invert or bottom 1 may be laid upon and
surrounded by concrete 9 as shown, if desired, and the manhole from the top of
the said invert or bottom piece 1 upwards may be of brickwork as usual, or it
may be built of other metal sections bolted to the top of the invert or bottom
piece. The invert or bottom piece may be formed with one ог more branch
inlets 10 as shown in the drawings and have connected to it one or more branch
pipes 11 the connection of the said pipes with the invert or bottom being effected
in a manner similar to that just described. The pipes 5 and 11 may have outer
ends of any desired form for connection to lead, stoneware, iron or other pipes.
Although I have illustrated a manhole invert or bottom piece formed in one
piece, such inverts or bottom pieces may be formed in sections or plates of cast
or wrought iron or steel or other suitable material connected together in any
convenient manner.
Also the illustration shows the joints between the pipes and the invert or
bottom piece to be bolted flanged or face joints, which, where necessary may be
rendered water-tight by means of rubber rings, red or blue lead, or other suitable
jointing material; the joints may be of various kinds, for instance, they may he
turned and bored, or spigot and socket joints, or may be jointed in lead, cement,
or other suitable material.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what
I claim is:
1. Sewer and like manhole inverts or bottoms formed in one or more pieces
and adapted to be readily connected to the adjoining sewer pipes so as to form
a watertight chamber extending upwardly above the level of the subsoil water
substantially as described for the purpose specified.
2. Sewer and like manholes in which the inverts or bottoms are formed in one
or more pieces and are adapted to be readily bolted to the adjoining sewer pipes,
said inverts or bottoms and pipes being formed with depressions or pockets sub-
stantially as described with reference to and shown in the accompanying drawings.
Dated this 26th day of November 1897.
ember 1897.
For the Applicant,
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C.,
Chartered Patent Agent.