An Improvement in the Construction of Tanks or Reservoirs.
Year: 1890

page_text: Date of Application, 10th Sept., 1890--Accepted, 11th Oct.,
1890
COMPLETE SPECIFICATION.
An Improvement in the Construction of Tanks or Reservoirs.
I THEODORE PRIDHAM of Lewisham Petersham near Sydney in the Colony of
New South Wales Civil Engineer do hereby declare the nature of this invention
and in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement :-
This invention refers to the construction of metal tanks or reservoirs which are
generally constructed of steel or iron by preference and of cylindrical form but
which may be constructed of any metal strong enough and of any form. The object
of this invention is to diminish the first cost, expense in carriage and maintenance
charges occasioned by constructing the bottoms of the said tanks or reservoirs as
hitherto of metal and it therefore especially provides a means of economy in those
cases where metal tanks or reservoirs of very large size are required.
The improvement in the construction of such tanks or reservoirs according to this
invention consists essentially in combining a metal shell with, over, or upon, an
artificial bottom such as concrete masonry puddled clay or the like and (as owing to
the expansive qualities of the various metals I have found that it is not possible to
make a rigid watertight joint between the shell and the bottom) providing a con-
nection between them which will allow the shell to expand and contract without
leaking through such connection. Any such watertight connection between the shell
and a bottom or foundation will by reason of obviating the necessity for a metal
bottom come within the scope of this invention.
But in order that my invention may be clearly understood reference will now be
made to the drawings herewith which show two part sections of cylindrical tanks or
reservoirs constructed as I prefer according to my improvement.
Figure 1 is a part section of a tank with a cast iron shell and Figure 2 is a part
section of a tank with a wrought iron shell.
A is a portion of the metal shell-A' is the bottom flange or resting piece of the
shell ( is a flexible connection of lead or the like-B is a lead or other watertight
joint fastening the flexible connection to the shell-D is a watertight cement joint,
fastening the said connection to the concrete floor E. The shell A is of iron or steel
and may be made by rivetting or bolting plates together as is well understood. The
floor or bottom E may he formed of watertight masonry, brickwork or other suitable
non-metallic material instead of concrete so long as the watertight fastening D can
be made.
The surfaces F should be covered with tarred felt or other suitable material of a
yielding nature which will allow of some contraction of the shell and the bottom
surface of the flange G should be tarred or covered with any suitable substance which
will prevent the concrete or masonry from sticking to the iron.
It is easily seen that, no matter what ordinary expansion and contraction of the
shell A takes place, the flexible connection C will compensate between such shell and
the bottom E and that the water will be retained in the shell and upon the bottom.
It will also be seen that the concrete bottom will last considerably longer than any
metal bottom.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to he performed I declare that what I
claim is -
First. The improvement in the construction of tanks or reservoirs consisting
essentially in combining a metal shell with, over, or upon, an artificial bottom not of
metal by means of a water-tight joint which will allow of the expansion and contraction

page_text: Second. The particular combination and arrangement, with the metal shell A and
bottom E, of the flexible joint namely the connection having fastening joints B
and which allow of expansion and contraction of the shell substantially as herein
described and explained and illustrated in the drawings.
Dated this 10th day of September 1890.
J. II. JOHNSON & Co..
Agenis.