An Improved Method of or Means for Carrying out the Operation of Enlarging Gasholders."
Year: 1897

page_text: Date of Application, 16th Jan., 1897
Complete Specification Left, 16th Oct., 1897-Accepted, 4th Dec., 1897
"An Improved Method of or Means for Carrying out the
Operation of Enlarging Gasholders."
We, EDWARD LLOYD PEASE, and ASHMORE, BENSON, PEASE AND COMPANY, LIMITED,
all of the Parkfield Works, Stockton-on-Tees, in the County of Durham, Engineers,
do hereby declare the nature of this invention to be as follows:-
This invention consists in effecting improvements in the method of or means for
carrying out the operation of enlarging gasholders.
The object of this invention is to enable this operation to be carried through without
emptying the tank of water.
This operation is at present carried out substantially in the following manner: In
order to convert. the top lift into an outer or intermediate lift, so that one or more
lifts may be added to the gasholder to increase its capacity, the wall or outer plating
of the said lift is detached from the roof by cutting away the tee bar girders or main
bars from their connections with the said outer plating and adjusting the length and,
points of connection of the corresponding tension rods leaving the roof and roof
framing inside the holder wholly unsupported by the wall of the lift and transferring
this duty to suitable framing erected for the purpose on the tank bottom, the water
of the holder being removed to enable the requisite framing to be erected.
By our invention, when the holder to be enlarged is emptied of gas, the timber.
props are introduced into the holder through a hole in the crown and floated into
their several positions so that each prop can be adjustably attached at its outer end
to a main bar of the roof framing by means of cleats and a through bolt, the several'
props floating on the water in positions radial to the centre post. Cast iron shoes
are now fitted on to the inner ends of each prop or subsequently if preferred, the
connection admitting of the shoes adjusting themselves to inequalities of the tank
bottom. Air is then forced into the holder until the inner lift rises to its full height,
in which position the props are suspended from their several connections in vertical
positions clear of the water. They are now all connected together as the posts of one
structure by means of trussing which can be carried out on any convenient design or
arrangement adapted for the purpose. The air being withdrawn from the holder
after this operation the props descend with the holder until they stand on the tank
bottom as members of one structure capable of taking the load of the roof framing
which is transferred to them in the ordinary way by cutting away the main bars
from the wall or outer plating and disconnecting the tension rods provided to act as
bow strings to the said main bars and which tension rods are now connected to the
props. The roof framing is now altogether detached from the holder and supported
on the props, thus relieving the holder of much weight and facilitating its enlargement
by additional lifts.
It will be observed that by means of the above described process, the water in the
tank does not require to be removed, the construction of the prop framing being

page_text: carried out in the air space above and when completed the said prop framing
lowered into the water until it finds its support on the tank bottom.
1
1004
“An Improved Method of or Means for Carrying out the
Operation of Enlarging Gasholders."
22
We, EDWARD LLOYD PEASE, and ASHMORE, BENSON, PEASE AND COMPANY, LIMITED,
both of the Parkfield Works, Stockton-on-Tees, in the County of Durham, 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 consists in effecting improvements in the method of or means for
carrying out the operation of enlarging gasholders.
The object of this invention is to enable this operation to be carried through
without emptying the tank of water.
This operation is at present carried out substantially in the following manner :-
In order to convert the top lift into an outer or intermediate lift, so that one or more
lifts may be added to the gasholder to increase its capacity, the wall or outer plating
of the said lift is detached from the roof by cutting away the tee bar principals or
main bars from their connections with the said outer plating and adjusting the
length and points of connection of the corresponding tension rods, leaving the roof
framing inside the holder, wholly unsupported by the wall of the lift and transferring
this duty to suitable framing erected for the purpose on the tank bottom, the water
of the tank being removed to enable the requisite framing to be erected. We have
discovered a convenient way of erecting this framing without removing the water
in the tank, thereby saving much labour and expense.
And in order that our invention may be clearly understood and readily carried into
effect, we will now proceed to describe the same with reference to the drawing hereto
annexed, in which
Fig. 1 illustrates in transverse sectional view a single lift gasholder and tank with
framing erected in accordance with our invention for the purpose of enlarging the
holder.
Fig. 2 is a corresponding part elevation of the framing bringing into view the
bracing bars of two adjoining standards comprised in such framing, all of which are
omitted in Fig. 1 except the two in line with the sectional view shown.
By our invention, when the holder to be enlarged is emptied of gas, the props a of
timber or timber and iron are introduced into the holder through a hole in the crown
and floated into their several positions so that each prop a can be adjustably attached
at its outer end to a main bar or principal b of the roof framing by means of cleats o
and a through bolt d. Cast iron shoes e are fitted either now or later onto the lower
end of each prop a, the pin connection admitting of the shoes adjusting themselves to
some extent to inequalities of the tank bottom. Air is then forced into the holder
until the inner lift rises to its full height, in which position the props a are suspended
from their several connections in vertical positions clear of the water. They are now
all connected together as the posts of one structure by means of trussing ƒ from post
to post as shown in Fig. 2 and by the tie rods g radially connected with the centre
post h, the structural arrangement of which can be carried out on any convenient

page_text: design or arrangement adapted for the purpose, it being essential that the bracing
rods forming the trussing be adjustable as to length, and that in the cleats which
connect the props with the roof framing arrangement is made for adjustment so that
if it is found that one prop is grounding before another this prop can slide up between
its cleats and the true level of the crown will not be interfered with through
irregularities in the bottom of the tank. The air being withdrawn from the holder
after this operation the props a descend with the holder until they stand on the tank
bottom as members of one structure capable of taking the load of the roof framing
which is transferred to them in the ordinary way by cutting away the main bars from
the wall or outer plating and disconnecting the tension rods j k provided to act as
bow strings to the said main bars. This is done after the bottom curb has been
placed on rest stones. The tension rods j & k are connected to the props, the cross
framing of which is provided with shoes wherever required to take intermediate
main bars or principals. The final operation is then to detach the iron trussing from
the holder. The roof framing is now altogether detached from the holder and
supported on the props thus relieving the holder of much weight and facilitating its
enlargement by additional lifts.
Having now particularly described and ascertained the nature of our said invention,
and in what manner the same is to be performed, we declare that what we
claim is :-
1.) When carrying out the operation of enlarging a gasholder by the addition of
one or more lifts, the means as herein shown and described for providing supporting
framework to the roof of a gasholder without removing the water in the tank.
2.) The mode of supporting framework to the roof of a gasholder which consists in
the following sequence of operations, viz:-introducing props into the holder through
the crown and floating them into position to be attached to the main bars or
principals of the holder roof; foreing air into the holder until the inner lift rises to a
height at which the props are suspended clear of the water, trussing the props
together and to the centre post as one structure so that by releasing the air, the
whole can be lowered into the tank until the roof is supported on the said structure,
all as and for the purpose set forth.
Dated this love day of Oct 1957.
G. J. CLARKSON
Chartered Patent Agent, Stockton-on-Tees and Hull
Agent for the Applicants.