CA1207970A - Demountable portable reservoir structure - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

A demountable, portable reservoir structure and method of erecting same. The reservoir structure has elements includ-ing a plurality of flat, elongated base plates, a plurality of similar rigid rectangular wall panels to be vertically seated on the base plates, the plates and panels forming a ring. A
column vertically positioned within the base plates and wall panels and a plurality of trusses are supported by and secured to the column and panels. A flexible liner is connected to the inside surfaces of the panels and provides an impermeable bar-rier on the area circumscribed by the panels to a desired height. Means are provided enabling controlled liquid flow through the flexible liner when in position. The elements of the structure are each releasably connected to contiguous ele-ments in the structure and are of dimensions and weight to per-mit containerization or palletizing for handling and trans-portation. In the erection of the reservoir, the column is adapted to serve as a support for a boom to raise trusses and a flexible roof cover for the structure into position. The reservoir structure according to the present invention may be readily erected and dismantled in remote locations with basic tools, and provides a reservoir system which can hold, for example, volumes of water such as 100 cubic metres to 1300 cubic metres.

Description

BACKGROUND OF THE INVENTION

The presen~ inven~ion rela~es to a demountable, port-able reservoir structure for holding large volumes of liquids such as water and free flowing solids such as grain, and to a method of erection of such a reservoir structure.
There i6 a real and continued need for a ligh-tweight, low cost, portable reservoir system which may be quickly erected and dismantled and stored, for example, when a town's existing reservoir is closed down for maintenance or cleaning.
Use of such a system would ensure that the town inhabitants may continue to be supplied with water for sanitary, drinking and fire protection purposes. Because of the difficulties in maintaining water service to a town while its reservoir is being serviced or cleaned, veLy often such maintenance and cleaning i6 neglected or delayed.

There is also a need for a portable reservoir structure which may be erected and dismantled as required in remote or frontier areas, for example where oil or mineral exploration is taking place and where a temporary town site has been established for those engaged in such operations.

The construction of temporary reservoirs, for example for water, usually involves standard methodæ of construction with the use of the usual building materials. Often standard materials are not readily available and site preparation is a problem. This is particularly true in earthquake or flood ,~

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devastated areas and in northern areas.

PRI0~ ART
.~

There have been few devices developed previously to provide a lightweight, low cost portable reservoir system for liquids ~hich could service ~he temporary needs of communities or provide a reservoir sys~em whîch is readily transportable to and erectable in remo~e areas. Two proposals for such structures are set ou~ in GLeen U.S. Patent No. 3,460,705 issued August 12, 1969 and Levens U.S. Paten~ No. 3,819,079 issued June 25, 1974. Green describes and illustrates a demountable storage container which has a cylindrical shell formed of a plurality of detachably connected panel members and a flexible liner member positioned within the shell. Levens teaches a modular, portable tank shell and tank that can be readily erected and dismantled, having an outer shell forming a generally circular enclosure with an innerO flexible liner.
Inlet and outlet pipes service the tank. The panel members of Leven6 and Green are both curved to conform to the periphery of the circle formed by the tank, and are secured directly ~o each other by a hinge-like mechanism in the case of Levens, and by bolts extending through the panels in the case of Green. Con-siderable attention to detail in construction of the elements of these previously described portable tanks is required, and considerable time and care in assembling the components is ~20'~'70 required by the workers constructing the tanks.
Other references of background interest describing various constructions of storage tanks, some of which are demountable and some of which are not~ include U.S. Patents Nos. 2,684,173 of Schmitz issued July 20, 1954: 3,355,052 of Kaups issued November 28, 1967; 3,471,053 of Endicott et al issued October 7, 1969: 3,861,552 of Adams issued January 21, 1975; 3,880,315 of Nelson et al issued April 29, 1975;

3,917,104 of Rossitto et al issued November 4, 1975; 3,951,294 of Wilson issued April 20, 1976; 4,240,562 of Holschlag issued December 23, 1980; and Canadian Patents Nos. 97,692 of Wright issued February 27, 1906; 194,203 of Nissen issued November, 25, 1919; 560,253 of Tolcott issued July 15, 1958; ~67,707 of Wiggins issued December 23, 1958; 623,230 of Lindstrom issued July 4, 1961; 671,336 of Jones issued October 1, 1963; and 1,091,883 of Cazaly is6ued December 23. 1980. As well, Nelson U.S. Patent No. 4,111,314 describefi and illustrates a trans-portable storage device (silo) and Svensson Canadian Patent No.

636,339 issued February 13, lg62, describes a method of erecting walls, for example, for a storage device. Again, these references are of general background interest.

OBJECTS OF THE INVENTION

It is an object of the pre6ent invention to provide a demountable portable reservoir structure which is capable of 7g~0 holding large volumes but which is ligh~weight and economical in cost. It is a further object of the present invention to provide a reservoir simple and quick to erect and take apart.
It is a further object of the present invention to provide such a structure which has elements which permit containerization and/or palletizing for easy and guick handling and transportation.

SUMMARY OF THE INVENTION

According to the present invention there is provided a demountable, portable reservoir structure having elements com-prising:
(a) a plurality of flat, elongated base plates connectable in a plane to form a ring;
(b) a plurality of similar, rigid wall panelæ, the edges of which define rectangles, the wall panels when in position to be vertically seated on the base plates;
(c) means at the base of each of the wall panels and on each of the base plates to position the wall panels on the plate6 so that the area within is enclosed when the panels are vertically oriented;
(d) column means to be positioned within the base plates and wall panels and to rise above the top edges of the panels when in position;

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(e) a plurality of trusses to be supported by and secured to, the column means and panels;
(f) a flexible liner to be connected to the inside surfaces of the panels when in position, the liner to provide an impermeable barrier on the area circumscribed by the panels and base plates to a height above the maximum level to which the reservoir liquid is to come; and (g) means enabling controlled liguid flow through the ~lexible liner when in position.
These elements are each releasably connectable to contiguous elements in the structure and are of dimensions and weight to permit containerization and palletizing for handling and trans-portation. For most applications of the invention, it is pre-ferred to also provide a flexible roof cover to be supported on the trusses, the lower edges of the roof cover, when in position, to circumscribe the upper, outer surfaces of the wall panels and to be secured in that position.
As well, according to the present invention there is provided a method of erecting a reservoir on a levelled surface serviced with liguid inlet and outlet means. A plurality of rectangular, s;milar rigid wall panels are mounted contiguously and in verticaL orientation to form a ring. A vertical column i6 centrally erected within the ring of wall panels, the column rising above the top edges of the panel~. Using the column as a scaffold, trusses are raised into position extending radially d~ 79 ~C~

outwardly from the column and supported by the panels and column. ~n impermeable flexible liner, within which liquid is to be retained is then fitted within the reæervoir on the sur-Eace circumscribed by the panels, and secured in proper 5 position to the panels, the inlet and outlet means providing controlled liquid flow through the liner.
In a preferred embodiment of the invention, the method further comprises using the column as a support for a boom to raise a flexible roof cover to the apex of the reservoir roof trus6es wheLe it will be unfolded into position on the trusses and will be supported by these trusses. The lower edges of the roof cover, when in posi~ion, circumscribe the upper, outer surfaces of the wall panels. ~'he roof cover is secured in this position.
The reservoir system according to the present in-vention is ideally ~uited to, although not limited to, the holding of water. The present design lends itself to the construction of reservoirs having capacities of from 100 cubic metres to 1,300 cubic metres (Z5,000 Imperial gallons to 300,000 Imperial gallons). The structure has proven to be easily transportable to remote areas and erectable by unskilled laborers in relatively little time. Once erected, it has proven reliable and capable of withstanding unusual stresses such as high winds and snow load~.

~2~7g~0 BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and advantages of the present invention will become apparent upon reading the following detailed description and upon referring to the drawings in which:
FIGURE 1 is a side view of an assembled reservoir structure according to the present invention;
FIGURE 2 is a partial plan view of connected base plates for the reservoir structure and unconnected wall panels ready to be mounted on the base plates FIGURE 3 is a perspective view of a number of wall panels for the reservoir stcucture in vertical posi~ion mounted on the hase plates:
FIGURE 4 is a schematic side view of the central support column of the present invention centrally mounted within the reservoir structure walls, used as a support for a boom for raising roof trusse6 into position;
FIGURE 5 i8 a half plane view from above of the reservoir structure according to the present invention with roof trusse6 in position;
FIGURE 6 is a schematic side view of the structure according to the present invention with the roof covering being raised into position;
FIGURE 7 on the second page of drawings is a detail view, from the side, of the lower section of the column which :~IL;20'7~'7~

is removable to enable positioning of the inner liner of the reservoir; and FIGURE 8 is a diametric section side view of the com-pleted reservoir structure according to the present invention, holding water.
While the invention will be described in conjunction with example embodiments, it will be understood that it is not intended to limit the invention to such embodiments. On the contrary, it i8 intended to cover all alternatives, modifi-cations and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.

DETAILED DESCRIPTION OF THE DRA~INGS

In the drawings, similar features have been given similar reference numerals.
Turning to FIGURES 1 and 8, there are illustrated respectively a side view and a diametric section side view of an assembled reservoir according to the present invention. The reservoir com~ri6es a plurality of flat, elongated base pla~es

2 (FIGURE 2) which are individually connectable to other base plates in a plane to form a ring 4 as illustrated in FIGURE 2.
The base plates are provided with hook shaped brackets 6 (FIGURE 3) of any appropriate con~truction, for a purpose which will be described hereinafter, the hook brackets being outwardly oriented, away from the center of the circle, when JI~

base plates 2 are secured in circular position. Base plates 2 are secured together by means of connec~ors 8 which are bolted, as can b0 seen in FIGURE 3, to the upper surfaces of adjacent base plates. A hole lO is provided in the central part of each 5 of these connectors 8 to receive, as required, an anchor bolt (not shown). It is preferred that connector~ 8 be pre-attached, one to the corLesponding side of each plate, to simplify and accelerate connecting together of the base plates in the field. It is relatively easy ~o place the re~uired number of these base plates into their required circle, fastened together as above, and to shift them slightly i the final plate doe6 not exactly close the circle. This plate placin~ is aided by describing a circle of aepropriate radius using the center of the centLal base plate as a turning point.
5 This completed circle (actually a polygon) assures tha~ the wall panels will, when mounted on the base plates, exactly fit to close the circle.
Forming the vertical, generally cylindrically shaped wall of the re~ervoir are a plurality of similar, rigid wall ~ panels 12. The panels are preferably~ but not necessarily, made of corrugated steel, the corrugations arranged in vertical fashion when the panels are in position, and positioned so that adjacent vertical edges of panels interlock on a vertical tongue and groo~e seam. The base of each of the panels is provided with base hinge bar 14, to the bottom of which are secured two hinge pins 16. Base hinge bar 14 of each panel '7~

fits between pairs of hook brackets 6 on each base plate, and hinge pins 16 are seated at the base of the hook portion of each hook bracket 6 when the wall panels are in vertical orientation as illustrated in FIGURE 3. This assures proper relative positioning of the wall panels. To the out~ide surface of each wall panel 12 are secured upper ten6ion bar 18 and lower tension bar 20. The adjacent, corresponding tension bars on adjacent wall panels 12 are secured together by appropriate bolts through pairs of tension bar connec~ors 22.
It should be noted that the bolts used to connect the tension bars are in double shear. The tigh~ness of the nuts on these bolts is not important. Thus, the use of torque wrenches is not required in this assembly. When thus connected, the tension bars 18 and 20 form complete rings about the ~uter surface of panels 12 to absorb approximately 90% of the pressure exerted against the inside surfaces of the wall panels by water contained in the reservoir. The remaining 10% is taken by the cap angles 26 on the wall panels. As can be seen in FIGURE 3, eye bolts 2~ are provided on tension bars 18.
At the top of each wall panel 12, as can be saen in FIGURE 3, there is secured a wall cap angle 26. Adjacent wall cap anglas of the panels, when in position, are secured together by wall cap angle connectors 28.
On the inside surface of each wall panel 12 there is preferably provided an appropriately sized rectangular panel 30 of insulation (FIGURE 8). For example, if the wall panels 12 ~l2~ '70 are 4 x 8 feet in outer diamensions, two foam insulakion panels 30 of 2 x 8 feet ou~er dimensions and three inch thickness may be used. A minimum thickness of one inch insulation is specified to keep the fabric liner from entering the corrugations of the wall panels.
In ~he center of the area to be circumscribed by wall panels 12 is positioned an appropriate column base plate 32 of, for example, 3/8 inch steel (see, eg., FIGURE 2 or 7).
Appropriate apertures are pro- vided in the base pla~e for liguid inlet and outlet pipes 34 and 36 respectively, and connection means 38 for these pipes are bolted to the lower surface of this column base plate 32 as illustrated in FIGURE
7. A third aperture is provided in column base plate 32 to which is connected by appropriate connection means 38 an overflow pipe 40 to remove overflow water from the reservoir.
To the upper surface of column base plate 32 is secured column 42 (see, eg., FIGURE 4). This column is concentrically positioned with respect to wall panels 12 and is positioned, on the base plate, over the aperture leading to overflow pipe 40. ~olumn 42 is made up of a base spool 44, a lower section 48 and an upper section 50. The column sections 48 and 50 and base spool 44 are pipe section~ (eg. eiyht inch diameter piping) with flanges at their ends. The lower flange 46 of base spool 44 is bolted to base plate 32. Lower section 48 and base spool 44, when in vertical position as illustrated in FIGURE 8 provide a passageway for overflow water from the

3'70 reservoir into overflow pipe 40. Lower flan~e 52 of upper section 50 and u~per flange 54 of lower section 48 are secured together, but ~paced rom each other, by means of nuts appropriately positioned on threaded rods 56 spaced about flanges 52 and 54. This arrangement of bolts and thread rods separates sections 48 and 50 and thus provides a space ~or overflow water to enter lower section 48. As well it provides a means for adjusting the height of column 42 and the vertical alignment of upper section 50.
It should be noted that the upper portion of base spool 44 and the lower portion of lower section 48 of column 42 are connected by hinge brackets 58. This enahles the positioning of base spool 44 on column base plate 32 before the upper part of column 42 is erected into vertical position, and then the pivoting of sections 48 and 50 of columns 42 into vertical po6ition once base spool 44 has been secured in position on column base plate 32 (see FIGURE 4). Hinge brackets 58 are relea6ably secured together. so that spool 44 may be disconnected completely from lower section 48 as required to allow the placement of the fabric liner after the erection of the reservoir structure and before the cover is positioned.
Ladder rungs 60 are provided on the outer surface of column 42 to provide access to the top of the column.
Supeorted by column 42 and the wall cap angles 26 at the tops of panels 12 are a plurality of trus6es 62 (eg. FIGURES 5 and :~2(~'7~
-8). These trusses are secured at one end to an upper portion of column 42 and at their other ends to wall cap angles 26. As can be seen in FIGURE 5 the trusses extend radially about the column and are spaced equally from each o~her about the column. If Lequired, for example, where the reservoir roof will carry heavy loads, the trusses are inter-connected by appropriate braces 64 as illustrated in FIGURE 5.
~ the top of column 42 is secured a cap 66 (FIGURE

5), this cap and the upper edges of truss braces 64 providing smooth surfaces for a flexible roof cover S~ which covers the cap and preferably extends over the wall cap anglas 26 and upper portions of wall panels. Flexible roof cover 68 is secured in ~hat position by means of a rope 70 secured through appropriate grommet6 in cover 68 and through eye bolts 24 on upper tension bars 18 on the outside surfaces of panels lZ.
This roof cover is made of a suitable polymer fabric.
Inside of the reservoir structure is provided an impermeable flexible fabric liner 74 (FIGURE 8) the upper edge of which is secured to the inside surfaces of the panels 12 or insulation pa~els 30~ above the desired high water level of the reservoir. For example, grommets may be provided on the upper wall edge of liner 74 and hooks ~eg. of stainless steel) may be secured to wall cap angles 26 to receive a rope pas6ed through the grommets, with its ends tied, and thereby hold the liner in place about the inner walls of the reservoir. Alternatively, the hooks may engage the grommets directly. This liner ` ~L207~

provides an impermeable barrier on the area circumscribed by the panels. In the center of the liner 74, a hole 76 (FIGURE
7) is provided, this hole to be seated over the apertures leading to inlet pipe 34 and outlet pipe 36 and overflow pipe 40. Liner 74 is sealed against leakage in the vicinity of hole 76 by means of a sealing ring 78 (eg. of stainless steel) of a size to circumscribe or cover the edge of hole 76. Sealing ring 78 is bolted to column base plate 32 to secure flexible liner 74 about hole 76 to the base plate and thereby prevent leakage of liquid through that hole.
As required, guide cables 84 (FIGURE 8) may be provided, preferably above ~he high water level of the reservoir, between the column and the wall panels to hold the column in a vertical position during arection and to reinforce it as a column under heavy snow loads.
Where the reservoir is to be used for holding drinking water, bolt head~ exposed to the interior of the reservoir, for example on sealing ring 78, may be covered with plastic.

ERECTION_PROCEDURE

(A) Ground Preparat on A site of appropriate surface area to receive the reservoir structure is first cleared and levelled. A trench to receive inlet pipe 34, outlet pipe 36 and overflow pipe 40 ~2(3~

(FIGURE 2) is made at an appropriate position, of àn appro-priate width and to an appropriate depth. The structure may be located on compacted earth. A level base area is important and a surveyor ' 6 level is recommended to ensure that the compacted area does not vary by more than say one-quarter inch in eleva-tion. For a 5~,000 Imperial gallon capacit~ reservoir, a com-pacted circumferential area about ~wo feet in width with an outside diameter of forty-two feet i6 appropriate.
For a more permanent application and/or w~ere soild conditions dictate, the reservoir walls may be erected on a prepared concrete base curb. In this case, be~ore finalizing the position of the concrete forms, the column base plate 32 should be located so that a tape measure can be stretched from the column center to the curb forms. The top surface of the con- crete should be screeded to provide a surface varying not more than say plus or minus one-quarter inch across and around the circumference. The inside edge of the top of the concrete should be bevelled with a trowel before the initial set so as not to present a sharp edge to the flexible liner 74.
~ three to four inch drop in elevation from the inside of the wall at the base to plate 32 is desirable.

tB) Placinq of the Center C lumn Base Plate Column base plate 32 may be laid on top of two timbers (such as two tiers or two six inch by six inch posts) about ~ ~L%(~ '7~

seven or eight feet long. Care should be taken to maintain the base plate level. The service pipes, inlet pipe 34, outlet pipe 36 and overflow pipe 40 may be connected a~ this time to base plate 32.

(C) Placinq Of The ~all Base Plates Using, for example, a tape measure and measuring out from the proposed center of the column on base plate 32, the wall base plates 2 are laid down. The plates are joined by means of connectors 8. The intended size of the reservoir dictates the number of base plates 32 to be used. The base plates, when in position, should form a completed circle. If a completed circle is not formed, then the plates should be shifted on the surface until such circle can be comple~ed.
Anchor bolts or anchor rods as required should be installed at this time through holes lO.

(D) Erection of Wall Panels Wall panels 12 should be brought to the site and laid out like spoke6 of a wheel (FIGURE 2). From this position, two men can elevate each panel and engage the pins 16 on the hinge bar 14 at its base into hook brackets 6 on corresponding plate 2. The first panel can be held in place by two workmen or ~ied in position for example by ropes. The second panel can then be lZ(~7~7~) . .~

erected and tension bar connectors 22 between adjacent upper ~ension bars 18 and 20 secured in placed. Care should be taken that the vertical groove at the edge of each of the panels fits into the edge tongue on each adjacent panel. The last panel i8 preferably left out to allow passage in and out of the reser-voir during construction. In this regard, the top wall cap angle 26 of that final panel can be removed and connected in position at the top to complete the upper circle of ~all angles and stabilize the top of the panels. The wall cap angle connectors 28 are connected at this time.
It should be noted that some outward give is provided in the construction of wall panels at their bases and at the ten6ion bar 18 and 20 surrounding the panels 12. This permits any existing slack in the tension bars to be taken up due to pressure, when the reservoir is filled with liguid.

lE) In6tallation of the Center_Column The column base 6pool 44 is bolted to the overflow hole of base plate 32. The hinge bracket 58, secured to the spool, is preferably oriented toward6 the panel gap left in the erected wall.
The lower sectiQn 48 of column 42 and upper section 50 are preferably prejoined with appropriate threaded rods or studs 56. The~e connected sections are joined, while in the horizontal position, to base spool 44 by their hinge brackets :~0'~9'7~) 58 by fitting an appropriate hinge bolt through these brackets ~see phan~om in FIGU~E 4). The top column cap 66 is then attached to the top of column 42 and a "Chicago" boom device 9O
(FIGU~E 4) is releasably secured through a hole in the cap to the ~op of the column 42. The boom device 9O con~ains a pulley 92 through which a rope 94 is threaded. The column is then elevated by pivoting it from horizontal to vertical position about hinge brackets (58), by the use of a powered or hand operated winch. Side guy ropes are attached to the column to keep it from falling sideways during this elevation procedure.

When the column is in vertical posi~ion, it is secured to base spool 44 with appropriate bolts through confronting flanges.
Of cour6e, although not shown, gaskets are used between the flanges of the base spool 44 and lower section 48 and in other connection6 of elements of the structure as required.
At this point, i~ is preferable that guide cables 84 be attached between the column 42 and wall cap angles 26. Four such guide cables, at about 90 angles to each other, have been found to be adequate. These guide cables 84 are tightened as required by adjusting the turn buckles 98 on guide cables 84 (FIGURE 8). The lower section 48 is thus brought into proper vertical position using a carpenter's level. The upper section 50 of column 52 can be brought into vertical alignment with lower section 48 at this point by appropriate adjustment of the bolts on threaded rods 56 and the use of the carpenter's level.

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(F) Installat on of Roof Trusses Trusses 62 are brought into the reservoir area through the panel opening one at a time. They are elevated with the lower end of the truss placed on a wall cap angle 26. A
workman climbs column 42, a snap hook is tied securely to one end of rope 94 and the snap hook is fastened to the upper end of the truss 62. Workmen on the ground can ~hen pull the upper end of the truss up to its position supported on truss plate lOO at the top of column 42. That end is secured in place and the other end is elevated and secured radially in place on a wall cap angle 26, supported by a wall panel 12. Additional trusses are brought in and placed in position in a similar fashion. The first four trusses are placed at 9O angles to each other. The threaded Lods at ~he overflow point on the column are then adjusted to provide the required elevation.
The remaining trusses can then be installed. Truss braces 64 may be installed as required at this time.

(G) Installation_of R servoir Fabric Liner Prior to installation of flexible liner 74, insula~ion panels 30 are put in place on the inside surfaces of panels 12. To install the liner, the lower bolts securing the upper flange of lower section 48 on threaded rods 56 are slackened off and the lower section 48 is elevated from the top of base :~ ~075~'71) .

spool 44 by tightening the lower nuts. This is done after remvoing the upper bolts on the base spool. The base spool can now be remo~ed after removal of the bolts on its lower flange, connecting it to the base plate. Section 48 and 50 are now supported by trusses 62. Final le~elling of the area within the walls is now carried out. The reservoir liner 74 is then brought in and unfolded. Grommets (not shown) may be provided around the lower edge of the liner to as~ist in manoeuvring it into position. Short ropes can be placed in these grommets to drag it into position. The large hole 76 in the centre of liner 74 is positioned with its edge on base plate 32. A
special neoprene gasket (not shown) may be provided to assist the seal at this location. The base spool 44 is now returned to its postion and bolted to the base plate. The nuts on ~he threaded rods 56 about the lower flange 54 are adjusted to close the gap to the base spool and to ensure a downward pressure ensuring a slight upwards thrust of the column to its truss plate and the trusses.

The final wall panel 12 is now to be secured in position before the raising of the liner up the weall to its final position.
A length of plastic rope is threaded through the grom-mets (not shown) on the upper wall edge of the flexible liner 74 and the rope ends are tied together. Stainless steel hooks are then secured in position in appropria~te holes on the inside edges of wall cap angles 26. The liner is pulled up the wall ~ ~Z~'~9'~

and the rope is hoo~ed onto the stainless steel hooks, OL ~he hooks may be engaged into the grommets directly. The edge of liner 74 should sit above the elevation of the highest level of liquid to be held in the reservoir structure, to ensure that the liquid does not overflow down between the liner and the insuation.

(H~ Installatio,n of the Reservoir Cover The Chicago boom device 90 is removed and a pipe fairlead 104 (FIGURE 6) installed. A rope is fed through pipe fairlead 104 and down to the ground on opposite sides of the reservoir structure. A special roller 106 to assist in raising flexible roof cover 68 is installed at the top of an appropLiate section of wall of the reservoir. Cover 68 is folded pie fashion so that the centre of the cover is at the point of the rope pull attachment. Using a clamp 105 secured to the rope, or by securing with the end of the rope itself.
the fold- ed roof cover 68 may be dragged up over roller 106, up the slope of trusses 62, to the apex of the reservoir. The rope is removed and pipe fairlead 104 removed. The roof cover 68 i6 then unfolded and ~ half pulled over the top to its final position. The r~of cover should be adjusted so that it extends evenly down over the outer surface of the wall panels 12. ~n appropriate nylon 70 is provided for lacing the cover to eyebolt~ 24 on the upper tension bar 18. Rope 70 is preferably ~..

3797(;) in parts 80 that a portion may be unlaced for access into the reservoir or for the addition of chemicals etc., without slackening the remainder of the ropes.
It will be understood that the reservoir structure according to the present invention may be quickly erected and dismantled in a manner requiring very little expertise and very ~ le manpower. The elements making up the structure are of regular shape, and of relatively small size, permitting their containerization or palletization and ready transportation.
The flexible liner is installed, according to the method of the eresent in~ention, as one of the last steps of the process of construction of the container. This means that, where the reservoir is intended to be used for a supply of drinking water, workers erecting the structure have minimum need to walk on the liner, thereby assisting in maintaining cleanline6s of the inneL surface of the liner as well as avoiding damage to it.
Moreover, it should be noted that there are very few bolts or sharp edges exposed to the flexible liner 74 when it is pulled into position through the column gap in the reservoir structure - flush inner &urfaces are provided by the wall panels and insulation, and by the bottom prepared surace within the walls. Another advantage of the present structure is that the central column 42 i6 seated not on the liner, but instead on column base plate 32. This reduces wear on the liner and improves the structural soundness of the system.

~ lZ(~'7~'7~

Thus it is apparent that there has been provided in accordance with the present invention a demountable portable reservoir structure that fully satisfies the objects, aims and advantages set forth above. While the invention has been de-scribed in conjunction with specific embodiments thereof, it isevident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing descrip~ion. Accordingly, it is intended to embrace all such alternatives, modifications and variationsnas fall within the spirit and broad scope of the appended claims.

Claims (27)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A demountable, portable reservoir structure for stor-ing a liquid, having elements comprising:
(a) a plurality of flat, elongated base plates connectable in a plane to form a ring;
(b) a plurality of similar, rigid wall panels, the edges of which define rectangles, the wall panels when in position to be vertically seated on the base plates;
(c) means at the base of each of the wall panels and on each of the base plates to position the wall panels on the plates so that the area within is enclosed when the panels are vertically oriented;
(d) column means to be positioned within the base plate, and wall panels and to rise above the top edges of the panels when in position;
(e) a plurality of trusses to be supported by and secured to, the column means and panels;
(f) a flexible liner to be connected to the inside surfaces of the panels when in position, the liner to provide an impermeable barrier on the area circumscribed by the panels and base plates to a height above the maximum level to which the reservoir liquid is to come;

(g) means enabling controlled liquid flow through the flexible liner when in position:
the aforementioned elements each being releasably connectable to contiguous elements in the structure and being of dimensions and weight to permit containerization or palletizing for han-dling and transportation.

2. A structure according to claim 1 further provided with:
(h) a flexible roof cover to be supported on the trusses, the lower edges of the roof cover, when in position, to circumscribe the upper, outer surfaces of the wall panels and to be secured in that position.

3. A structure according to claim 2 wherein the column means is a column when in position to be concentrically posi-tioned with respect to the base plates and panels, the trusses to extend radially from the column.

4. A structure according to claim 3 wherein the liner is provided with a hole to circumscribe the base of the column, the structure being further provided with:
(i) sealing means to circumscribe the base of the column and the edge of the hole to prevent the escape of liquid within the liner through the hole.

5. A structure according to claim 4 wherein a plate is provided on which the column when in position is to be directly supported, and wherein the hole is to be centred over the plate, sealing means (i) comprising a sealing ring circum-scribing the hole and to be secured to the plate.

6. A structure according to claim 5 wherein the column has, at its lower end, a section which is removable when the column is in position supporting the trusses for easy installation and removal of the liner.

7. A structure according to claim 6 wherein, when the base plates, wall panels, column and trusses are in position, the stability of the structure is such as to permit removal of the removable section from the column to permit positioning of the flexible liner.

8. A structure according to claim 3 wherein the central column is provided with an overflow means for removing liquid over a predetermined level within the structure.

9. A structure according to claim 8 wherein the column is a pipe having an opening at a predetermined height, when in vertical position, to carry away overflow liquid from within the reservoir structure.

10. A structure according to claim 1 wherein the wall panels when in vertical position are circumscribed horizontally by a plurality of adjacent tension bars secured to the outer surfaces of the wall panels, the ends of adjacent tension bars being secured together.

11. A structure according to claim 1, 2 or 3 wherein the wall panels are made of corrugated matarial having vertically oriented grooves when in position, the vertical groove at the edge of each panel to fit into the edge tongue of an adjacent panel.

12. A structure according to claim 1, 2 or 3 wherein each wall panel is provided near its base with a hinge bar having pins, these pins to be seated under upwardly and outwardly extending hooks on the base plates, when in position, to properly posi- tion the wall panels.

13. A structure according to claim 1, 2 or 3 wherein a plurality of wall cap angles connectors are secured to the top edges of the wall panels when in position, adjacent angles being secured to each other, to stabilize and secure in position the upper edges of the wall panels, the trusses to be supported on these angles.

14. A structure according to claim 10 wherein each wall panel has secured to it on its outside surface when in position a tension bar, and wherein the tension bars of adjacent wall panels are secured together, when in position, by means of connector bars bolted thereto.

15. A structure according to claim 1 wherein a base plate is associated with each wall panel and wherein adjacent base plates, when in position, are secured together by means of con-nectors releasably bolted thereto.

16. A structure according to claim 15 wherein the con-nectors, when in position, are provided with vertically oriented holes to receive anchor pins or bolts for securing the base plates in position.

17. A structure according to claim 16 further provided with anchor pins to pass through the holes in the base plate connector bars to secure the base plates in position.

18. A structure according to claim 3 further provided with means for orienting the column in vertical position.

19. A structure according to claim 3 wherein the column comprises a pair of pipe sections with flanged ends, and a plurality of elongated threaded rods are provided to be bolted through confronting flanges to secure the sections of the column in spaced aligned relationship.

20. A structure according to claim 19 wherein the upper flange of the lower column section, when in vertical position in the structure is at a predetermined, overflow height, and wherein overflow liquid from the reservoir structure may enter the lower section of the column from the space between the sections, the lower pipe section of the column to be in fluid communication with an overflow pipe to carry excess liquid from the reservoir.

21. A structure according to claim 1, 2 or 3 further provided with insulation to circumscribe the reservoir between the flexible liner and the wall panels, the insulation to extend a height which is at least that of the predetermined maximum height of the liquid in the reservoir.

22. A structure according to claim 1, 2 or 3 wherein a plurality of hooks are attached to the panels when in position at a height above the desired maximum height of liquid in the reser- voir, a securing means being provided along the upper edge of the flexible liner, when in position, the securing means to be removably received by the hooks so that the liner is supported in position for the reservoir.

23. A structure according to claim 2 wherein the edge of the roof cover is provided with a plurality of holes and where-in a plurality of grommets are secured to the outer surfaces of the wall panels, a rope means being provided to pass between these holes and grommets to secure the roof cover in position on the trusses and outer surfaces of the wall panels of the reservoir.

24. A method of erecting a reservoir on a levelled surface serviced with liquid inlet and outlet means, comprising:
(a) mounting in vertical orientation and contiguously a plurality of rectangular, similar rigid wall panels to form a ring;
(b) erecting a vertical column centrally disposed within the ring of wall panels and rising above the top edges of the panels when in position:
(c) using the column as a scaffold, raising trusses into position extending radially outwardly from the column and supported by the panels and column; and (d) fitting an impermeable flexible liner within which liquid is to be retained within the reser-voir on the surface circumscribed by the panels, and securing it in proper position to the panels, the inlet and outlet means providing controlled liquid flow through the liner.

25. A method according to claim 24 in which, when the wall panels are being erected, one wall panel is not mounted until after the impermeable flexible liner has been brought into the reservoir interior, but before it is fitted in place, to provide access to the space circumscribed by the wall panels during erection of the structure.

26. A method according to claim 24 further comprising the step of:
(e) using the column as a scaffold to raise a flex-ible roof cover to be supported on the trusses into position on the trusses and positioning the roof cover over the trusses so that the lower edges of the roof cover, when in position, cir-cumscribe the upper outer surfaces of the wall panels, the roof cover being secured in that position.

27. A method according to claim 24 which comprises the step of removing a lower portion of the column when the trusses are in position supported by the panels and column, to leave the upper portion of the column supported by the trusses, so that the fitting in position of the impermeable flexible liner may be accomplished without obstruction by the column, and re-placing the lower portion of the column when the flexible liner is in position so that the column can again carry the weight from the trusses supported thereon.