US3471983A

US3471983A - Wall corner construction

Info

Publication number: US3471983A
Application number: US639881A
Authority: US
Inventors: Jean Alleaume
Original assignee: Technigaz
Current assignee: Technigaz
Priority date: 1966-05-20
Filing date: 1967-05-19
Publication date: 1969-10-14
Anticipated expiration: 1986-10-14
Also published as: GB1187304A; NL6707031A; JPS4823563B1; DE1506779C3; FR1492959A; ES340739A1; DE1506779A1; DE1506779B2

Abstract

1,187,304. Tanks in ships. TECHNIGAZ. 18 May, 1967 [20 May, 1966], No. 23061/67. Headings B7A and B7S. [Also in Division F4] A generally rectangular liquefied gas storage container comprises an inner liquid-containing tank formed of primary and secondary barrier walls 17, 16 of Fig. 2 of thin flexible corrugated metal surrounded by heat insulation material e.g. foamed polyurethane (not shown) and which is itself surrounded by a rigid supporting wall structure, e.g. a ship's hull 1, and the spaced adjacent edges 2<SP>1</SP>, 2 of the inner tank and support structure, and referred to as corners are connected together by longitudinally spaced cleats 5, Fig. 3, of heat insulating material e.g. wood bolted at 6, 7 to the hull and at 8, 9 to a flange 10 of a pair of nested inner and outer angle plates 3a, 3b to which are secured the primary and secondary barriers 17, 15. Stiffening members 13 secured by brackets 14 to either side of each cleat 5 extend between the hull 1 and the plate 3b. The gap between successive angle plates 3b is covered by an angle piece 20 of the same material as the secondary barrier 16 whilst the gap between successive plates 3a is covered by pieces 25 of the primary barrier 17. Each corner (53<SP>1</SP>), Fig. 9 (not shown), formed by the intersection of three walls of the tank is also connected to the adjacent corner (53) of the hull by three spaced cleats (56a, 56b, 56c) straddling the three dihedral angles and bolted to a trihedral angular element (54) formed of nested inner and outer corner plates (54a, 54b).

Description

Oct. 14, 1969 J, ALLEAUME 3,471,983

WALL CORNER CONSTRUCTION Filed May 19, 1967 '7 Sheets-Sheet 1 U) QT le?. hij" V 1 lvENToR .JEAN ALLEAUME ATTO EYS Y Oct. 14, 1969 J. ALLEAUME 3,471,983

WALL CORNER CONSTRUCTION I Filed May 19, 1967 '7 Sheets-Sheet 2 INVENTOR JEAN ALLEAUME 9M@ ATTCR EYs Oct. 14, 1969 Filed May 19, 1967 J. ALLEAUME WALL CORNER CONSTRUCTION 'T Sheets-Sheet 3 INVENTOR JEAN ALLEAUME ATTOR EYS J. ALLEAUME 3,471,983

WALL CORNER CONSTRUCTION 7 Sheets-Sheet 4 Oct. 14, 1969 Filed nay 19, 19e? INVENTOR JEAN ALLEAUME @,/l'fd/ ATTOR EYS Oct. 14, 1969 J. ALLEAUME WALL CORNER CONSTRUCTION 7 Sheets-Sheet 5 Filed May 19, 1967 INVENTOR JEAN ALLEAUME Oct. 14, 1969 J. ALLEAUME 3,471,933

WALL CORNER CONSTRUCTION Filed May 19, 1967 7 Sheets-Sheet 6 INVENTOR JEAN ALLEAUME ATTOR Oct. 14, 1969 J, ALLEAUME 3,471,983

WALL CORNER CONSTRUCTION Filed May 19, 1967 7 Sheets-Sheet V I l l l INVENTOR JEAN ALLEAUME ATTORN YS United States Patent O 3,471,983 WALL CORNER CONSTRUCTION .lean Alleaume, Saint Cloud, France, assignor to Technigaz, Paris, France, a company of France Filed May 19, 1967, Ser. No. 639,881 Claims priority, applicationzFrance, May 20, 1966,

2 2 im. ci. E041 1/739, 2/60; Eo4h 7/04 U.S. Cl. 52-276 21 Claims ABSTRACT OF THE DISCLOSURE The present invention essentially relates to a structural arrangement forming a corner construction for a wall with at least two intersecting or meeting sides or faces, having the configuration of a salient or re-entrant solid angle in space of any shape, projecting inwards into or outwards from the inner wall of a for example fluidtight and heat-insulated confining enclosed space, dening in particular a tank or the like, preferably of the so-called integrated type, as well as the method of making said arrangement and the various applications of the latter.

Tanks are already known, which are adapted for example, but not exclusively, to the transport or conveyance and/ or to the storage and preservation of fiuids kept at a temperature very different from the ambient, normal or ordinary temperature, such as for example cryogenic or strongly cooled fluids and more especially liquefied gases at very low temperature and at a pressure approaching for example the ambient atmospheric pressure, such tanks being also able to be used at high temperatures and/ or pressures. Tanks adapted for such a purpose are advantageously of the so-called integrated type, such as for instance the tanks for transporting or conveying liquefied natural gases, such as liquid methane, directly incorporated into the hull of a transporting ship. Such a tank generally comprises an inner envelope, shell or casing, mostly made from metal-sheets or foils, of a metal such as stainless steel, capable of sustaining the low service or operating temperatures and forming a socalled impervious primary barrier, adapted to be in direct Contact with the contents. This primary barrier is relatively thin and exible or yieldable and preferably corrugated or creased, generally along at least two sets or systems of corrugations extending in substantially parallel spaced relationship in a same set or system and intersecting substantially at right angles the corrugations of the other set or system so as generally to form a kind of network of substantially orthogonal pattern the crests of corrugations of which are preferably all projecting from a same inner side or face of said metal-sheet. This primary barrier thus forms a kind of membrane bearing preferably in a substantially uniform manner against an outer surrounding supporting and self-carrying or rigid structure, constituted for instance by the ships hull and this, through the medium of at least one layer or sheet of heat-insulating materials or lagging, wherein may be JCC interposed or embedded at least one intermediate envelope, shell or casing, forming an impervious secondary barrier, surrounding or encompassing the primary barrier and of a configuration often similar thereto. This intermediate insulating material is thus adapted to transmit to the outer self-carrying supporting structure, all the forces exerted or applied on the primary barrier by the contents thereof or confined thereby.

Such integrated tanks may of course exhibit any geometrical shape, but they frequently are of a substantially or approximately prismatoidal or parallelepipedic and even possibly cylindrical shape. These tanks generally embody wall corners formed by the intersection or meeting of two or more wall faces or sides. At each Vertex or apex of the geometrical solid body formed by the tank, the corresponding corner constitutes a solid angle formed by the intersection of three or more faces or sides converging towards or meeting at the common point forming the vertex or apex. When such faces or sides are plane and therefore intersect each other two by -two along a straight line or edge of intersection, the corner formed by said solid angle is polyhedral (for example trihedral in the case of a parallelepipedic tank), each pair of adjacent faces or side-walls of which forms a dihedron. However, the faces or wall sides forming said solid angle may also be skew, that is warped, curved, convex or concave surfaces and intersect each other along a curvilinear edge-line, the plane angle between two adjacent faces being then also curvilinear. Of course, in the case of a cylindrical tank for example, there are no corners in the form of solid angles, but only the two corners the lateral surface forms with the (plane, dished or `bulged) heads or bases of the cylinder and therefore comprising each one two faces intersecting along a curvilinear edge-line.

The tanks more especially of a general prismatoidal or polyhedral and more particularly parallelepipedic shape may exhibit inner corners or solid angles, such as dihedron or trihedrals, which may be either salient or re-entrant. In the prior known constructions, it occurs that the angular spacing or dihedral angle of each pair of adjacent faces of these corners or solid angles tends to vary, that is to open or increase or to close or decrease more or less under the inuence of inner or outer pressures applied to the wall, and this is a serious inconvenience. One main object of the present invention is to obviate or to remove such a drawback by providing a corner or solid angle construction rigid enough to be substantially nondeformable, that is to render substantially invariable the angular spacing of each pair of adjacent faces, forming for example a dihedron, or at the very least to obtain that any variation of this angular spacing.

The invention is also concerned with the process of making the aforesaid construction, resulting from the design of the latter.

Finally, the invention is also directed to the various applications and appliances resulting from the use or Working of constructions of the type broadly set forth hereinabove, as well as to the various constructions, systems and buildings which are provided therewith, such as preferably closed vessels or enclosures for example integrated into or combined with an outer self-carrying, stationary or movable support, and defining an insulated space for containing or confining a product, device or apparatus, such vessels or enclosed spaces forming in particular containers, tanks, vats, cisterns, reservoirs or the like for storing and preserving a product, erected at a stationary position or incorporated into transport or conveying vehicles of any kind, for example floating or rolling vehicles, as well as the safety, protecting or shielding casings, shells or vessels for nuclear plants and the nuclear reactor vessels, tanks or casings or the like.

The invention will be better understood and further objects, features and advantages thereof will appear as the following detailed explanatory description proceeds, with reference to the accompanying diagrammatic drawings, given by way of examples only illustrating several forms of embodiments of the invention, as applied to a tank of a general substantially parallelepipedic shape. In the drawings:

FIGURE 1 shows a fragmentary, perspective and somewhat exploded view, with parts broken away, of a corner construction in the shape of a re-entrant dihedral angle, according to the invention;

FIGURE 2 is a side view in cross-section taken upon the line II-II of FIGURE 3, of the preceding construction with parts broken away;

FIGURE 3 is a top view in multiple cross-section taken upon the lines III- III of FIGURE 2, of the preceding construction;

FIGURE 4 is a partial view, similar to that of FIG- URE 2 and showing an alternative embodiment or modiiication of the fastening arrangement of the primary barrier;

FIGURE 5 is a prole or side-face view, in cross-section taken upon the line V-V of FIGURE 6, of a salient dihedral-shaped corner construction according to the invention;

FIGURE `6 is a front view, in section taken upon the line VI--VI of FIGURE 5, with parts broken away;

FIGURE 7 is a top view of the construction shown on FIGURE 5;

FIGURE 8 is a partial sectional view of a detail of an alternative or modified fastening arrangement of the primary barrier;

FIGURE 9 is a fragmentary cross-sectional view, with parts broken away, of a re-entrant trihedral corner construction according to the invention;

FIGURE 10 is a partial view in section taken upon the line X--X of FIGURE 9;

FIGURE 11 is a fragmentary view in section taken upon the line XI--XI of FIGURE 9.

According to the illustrative form of embodiment shown on FIGURES l, 2 and 3, the reference numeral 1 denotes a self-carrying outer supporting structure, formed for example by the double wall of a ships hull in the region of a corner 2 having the shape of a re-entrant dihedral angle inside of which is mounted the corresponding reentrant dihedral corner 2 of the integrated tank. The plane or straight angle of this dihedron is substantially orthogonal or right in the example shown, but it can of course be of any value, for example an obtuse or acute angle. Likewise, instead of having substantially generally plane faces or sides, it may have skew faces or possibly mixed or combined that is plane and skew faces. The rigid and solid structure of this angle 2 consists of a series or row of dihedral-shaped angular elements 3, preferably but not compulsorily all identical with each other, spaced from each other, facing towards the same direction and substantially aligned in a row extending along the edge of the dihedron 2. Such a breaking or dividing up or splitting of the solid structure of this dihedral angle 2 into several spaced elements, parts, portions, pieces or sections of a dihedron is necessary to allow the thermal deformations and strains of the impervious, relatively thin and flexible, membrane-like primary and secondary barriers which are adapted to be rigidly secured to the angular elements and in particular, the expansions and contrac- *ions parallel to the direction of the edge of the dihedron. ,.lthough each angular element 3 may possibly be made of one single piece, it is advantageous, to simplify the manufacture and mounting or erection, that each angular element 3 consist of two inner or primary and outer or

secondary angle members

3a, 3b, respectively, which are overlying or coupled so as to be nested or fitted into each other. Each primary angle member 3a is made integral with the secondary angle member 3b which is associated therewith, for example by screws or the like 4 the head of which is preferably sunk or embedded in a counter-bored recess of the angle plate 3a, in order that it does not raise or project from the inner face of the angle plate. Each screw 4 is screwed in a blind threaded hole of the secondary angle plate 3b, so that in case of a breakage or failure of the primary barrier, no leakage can occur through the fastening holes for the screws. Each angular element 3 is supported by one or several supporting or carrier spacer blocks 5 consisting each one of a connecting cleat or dog or the like, made from a compact and heat-insulating material, such as for example plywood, compressed wood, laminated wood or the like. Each spacer block or cleat is adapted or designed to connect the angular element supported thereby to the outer rigid supporting structure 1, such as the doublewalled hull of the ship and is preferably recessed so as to minimize any heat transmitting bridges or conductive connections. Each spacer block or cleat 5 is secured to the inner wall of the outer structure 1, in the re-entrant dihedral corner thereof, by stud pins, bolts or the like 6, for example by means of studs welded to the Wall 1. Each cleat is thus applied edgewise against both faces of the dihedron formed by this wall 1 and extends between pairs of registering or opposite studs, disposed on either side of the cleat, respectively and holding same by means of clamping or tightening strips or bars 7, extending through a recess or cut-out portion of the cleat. All the recesses or cut-out portions of the cleats as well as the hollow or void spaces left thereby are adapted to be subsequently lilled with insulating material, not shown, which will subsequently iill up all the intermediate space between the secondary barrier and the outer supporting structure. This insulating material may advantageously consist of a suitable synthetic or artificial material s uch as a foamed plastic material such as expanded polyurethane or the like, applied by spraying by means of a spray-gun or the like. The inner edge of each cleat 5 is cut out or shaped to conform to the angular element 3 to be supported thereby, that is, in the shape of a reentrant dihedral angle wherein the secondary angle plate 3b is applied thereagainst by its outer face which is thus conformed to by the cleat. Each secondary angle plate 3b is firmly atiixed or secured against each one of the cleats 5 supporting same, by one or several tie-rods, bolts or the like 8, fastened each one to the angle plate 3b. Each tie-rod consists desirably of an eye-bolt or the like, pivotally connected, through the medium of a pin 9 to a clevis, lug, bracket or like flange or member 10, integral with the angle plate 3b (FIGURE 3). Each bolt such as 8 desirably extends edgewise through the cleat 5 to project by its screw-threaded end adapted to receive a clamping nut, into a recess or cut-out of said cleat so that such nuts be easily accessible. The tightening of each nut against the edge of the corresponding recess or cutout portion of the cleat is desirably effected through the medium of a boat-shaped washer, a yoke or strap, a cramp, a clip or the like 11, conforming to the local shape ofthe edge of the recess or cut-out. The cleviscs 10 consist advantageously of a pair of substantially parallel stitfening or reinforcing members or lianges, welded to the outer face of the angle plate 3b and between which the corresponding cleat 5 is fitted. To avoid any deformation of the angle plate 3b when welding the stiffeners 10, the latter are provided with slots, notches or jags 12 along their edge bearing against the angle plate 3b.

When each angular element 3 is relatively long, it is supported by several spaced cleats, whereas when it is relatively short, it may only be supported by a single cleat disposed substantially in the medial transverse plane of the angular element. In this case, since each cleat 5 is generally of a substantially flat shape, there is provided, to prevent any tilting of the angular element 3 transversely towards either side of the cleat, at least one pair and preferably two pairs of stiifening members or ribs 13, preferably consisting of the same material as the cleat 5 and bearing substantially at right angles against same on either side of said cleat. Each reinforcing member 13 also bears by one end thereof against the Wall of the structure 1 and by the opposite end against the outer face of the angular plate 3b. Each one of these reinforcing members 13 may be secured in a simple manner to the cleat 5, for example by at least one pair of connecting corner plates or angles 14 secured to the cleat 5 and to the reinforcing member 13 by bolts such as 15. In the example illustrated, each angle plate 3b is secured by three tie-rods 8 one of which is arranged in the bisecting plane of the dihedron and the two other ones are respectively at right angles to both flanges or faces of the angle plate 3b. In view of their pivotal connection, these two latter tie-rods are capable of swinging or pivoting within the corresponding recess or aperture of the cleat to follow the thermal deformations of the angle plate (see FIGURES 2 and 3).

The metal sheets of the primary and

secondary barriers

17 and 16, respectively, may assume the shape shown on FIGURE l, that is exhibit for example an orthogonal pattern of corrugations arranged in two intersecting systems, sets or series of parallel spaced corrugations dening therebetween smooth or uncormgated areas, for example substantially flat or plane and defined by a substantially rectangular or square contour. The patterns or configurations of the corrugations of both primary and secondary barriers, respectively, may be similar to or identical with each other or different from each other. In the present example, the spacings or pitches of the corrugations of both barriers are substantially identical with each other, so that the corrugations of both barriers differ somewhat from each other by their shape and size. The secondary barrier 16 is connected or attached in a fluid-tight maner to the respective flanges or sides of the secondary angle plates 3b `and for this purpose, each secondary angle plate 3b comprises, on the periphery of each flange lthereof and on the Side of the inner face, a reduced, thinned or edged olf marginal portion, forming a rabbet or the like 18, machined into the angle plate to form thereby a marginal shoulder, recessed with respect to the inner face of the flange. Against this shouldered edge strip of the angle plate 3b is applied the edge of the secondary barrier 16, all along the flanges or faces of the angle plates 3b. On each flange or face of angle plate 3b, the barrier 16 is secured by welding, for example by an arc-welded lap-joint along its edge at 19. The secondary barrier is so directed that its corrugations, which are all projecting from a same side of the metal-sheet, are facing outwards. Each spacing or gap left between two successive angle plates 3b is covered from the outside by an angular piece 20, conforming to the shape of the angle plate 3b and preferably consisting of a sheet portion of the secondary barrier, so as to exhibit at least one corrugation extending in parallel relation to the spacing or gap between the two successive angle plates 3b and straddling such a spacing or gap. Each angle piece 20 covers by the ends of its flanges, the edge of the secondary barrier secured to the flanges of the angle plates 3b and is welded, for example arc-welded according to a lap-joint to said secondary barrier at 21. All the `welds are continuous and the covering or overlapping between the secondary barrier and the angle piece is achieved owing to the presence of a crease or the like, formed in each covering angle piece to take up or compensate for the thickness of the covered secondary barrier. Moreover, in general, each portion of covering metal-sheet or foil of an assembly with mutually overlapping edges preferably comprises such a crease or the like, known per se, corresponding to the thickness of the portion of covered metal-sheet or foil.

Each angle piece 20 extends over the whole width of the flanges of each angle plate 3b and is secured to said angle plate outside of the covering or overlapping areas of the secondary barrier by a continuous well along its edge.

Each primary angle plate 3a is preferably thinner than the associated secondary angle plate 3b and larger so as to protrude, for example along its whole periphery, in overhanging relationship beyond the secondary angle plate 3b. The primary barrier 17, the corrugations of which all projecting from a same side are directed or facing inwards, that is, in the direction opposite to that of the corrugations of the secondary barrier 16, bears with its edge against the edge of the anges of the primary angle plate 3a and is secured thereto. In the example shown on FIGURES 2 and 3, the primary barrier 17 is secured to the anges of each primary angle plate 3a, respectively, by screws or the like 22, screwed into strips or small plates or into a strip forming a backing pla-te, or the like, 23, fastened, as by welding, to the protruding portion of each flange of angle plate and behind or rearwards thereof, that is on the outside. The head of each screw 22 is preferably sunk or embedded in a recess or the like, machined, milled, counter-bored or cut in the inner face of the primary angle plate 3a.

According to the alternative embodiment or modification shown on F'IGURE 4, the screws 22 for fastening the primary barrier 17 to the primary angle plates 3a may be replaced by spot or tack welds, effected for example by arc-welding, such as 24, extending through the primary barrier 17, thereby avoiding any piercing or drilling thereof as well as the fastening of small plates 23. Inner or primary angle pieces 25, respectively homologous of the outer or secondary angle pieces 20 are provided to straddle the gaps or spacings separating the successive primary angle plates 3a. These angle pieces 25, which are preferably made or taken from a primary barrier sheet-metal and comprise one corrugation bridging Ithe gap or spacing between two primary angle plates 3a, conform to the inside shape of the primary angle plates 3a and connect to each other the portions of primary barrier 17 secured to the anges of each primary angle plate, respectively. To this end, the central corrugation of each angle piece 25 is connected preferably by welding to the corresponding corrugation of the primary barrier, substantially in aligned or registering relation to this corrugation. Each angle piece 25 is long enough, in parallel relation to the edge of the corner or dihedron so that the successive angle pieces are preferably alternately overlapping by their adjacent edges which are connected in sealing relationship by a continuous Weld along a lap-joint and also cover the edges of the secondary barrier at both ends of the flanges of the primary angle plates. To this end, each angle plate comprises a creased or swaged portion adapted to take up or to compensate for the thickness of the primary barrier (see FIGURE 2). Outside the areas where each angle piece covers or overlaps the secondary barrier, each angle piece is secured to the primary angle plates 3a which it connects by spot or tack welds, for example carried out by arc-welding, such as 26 (see FIGURE 3). Thus, according to the embodiment used, when the screws 22 or spot or tack welds 24 for fastening the primary barrier I7 to the primary angle plates 3a break or fail, then the spot or tack welds 2-6, Securing the angle pieces 25 to the primary angle plates 3a, provides the necessary mechanical strength. The fluid-tightness at each screw 22 or each spot or tack weld 24 is achieved owing to the overlapping or covering of the sheet-metal of the angle piece 13, overlying or extending over said screws or said spot or tack welds.

FIGURES 5, 6, 7 and 8 show the solution adopted in the case of a salient wall corner, for example of a salient dihedron 27 of the inner wall of the double-walled ships hull 1, to which corresponds the salient dihedron 27 of the inner wall of the integrated tank. Here, also, as in the case of the re-entrant dihedron, the construction of the dihedral angle consists likewise of the spaced angular elements 28, arranged or distributed along the edge of the salient dihedron and consisting each one advantageously of a pair of primary and

secondary angle plates

28a and 28b, respectively, nested or `fitted into each other yand having their concavity facing outwards, so as to be convex inwards or towards the inside of the tank. Apart from their reversed orientation, these pairs of angle plates have a configuration and assembly similar to those of said angle plates of the re-entrant dihedron. Moreover, the secondary barrier 16 and the primary barrier 17 are secured to the

angle plates

28a, 28b, in a manner similar to that of the re-entrant dihedron and inner or primary and outer or secondary angle pieces, respectively, are provided at each spacing or gap left between successive 'angle plates and are similarly fastened. Such primary angle pieces have been denoted by the reference numeral 29 (see FIGURES 5 and 7), Whereas the secondary angle pieces have been designated by the reference numeral 30 (see FIGURE 6). The coupled

angle plates

28a, 28b are joined together by screws 31. On FIGURE 5, the primary barrier is attached by spot or tack welds, for example carried out by arc welding, to each primary angle plate 28a, whereas FIGURE 8 shows the alternative embodiment where the primary barrier 17 is fastened to each primary angle plate 28a by screws such as 32 screwed into a corresponding backing plate 33, integral with said primary angle plate.

The angular elements 28 are supported or carried by assemblies 34, distributed along the edge of the salient dihedron and comprising each one a box-shaped member or like casing 35, for example made from wood, secured to the supporting structure 1 forming the doublewalled ships hull and exhibiting inwards or towards the inside, two faces 36 meeting according to -a salient angle similar to the salient corner or dihedron and on the edge of which are fastened straddlewise, along the latter, a series of spaced brackets or spacers 37, carrying the secondary angle plates 28b and integral therewith.

`Each box-like member or casing preferably consists of a series of connecting spacer blocks formed of cleats or the like 38, made for example from wood and preferably recessed, cut out or apertured, which cleats are secured to the supporting structure or double-walled hull 1, in straddling relation to the dihedral angle thereof. Such a fastening is elected preferably in a manner similar to that shown on FIGURES 2 and 3 in the case of the re-entrant dihedral angle, that is, by pairs of stud pins 39, welded to the wall of the structure 1 and clamping stirrups or straps 40. These cleats 38 are for example equally or uniformly spaced from each other. The cleats of a same box-like member 34 are covered or lined inside by an angle member 41, for example made of plywood, which angle member may consist, to simplify the manu facture, of two boards or plates of plywood, joined angularly together at a salient angle by at least one inner connecting angle 42 secured to both plates or boards for example by screws 43 extending through said plates or boards and screwed directly into the angle 42. The successive adjacent box-like members, distributed along the salient dihedron 27 and straddling the latter, are spaced or separated from each other by gaps such as 46 (see FIGURE 6) adapted to allow for thermal stretch or expansion of the box-like members. Two successive boxlike members are preferably made integral with each other by at least one system of plates, fish-plates or the like 44, fastened by bolts to both adjacent panels 41 of the two adjacent box-like members. Each secondary angle plate 28b is welded for example on two spaced spacers 37 having possibly the shape shown on FIGURES 5 and 6 and each spacer comprises at its outer end a recess in the form of a re-entrant dihedron or corner, complementary of the salient corner or dihedron formed by the panels 41, so that it may be secured straddlewise on said salient corner of the box-like member 34, by the same screws extending through a ange or edge of said spacers. Particularly on FIGURES 5 to 8 are seen the swaged or creased portions, joggled machined or cut in the periphery of the anges of the secondary angle plates 28b and adapted to receive the angle pieces 30, So as to be flush with that face of the angle plate 28b which en gages the angle plate 28a and as in the previous example; each

angle piece

29 or 30 joins by its central corrugation, a corresponding corrugation of the primary or secondary barrier.

Each assembly 34 may be Prefabricated advantageously at the workshop so as to be ready for erection or mounting in the field. To this end, each box-like member 35 is made by temporarily assembling a series of spacer blocks forming cleats 38, for example six in number for each box-like member, by wooden plates or spacers 47, secured to the various cleats by screws '48 and joined together, to form angle members, by metal angles 49, secured to the plates 47 by bolts 50. On this Igroup of like and aligned cleats are then secured the panels or boards 41, for example by gluing or sticking or by screws and they are connected together by means of the angle 42 and then they are mounted on the box-like member thus formed by the spacers 37 previously welded to the secondary angle plates 28b. Each box-like member having thus been prefabricated separately, all the hollow spaces or voids, which are inside of the box-like member, are filled with a heat-insulating material, for example with a synthetic or artificial material, such as a foamed plastic material such as expanded polyurethane or an equivalent substance, applied by spraying or injection by means of a spray-gun before setting or mounting each assembly 34 in the field. During the building of the tank, a subsequent operation of the method of manufacture or building obviously consist in filling up, with insulating material, for example with expanded polyurethane, all the space 51 left between the inner wall of the supporting structure 1 formed for example by the ships hull and the secondary barrier 16. Outside the corner angle plates or sections, the space left between the primary and

secondary barriers

17 and 16, respectively, is desirably filled up with plates or panels made from heat-insulating material and compact and rigid enough to sustain or support both barriers bearing thereagainst and to serve to distribute the forces and pressures exerted by said barriers. These relatively rigid or stiff panels or plates consist for example of plywood or of compressed, laminated or like wood, 52 (see FIGURE l).

FIGURES 9, l0 and ll show an embodiment of`a corner having the shape of a solid re-entrant angle, such as a corner in the shape of a re-entrant trihedral angle 53 in the outer supporting structure 1 formed for example by the double-walled ships hull, to which corresponds the re-entrant trihedral angle 53 of the integrated tank. This re-entrant trihedral angle 53 consists, similarly to the configuration of dihedral angles, of two primary and secondary

angular elements

54a and 54b, respectively, nested or fitted into each other and joined or connected together in overlying relationship by screws 55, this assembly having substantially the desired geometrical shape for such a re-entrant trihedral corner. This angular assembly is supported in a manner similar to that of the preceding examples, by spacer blocks forming cleats or the like 56, secured to the inner wall of the hull 1 by pairs of studs 57 with clamping or tightening stirrups, clips, dogs, straps or the like 58. This angular assembly 54 is thus supported by at least three cleats such as 56a, 56b and 56C, straddling the three dihedral angles, respectively, forming the trihedral angular element S4 and these three cleats can advantageously be imbricated mutually into each other in view of interiitting slots, notches, grooves or like recesses formed to this end in each cleat, respectively. The angular assembly 54 is secured on each of these three cleats by tie-rods or like bolts or fasteners 59, in the manner previously described. Each dihedral angle of the trihedral angular assembly 54 is extended in alignment therewith by the series of spaced, double angle plates 3, `shown on FIGURES 2 to 4 and on which the primary and Isecondary barriers are fastened in the manner already described. The secondary angular element 54b comprises on the periphery of its three faces, swaged or creased striplike portions machined as in the case of the secondary angle plates 3b, and adapted to receive the secondary barrier metal-sheet 116 bearing thereagainst; likewise, the primary barrier 17 is applied in a manner similar to that previously described on the edge of the faces of the primary angular element 54a and the gaps or spacings left between or separating each dihedron of the trihedral assembly 54 consisting of the adjacent double angle plates 3 are respectively covered in overlapping relationship by the primary and

secondary angle pieces

25 and 5, respectively, set or mounted in the manner already described. 'Each one of these angle pieces is secured on the inner face of the trihedral element 54a by spot or tac-k welds such as 26. An angle piece 60' of trihedral shape is nested or iitted into and applied against the inner face of the trihedral element 54a, so as to cover or overlap the adjacent edges of the primary angle pieces 25 bearing or applied against this trihedral primary element 54a.

The concept or principle of this construction is obviously applicable to any solid polyhedral angle exhibiting for example more than three faces meeting at a common point. -In the case of a salient polyhedral angle, the principle of the construction illustrated by the FIGURES 5 to 8 is applicable while being of course adapted to the case of a salient trihedral angle.

It is to be understood that the present invention should not be construed as limited to the forms of embodiments described herein and shown which have been given by way of illustrative examples only, as many modifications, alterations and changes may be made by those skilled in or conversant with the art without departing from the scope and teachings of the invention as delined in the appended claims.

What I claim is:

1. A corner construction with at least two meeting sides for a uid-tight composite lagged wall separating an inner space from an outer space and comprising an impervious, relatively thin and flexible membrane-like primary barrier bounding said inner space, made of corrugated sheet-metal, bearing against and spaced from a self-supporting structure bounding said outer space through the medium of at least one layer of heat-insulating material interposed in and filling the intermediate space left therebetween, a plurality of substantially rigid, spacer blocks made from heat-insulating material, secured in spaced relationship to said supporting structure in said intermediate space and distributed in spaced relationship substantially along each edge line of intersection of two adjacent sides of said corner, and a plurality of substantially registering metal angle members arranged in at least one row, having outwardly and inwardly substantially the geometrical shape of said corner to form same by themselves and secured to said blocks, respectively, said primary barrier being divided along each aforesaid edge line of intersection into at least two separate portions lining said meeting sides, respectively, in spaced relation to each other and to said edge line and which are connected in sealing relationship to the end portions of both flanges of each angle member, respectively and means for tightly closing each gap left between any two successive angle members of each row thereof and the adjacent barrier portions.

2. An arrangement according to claim 1, comprising at least one impervious thin and flexible, secondary barrier, made of corrugated sheet-metal and provided between and in spaced co-extensive relation to said primary barrier and supporting structure, at least the secondary barrier nearest to said primary barrier being divided along each aforesaid edge line of intersection into at least two separate portions lining said meeting sides, respectively,

in spaced relation to each other and to said edge line and which are connected in sealing relationship to the end portions of both flanges of each aforesaid angle member, respectively, each pair of co-extensive primary and secondary barrier portions being connected through lap-joints to said ilanges, on either side of each flange, respectively and means for tightly closing each gap left between any two successive angle members of each row thereof and the adjacent barrier portions.

3. An arrangement according to claim 2, wherein each barrier portion is connected to the corresponding ilanges of the associated angle members by smooth uncorrugated at least marginal areas of said barrier portion separated by corrugations, respectively, each of which terminates at one gap between two successive angle members and each gap left between the successive angle members of each row thereof is covered at least from one side by a thin and flexible integral angle piece which is wider than said gap and of the same nature as said barrier lying on this side and overlapping same at least locally while being secured thereto in a fluid-tight manner, so as to connect both barrier portions attached to both flanges of a same angle member, respectively, said angle piece being formed throughout with at least one corrugation adjacent to and continuously integral with co-extensive plain sections on either side thereof and extending at and at least along said gap and covering in snugly overlapping and intertting relationship a corresponding corrugation of the associated barrier.

4. An arrangement according to claim 3, wherein each angle member consists of a pair of primary and secondary single piece angle plates nested into and secured in overlying relationship to each other and said primary and secondary barriers are connected in sealing relationship to the flanges of said primary and secondary angle plates, respectively, each primary angle plate being thinner and larger than its associated secondary angle plate fitted therein so as to protrude beyond the corresponding anges of the latter.

5. An arrangement according to claim 4, comprising primary and secondary angle pieces connected to said primary and secondary barriers, respectively and wherein at least each primary angle piece is long enough in parallel relation to the corner edge so that the successive angle pieces overlap each other alternately by their adjacent edges which are rigidly connected to each other in a continuous fluid-tight manner.

6. An arrangement according to claim S, wherein each secondary angle plate is formed on the periphery of each flange thereof, with a thinned rabbet-like marginal portion forming a stepped ledge, recessed in that face of the ilange which faces the associated primary angle plate to receive and seat a corresponding edge portion of said secondary barrier along said flange and a corresponding edge portion of said angle piece over the width of said flange, the fastening of said secondary barrier to said flange and of said angle piece to said secondary barrier being achieved by a continuous weld extending along lapjoint means.

7. An arrangement according to claim 6, wherein each covering metal-sheet portion of any assembly thereof having mutually overlapping edges comprises a joggled portion corresponding to the thickness of the covered metal-sheet portion of said assembly.

8. An arrangement according to claim 7, wherein each primary angle plate is secured to its associated secondary angle plate by screws having their heads sunk into re spective counter-bored recesses and which are ,screwed into tapped blind holes of said secondary angle plate and covered by the associated primary angle piece.

9. An arrangement according to claim 8, wherein said primary barrier is secured to each primary angle plate by spot welds extending through said barrier and covered by the associated primary angle piece.

10. An arrangement according to claim 8, wherein said primary barrier is secured to each primary angle plate by screws, having their heads sunk into respective counterbored recesses and screwed into respective backing nut plates, attached to the protruding portion of each ange of angle plate on the opposite face thereof, said screw heads being covered by the associated primary angle piece.

11. An arrangement according to claim 8, wherein each primary angle piece connecting said primary barrier is secured to each primary angle plate by spot welds outside the areas where said angle piece covers said secondary barrier.

12. An arrangement according to claim 11 for a corner in the shape of a solid polyhedral angle with at least three faces meeting at a common point, comprising two angular elements nested into each other and joined together in overlying relationship and conforming to the geometrical shape of said corner, said barriers being likewise secured to said angle plates and a covering piece which has the shape of said corner, being provided on said primary barrier.

13. An arrangement according to claim 12, wherein said polyhedral angle is a re-entrant trihedral angle provided with three cleats straddling the three dihedral angles of said trihedral angles and imbricated mutually into each other by means of intertting slots formed in each cleat, respectively.

14. An arrangement according to claim 13, wherein said primary barrier and the secondary barrier nearest thereto are spaced by continuous, stiff, heat-insulating panel means sandwiched therebetween and each barrier is formed according to a waffle-like pattern with two sets of substantially parallel spaced corrugations projecting all from a same side of said barrier, each corrugation of one set intersecting at right angles the corrugations of the other set, thereby defining smooth uncorrugated areas therebetween, and the corrugations of one set extending parallel to one corner edge line, the corrugations of both barriers registering substantially with each other.

15. An arrangement according to claim 11 for a corner having the shape of a re-entrant angle which is concave towards said inner space and wherein each spacer block consists of at least one apertured openwork connecting cleat made from a compact material, secured by stud bolts to said supporting structure and to which each secondary angle plate is fastened by at least one eye-bolt pivotally connected by means of a pin to a clevis-like bracket integral with said angle plate.

16. An arrangement according to claim 15, wherein said primary barrier and the secondary barrier nearest thereto are spaced by continuous, stiff, heat-insulating panel means sandwiched therebetween and each barrier is formed according to a wallie-like pattern with two sets of substantially parallel spaced corrugations projecting all from a same side of said barrier, each corrugation of one set intersecting at right angles the corrugations of the other set, thereby defining smooth uncorrugated areas therebetween, and the corrugations of one set extending parallel to one corner edge line, the corrugations of both barriers registering substantially with each other.

17. An arrangement according to claim 15, wherein each cleat is a at rigid element bridging said two meeting sides of said corner and recessed endwise for accommodating and conforming to said secondary angle plate,

said stud bolts being arranged by pairs on either side face of, adjacent and in parallel registering relation to said cleat so as to clamp a web portion thereof against said self-supporting structure by means of a binding stirruplike clip extending through one aperture of said cleat and straddling one edge of said web portion and connected to said stud bolts, said clevis-like bracket straddling the end edge of said cleat, each pin extending through an open notch formed in said end edge of said cleat and each eye-bolt extending through a bore formed in the thickness of said cleat and opening at its opposite ends into said notch and into an aperture of said cleat, respectively, and the nut of each eye-bolt bearing against the edge of said aperture through the medium of a pressure plate.

18. An arrangement according to claim 17, wherein each cleat comprises at least one pair of stays of heat insulating material made integral with said cleat on either side thereof and engaging the outward face of one flange of the associated secondary angle plate.

19. An arrangement according to claim 14, wherein said primary barrier and the secondary barrier nearest thereto are spaced by continuous, stiff, heat-insulating panel means sandwiched therebetween and each barrier is formed according to a waie-like pattern with two sets of substantially parallel spaced corrugations projecting all from a same side of said barrier, each corrugation of one set intersecting at right angles the corrugations of the other set, thereby defining smooth uncorrugated areas 30 therebetween, and the corrugations of one set extending parallel to one corner edge line, the corrugations of both barriers registering substantially with each other.

20. An arrangement according to claim 11 for a corner v in the shape of a salient angle which is convex towards said inner space and wherein each aforesaid spacer block consists of a box-like assembly secured to said supporting structure and exhibiting inside thereof two faces meeting at a salient angle similar to said corner and to the meeting edge of which are secured straddlewise therealong, a series of spaced spacer elements supporting said secondary angle plates.

21. An arrangement according to claim wherein each box-like assembly consists of a plurality of spaced, apertured connecting cleats secured by stud bolt fasteners to said supporting structure and covered by angular panel means forming a salient angle.

References Cited UNITED STATES PATENTS 1,855,357 4/1932 Kuehn 52-94 2,254,780 9/ 1941 Quimper 220-15 2,394,229 2/ 1946 Bergstrom 220-15 2,601,241 6/1952 Boddy 220--15 50 2,737,266 3/1956 Gross 52-280 2,892,564 6/1959 Morrison 220-15 3,332,386 7/1967 Massac 220--15 FRANK L. ABBOTT, Primary Examiner JAMES L. RIDGILL, JR., Assistant Examiner U.S. Cl. X.R.