US2353260A - Metal plate construction - Google Patents

Description

July 11, 1944. R. PAULSEN METAL PLATE CONSTRUCTION Filed July 1l, 1941 2 Sheets-Sheet l KW. gpg.

-r- CU?- R. PAULSEN METAL PLATE CONSTRUCTION July 11, 1944.

`FiledJuly l1, 1941 2 Sheets-Shea?. 2

Patented July 11., 1944 parte UNITED S'IATES- PATENT vOFFICE METAL PLATE CONSTRUCTION Reginald Paulsen, Hingham, Mass. Application July 11, 1941, serial Noioigyzov 4 Claims.

This invention relates to metal plate construction in general, and in particular to the manufacture of metal ship hulls, bulkheads, tanks, decks, superstructures, and other structural parts of vessels. It has as its object the quicker and cheaper building of strong and seaworthy vessels,

and the lightening of the total weight or struc--` tural elements used, so as to increase the available load-carrying capacity of the improved ships over the same sizes of vessels built according to prior methods of construction. This it accomplishes by applying the known principles of prefabricating the ships in parts as large as can be conveniently handled, and by joining the structural elements by welding, but through use of the invention. principles reducing the number of stiiiening elements auxiliary to the component plates and reducing the number of welds required and the time and labor needed to make such welds as remain necessary. To these ends, the invention comprises the use in forming the outer shell, the decks, the bulkheads, tank tops, and other parts of the hull, of steel plates which characteristically have their marginal areas flat and disposed in a single plane as usual, but with their intermedia-te areas dished, bulged, buckled, swamped, or bent to form one or more areas having sufficient convexity at one surface and suflicient concavty at the other surface to irnpart greatly increased resistance to bending in any direction and thus to render the plates iny herently much stiffer than the ordinary flat steel plate oi corresponding extent and thickness. Just as corrugation of sheet metal greatly increases its resistance to bending in directions running across the corrugations, so the intentional shaping or disf torting of the plates to create the bulges or buckles previous to their use imparts greatly increased resistance to subsequent bending in any direction, rendering the plate self-supporting if their edges are held. For this purpose, the buckling i1:

need not involve great departures of the points of greatest height or depth of the bulges out of the original plane of the sheets, in which pla-ne the marginal portions of the sheets for a distance of several inches inward all around their edges are left, since a displacement of two or three inches at the highest point of a plate 6 feet in width increases manyfold its resistance to bending. To render the stiiening action of the bulges more effective without increasing the maximum departure from the original plane of the sheet, where plates of relatively great extent are involved, a plurality ci buckled or bulged areas or panels are provided within the extent of the plate, rather than onel single buckle sub-.

stantially coextensive with the area of toe plate. Since the plates used are in nearly all iustances rectangular, the buckled areasl are correspondingly shaped in outline so as to give the maximum area of the plate the desired set or bulge out ofits original plane relation, s0 as to impart the stiffness thus achieved to the greatest possible amount of the area of the plate. However, in dealing with plates shaped other than rectangular, the outline of the buckled portions follows the outline of the sheet, with the marginal portions bounding the buckled area left in the original plane of the sheet as is characteristic ci the invention. l

Plates of this type are practically self-supporting under any fair loads to which they may be subjected in use in a ship, thereby eliminating the need of the stiieners or beams essential hitherto at intervals of 24- to 30 inches apart within the areas'of the ilat plates previously employed in ship building, withresulting great reduction in the number of stieners since the lat-- ter need only be used at the seams where two plates butt together in the same plane, even when the plates are 6 feet Wide. This reduction in the number of stilenersV through eliminating many or all those intermediate the extent of the plates,

both in material and in the time and labor otherwise put into cutting, fitting, shaping and welding the stirleners no longer needed. The avoidance of lapped seams not only saves material but obviates the ragged surface produced by such seams. The slight increase inthe drag of the water against the dished plates `when used for the wetted surface of the hull is compensated for by the increased carrying capacity of the ship through thus lightening its construction without loss ci strength, since the increased carrying capacity more than pays for the necessary increase in power to drive the ship at thev same speed; or, from another viewpoint, the greater buoyancy of the lighter hull reduces displacement with the same power and load, thereby maintaining speed.

Further in accordance with the principles oi the invention7 a novel welded seam is provided, especially adapted for use in building-ships out of preia-bricated sections employing the novel buckled plate construction, but also adapted for use in conjunction withA flat and other types of plates. An essential characteristic of this novel seam is that the two plates to be joined, or the corresponding surfaces of two of the plurality of elements-joined by `theweld, are disposed at greater than a right angle to each other and preferably flush "with each other in the same plane, so thatin prefabricating the section in the shop previous to taking it to the ways to be built into the ship the entire seam can be welded through the use of a welding machine instead of by hand, since the welding machine is thus given access to the seam and can be accurately guided by the seamv itself in its traverse therealong. Since the use of the buckled plates confines the welding-operations ,to the edges of the plates and eliminates the welding-on of stiffeners at intermediate portions, and since the stiffening elements always are located at the edges of the plates, there is always an open seam as deep as the thickness of the plates being welded into which the welding machine can introduce the molten electrode or welding material to weld the plates simultaneously to each other and to the stiieners, and this open seam either faces upwardly in the natural relation of the parts or the parts can be turned to cause it to face upwardly, so that the molten material will flow into and fill it in the desired manner, with the stiffener damming the seam from below; and the parts meeting at the seam are either disposed in the same plane and substantially flush with each other, or by previous intentional shaping of the section of the parts at the meeting line can be .made to provide an angle substantially extents of the elements meeting at the seam lie :T233

at right angles to eachother. The saving in time and expense resulting from thus making all major seams of the ship capable of being welded by machine instead of compelling a great deal of hand-welding as in prior methods is most substantial, since welding machines on the order of the well-known Unionmelt machines are capable of welding the seams of ships plates at the rate of 140 feet per hour, while the best pro duction of skilled hand-Welders amounts to from zi 15 to 20 feet of seam per hour. A further saving derives from the fact that two, three, or even four elements extending in different directions can be welded together in a single operation and at a single traverse of the machine along the r seam, with completely adequate strength in the finished seam and without recourse to additional fillets welded into other angles of the plates joined at the seam with consequent need to turn over the structure successively into a variety of positions,

as heretofore.

The invention principles are also applicable in the building of drydocks, grain elevators, coal hoppers, and other structures formed of large metal plates where strength to resist deflection of the component plates at right angles to their extent is needed.

Other objects of the invention, and the manner of their attainment are as made plain hereinafter.

An illustrative embodiment of the invention is shown in the accompanying drawings in which- Fig. 1 is a perspective view of a vertical section of a portion of a ship embodying features of the invention.

Fig. 2 is a horizontal section on line 2-2 of Fig. 1.

Fig. 3 is an enlarged view of the triple-element welds shown at A and B in Fig. 1.

Fig. 4 is an enlarged view of the quadrupleelement weld shown at C in Fig. 1.

Fig. 5 shows on an enlarged scale one dualelement weld and one triple-element weld located and deck plate 3, is formed of the special plate having rectangular panels 5 pressed out from the plane of original extent of the sheet so as to form the smoothly rounded bulges or buckles 1 shown in section in Figs. 2 and 6, the marginal portions 9 as well as the areas II between adjacent bulges 1 in the same sheet being left at and therefore undisturbed in the original plane of the sheet. The panels 5 are narrower than they are long, and disposed with their length running crosswise of the plate in which they are formed, and for nearly its complete width; by making them narrower than their length there is provided an ample number of areas Il which act as ribs to prevent bending of the plate along its length. It will be understood that the customary fiat plates may be used in conjunction with the buckled plates insofar as is deemed preferable or necessary. Having a far greater inherent rigidity and resistance to bending than a flat sheet, the buckled plates are employed without the hitherto necessary use of stiffening or bracing elements within the area of the plates thus formed, such stifening means being applied only along the line of junction of two adjacent plates, except in rare instances. For example, plate I3 with its three dished or bulged panels is supported at its inward end adjacent the plate l5 by longitudinal beam l1, at its outward end by the lip I9, Figs. 1 and 5, of the Stringer plate 2l, at its front edge by transverse beam 23 and at its rearward edge by the vertical bulkhead 25 extending athwartship. Similarly, plate 21 with its three dished or bulged panels is supported at its inward end by side girder 29, at its outward end by the flange 32 of bottom shell 3| along the bilge, and at its forward and ait edges by two of the vertical floor plates 33 extending transversely of the ship at the junction-line of each successive pair of plates 21.

As shown, the side shell 35 and the topside plate 31, and the bottom shell 3| as well, are all made of buckled plates such as described, the concave surfaces of the bulges facing outward and being presented to the water. The oblique bilge portion of bottom shell 3l is also buckled, but the curved portion of side shell 35 adjacent the bilge has no bulge,

The shell plates 35 are arranged with their longest dimension in vertically extending relation with the length of their bulged panels running crosswise of the plates and lengthwise of the ship, and are supported at their upper edges by Stringer plates 2l, at their lower edges by the curved construction of the foot of the plates and flanged end-portion 32 of bottom she113l, at their rear edges by bulkheads 25, and, when no bulkhead occurs at the other vertical edge, as in Fig. l, by stifeners 39 of U-section. Deck plates 4l are of either small or large area as desired, and supported by longitudinal beams 43 and transverse beams 45 along their four edges, the hollows in their top surfaces being filled in with cement or other suitable material flush with the marginal portions Il to give a substantially level surface to the deck.

The principles and novel elements used in the improved construction lead directly to a further feature and advantage of the invention, namely the novel welded seam. It will be noted that the stifening of the plates by the bulges so that the plates need be supported only at their edges results in locating the butted seam joining any two adjacent plates exactly at the point where the plates are supported by a third element, a beam, a stiffener, a bulkhead, or a portion of the bottom shell, in practically all cases except Where the second deck plates meet the stringer plate 2i, the stiifening element usually bridging the seam. Further, this meeting of the two adjacent plates at the third or stiffening element enables the two plates to be spaced, and also shaped if necessary, at their adjacent edges so as to give access of the molten welding material and the heat to the third or stiffening element in the same operation by which the adjacent ends of the two plates are joined to each other. By this arrangement the two adjacent plates are joined to each other and also to the element which sup ports their meeting edges by a single welding operation. Thus, as shown in Fig. 3, bottom'shell plates 3| and 34 are joined to each other and to side girder 29 by a single welding operation of which the electrode material deposited in and lling the seam in molten condition is indicated at 4l, and tank top plates 21 and 28 are likewise joined to each other and to side girder 29 by the single deposit of welding material 49. Similarly, in Fig. 6, side shell plate 35 is joined to tank top plate 2l forming the inner bottom and to the ange 32 of bottom shell 3| by a single weld indicated at 5|. Actually, when good welding is performed, as with the machines referred to hereinbefore, the fusion and union of the three parts occurs throughout a zone beyond the actual deposit of metal indica-ted. by the blacked-in areas M, 49, 5|, such zone being roughly as indicated by the dotted lines 53 in Fig. 3, thus forming a joint having completely adequate strength to stand the strains and stresses to which the parts are subjected in use, its strength exceeding that of the plates being joined.

It is to be noted that all the welds thus provided for are made from one side only of the structure resulting from the joining of the parts involved in the seam, and that in al1 instances one of the parts can be placed in horizontal relation and yet the molten electrode material will flow vertically downward to ill the seam correctly and without iiaws. The important results of this achievement are, first, that the horizontal element forms a supporting surface on which the wheels of the welding machine can rest while the machine travels along the seam to effect the welding, the seam itself being used in some instances to guide the machine accurately; second, the parts, being joined by a single weld, do not have to be turned over after the rst weld as heretofore in order to make the second, third, or more welds hitherto required in making each seam when plates are joined by a butt strap; thus, parts meeting at a right angle, as tank top 28 and side girder 29, Fig. 3, do not have to be placed respectively at 45 angles to the vertical for the purpose of welding a fillet into the right angle between the two parts as heretofore, which operation incidentally compels resort to handwelding and excludes the welding machine because proper access of the machine to the joint is not provided for, and also no proper supporting surface for the machine is provided.

Thus. in prefabricating the parts of the ship shown in Fig. 1, bottom shell plates 3| and 34 will be placed in inverted and horizontal position with side girder 29 standing on edge beneath and supporting the meeting line of the two plates and with a space of 1/8 inch or so between the meeting edges of the two plates bridged by the flange on the edge of girder 29; the welding machine is then placed on the upward surfaces of plates 3| and 34 with its guide in the 1/8 inch space between the edges of the two plates and run down the seam, welding the three parts together; a similar operation is performed with the bottom plates 3| and 34 still in inverted relation, to join additional bottom plates to the forward and after ends of the original bottom plates 3| and 34, these transverse seams being supported by and welded to the transversely extending floor plates 33, the size of the section thus assembled being limited only by considerations of available space and the handling capacity of the cranes which will take the prefabrcated section out of the shop and set it up on the ways, or which will turn it over if fabricated at the ways. The structure thus partly assembled is then turned over, to bring it right-side up, and tank- top plates 21, 28, put in position with their meeting edges supported by and overlapping on the upper ange of side girder 29, such plates being in horizontal relation, and the welding machine then self-propelled along the space between the two plates to weld seam A. Thereafter additional plates to form the tank top are 'put in position with their rearward edges adjacent the frontward edges of plates 21 and 28, and supported by flanged upward edge 36 of floor plate 33, while spaced slightly from plates 2'! and 28 as described, and this seam then welded by the welding machine as before. The seams between these plates extending fore and aft and supported by side girder 29 are then welded to join these plates together and to the side girders, the construction of the prefabricated unit or section being carried as far as desired in a direction forwardly of the ship and either inwardly as far as the keel or clear across the bottom in the shop, and then transported to the ways where it is joined to other prefabricated sections chiefly by machine-welding opera-tions, hand-welding being resorted to only where the seams face downwardly or ob liquely so that the machine cannot be used.

Shell plates 35 are put together as far as convenient in the shop, two adjacent plates being laid on their inward sides with their outwardly facing surfaces disposed horizontally, and their meeting edges supported in slightlv spaced relation on the flange of a stiffener 39, in the relationship shown at the lower end of Fig. 2. and the welding machine then run along the horizontal surfaces adjacent the seam to weld together the two plates and the stiffener in a single operation. Next the topside plates 31 are placed horizontally in abutting relation to whatY will be the upper edges of the shell plates thus joined. together, being supported on the edge of Stringer plate 2|, and the shell plates, topside plates, and Stringer plate all joined together by a single weld formed by propelling the welding machine along the seam.

While in this horizontal position, the end of the outermost plate of a series of plates forming bulkhead 25 can if desired be joined to the shell plates as indicated in 2. In this instance. either the edge of the marginal portion 8 of such outermost plate of the bulkhead is introduced between and flush with the adjacent edges of two successive shell plates 35, which edges are beveled ol as indicated in Fig. 2, and the welding machine run twice alongthe to form at each operan tion a wedge-shaped weld 5l joining one side of marginal portion 9 to one plate 35, or this outermost plate is formed with a llanged edge such as occurs at 32 on bottom plates 3|, Fig. 6, or at the top and bottom edges of side girder 28, Fig.

3, the weld being made exactly as shown in either Fig. 3 or Fig. 6.

Bulkhead and other bulkheads throughout the ship so far as possible are made up of buckled plates laid down side by side in horizontal relation with their meeting edges spaced slightly apart and supported on one ange of stiffeners 53 of suitable section as for instance those shown at 43, and welded together and to the underlying stifleners while in horizontal relation through the use of the welding machine.

After this prefabricatecl section has been carried to the ways and set up in proper relation to the tank top section including plates 21, 28, and bottom shell 3|, the inwardly curved foot of shell plates is welded to the adjacent outward edge of plate 21 and to the ange 32 of the bottom shell while the latter supports the shell plates, by a single welding operation employing the machine, the parts then being in horizontal relation. It is noted that the foot of bulkhead 25 has a special offset edge portion formed thereon, While tank top plate 51 also has a substantially formed double-thick margin or ange 59. Thus, when the `prefabricated section just described and including tank top plates 21, 28, and bulkhead 25 is set up in the ways, additional tank top plates 51 admit of being added by the use of the welding machine, as shown in Fig. 4, since the seam between the foot of the bulkhead 25 and plate 51 opens upward, is supported on the flange of oor plate 33, and the novel olset in the foot of bulkhead 25 gives the machine access to the seam. Plates 21 also enter into the seam, and thus a new and improved 4-element weld is formed in a single machine welding operation.

In existing shipyards the facilities for handling prefabricated sections are limited, and it is found advisable to limit the length of the sections just described to the distance between the bulkheads of tankers, which is around 40 feet maximum extent; the novel seam used at the bulkhead, shown at C in Fig. 1 and again in Fig. 4, is specially adapted for effecting the union of one such section to the next by machine welding while the sections are right side up on the ways. In cargo vessels, where the bulkheads are from 80 to 100 feet apart, half this length will ordinarily be the limit of the sections. However, the use of rocking ways permitting the entire hull of a vessel tobe rolled from one side to the other for the purpose of owing the molten electrode material deposited by the welding machine into the seams by gravity after the manner described is within the scope and contemplation of the present invention.

The special plates and the special welds of the invention are used throughout the construction of the entire ship in analogous manner to the examples set forth, to enable most if not all of the seams to be made right-side up through the use of the welding machine so as to assemble the elements into prefabricated sections of the largest size convenient for handling, and with proper foresight the majority of the seams needed to join the prefabricated sections together are likewise arranged to come right-side up to permit the use of the welding machine, as in the case of the deck seams 6I, seams 63 joining the Stringer plate 2| to lower deck plate I3, seam 51, and seam joining the foot of the shell plates 35 to the tank top plates such as 21. This principle of construction is utilized throughout the ship with obvious great saving in time, labor, and weight of material involved and hence in the cost of construction of the ships built in accordance wtih the invention principles.

While I have illustrated and described certain forms in which the invention may be embodied, I am aware that many modifications may be made therein by any person skilled in the art, without departing from the scope of the invention as expressed in the claims. Therefore, I do not wish to be limited to the particular forms shown, or to the details of construction thereof, but

What I do claim is:

1. Metal plate construction having in combination a supporting member, two metal plates having their marginal portions extending along and supported on the edge of such member with the edges of the plates in abutting relation but spaced apart to give access through the seam between them to the edge of the supporting member, a third metal plate disposed along the seam at an angle to the plane of the two preceding metal plates having its edge adjacent the seam offset from the .plane of such plate,

and welding metal deposited through the seam on the edge of the supporting member and on the edges of the two preceding plates and the portion of the third plate adjacent the seam, uniting the four parts and lling the seam.

2. Metal plate construction having in combination two plates disposed edge to edge in spaced relation, a supporting member extending along and bridging with its edge-portion the .1 seam between the two plates, a third plate extending along and adjacent the seam and having its edge offset from the plane of such plate and disposed against one only of the two plates, and welding metal filling the seam and uniting all four parts.

3. Metal plate construction having in combination two plates disposed edge to edge in spaced relation, one thereof having a thickened edge and the other a plain edge, a supporting memben extending along and bridging the seam between the two plates, a third plate extending in a plane at an angle to one of the rstnamed two plates having a marginal portion bent out `of such plane and disposed against the plate having the plain edge and adjacent the seam, and welding metal in the seam uniting all four parts.

4. Ship yplate construction for bulk heads, tank tops, and the like, having in combination metal plates of a width ordinarily requiring added stiffening elements intermediate their width and having plane marginal portions abutting in a common plane and welded together by a single line-weld at their adjacent edges, and stiifening elements comprising plates disposed edgewise to the said plates and each having a marginal portion bent at right angles to the general plane of the intermediate portions thereof to form an extension at one side only of such plane, such elements being applied only along and with their marginal portions spanning the lines of junction of the plates and Welded by the single line-weld to both of the plates meeting along the said lines of junction, intermediate areas of the first-named plates being dished to render such areas self-supporting with elimination of the additional intermediate stiffem'ng elements ordinarily required in the use of flat plates of equivalent width.

REGINALD PAULSEN.

Images