US2419218A - Construction of metal vessels - Google Patents

Description

April 22, 1947. 'N. c. JANNSEN 2,4

' CONSTRUCTION OF METAL VESSELS Filed March 29, 1943 43 NEW A/ 0. JAN/VSEN rllrllilull' Fm. 7 BY 0mg A. TTORNEYS Patented Apr. 22,1947 a T YUNITED STATES PATENT. OFFICE Newman 0. Jannsen, Seattle. Wash.

Application March 29, 1943, Serial No. 480,897

The present invention relates to the construction of metal vessels and more particularly appliesto the construction of welded steel ships.

In the prior art of welded ships, construction practices have been much the same as for riveted vessels. The usual welding practice has been to abut or overlap continuous shell plates as in the prior riveting art, and then to secure them by welding instead of riveting. Such practice results in stresses due to the temperatures created during welding as Well as the technique involved in welding and is well known in the art. This also means that the transfer of stresses throughout the shell from plate to plate is through a welded joint which may already have internal stresses due to the welding, and which stresses may be largely concentrated at a single point or section of the weld without chance for distribution along a considerable portion of the joint.

Any increase in the flexibilit of the welded plating joints without a corresponding decrease in the strength thereof, will mean a decrease in the unit stresses on the welds and an increase in the overall strength of the vessel and its shell.

I Having in mind these and other defects of the prior art, it is an object of the present invention to provide increased flexibility in the connections between the plates of a vessel in order to prevent the localizing of stresses at the joints.

It is another object of the invention to increase the flexibility of a vessel without reducing the strength thereof.

A further object of the invention is the reduction of internal stresses usual in a welded shell.

A further object of the present invention is the provision of a construction which will allow dampening of vibration in and sudden shocks to the shell of a vessel.

Still another object of the invention is the provision of numerous transverse and longitudinal resilient bridging members formed integral with and between portions of the shell plating of a vessel.

Yet another object of the present invention is the provision, in the shell of a vessel, of an offset bridging member for resiliently connecting together portions thereof.

The foregoing objects and others pertinent thereto, are accomplished according to the practices set forth hereinafter.

' In a preferred embodiment of the invention a ship's plating is divided into spaced apart sections and the sections are joined together by meansofresilient offset bridge members which maytake the form of a troughhaving one leg 1 Claim. (Cl. 114-79) secured therealong to one of two adjacent sections and the other leg secured therealong to the other section. In the use of this trough member transversely of a ship, the open part of the trough is faced outwardly and the opening filled with a suitable closure element such as a mastic or bitumastic. If the trough is placed longitudinally of the ship between strakes of the plating, the trough may be closed by the use of a corresponding mating trough with the two openings in opposition, thus forming a closed tubular member separating and joining adjacent strake sections, a tubular member being no more than two resilient troughs joined along their edges.

The novel features that I consider character istic of my invention are set forth with particularity in the appended claim. The invention itself, however, both as to its organization and its method of operation, will best be understood from the following description of a specific embodiment when read in connection with the accompanying drawings, in which I Figure 1 is a side perspective view of a vessel constructed, according to the principles of my invention;

Figure 2 is a transverse sectional view through a vessel having my invention incorporated therein;

Figure 3 is a vertical fragmentary sectional perspective View taken on line 33 of Figure 1;

Figure 4 is a horizontal sectional view taken on line 44 of Figure 1;

Figure 5 is a fragmentary perspective view of a modified form of the invention; and

Figures 6 and 7 are cross-sectional views taken in planes similar to the showing of Figure 4, but illustrating modified embodiments of the invention.

A system of ship construction, to overcome the defects hereinbefore enumerated, must have at least two totally distinct characteristics: it must be capable of increasing the flexibility of the vessel throughout its mass as well as throughout the joints between adjoining sub-sections; and it also must permit the distribution of stresses throughout the vessel while preventing their undesirable localization at joints and seams in the shell plating. Accordingly, a preferred embodiment of my invention, referring to Figures 1 and 2, is constituted by a vessel in the framing of which is incorporated resilient members which bridge adjacent sections of shell plate while at the same time connecting the same together.

The vessel comprises the usual keel lllthat extends longitudinally of the vessel and rises on its bow end at the forefoot to merge into the stem l2. At the rear of the vessel, the keel joins the counter and skeg in the conventional manner. On either side of the keel and extending laterally of the vessel throughout its length in spaced apart relationship are the frames is which structurally stifien and transversely form the vessel. The usual longitudinals and inner bottom'plating may be employed but are here omitted for convenience of illustration. Beams areindicated at IE, IS between the upper portions of the opposed ribs and, of course, suitable plating or planking will normally be employed to form the decks 11, I8 on the respective beams. A deck house is indicated at 2B and interiorly the vessel may be divided as desired into compartments or tanks.

Externally the vessel frame is enclosed by the usual shell plates which cover the entire framingv structure. The plating of the vessel is divided longitudinally of the shell into a plurality of disjoined strake sections; that, is, disjoined in distinction to usual mode of construction wherein the many plates from the keel to the bulwark are each joined to the next adjacent plate of series into a solid plating for the frame.

Longitudinal resilient members 22 are associated with the frame and run from stem to stern as shown in Figure 1. In this specific showing the members 22 comprise tubes that are secured to the frames wherever they cross the same and it is my experience that they may best be notched into the frames for secure joinder by welding.

As can best be seen in Figure 2, the plating rising on either side of the keel is divided into a plurality of strakes longitudinally of the vessel. These sections are designated by the reference numerals 24, 2B, 28 and 30. In pairs, adjoining strakes are welded to the opposed sides of the various lon itudinal members. For example, plates 28 and 30, as shown in the fragmentary perspective view of Figure 3, are butt welded along their edges to one of the resilient longitudinal members here designated 22A. Similarly, other longitudinal strake sections in pairs are spaced apart from each yet joined to those adjacent by the resilient longitudinal tubes.

At certain spaced intervals along the length of the ship I also provide transverse resilient frames 32 such as shown in Figure 4. These rib frames describe the curve of a transverse section of the boat similar to the adjoining frames M and extend from the keel to the bulwark of the vessel. In cross-section the resilient frames are U--shaped with the legs thereof directed outward of the vessel and with the body lying, preferably, within the skin of the hull. Note that the legs 33 of frame 32 are shown somewhat thicker than the web 3d and that said legs are tapered slightly across their ends in accord with pre-welding practices.

The plates of any of the various strake sections of the skin of the vessel are divided into a plurality of adjacent but disjoined sections in accordance with the number of resilient frames 32 that are incorporated in the hull frame. In Figure 4 two of these plate sections are fragmentarily shown and marked for reference as 35 and 33. The inner face of each such section, slightly back from the edge, is joined by welding to a taperfaced leg 33 of a resilient frame member 32. The abutted edges of such an adjoining pair of plate sections are spaced apart slightly to permit flexing of the plates relative to each other through the instrumentality of the bridging effect of the frame. It will be recognized that each frame 32 forms an. offset bridge for such a joint and permits the relative movement of adjacent sections and the consequent distribution of the stresses of the structure more evenly throughout the whole hull--more than is customary with rigidly joined sections of a vessel.

In'the specific showing of Figure 4, the gap between the edges of plates 36, 38 is closed by suitable resilient calking 40 to seal the joint. The hollow interior of the frame is filled with a resilient filler material 42 which may comprise a plastic, asphalt, bitumastic or other similar mastic or plastic sub-stances. In this arrangement when the plates of adjoining sections move relative to each other, a deflection of the frame 32 will occur and the change in shape is accommodated by a flexing of the filler. Similarly, the calking strip w flexes as the plates edges move together or ,of metal and is formed in such dimensions that the inner head of the T bar overlaps the inner edges of the opposed plate edges of adjoining sections. The fillet of the T bar shifts slightly with movement of the sections and at the same time seals the gap.

In certain installations of this invention, it is desirable to construct the entire hull with the plates attached and the sections thereof resiliently joined around their peripheries to permit the distribution of the stresses produced during fa rication, and then subsequently to inflexibly join these sections when the stresses have been relieved. Such a procedure is illustrated in Figure 6, wherein the gap between plates 31 and 39 is closed by a bead of welding running with the joint thus transferring the load initially carried by the resilient member 68 to the plating itself between adjoining sections thereof.

The plates at, 48 of adjoining sections, as shown in Figure 7, may be overlapped in offset relation so that relative flexing can be accommodated by greater or lesser overlapping. Normally the outer lapped plate 45 of the pair is chamfered on its edge to reduce the skin friction that such an arrangement would present to the water.

From this description it can be seen and understood that the hull of a vessel is divided into a plurality of spaced apart plating sections, adjoining pairs of which are secured together by means of a resilient oifset bridge member 22 or 32. The vessel may be only subdivided into superimposed longitudinal strake sections or sequential sections longitudinally of the vessel, or, on the other hand, combinations of both sections may be employed.

The longitudinally extending resilient bridge member 22 is here shown as a tube, but it will be apparent that that the U-shape of the ribs can equally well be employed. I prefer to use the tube lengthwise of the vessel as it is simple to incorporate in the structure and not only does not interfere with the forward movement of the ship, but also will serve as a supplemental keel if that be desired. Conversely, the tubular construction of the resilient member may, as well, be used vertically where skin friction can be neglected as a factor in the operation of the ship, it being apparent, of course, that the protruding half of the tubular member would offer certain resistance to a body of water through which the vessel may move. Each type of resilient member, in its basic concept, is substantially the equivalent of the other, since each includes an offset bridge portion disposed between adjoining shell plate sections of the vessel. The mere addition of an opposed offset member in the case of the tubular form of the resilient member does not fundamentally alter the function of the tube in the distribution of flexing stresses of the vessel.

From the foregoing it will be seen that ships can be constructed by the use of welding practices with a resultant resiliency that will prevent the concentration of stresses at a single point or section of the welded steel plate and will permit the distribution of such stresses along a considerable portion of the vessel. Such a vessel will have increased flexibility without sacrifice of strength and there will also be a decrease of the unit stresses on the welds while at the same time an increase of the overall strength of the hull. The principles herein taught may easily be incorporated in a vessel without material change in the current shipbuilding practices and, in any specific undertaking, all that need be done to employ the invention is to calculate the pattern of subdivision of the structure into sections and their joinder by the preferred form of bridge member, size and shape being governed by conventional engineering practices.

Although I have shown and described certain specific embodiments of my invention, 1 am fully aware that many modifications thereof are possible. My invention, therefore, is not to be restricted except insofar as is necessitated by the spirit of the appended claim.

I claim:

A ship, comprising: a plurality of plate sections disjoined transversely and longitudinally of the vessel, open U-shaped troughs arranged transversely between said plate sections to join together the transverse edges of said sections by welding an edge of one section to one leg of the trough and an opposed edge of the adjacent section to the opposed leg of said trough, said trough being placed interiorly of the said ship and directed outwardly thereof, and a tubular member arranged longitudinally of said ship between opposed longitudinal edges of adjacent strake sections and having opposite sides thereof welded therealong to the opposed edges of said adjacent strake sections.

NEWMAN C. JANNSEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,807,714; Taylor June 2, 1931 1,810,097 Wheeler June 16, 1931 2,246,579 EWertz June 24, 1941 1,882,580 Harris Oct. 11, 1932 FOREIGN PATENTS Number Country Date 316,751 British Aug. 8, 1929 32,657 Norwegian July 11, 1921 149,220 British Oct. 12, 1921

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