US1933861A

US1933861A - Hull for ship construction

Info

Publication number: US1933861A
Application number: US425091A
Authority: US
Inventors: Kjekstad Johannes
Original assignee: Individual
Current assignee: Individual
Priority date: 1930-02-01
Filing date: 1930-02-01
Publication date: 1933-11-07
Anticipated expiration: 1950-11-07

Description

NOV. 7, 1933- J KJEKSTAD 1,933,861

HULL FOR SHIP CONSTRUCTION Filed Feb. l, 1930 2 Sheets-Sheet l BY @4; @07am/f ATTORNEY Nov. 7, 1933 J. KJEKSTAD HULL FOR SHIP CONSTRUCTION Filed Feb. l, 1950 2 Sheets-Sheet 2 INVENTOR .10H/W55 m/fwr/m.

BY v

www

ATTORNEY Patented Nov. 7, 1933 UNITEDISTATES Price PATENT 6 Claims.

In order to reduce the Weight of the hull for ship construction, for a given carrying capacity, and at the same time provide suiiicient strength to adequately resist the forces acting upon a hull 5 when a vessel is propelled through the Water, it has been proposed to construct the sides, bottom and deck of the hull from a plurality of members of channel shape in cross section running fore-and-aft and having the flanges of adjacent 10 members abutting and secured together, and it is to such a hull that my invention relates.

Heretofore, in constructing hulls from a plurality of members o f channel shape in cross section running fore-and-ait and having their flanges abutting and secured together, the web sections of the members making up the sides, bottom or deck of the hull, have been placed in a common plane. In such constructions, the neutral axis of the 1built up section forming the deck, side or bottom of the hull is in the same position relative to the extreme bers of the built up section as the neutral axis of the individual members making up the section. Therefore, the moment of inertia and the section modulus of the members combined in such built up sections remains the same as in the individual member acting alone. Thus, the ab-ility of the members to resist lateral forces acting thereon is the same in the built up section as in the individual menibers and the moment of inertia of the built up section is increased only in accordance with the increased sectional area.

By my invention, I am enabled to increase the k section modulus or" the members in the built up section forming the deck, side or bottom, over that of the individual member acting falone, thereby imparting greater strength to the hull or the same strength to a hull constructed from members of less Weight. I employ a construction in which the web section of the individual members are onset with respect to the web section of the members secured thereto. In conn structing the deck, side or bottom of the hull in this way, the neutral axis of the built up section 15 is shifted so that the moment of inertia of the members of the built up section is greater than the moment of inertia of the individual member acting alone. Consequently, the section modulus of the individual member in the built up section, 50 With respect to the neutral axis of the built up section and the resistance of the member to bending under the action of lateral forces, is increased.

Among the characteristics oi my invention, is the fact that I am enabled to avoid locked in stresses in Welding the individual members of the hull together.

An importantfeature of my invention is the fact that all of the joints between the individual members are lap joints and, therefore, may be caulked if desired.

Another advantage of my construction is the fact that the members are secured together in close proximity to the neutral axes Where the stresses are nominal.

A further advantage of my construction is the fact that there is ample material for the sides or bottom of the hull to yield Without rupturing in case of excessive straining.

Speciiically, I employ a construction for hulls for vessels in which the sides and bottom are constructed from a plurality of members of channel shape in cross section running ore-and-aft, having their flanges abutting, and secured together. The individual channel shape members are so arranged that the Web sections thereof are reversed with respect to the web sections of the members secured thereto on either side thereof. 1n arranging the members in this manner, the neutral axis of the built up section is midway of the distance between the planes containing the outer surfaces of tvvo succeeding channel shape members, and the moment of inertia of the members about this neutral axis is greater than the moment of inertia about the neutral axis of the individual member acting alone, thereby increasing the section modulus of the members combined to form the built up sections, and consequently their ability to resist lateral forces.

The deck of the hull is also made up of members of` channel shape in cross-section running foreand-aft with their flanges abutting and secured together. The individual members in the deck are not reversed with respect to each other but r are placed in stepped relation progressing. from the sides of the hull to the longitudinal center thereof, thereby offsetting the web section of each member with respect tothe members secured thereto and shifting the neutral axes of the deck, which increases the section modulus of the combined members and vtheir ability to resist v lateral' forces. The sides and bottom are'secured together by bilge members which are arcuate in cross-section and which may be formed from channel shape members by bending the Webs thereof arcuate in cross-section. The hull so formed is strengthened by deck, bottom and side web frame members which aresecured together and secured along one edge to the webs ofthe channel shape members forming the deck, sides and bottom of the hull respectively.

Bullrheads may be provided and made similar to the sides and bottom, the channel shaped members running transversely, longitudinally or vertically of the hull. Due to the inherent stitiness of these bulkheads, no additional stifening means is required. The end of the bulkheads are, of course, secured to the sides, the upper edge to the deck and the lower edge to the bottom of the hull.

Other features and advantages of my invention will be apparent from the following particular description of one embodiment thereof taken in connection with the accompanying drawings in which:

Fig, 1 is a plan of a barge embodying my invention;

2 is a longitudinal central section of the same; and V Fig. 3 is an enlarged transverse section thereof, taken on the irregular line 3 3 of Fig. 1.

In the drawings, I have illustrated my invention as applied to the barge 'which is divided into four compartments in which the cargo is carried. The sides l, bottom 2, and deck 3 of the hull are formed from a plurality yof members of channel shape in cross-section having their flanges 4 abutting and being secured together.

The channel shaped members making up the sides and bottom of the hull are reversed with respect to adjacent members. The ends of the flanges 4 of adjacent members overlap. The overlapping portion of the flanges of adjacent channel shaped members abut Vand are secured together, preferably by welding, although it is obvious that any other suitable securing means may be used. The overlapping of the ends of the franges 4 of the channel shape members constitute a lap joint, and in being welded together avoid the locked in stresses which are incident to the welding of a butt joint. In building up the sections in this manner, that is, by reversing the successive channel shape members, the neu-V tral axes of the built up section lies midway between surfaces of the web sections 5 of succeeding members. The neutral axes of an individual section is in close proximity to the web of the section. lTherefore, by reversing succeeding channel shape membersin this manner, the neutral axes is shifted so that the moment of inertia of the mem. ers combined to form the bottom and sides, is increased, thereby increasing the section modulus of the members and consequently, the ability ofthe material to withstand lateral forces.

The sides and bottom are secured together by bilge members which are shown as channel shape members with the web 6 thereof bent arcuate in cross-section, lthe iianges 7 of the bilge members being secured to the flanges of the adjacent bottom and side members. At spaced intervals longitudinally o the hull there are provided reinforcing cleats 8 for the bilge members. These cleats are secured at one end to the bilge member and at the other end to the adjacent bottom member. f

The deck 3 of the barge is also formed from a plurality of channel shapey members running fo1e'andaft and having their flanges abutting and secured together. The deck members are not, however, reversed with respect to adjacent members, but are stepped progressively from the sides toward the longitudinalcenter of the hull. This arrangement of the members also shifts the neutral axes of the built up sections `so as to increase the section modulus and the ability of the members in the built up section to resist lateral forces. Furthermore, the oi'setting of the webs of the succeeding members of the deck, presents the flanges of the members so as to forni a lap joint rather than a butt joint and its consequent advantages in welding the members together.

At spaced intervals along the hull, transverse frame members are provided. The transverse frame members consist of side, deck and bottom webs, 9, 10 and 11 respectively, which are secured along one edge to the web sections of the members of the sides, deck and bottom respectively and are secured together at their points of crossing. At the connection between web frame members, there is secured a triangular reinforcing ilange 12. I Along the inner edge of the web frames, there is secured a reinforcing bar 13.

On the deck along the edge of the hatches, there is provided a combing 14 which is also constructed from members of channel shape in crosssection. The combing is supported by brackets l5 secured at one end to the combing and at the other end to the deck 3.

The athwartship bulkheads 16, which divide the hull into compartments, are also formed from a plurality of members of channel shape in cross-v section, the members running transverse ofthe hull and being reversed relative to'adjacentmembers. The bulkheads arer secured along their upper edge to the deck and at their ends to the sides and along their lower edge to the bottom. Longitudinal bulkheads similarly constructed may also be provided.

The curved bow and stern of the hull may be constructed from overlapped steel plates or with channel members bent to the desired form.

If desired, bumper rails 17 may be provided and may be secured between the iianges of one or more of the channel shape members forming the sides.

In the construction shown in the drawings and described immediately above, the increased ability of the'material to withstand lateral forces may be utilized in reducing the weight of the channel shape members of which the hull is constructed and thereby decrease rthe weight of the hull for-a given carrying capacity. k

The effect of the reversing of the members in the side and bottom is to form substantially corrugated sides and bottom which provides suiiicient material to permit the sides or bottom to yield considerably before rupturing when subjected to excessive straining. `Furthermore, the

reversing of the members forming the bottom rey sults in the formation of a series of parallel keels which materially aid in stabilizing the vessel.

It is also to be noted that all of the joints between members in the deck, sides and bottom of the hull are lap joints and may be caulked if desired. i

It is obvious that various changes may be made in the illustrated embodiment above particularly described within the principle and scope of my invention as expressed in the appended claims.

I claim:

1. In a hull for ship construction, a deck constructed from a plurality of members of channel shape in cross-section running iore-and-aftV and having their flanges abutting and secured together, the web section of the channel shaped members being in stepped relation. v

2. In a hull for ship construction, a deck constructed from a plurality of members of channel shape in cross-section running fore-and-aft and roo having their ilanges abutting and secured t0- gether, the web section of the channel shaped members being in stepped relation progressively from the sides to the longitudinal center of the hull.

3. In a hull for ship construction, bottom, deck and sides constructed from a 'plurality of members of channel shape in cross-section and having their iianges abutting and secured together, the web sections of the channel shaped members forming the deck being in stepped relation, and the web sections of each of the members forming the sides and bottom being reversed with respect to the members secured thereto.

4. In a hull ior ship construction, bottom, deck, sides and bilge constructed from a plurality of members of channel shape in cross-section and having their flanges abutting and secured together, the web sections of the channel shaped members forming the deck being in stepped relation progressively from the sides to the longitudinal center of the hull, the Web sections of each of the side members being reversed With respect to the members secured thereto, and the Web section of the bilge member uniting the sides and bottom being bent arcuate in cross-section.

5. In a hull for ship construction, bottom, deck, sides and biige constructed from a plurality of members of channel shape in cross-section and having their flanges abutting and secured together, the web sections of the channel shaped members forming the deck being in stepped relation progressively from the sides to the longitudinal center of the hull, the Web sections of each of the side members being reversed with respect to the members secured thereto, the Web section of the bilge member uniting the sides and bottom being bent arcuate in cross-section, and transverse deck, bottom and side web frame members secured together and' along one edge to the Web sections of the channel shaped members.

6. In a hull for ship construction, bottom, deck, sides and bilge constructed from a plurality of members of channel shape in cross-section and having their flanges abutting and secured together, the web sections of the channel shaped members forming the deck being in stepped relation progressively from the sides to the longitudinal center of the hull, the Web sections of each of the side members being reversed With respect to the members secured thereto, the Web section of the bilge member uniting the sides and bottom being bent arcuate in cross-section, reinforcing cleats secured at one end to the bilge member adjacent the side of the hull and at the other end to the bottom channel shaped member to Which the flange of the bilge member is secured, and transverse deck, bottom and side Web frame members secured together and along one edge to the Web sections of the channel JOHANNES KJEKSTAD.