US1805669A

US1805669A - Metal boat construction

Info

Publication number: US1805669A
Application number: US298479A
Authority: US
Inventors: Liamin Dimitri
Original assignee: Individual
Current assignee: Individual
Priority date: 1928-07-17
Filing date: 1928-07-17
Publication date: 1931-05-19
Anticipated expiration: 1948-05-19

Description

May 19, 1931.

n; LIAMIN METAL BOAT CONSTRUCTION Filed July 17, 1928- l st-rented May id,

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racer eastern-season Application filled July 17,, serial l lo, 2%,4753.

This invention relates to the art of ship building and is more particularly a method.

( tion without the ordinarily employed cast- I secured to the keel ing and forging or hot bending o erations.

It is a particular object of this invention to develop a process whereby the members of a boat or ship may be placed in position to conform to the contour of a cubic parabola which has been found to be one of the most efficient forms of stream line construction. It will be understood however that boats may be constructed by this process having any desired shape of stream line such construction being; dependent entirely upon the design of the vessel.

It is a further object of this invention to develop a process in which the fabrication of the boat is done entirely by welding, there being no rolling or stamping oi the shell plates. These members are cut in sections and are applied directly by pressure against cell'sin the frame work which are formed by a system of transverse and longitudinal rib members, such members being secured to one another and the transverse members being by means of welding. The longitudinal rib members are cold bent about the transverse rib members and are preferably received by suitably formed recesses in the last mentioned members.

It will be understood that the process has a further object of greatly decreasing the cost of boat construction since the forging or rolling or stamping operations are eliminated, and the placement of rivet holes and the riveting of the respective parts which is a large factor in the expense of boat construction, are also veliminated.

Other objects and advanta es in this method of boat construction w ll- -be better onstrating the manner understood from the followin description ofan illustrative embodiment o a vessel constructed by this method as shown in the accompanying drawings, in which Fig, 1 illustrates the bed as may be constructed by the herein described process.

Fig; 2 is a plan View illustrating the frame work of a boatrsuch as may be constructed by the Process herein described.

F 1g. 3 is a sectional elevation taken sub- 7 stantially in a 3- in Fig. 2.

Fig. 4 is an enlarged perspective view plane represented by the line showing a portion of the frame work of a 69 boat such as is illustrated in Fig. l and dQllQ-r of arranging and placing the respective parts or sections Fig. 5 is an enlarged sectional view which 1 may be considered as having been'talren sub stantially in va plane by the line 5-5 in Fl a dis an enlarged sectional view which may be considered as having been taken in a plane indicated by the line 6-43 in Fig. 4.

Fig. 7 is a plan view illustrating'a preferred manner of forming the transverse rib members, i

More particularly describing the invention,

as herein illustrated reference numeral 11 indicates a metal boat of the type herein described which has a lreel l2 and side plating 13. It will be understoodwhile this invention s described in connection with a small craft that it is not confined to any particularsize so or type of vessel and although in the vessel herein described the keel 12 is illustrated as supporting directly the transverse ribs indicated by reference numeral 14, these ribs may; in a larger type of vessel be secured to as the keelsons.

' The ribs 14 may be formed in any desired manner and it will be understood that their curvature and strength are determined by the design of the vessel. I have found in the w) y of a boat such de'velopment of this method that most satisfactory results are economically obtained by using substantially flat metal bars which may be bent upon a bendin floor to conform to pattern or design which is laid out by the formed, they are er of the vessel, is marked out upon the at metalsheet 14, such marking being indicated b reference numeral 15, and the transverse llbS 14 are cut therefrom by means of an acetylene torch or any other suitable cutting mechanism commonly known to those familiar with the art." I

After the transverse members have been provided with a series of notches indicated y reference numeral 16, the 'tion of such notches being also calculat by the designer of thevessel and being arranged in alignment throughout the length of the transverse ribs. i

The transverse ribs are then placed in po-' sition upon the keel as indicated in the perspective view shown'in Fi 4 and are secured to the keel which may' be in a form of united channel irons or an I beam, by means of welding such welding being indicated by reference numeral 18 on Fi 4.

After the transverse r bs have been placed in position, the longitudinal ribs 19 are at-v tac thereto by taking substantially straight and flat metal bars, welding one end of such bars toone of the end transverse members such as is indicated at 20in Fig. 2, and by means of a Windlass or by any other suitable power applying means, these bars,

formin the longitudinal members are bent throu out the respective positions illustrat-' ed in otted lines of'Fig. 2,.to be received by the reocesses 16in the transverse ribs and to conform thereby to the designed outline or profile of the vessel.

It will be understood that in bending these longitudinal ribs, it is preferable to weld the bar pro 'vely to each transverse member as t e longitudinal bar 'is'brought into gement with the mentioned recess.

t will be understood by those familiar with the art, that metal such as steel, which is cold bent, during such a bending opera- 'tion a substantially cubic parabola, the dimensions or outlines of which are dependent .u n the magnitude of the bending moment,

cross sectional area of the barand its bending or elastic strength. It will therefore be apparent to those familiar with the action of metal under such. a strain, that themetal which is bent in this manner tends to develop surface correspondin a cubic parabola which represents one o the closest approaches to a -s0-ca'lled idealv stream' line curvature.

I eliminates the 11: mm of artificial or hot bendin "which is costly fromthe' standpoint of la r and requires skill much greater than demanded in the It is a comparatively simple matter to out- I line from these sections or to calculate in the design ofthe vessel the pattern or form necessary to obtain .a uniform covering of such a section from a substantially flat metal plate and from these patterns the mentioned plates are laid off and cut from sheets of metal plating. The plate sections 21, 21', so out,

are attached to the rib members by means of welding. In such an attachment one edge of the plate is welded to one of the. rib members and the plate is then bent to 'conform'to the curvature of the outline of the frame work by means of a plurality of C clamps, such as are indi cated at 22 in Fig. 4.

The plate 21 is illustrated as having been placed in position and the plate 21 being eld in'place preparatory to the welding operation, it clamps which press the plate to the longitudinal and transverse; rib members exercise a double bending moment around the horizontal and vertlcal axes of the plate and owing to the elasticity of the metal,- the platerec'eives a double deflection.

The horizontal deflection is guided by the run of the longitudinal ribs and the vertical. deflection depends upon the thickness of the plate and-the magnitude of the curvature of these ribs at the point at which the plate is bein applied.

The rst factor may be considered as being a constant and the second one as a variable w1ll be understood that the C stream line curvature. The magnitude of the vertical deflection should not trespass the contractional limit of the elasticity of the metal, surpassing which the metal would tend to corrugate or buckle. This limit as was mentioned above is guided by the curvature of the vessel at the point at which the plate is to be applied, audit will be understood that the'exact area to which each plate must conform in order to define a certaincu'rvawere; readily calculated and'by means of such calculations, members ma which will) a maximum area.

be arranged to form spaces 't the use of plates having :1

Such calculations are howevera' matter of the ship design which will the intersecting rib asoaeea corpugation (l) (D /2+ i 0=d (2 swede-sesame b=vertical width of plate I Z=horizontal length of plate D=maximum horizontal deflection 0 plate d=maximuni vertical deflection of plate t=thickness of plate G=constant dependent upon the elasticity of the plate material The length L may represent either one or a plurality of spans between the transverse frames. The thickness of the plates 25 is determined in accordance with Lloyds Regulations. The maximum longitudinal defiection D for the assumed length of plate L is determined from the boat oil'sets what ever the design may be. The constant ,C is calculated from the following equation:

0 .75 "EX it in which:

Y=yield point of the metal used E=coeiiicient ofielasticity of the metal maximum allowable stress ultimate strength After the values of L, D and C have been determined, the value of (i may be calculated by substitution in Equation 1. From the value of 03 thus computed the value of b is found from table of the boat offset, whatever the design may be. I

Formula 2 is used to check the validity of the above obtained values with reference to the thickness of the particular plate section being used. The minimum allowable thickness 25 may be obtained from any standard hand book such as Lloyds or the United States, Shipping Bureau Regulations. In

case the values of d and 25 found from Equation 1 do not satisfy Equation 2, the assumed length L must be taken shorter by one or more spans between the transverse frames so that the new values of d and b will satisfy Equation 2.

In-the usual practice of my invention I employ a few mainlongitudinals running the entire length of the ship. If the value ,b found-from the value of d calculated from Equation 1 cell, or-area between longitudinalsand ribs at one section, is found to,be less than the above,, for any particular l distance between the main longitudinals at this point, one or more supplementary longitudinals must be positioned between the main longitudinals to bring the area of the cell down to a point at which the desired curvature can be obtained without buckling or corrugating the plates.

In welding the plates to the mentioned rib members, it will be understood that the plates are provided with a dual Weld such as is indicated in Figs, 5 and 6, in which the plates indicated by

reference numerals

21 and 21,

are illustrated as being welded to the transverse ribs 13 at the points indicated by reference numeral 23 and the edge of each plate is attached to an adjoining plate and to the transverse rib by a second weld indicated by reference numeral 24. In a like manner the

plates

21 and 21" are attached to the longitudinal ribs 19 by the welding indicated at 25 and the edges of these adjoining plates are attached to each other and to the longitudinal ribs by means of a center weld 24.

It will be understood that while I have herein described this process as applied to one particular form of small craft, the di-.

mensions and arrangement of .the members described one application of this method, the same is not limited to the specific illustration, but includes Within its scope such adapmay of course be varied depending upon the design and size of the vessel, and while I have transverse ribs by cutting such ribs from substantially flat plates; providing said transverse ribs with aligned recesses; welding saidribs in spaced relation with eachother to a keel; placing longitudinal ribs upon said transverse ribs by cold bending substantiallystraight metal bars into said aligned recesses and welding thereto to form a frame work; and plating said frame work by cold pressing fiat metal plate sections into engagement with said ribs and welding said plate sections 7 to said ribs, said transverse ribs and said longitudinal ribs being so positioned that the plates may be cold bent into engagement therewith without buckling.

2. A method of constructing metal boats which includes: the formation of curved transverse ribs by cutting such ribs from substantially flat plates; providing said transverse ribs with aligned recesses; welding said ribs inspaced relation with each other to a heel; placin longitudinal ribs upon said transverse ri s by cold bending substantially straight metal bars into said aligned recesses and welding thereto to form a frame work; and plating said frame work by cold pressingfiat metal plate sections into engagement with said ribs and welding said plate sections plates may be co d-bent into engagement therewith without buckling.

3. A method of constructing metal boats which includes: providin transverse ribs with aligned recesses; wel ing said ribs to a a m keel in spaced relation with each other;

mountin longitudinal ribs upon said transverse ri s b co'ld bending substantially straight meta bars into said aligned recesses and welding thereto to form a frame work; 15 and platin said frame work by pressing substantially at metal plate sect ons into engagement with said ribs and welding the, edges of said plate sections to said ribs, said transverse ribs and said longitudinal ribs 90 being so positioned that the plates may be cold bent into engagement therewith without buckling. I 4. A met 0d of constructing metal boatswhich includes: providin transverse ribs as with aligned recesses; wel ing said ribs to a keel in' spaced relation with each other; mountin longitudinal ribs upon said transverse ri s' by cold bendin substantially straight metal bars into sai aligned recess I so and welding thereto to form a frame work;

and platin said frame .work by pressing substantia y flat metal late sections into engagement with said ribs and welding the edges of-said plate sections to said ribs, and 85 to theedges of adjacent plate sections, said transverse ribs and said longitudinal ribs being so positioned that the plates may be cold bent into engagement therewith with out buckling. v o 5. A met 0d of constructing metal boats I which com rises: building a framework consisting o a plurality of transverse and longitudinal ribs, arranged to'form a plurality of cell spaces; cold bending flat metal p ate sections into positions such that the ed es of said plate-sections enga e the ribs do 'ng said cells;and attachingt eedges of said plates to said ribs, the'area of said plates being such that the vertical deflection of said "50 plates resulti'rzfi from said cold-bending doesnot trespass e contractional limit of the elasticity of the metal.

In testimony whereof, I have hereunto set my hand at Los Angeles, California, this 9th 55 day of July, 1928.

. I DIMITRI LIAMIN.