US1342408A - Alfredo carlo jaztni - Google Patents

Description

A. c. JANNI? f REINFORCED-CONCRETE.VESSEL AND METHOD 0F BULDING THE SAME. APPLICATION F|| .ED MAR. 21,1918.

Patented June 1, 1920.

UNITED STATES TENT OFFICE..

ALFREDO CARLO JANNI, OF NEW YORK, N. Y.

Application filed March 21, '1918.

T 0 all 4whom t may Concern.'

Be it known that I, ALFREDO CARLO JANNI,

a subject of the King of Italy, residing at N ew York, in the State of New York, have invented a certain Reinforced-Concrete Vessel and Method of Building the Same, of which the following is a full, clear, and exact description, such as will enable others skilled in the art to make and use the same.

.a My invention consists in the method and in the construction and arrangement of parts hereinafter described and particularly pointed out in the claims. In describing the various arrangements employed and shown in the drawings hereto attached and described in the specification I do not limit my invention to the precise mode, manner, form or construction of vessel shown, or the several parts thereto, inasmuch as various alterations may be made without changing the scope of my invention.

In the drawings, Figure 1 is a side view of my vessel with sections broken out to illustrate the frame work; Fig. 2 is a half crosssection of a midsliip portion looking at a bulkhead, partly broken out to illustrate the reinforcing thereof; and Fig. 3 is a crosssection through one of the diagonals of the truss showing a truss member and slabs.

In the drawings, the numeral 4 designates the keelson, 5 and 6 the side keelsons and bilge stringer respectively, 7 the bottom truss chord element, 8 the longitudinal lower deck beam, 9 the upper truss chord element, 10 the upper deck, 11 the main deck, 12 the lower deck, 13 the cross beams, 14 collision bulkheads, 15 complete bulkheads, 16 stiening frame, 17 transverse deck beams, 18 stem, 19 rudder frame, and 20 longitudinal bottom reinforcing members. Where vessels are of smallsize, it is not necessary to use stress members or bridging upon the bottom of the vessel, but in large vessels such construction may be found of great benefit. 21 designates truss, stress or bridging members forming a truss extending longitudinally on either side of the vessel. This truss, it will be noted, extends substantially the whole length of the ship, in a substantially vertical plane. Two of these trusses are used, being respectively placed along the sides of the vessel, and extending, in a vertical direction, between the lower chord 7 and upper chord 9, Fig. 2. While I have shown for the purpose of illustration, these mem- Speccaton of Letters Patent.

Patented Julie 1, 1920.

serial No. 223,742.

bers in lattice or checkered arrangement, it is obvious that other forms of trusses may be used. 22 designates longitudinal deck beams; 23 reinforcing bars as may be used in the various truss members, either for the sides, bottom or decks of the vessel. 24 designates connecting stirrups; 25 bonding stirrups that extend from one slab 27 to the other and are bent over the reinforcements 31 to be anchored in place; and 26 bonding wires or stirrups that are bent around the reinforcements 23 and that are bent over the stirrups which I prefer to use in supporting the plates, slabs or sections 27 to the truss or frame members 21. The stirrups 24 extend about the reinforcing bars 23 and thence out of the truss members 2l to become a part of the reinforcing in the plates 27 that form the plating or skin of the vessel. rThe bonding wires 26 likewise extend about the reinforcing bars 23 and are turned about the reinforcing wires 25 that lie buried in the plating or slabs. The arrangement of bars, wires and stirrups may be changed to conform to the particular requirement of vessels using my invention. The truss member 21 and the plates overlying such member are preferably capable of certain limited movements with each other. The slabs 27 consist of cement or concrete with wires or reinforcing bars embedded therein shown at-37 and preferably bonding wires or reinforcing extending through from one slab to another as indicated at 25. The shape of these slabs may be varied, but I prefer to use slabs of rectangular form. The plates, slabs or sections 27 preferably have their abutting margins overlying the truss or frame members as shown in Fig. 3, but, if desired, the abutting margins need not be madeso as to overlie truss or frame members. That is to say, the slabs 27 may be made somewhat smaller, and of a size to fit in the spaces 21', whereby the outer faces of the slabs 27 will be flush with the other faces of the truss diagonals 21.` rIhere is, however, an advantage in having the abutting margins of the plates overlying the truss or frame members, in that leakage is materially reduced thereby. 2S designates a calking channel located between adjacent plates and 29 is an open seam between such plates to the calkthe drawing, it is obvious that any aperture left between the plates and extending part Way therethrough, Which is capable of receiving and holding calking, Will accomplish the purpose desired. lhere desired, the recess between abutting plates, after the calking has been put in, may be closed or sealed by cement or other closure. 31 desig' I nates small bars in the plates 27; 32 continues outer marginal reinforces in bulkhead; 33 continues inner marginal reinforces in bulkhead; 3l diagonal. corner reinforces in bulkhead; 35 the ribs, and 36 the diaphragm of the bulkhead.

Concrete vessels have been constructed in two different Ways, either in the manner of Wooden and steel vessels, or being' builtl upside down and being turned over in launching. When building my vessel in the manner steel vessels are built, I prefer to construct the plating or skin and thereafter construct the frame Work or skeleton therein, but when building a vessel upside doivn, it is believed to be more economical to construct the frame Work or skeleton and upon it place the plates or skin. y

In steel ship construction, vert-ical steel frames are used With steel plating and the shearing stresses to which such vessels are subjected are transmit-ted by the steel. plates stiiiened by the if "amc, lllhen, however, reinforced concrete is used in the construction of a vessel a'dilliculty arises owing to the .fact that on account of the thinness of the concrete skin of the vessel, it is unable to stand the enormous amount of shear to which the vessel .is almost continuously subjected in service. Concrete cannot be depended upon in tension, on account of eventual cracks which might appear even during the construction and do appear when a concreto vessel of the type heretofore constructed is subjected to the ordinary shearing stresses cncountered in actual service. Such cracks, aside from causing leakage into the ships, permit the sea-Water to reach and attack the reinforcing steel, which, if not galvanized., rapidly expands as a consequence of rusting and so breaks the concrete. Moreover, if the ship has not been properly designed as to the arrangements of its structural units, these cracks gradually expand as a result of torsional and shearinr stresses. Therefore, concrete in tension cannot be relied upon, but all chances for cracks must be eliminated. The important points to be remembered in building reinforced concrete vessels are l. The Working stresses of the concrete should be so low that the alternating stresses do not fatigue the material and the Working stresses of the steel are determined as a consequence of those in the concrete so that the two materials may act together;

2. The structural members should in general be preferably of such a geometrical shape that shear, at least in all vital points of the ship, is eliminated and substantially axial compression and tension substituted therefor; I

3. The hull should be so constructed as to eliminate all cause of accidental cracks, shrinkage and the like; and

4:. The hull should be so designed that eventual cracks may be easily repaired.

In a ship, the stresses are subject to a great number of repetitions and in Vmost cases to a reversal also. Repetition of stresses is of minor importance, While the reversal of stresses is of major importance as aifecting the crushing strength of concrete.

In order to relieve the skin of the vessel from these internal strains I have devised the hull of the vessel composed of a skeleton of truss construction, designed in such a Way that substantially the entire shear, at any point of the vessel, is taken up by the mem.- bers of the truss skeleton, falling in that point, and substituted by substantially actual axial tension and compression along said elements; and by a slab connected to this skeleton in such a manner that it cannot Work but in compression and tension, according to the elements of the truss with Which it is connected; besides its withstanding the hydrostatic pressure.

Since this shear in a floating vessel may .occur also, on account of rolling, when the position of its decks is not horizontal 'the system of truss construction in many cases should he extended to the bottom of the vessel as Well as to one or more decks.

By means of the top and bottoni chord members, the system of diagonals of the truss transmit their loads to a deck and bottom of the ship, which latter preferably are in turn part of the chord members.

It will be seen from F ig. l, showing the longitudinal section of the ship, that shearing stresses in the concrete are practically eliminated and that the shear occurring in the ship as a Whole is transformed into substantially axial compression and tension in structural members specially designed for that purpose.

The system of framing, which assists the hydrostatic pressure against the bottom of the ship, transmits its load chiefly to the two main side trusses.

In a ship of large size the arrangement of trusses shown With diagonals may be used on the bottom of the hull as Well as to the decks, as shown in Fig. 2 of thedrawings.

The longitudinal trusses preferably have for the upper and lower chords a deck and the bottom of the vessel; and bulkheads may be provided to obtain additional reinforcement of such trusses. In Fig. 2 I have shown the decking and bulkheads integrally east with the truss members or skeleton. Where a vessel will not be subjected to the stresses which ocean going vessels may meet with, it may be found desirable to cast the decks or bulkheads separately from the truss members or skeleton.

The slabs or plates which constitute the skin of the hull are not relied upon to assist any of the principal stresses of the ship but are designed merely to withstand the hydrostatic pressure and their reinforcement is preferably laid in two ways parallel to the diagonal of the main truss. In constructing the slabs or plates, I prefer to embed wires, shown at 25, in abutting plates, which wires may also be passed about a frame or truss member. These wires or reinforces permit a limited movement of the plates relative to each other or to the frame. It Ishould be noted that the sides of the vessel are non-monolithic; that is to say, there is no cementitious connection between the slabs and the truss elements 2l. The slabs are connected to the truss elements by metallic reinforcing elements only. Such a connection, while nearly rigid, is not quite rigid, due to the fact that the steel is more bendable and elastic than the concrete. There is then possible a very small relative movement between the slabs and the truss elements, that is taken up-by a small deformation of the mentioned metallic reinforcing connections. I have not shown slabs used for that portion of the siding of the vessel above the upper deck because the amount of leakage would be negligible through cracks in a monolithic construction for such portion of the vessel. If desired, however, a similar arrangement of skeleton and slabs may be used there.

It is obvious that the slabs may be cast at a distance from the skeleton and thereafter attached to the frame work in any suitable manner. I prefer, however, to cast these slabs upon the skeleton itself and to cast the plates in such manner that a plate shall have contracted before a plate abutting same is cast. Plates may be cast on the frame work next to plates which were cast at a distance and later attached to the frame. In view of the fact that the skin of the vessel is formed of a number of separately formed concrete slabs, it is apparent that a crack originating in any one slab is strictly confined to that slab, and would not progress beyond that slab' to weaken that part of the vessel, a disadvantage that is present in a monolithic structure.

Furthermore, a cracked slab may be readily broken out and a new one inserted, or cast in place. This ease of repair is an important advantage arising from the nonmonolithic design. In the preferred arrangement of plates, it is thus seen that the bottom row of plates may be cast at one time, then when they have contracted the neXt row of plates may be cast, and so on until the uppermost row of plates shall be cast.

The bulkheads are of reinforced concrete having marginal portions preferably integral with a deck, the bottom of the vessel and the side trusses of the vessel. These marginal portions preferably have continuous outer marginal reinforces 32 and continuous inner marginal reinforces 33, together with diagonal corner reinforces 34. Within the marginal portion of the bulkhead are ribs 35 and the diaphragm 36, likewise constructed of reinforced cementitious material.

While I have shown a preferable arrangement of plates having between them a calking recess extending partly through the plates, it is obvious that I may extend the calking` recess between the plates as far as the underlying truss member.

While for smaller vessels it may be desirable to have but one row of plates between the upper and lower chord of the truss or skeleton, yet, in seagoing vessels it is highly desirable to have a plurality of plates between keelson and gunwale. Such an arrangement I have shown in Fig. 1 of thc drawings.

Regardless of whether my reinforced concrete vessel is built inverted or in the usual manner in which wooden or steel ships are built, I arrange the frame work or skeleton of my vessel in such a manner in relation to the slabs, plating or skin, that the slabs, plating or skin practically serve merely to exclude the water from the vessel, not being relied upon as an element of strength of the vessel as a whole, while the frame work or skeleton takes care of the stresses to which the vessel is or may be subj ected.

I do not limit myself to the casting of the slabs or plating at different times or in different tiers. There is an advantage resulting from allowing a slab to contract before the slabs next to it are cast, but frequently this separate casting of slabs is unnecessary. Likewise, I do not limit myself to a plurality of slabs between the gunwale and bottom for in smaller vessels this has been found not to be needed.

I claim as -my invention:

1. The hereinbefore described method of building a reinforced concrete vessel which consists in constructing a frame work of diagonal truss members so arranged as to convert shear to which the vessel will be subjected into substantially aXial tension and compression, and upon said frame work independently forming slabs of cementitious material in such a manner as to allow a certain limited movement of said slabs relative to the frame work.

2. The hereinbefore described method of building a reinforced concrete vessel which consists, first, in forming a frame work of` truss elements on the sides thereof and in forming upon portions of said truss elements independent slabs of cementitious material and when the said slabs of cementitious material so formed have become contracted then forming adjacent slabs of cementitious material until the sides of the vessel shall be covered with said slabs.

3. In a concrete vessel, a truss forming part of the framing of the vessel, a series of independently7 formed matched concrete slabs carried by said truss and forming the skin of the vessel, and interconnecting reinforcing elements mutually engaging adjacent slabs7 whereby a non-monolithic structure is formed.

4. In a concrete vessel, a longitudinally extending truss, a series of independently formed, matched concrete slabs carried by said truss and forming the skin of the Vessel, reinforcing elements connecting adjacent slabs, and further reinforcing elements connecting the respective slabs to adjacent truss elements.

5. In a reinforced concrete Vessel, a reinforced concrete truss extending longitudinally of the vessel, comprising substantially horizontal upper and lower chords extending longitudinally of the vessel, the upper chord being located in proximity to an upper deck, the lower chord beinglocated approximately on a level with the keel of the vessel, reinforced concrete truss elements interconnecting the upper and lower chords and a plurality of separately formed concrete slabs attached to and supported by the reinforced concrete truss elements that interconnect said upper and lower chords, to form a non-monolithic skin for the Vessel.

6. In a reinforced concrete Vessel, a concrete truss comprising upper and lower chords extending lengthwise of the vessel, the lower chord being approximately on a level with the keel, a plurality of diagonal truss elements interconnecting the upper and lower chords, a plurality of separately formed concrete slabs attached to and supported by the diagonal truss elements to form a non-monolithic skin for the Vessel, the slabs being connected to the diagonal truss elements that interconnect the upper and lower chords of the truss by reinforcing elements mutually embedded in individual slabs and adjacent corresponding diagonal truss elements.

7. ln a reinforced concrete Vessel, a reinforced concrete truss comprising upper and lower chords extending longitudinally of the vessel and along one side, the lower chord being approximately on a level with the keel, a plurality of reinforced concrete truss elements interconnecting the upper and lower chords and a plurality of separately formed concrete slabs attached to and sup ported by the reinforced concrete truss elements that interconnect the upper and lower chords, to form a non-monolithic skin for the vessel, the several edges of said slabs be ing arranged to overlie corresponding reinforced concrete truss elements.

ALFREDO CARL() JANNI.

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