US2396721A - Boat - Google Patents

Description

March 19, 1946.

A. C. PATTERSON ET AL BOAT Filed May 4, 1942 2 Sheets-Sheet 1 flbnza (ll ai'iisrson H haaanzer, 3 JM flful fm 2 Sheets-Sheet 2 l ammto BOAT uqlonzo CZPwZZer-son,

Filed May 4, 1942 A. c. PATTERSON ET AL 70.01 (yianikr, J M M 11470,

m. S LL m WMN H 1N. W P WW 0 k WW MN MW March 1 9, 1946 Patented Mar. 19, 1946 BOAT Alonzo 0. Patterson and Hugh C. Ganter, New Orleans, La.; said Ganter assignor to said Patterson Application May 4, 1942, Serial No. 441,723

6 Claims.

The present invention relates to a boat construction and more particularly to a novel hull and step construction particularl eiiective in shallow draft boats of the hydroplane type.

Various types of boats have been proposed which are relatively incapable of being sunk due to the presence of various types of air chambers and other constructions. In general, however, this type of construction has been unsuitable for application to a boat of the hydroplane type since the increased weight of various air chambers usually increased the draft of the boat and also prevented the effective use of bottom forms which have been proved to be most desirable in a boat of the hydroplane type. The use of partitions and/or air chamber also has the disadvantage in that if a plurality of air chambers are used, the

weight of the boat is greatly increased thereby and the difliculties of construction enhanced, and if, on the other hand, a small number of air chambers were used, the boat would become relatively easy to sink. In general, it may be stated that the use of air chambers and other partitioning arrangements is unsuitable in a boat which is intended to be used principall for miiltary landing operations. Nevertheless, it is essential that this type of boat be hard to sink, since in addition to being subjected to the normal navigation hazards, it is also subjected to enemy fire.

The flat bottomed hydroplane is a type of boat which should be particularly advantageous for operation in shallow water. However, boats of this type, if of large size, draw a substantial amount of water until they reach a suiliciently high speed for planing purposes. Further, most hydroplanes, although substantially out of the water at their bow end, draw considerable water at their stems and therefore it is normally difiicult to run this type of boat for any substantial portion of its length up onto a fiat beach. It has previously been proposed to lift the stern of the hydroplane out of water by providing an air inlet terminating just behind the step, this air inlet consisting of a vertically disposed pipe or a simple opening which led upwardly from beneath the step within the boat. Naturally, if an ordinary pipe or plurality of pipes are used, no substantial amount of air is thus delivered underneath the step and no great lifting effect is experienced due to this air finding its way beneath the stern. n the other hand, if a considerable proportion of the bottom of the boat just behind the step is left open, the bottom is greatly weakened thereby and such a boat obviously would be too fragile for landing operations involving the transport of heavy equipment. It has been found, in accordance with the present invention, however, that air inlets can be provided which open to the sides of the boat and which greatly facilitate the lifting of the stern of a hydroplane out of the water even at relatively slow speeds,

It is one of the objects of the present invention, therefore, to provide a boat construction preferably of the hydroplane type which is relatively incapable of sinking.

Another object of the present invention is to provide a, boat with a homogeneous layer of material having a low specific gravity and incapable of being adversely aiiected by water.

A third object of the present invention is to provide a boat with a laminated bottom construction including a substantial proportion of material of a low specific gravity bonded by a bonding medium inert to water action.

A fourth object of the present invention is to provide a boat construction including a bottom portion having a homogeneous layer of material of low specific gravity of varying thickness so that the portions thereof normally contactin the water have the largest proportion of light material incorporated therein.

A fifth object of the present invention is to provide a boat of the hydroplan type having a stepped bottom, and comprising a series of transversely extending ribs, an outer skin on the outside of said ribs, an inner skin on the inner side of said ribs, said ribs being of varying widths so that the widest widths are at the areas of greatest water contact, a layer of material between said inner and outer skins of low specific gravity bonded by a water proof bonding medium, said material layer being thickest at the stern end of the boat bottom and just forward of the bottom step so that the two areas of greatest water contact are provided with the thickest layers of material.

Other objects and advantages of the present invention will become apparent from the subsequent description and figures of the drawings. wherein:

Figure 1 is a diagrammatic side elevation of a boat in accordance with the present invention;

Figure 2 is a diagrammatic plan view of a longitudinal half of the boat in Fig, 1;

Figure 3 is a diagrammatic illustration of the various contours taken at designated stations of Figs. 1 and 2;

Figure 4 is a transverse section of the boat taken to the rear of the step;

Figure is a section of a portion of the boat taken along the line 5-5 of Fig. 4;

Figure 6 is a section similar to Fig. 5 taken along the line B6 of Fig. 4;

Figure 7 is a section taken along the line l-1. of Fig. 4;

Figure 8 is a side elevation partly diagrammatic showing a drive mechanism for the boat; and

Figure 9 is a bottom plan view of a portion of the boat taken at the step.

Referring to the figures of the drawings, and particularly Fig. 1 thereof, a boat of the hydroplane type is shown in general outline and indicated in general by the reference numeral l0. As shown, the boat is provided with a generally pointed and turned up bow and a relatively square stem. The bottom of the boat is provided with a step which is indicated in general at H. As will be hereinafter set forth in detail, the step is provided with an overhang particularly adapted to draw air beneath the boat and lift the stern thereof out of the water.

Referring to Fig. 4, it will be noted that the bottom of the boat is formed of a double thickness of material, preferabl plywood, having an inner layer of comminuted cork or balsa interposed therebetween. The outer skin is indicated at [2 and preferably consists of plywood of onehalf inch thickness or greater. The inner layer 13 may also be formed of plywood, preferably of relatively thin character. The outer skin I2 is fastened to the ribs, which extend transversely from the keel M. As shown in Figs. 5 to '7, these ribs may be of varying thicknesses. Thus, the rib indicated at I5 is relatively wide and heavy since the portion of the boat just in front of the step is subject to a substantiall great strain. On the other hand, the rib indicated at I6 is relatively narrow since this portion of the boat is not subject to any stress as it is normally completely out of the water. The general variance in rib width is illustrated somewhat diagrammatically in Fig. 1 by the dotted lines I! and I8. If, therefore, the inner skin I3 formed of relatively thin plywood is fastened to the inner side of the ribs, there is provided a space which varies in thickness with the rib thickness throughout the length of the boat. If this space is then filled with a suitable light-weight composition such as comminuted cork or balsa wood, together with a suitable binder such as casein glue or other waterproof glue, sufficient buoyancy will be given to the boat to prevent the sinking thereof even if the hull is pierced. It will be noted further that by thus varying the thickness of the layer of cork or balsa, the areas of the boat which contact the water are also those areas which are provided with the greatest thickness of light-weight material. It is the result of this construction, therefore, that the boat will always ride high in the water, even if the sides thereof or bottom thereof are pierced, and in addition to being unsinkable, a boat so constructed has substantiall the same operating characteristics under substantially all conditions. The cork or balsa layer may vary in thickness in a boat of approximately 40-foot length from four to five inches just forward of the step H and at the stern of the boat, to approximately one inch just to the rear of the step and toward the bow of the boat. Preferably, however, no cork or balsa is inserted forward of the point indicated at l9 in Fig, 1, since from this point on toward the how, the boat is out of the water at all times.

Although comminuted cork and comminuted balso. have been described as suitable materials, it is evident that other materials may be used provided they have an extremely low specific gravity and are not affected by water. Thus. various pith materials and other vegetable materials may be used. In general, these materials may be bound together by a minor proportion of a binder which is not affected by water,

In addition to casein glue, urea formaldehyde glues may be used, various glues formed from phenol condensation products, and natural or artificial resins. Preferably the light-weight material is comminuted so that it may be sprayed or easily deposited between the two skins l2 and 43. It is essential that the pieces be sufficiently small so that when deposited between the two skins, no substantial proportion of voids is present. A large proportion of such spaces would result in loss of buoyancy since water would find its way into the voids and contribute to the weight of the boat. Although as described, the layer of light composition is in general only present on the bottom of the boat of the type described and shown herein, it is evident that in a boat other than a flat bottomed hydroplane type, the cork layer may be carried partially up the sides thereof, although as stated, this provision is particularly effective in preventing the sinking of a flat bottomed boat of shallow draft.

The step construction in general includes an overhanging portion 20 which is a continuation of the outer skin of the bottom of the boat and a vertical transversely extending portion 2| which is rectangular in cross section at the sides of the boat, as shown in Fig. 7, and is widened toward the center of the boat at its lower extremity, as shown in Fig. 5. The width of the overhanging portion 20 will therefore be greater at the sides of the boat than at the center line thereof, as illustrated in particular in Fig. 9, wherein the general shape of the base of the member 2] is indicated. There is therefore provided a space under the step which is relatively wide and large toward the sides of the boat and narrow at the center line. This will create a suction in the direction of the arrows 22, as best shown in Figs. 4 and 9. In other words, when the boat is moving at relatively low speed, the water will tend to accumulate toward the center line behind the step and as the speed is increased, this water will be swept toward the stern of the boat, drawing air transversely toward the center, under the overhanging portion 20. This air will then be distributed behind the step and tend to raise the stern of the boat out of the water. As a result, a boat of the character described herein, even at relatively slow speeds, will draw only a small amount of water, as, for example, in the neighborhood of five or six inches, and is exceedingly effective as a landing boat since it can be run almost completely out of the water. In addition, the present step greatly decreases the frictional resistance to forward movement of the boat and therefore substantially enhances the speed thereof. Preferably, the boat of the present invention is driven by an air propeller, as illustrated in Fig. 8, since any form of screw would have to project downwardly into the water and might prevent the use of this boat in very shallow waters. As shown in Fig. 8, a motor 23 drives by means of a belt 24, a propeller 25 mounted on the shaft 26. It will be noted that the shaft 26 is slanted upwardly from the horizontal at its forward end, and consequently the propeller 25 does not revolve in a vertical plane, but at a slight angle. This will also assist in lifting the stern of the boat out of the water.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. In a hydroplane construction including a stepped bottom comprising an outer skin and an inner skin spaced from said outer skin, a layer of material between said inner and outer skin of low specific gravity bonded by a waterproof bonding medium, said material layer being thickest at the stem end of said bottom and just forward of said step so that the two areas of greatest water contact are provided with the thickest layers of material.

2. In a hydroplane construction including a stepped bottom comprising an outer skin and an inner skin spaced from said outer skin, a layer of material between said inner and outer skin of low specific gravity, said material layer being thickest at the stern end of said bottom and Just forward of said step so that the two areas of greatest water contact are provided with the thickest layers of material.

3. In a hydroplane construction including a stepped bottom, comprising a series of transversely extending ribs, an outer skin on the outside of said ribs, an inner skin on the inner side of said ribs, said ribs being of varying widths So that the widest ribs are at the areas of greatest water contact, a layer of material between said inner and outer skins of low specific gravity bonded by a waterproof bonding medium, said material layer being thickest at the stern end of said boat bottom and just forward of said step so that the two areas of greatest water contact are provided with the thickest layers of material.

4. In a hydroplane construction including a stepped bottom, comprising a series of transversely extending ribs, an outer skin on the outside of said ribs, an inner skin on the inner side of said ribs, said ribs being of varying widths so that the widest ribs are at the areas of greatest water contact, a layer of material between said inner and outer skins of low specific gravity bonded by a waterproof bonding medium, said material having a varying thickness so that said material layer is thickest at the areas of greatest water contact.

5. In a hydroplane construction including a stepped bottom comprising a series of transversely extending ribs, an outer plywood skin on the outside of said ribs, an inner plywood skin on the inner side of said ribs, said ribs being of varying widths so that the widest ribs are at the areas of greatest water contact, a layer of material between said inner and outer skins of low specific gravity bonded by a waterproof bonding medium, said material layer being thickest at the stem end of said boat bottom and just forward of said step so that the two areas of greatest water contact are provided with the thickest layers of material.

6. In a hydroplane construction including a stepped bottom comprising an outer plywood skin and an inner plywood skin spaced from said outer plywood skin, a layer of material between said inner and outer plywood skin of low specific gravity bonded by a waterproof bonding medium, said material layer being thickest at the stem end of said bottom and just forward of said step so that the two areas of greatest water contact are provided with the thickest layers of material.

ALONZO C. PATTERSON. HUGH C. GANTER.

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