US2167688A - Hull for boats and ships - Google Patents

Description

Allg. l, A A SCOWLEY I 2,167,688

HULL FOR BOATS AND SHIPS Original Filed July l5, 1935 3 Sheets-Sheet 1 Aug. l, 1939. A A, A SCOWLEY 2,167,688

HULL FOR BOATS AND SHIPS Original Filed July 15, 1935 5 Sheetsv-SheetZ Allg- 1, 1939- A. A scowLEY 2,157,688

K HULL FOR BOATS-AND SHIPS l A Original Filed July l5, 1955 3 Sheets--Sheetl 3 f l Zyl-@faim Patented Aug. 1, 1939 UNITED STATES YPATENT OFFICE Application July 15, 1935, Serial No. 31,300 Renewed October'Z?, 1938 4 Claims.

The invention relates to hulls for boats and ships, and may be used for every kind 'of boat or ship, which will hereinafter be referred to as ships.

The principal object of the invention is to reduce the resistance of the water to th'e movement of the ship through the `water and thereby attain a maximum of speed with a minimum expenditure of power. The principal factors which impede the movement of `a ship through water are the resistance to displacement of the water at the bow and its replacement at the stern in th'e path through which the ship moves.

This invention is based on a knowledge of certain characteristics of the action of water with relation to the movement of bodies through it. The water reacts in different ways with ships traveling at different speeds, that is to say, (if vit might be so stated) the water does -not present the same willingness and ability to change its form to permit a ship to pass. through it when it is moving at the rate of 10 miles per houras to a ship moving at the rate of 20 miles per hour, in relation to the speed.

An important feature of the invention is to produce a structure which successfully takes `advantage of the different actions of the Vwaterdue to the different rates of speed of the ship. Theaction and pressure of the water at the bow of the ship caused by the vmovement thereof, assuming a ship with the conventional, ordinary and usual type of hull, must be transmitted along its curved sides to the stern and in this, the action and pressure of the water is governed, xed and limited by three factors, time, distance traveled and the -path of travel. The time it takes to transmit :a given pressure or to rearrange or transpose the pressure a certain distance is xed at all times.

It is less both in time and effort when operated in a straight line than when operated Iin a curved or circuitous one, hence a greater 4effort or work is required to move a ship of fuller, larger or rounder form.

The speed attainable by the conventional type of ship is limited to and fixed by the ability of the water to yield to pressure, and hence no perceptible advancement in speed of shi-ps would take place without undue expenditure of power, due to the theory that the pressure can be transmitted more readily through the body of water itself than by removing part of it. This is true only up to any given rate of speed, when the displacing and replacing process becomes the more advantageous.

In the conventional type of ship, the bow or forebody usually has a V-shape, the two inclined surfaces of the bow commencing at the stem forming the apex, and also tapering downwardly to the keel. As the ship progresses through the water, the inclined surfaces forming the bow 5 exert a pressure or thrust downwardly and outwardly. This pressure or thrust lin a relatively slow moving ship is transmitted through the water along the curved outside surfaces of the hull to the stern, but as the speed of the ship 10 increases, the inherent characteristics of the water will-not permit such transmission through its body or rearrangement of pressure in the time allowed by the faster moving ship but will follow the lines of least resistance.

As the ship progresses through'the water, the water yields to the pressure of the bow and is built up or massed above the normal water line. It recedes and is built up or massed again in continuous successions and flows away from the 20 ship in about the line formed by the V shaped bow, or diagonally with the ships -line of travel, forming waves.

The principal purpose of the present invention is to produce a ships hull with a bow, where the 25 pressure Iagainst the water will be outward and upward instead of outward and downward as vin the conventional lform of ship. To attain this, the bow isv formed with a concave-convex construction, being concaved at the lower portion 30 inwardly to two straight lines diverging from the intersection of the stem and keel from a relatively sharp point thereat, and curving into the chine or water line aft of the stem and forming .a point bow, being convexed from the end of the 35 concave portion, the convexed portion extending into the upper portion or into the bow and toward the foredeck. The straight lines are formed by the intersection of the inclined bottom surfaces and the inwardly concaved bow surfaces formed 40 on the sides of the stem and produce inclined cutwaters. 'Ihese cutwaters, with the aid of the stem, divide the water to be displaced in two equal parts, which by the inwardly concaved bow surfaces are rolled up and on the adjoining 45 surface of the water.

Each body or column of water supports another and must yield upwardly to provide a path for the oncoming ships hull, in the faster moving ships. To a comparatively slowly moving ship, 50 the water will yield readily and 'the pressure at the bow will be transmitted through the water itself. The skin friction is the principal resistance `factor to be overcome, but as the ship attains higher speed, the residual resistance in- 55 creases accordingly as the water becomes more and more unyielding. If suicient power is developed within the ship to drive it against these unyielding columns of water, the bow will raise and the stern depress from the normal water line level of the ship, which proves that the water is yielding only up to a certain point as it will not give way to the bow, but when the stern has reached the same point of progress, it has had time to yield suciently for the stern to settle down to or below its normal waterline level, depending on the speed and shape of the hull.

One of the objects of this invention is to keep the ship at its proper displacement and water line level, irrespective of size and speed, with a View of enabling it to be driven with a given expenditure of power at a higher speed than can be attained with the construction heretofore produced.

Further advantages of the present invention are found in the construction of the bottom of the ship which consists of two straight surfaces slightly inclined to one another, the degree of inclination being fixed to meet the requirements, depending on the purpose and use for which the ship is designed. The bottom edge of the inclined surfaces forms the keel, the upper edge the chine and both running in straight lines the entire length of the ship, ending at the stern as hereinafter described or in any other desired form best suited to the particular ship and its propeller arrangement.

The advantages of having a straight bottom, or with lines and surfaces running straight longitudinally with the keel, is that it does not unnecessarily set in motion an unknown quantity of water, as is the case with conventionally formed hulls having curved and irregular lines, but travels on its own bed the entire length of the ship, and as it attains speed separates itself from its bed and sets in motion innumerable molecules next to the ships bottom which revolve and which in turn set other molecules in motion and revolution, the entire mass acting as rollers, and the frictional resistance decreases as the speed increases at a fixed ratio.

A further object of the invention is to form a ships hull in such a manner that, as a better way of displacing the water at the bow is produced so must the water be replaced at the stern, and the chasm in the water caused by the passage of the ship be closed by its own gravitation without being pulled together by the tapering afterbody in the conventional form of ship, by reason of the cohesion of the water and its adhesion to the ships hull.

As the inertia and hydrostatic pressure remains about xed at all times, it becomes increasingly difiicult for the water to close in and follow the tapering lines of the conventional hull, and as the speed increases so the hydrostatic pressure on the afterbody or stern of the ships hull diminishes in relation to the speed and the ships form. At a given point, this pressure will entirely cease and a drag will then set in by the ship trying to free itself from a solid mass of water clinging to the after part of the wetted ships hull. This element seems to have been overlooked in the general discussion of ships resistance, but as the speed increases so the construction of the stern becomes an all important factor.

With these objects in View, a feature of the present invention is to have the underwater part of the hull end at the stern with a perpendicular cut running diagonally across the sides of the bottom from the chine or water line aftwardly to the keel, thus permitting the ships bottom to slip and move 01T its bed and permit the water to go back to its normal structure by its own inherent forces, without retarding the ships progress.

Finally, this invention permits of measurements by which one may readily ascertain in advance the shaft horsepower required for any size ship employing the invention, to attain a given speed, the ships lines to come within certain xed limits.

Two factors in connection with such measurements need only be considered. First; The power required to displace the water at the bow, i. e. turn sufficient water up and out on the adjoining surface to permit the ship to pass and retain its normal displacement which in this type of construction can be fixed within narrow limits. Second; Frictional resistance, which may readily be figured in pounds per square foot will vary however in accordance with the speed, eliminating entirely unknown resistance to ships of irregular form and in particular, in approximately plane surfaces moving at an angle with their own plane.

The invention will be further understood from the accompanying drawings illustrating a construction embodying the invention in its preferred form, and the following detailed description of the construction therein shown.

In the drawings:

Figure 1 is a side view of the ships hull showing the shape of bow and stern, one of the chines and two of the cutwaters, the hull having a straight keel.

Figure 2 is a bottom plan View of the ships hull shown in Figure 1, illustrating the concave-convex bow portion, including the three cutwaters, the keel, the two chines and the stern portion.

Figure 3 is a front view of the bow of the hull showing the three cutwaters and the concavoconvex bow portions.

Figure 4 is a rear View of the stern of the hull showing the stern post and the angles of the ships bottom.

Figure 5 is a cross sectional view of the hull on the line 5--5 of Figure 1 looking toward the stem of the bow.

Figure 6 is a cross sectional view of the hull on the line 6 6 of Figure l looking toward the stern.

Figure 7 is a cross sectional View of the hull on the line 1 7 of Figure l looking toward the stern.

Figure 8 is a view of the bow or forebody with a variation or modification of the bow or stem cutwater and including one of the side cutwaters and the straight keel.

Figure 9 is a view of the afterbody of the variation or modification of Figure 8 including also a modified form of stern, and a straight keel.

Figure 10 is a View of a further variation or modification of the hull, the principal difference from the form shown in Figure 1 being in the afterbody.

Figure 11 is a cross sectional view of the hull of Figure l0 on the line I l-I I of Figure 10 looking in the direction of the stem of the bow.

Figure 12 is a cross sectional View of the hull of Figure 10 on the line |2-l2 of Figure 10 looking in the direction of the stern.

Figure 13 is a cross sectional view of the hull of Figure 10 on the line |3-i3 of Figure 10 looking in the direction of the stern.

Figurel. is a View of a further variation of the forebody of the hull of Figures 1 and 10 including an upwardly inclined keel, and curved and uncurved surfaces in the forebody of the hull.

Figure 15 is a cross sectional View of the hull of Figure 14 on the line I5-I5 looking in the direction of the bow and shows the curved and uncurved surfaces in the forebody of the hull.

Like reference numerals in the various gures of the drawings indicate similar parts of the 'hulls which have been shown.

The bow in the case of each of the hulls shown in the drawings is of a concaVo-convex contour or configuration, but each form of the hull will be referred to separately hereinafter.

Referring rst to the hull which has been illustrated in Figures 1 to 7, the forebody or bow I is formed with the stem I6. Commencing at the foredeck edges I1 and I8, the exterior surfaces I9 and 25 of the forebody or bow I5 are convexed and then curved into the concave surfaces 2| and 22. These convex-ed and concaved surfaces extend from the stern I5 and the two central cutwater sections 23 and 24 to the straight lateral or side cutwaters 25 and 26. The upper cutwater section 23 extends from the intersection or junction of the foredeck edges I1 and I8 and the stern I6 rearwardly and downwardly in a curved line to a point 21 on the stem which is preferably at the water-line 28, but not necessarily so. The lower cutwater section 24 extends from the point 21 on the stem I6 forwardly and downwardly in a straight line to the forward end of the keel 29. The lower end of the lower central cutwater section 24 and the lower ends of the lateral cutwaters 25 and 25 and the for- Ward end of the keel 29 meet and form the relatively sharp forward or bow point 39.

The convex surface I9 merges into the concave surface 2I and the convex surface 29 merges into the concave surface 22. As stated these concaVo-convex surfaces extend from the foredeck edges I1 and I8 downwardly in curved surfaces to the straight lateral cutwaters 25 and 26.

In Figure 2, the dotted lines 3l and 32 indicate the inner extent of the meeting lines of the concavo-convex surfaces I9, 2l] and 2| and 22. The cutwaters 25 and 26 extend upwardly and aftwardly from the bow-point 39 to the chines 33 and 34. There is a slight curve where the cutwaters 25 and 26 merge and join the chines 33 and 34. The chines are on substantially straight lines aft to the stern 35, although, of course, following the ships outer contour. That is, the lines of the chines are substantially parallel with the water-line 28.

The curved surfaces I9, 20 and 2I, 22 merge into the side surfaces 36 and 31 of the hull and these surfaces extend the full length of the hull between the main deck lines 38 and 39 and the chines 33 and 34 to the aft surface 40 of the stern.

The bottom of the hull is formed with the two flat, straight, downwardly inclined surfaces 4I and 42 which extend from the chines 33 and 34 to the keel 29 and from the side cutwaters 25 and 26 aftwardly to the stern downwardly extending lines 43 and 44. Triangular surfaces 45 and 46 are provided beneath the chines 33 and 34 and extend from the downwardly extending lines 43 and 44 to the vertical stern post 41, and below the water-line 28. The stern is provided with the surface 48 lying between the stern afterbody and the surfaces 45 and 46. The surface 48 extends to the points 49 and 50 which may be located at any desirable location on the chines forwardly of the stern post. It will be understood that the hull bottom inclined surfaces 4I and 42 may be constructed at any practical angle which may be desirable.

As viewed from the front of the hull, as best shown in Figure 3, the hull presents three clearly dened lines, the center or stem cutwater in the curved and straight sections 23 and 24, and the two inclined cutwatersr25 and 26. The bottom of the hull extends aftwardly in straight lines fromV the side cutwaters. The three cutwaters divide the water to be displaced into two equal parts. The water is raised up by the specially formed bow and rolled or cast on to the adjoining surface of the water by the sides of the ship, the displaced water being case up and out instead of out and down, to be replaced in its original form at the stern of the hull without the formation of so called waves, heretofore considered inevitable in the progress of the ship through the water, and in the speedier ships, the principal resistance to their progress.

Referring now to the modied structure shown in Figures 8 and 9, a hull is represented having a modified bow construction shown in Figure 8 and a modified stern construction shown in Figure 9. VThe stem is formed as a front cutwater comprising a convex section 5I extending from the deck line of the bow I5 in a curved line to the water line 28 and a concave section 52 extending from the water line 2S in a curved line to the bow-point 39, the bow-point being the intersection of the cutwater section 52, the lateral cutwaters 25 and 25 and the keel 29. The surfaces of the hull between the deck lines and keel are convexo-concave at 53 and 54, respectively. The same is true of the curves and contours of the other side of the hull corresponding to the portions indicated at 53 and 54.

The stern construction shown in Figure 9 is identical with that shown in Figures 1 and 4, except that the stern post 55 is curved from the stern end of the chines 33 and 34 to the stern end of the keel 29, the stern post being of a concave construction as shown in Figure 9.

Referring to the hull shown in Figures to 13, inclusive, there is illustrated a further modification of the invention. The bow I5 is provided with the convexe- concave surface portions 25 and 22, respectively. The surface 29, however, rapidly takes the form shown at 56 and the surface 51 corresponds thereto. This becomes concave and continues to the concave portions 58 and 59 below the water line 28. The straight bottom surfaces of the hull as shown in Figure 11 are represented at 59 and 6I. The shape of the hull then changes as shown in Figures 12 and 13 with the side portions 62 and 63 which curve into the portions 64 and 65 and terminate in the bottom surfaces 56 and 51 to the keel 68. The surfaces 62 and 53 terminate at the stern and below the stern. The bottom 65 and 51 is shortened to the stern post 41.

Referring to Figure 14, an additional modified hull is shown. In the hull shown in this figure, the bowpoint 39 is raised above the major portion and plane of the keel 29 as shown at 69. The portion of the keel 59 serves as an auxiliary cutwater to the two cutwater sections 23 and 24 as shown in Figure 14 and for some uses and purposes aids in the progress of the hull through the water. In this construction, the curved surfaces 'I8 and 1I extend from the deck line I8 of the bow I5 to the junctures 12 and 13 of the curved surfaces 19 and 1I and the uncurved or straight flat surfaces 14 and 15. These straight surfaces 14 and extend outwardly at angles as shown in Figure 15 to the side cutwaters 25 and 26. The straight flat downwardly inclined bottoms 4I and 42 extend from the cutwaters 25 and 26 to the raised keel line 69.

Having described the invention, what I claim and desire to secure by Letters Patent is:

l. In a hull, a forebody, an afterbody, said forebody being provided with side cutwaters, one on each side of said forebody, said hull having a chine on each side thereof, said forebody including a bow, said bow having a convexo-concave formation, a stem cutwater at the forward end of the said forebody having a forwardly projecting portion, a re-entrant portion and a lower portion, said convexo-concave formation terminating at said stem cutwater, the said bow being inwardly concaved and narrowed from the said side cutwaters, each of said side cutwaters extending in a straight line at an angle from the foremost point of said lower portion of the stem cutwater, and each of said straight angular side cutwaters extending upwardly and aftwardly to the chines on the respective sides of said hull at or adjacent the normal load waterline of said hull.

2. In a hull, said hull comprising a forebody and an afterbody, said hull having a chine on each side thereof, said forebody being of a convexo-concave formation and having three cutwaters, a stem cutwater and two side cutwaters, said stem cutwater having a forwardly projecting portion, a re-entrant portion and a lower portion, the said lower portion extending forwardly to the bow point of the keel of said hull, the two side cutwaters extending aftwardly and upwardly from the junction of the said lower portion of the stem cutwater with said bow point of said keel, one side cutwater extending in a straight line at a diverging angle from the said junction and extending to the chine at or adjacent the normal load water line of said hull on one side of said hull, and the other side cutwater extending in a straight line at a diverging angle from said junction, said latter diverging angle being opposite the first mentioned diverging angle and extending to the chine at or adjacent the normal load water line of said hull on the other side of said hull, the exterior lines of said side cutwaters being outside of and beyond said convexo-concave formation.

3. In a hull, said hull comprising a forebody, an afterbody, and a substantially straight bottom, said hull having a chine on each side thereof, said forebody being of a convexo-concave formation and having three cutwaters, a stem cut- Water and two side cutwaters, said stem cutwater having a forwardly projecting portion, a re-entrant portion and a lower portion, the said lower portion extending forwardly to the bow point of the keel of said hull, the said stem cutwater being in a convexo-concave line, the two side cutwaters extending aftwardly and upwardly from the junction of the said lower portion of the stem cutwater with said bow point of said keel, one side cutwater extending in a straight line at a diverging angle from the said junction and extending to the chine at or adjacent the normal load water line of said hull on one side of said hull, and the other side cutwater extending in a straight line at a diverging angle from said junction, said latter diverging angle being opposite the rst mentioned diverging angle and extending to the chine at or adjacent the normal load water line of said hull on the other side of said hull, the portion of said forebody adjacent said junction above said two side cutwaters being concave, and the two surfaces of said bottom adjacent said point of junction being in angular straight planes, the exterior lines of said side cutwaters being outside of .and beyond said concave formation.

4. In a hull, said hull comprising a forebody, an afterbody, and a substantially straight angular bottom, said hull having a chine on each side thereof, said forebody being of a convexo-concave formation and having three cutwaters, a stem cutwater and two side cutwaters, said stem cutwater having a forwardly projecting portion, a re-entrant portion and a lower portion, the said lower portion extending forwardly to the bow point of the keel of said hull, the said stem cutwater being in a convexo-concave line, the two side cutwaters extending aftwardly and upwardly from the junction of the said lower portion of the stem cutwater with said bow point of said keel, one side cutwater extending in a straight line at a diverging angle from the said junction and extending to the chine at or adjacent the normal load water line of said hull on one side of said hull, and the other side cutwater extending in a straight line at a diverging angle from said junction, said latter diverging angle being opposite the first mentioned diverging angle and extending to the chine at or adjacent the normal load water line of said hull on the other side of said hull, the afterbody of said hull comprising two sections, the upper section and the lower section respectively, said upper section forming the stern and counter of the hull, the lower section formed with a stern post, triangular straight vertical plane surfaces extending upwardly to the chines on both sides of the hull, each of said triangular plane surfaces being at an angle, also being at and straight, and extending angularly and downwardly to said keel, the exterior lines of said side cutwaters being outside of and beyond said convexo-concave formation.

ANDREW A. SCOVVLETY.

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