US2521268A - Boat - Google Patents

Description

Sept. 5, 1950 Filed May 28, 1945 l. TROENG BOAT 2 Sheets-Sheet 1 Sept. 5, 1950 Filed May 28, 19 45 TROENG 2,521,268

BOAT.

2 Sheets-Sheet 2 Patented Sept. 5, 1950 ,omreo STATES AT E OFF I 6 BOAT Ivan Trong, Alvsjb; Sweden Application-M21328; 1945; SeriaI No'. 596,155

6- Glaimss 1 The problem of: building azfast boatuwhich: at the same; time is economical is noti onl zaiprobz lem; of resistance.v The particular difiiculties connectedwith high speed, in theform of: wave:-

shoc'ks, damage: caused by. floating-bodies. and? the centrifugal force in the takingr'oiturnsz-muste alsogbe mastered: if axboat-with low. resistance at high-speed shallnbeof any practicaluse;

Many' earlier inventors" have realized-the importance off'aero' Wings-like members." as being: S111 perior from the viewpoint of'resistance, to the; bottom surfaces generally used; in; planingboats. As. a rule, the Winghas beensituatediin: thew-atom which, however, has involved 1. considerable: drawbacks The boatbecomes deepgoing'andpis-sum jectedtoenormous stresseszatheavy'sea When-the; profiles are passing new in the: air: nowin thewaten. MOIGOVBI'JH] is' easilyli'able to getdamaged: by? floating bodies; The object of thezpresentine vention" is to completely eliminate: these drawbacks.

The" boat accordingto the: invention consists of at-least'two (possibly three) pontoonsandnne; or moreiwing-elilreintermediate members located 1 aboyethe water surfaceand connectingthesa-id;

pontoonsr. The, said: intermediate: member is adaptedito substantially -carry'the boat when the boat is moving; The invention issubstantiall'y" characterized by the fact thatthegpontoons or-z' outer-pontoonsare provided; with: inwardly and downwardly: directed; 1ongitudinal;., fin which; whenrturnssare tome-taken. are adapted". toypresss down; the; pontoon; located nearer to; the. turn; centre: and to press upwardly; the pontoon: vv-i'iichav is locatedmoretremote from the: said-Lcentre.

The underside of" the; intermediate.-membenis; preferably: formed" as" one or morextransverse arches saathat particnlarly the rearzportionebee comes strong. and capable of being used. as bot?- tom surface at.low"speed The primimityitcrthe:v Water: is of Very: great; importance for obtaining good; aerodynamic values. isiobtained in; that,.,when the boatris' lyingzstilla; the rearportin;of the intermediate. member" trailsinithez Water" sothat; when moving, its comes-nearer: to; the water surface" thantitwouldiotherw-isez do").

The pontoons can be made-of. ashapesimilarr tov those of. a seaplane; the step--being.; however;' provided; much farther forward. Between; the; said; pontoons there are provided oneo-rumore wing-likewmembers, having the profile and aeroe dynamic. dualities ofv an .airplane-wing-which: may:

contain compartments,- motors or load; spaces It may; often beadvantageous? to use: relatively, thick profilese-aboutz %v of a the chord--and-v to hiv l speed-producing shape.

cut off the. rear edge which" might have are-- sistance diminishing. effect. It? now the centre of, gravity lies at or" just before the centre' of pressure of this Wing member (or these: wing: members) only' a small part of: the. vveightr-av few hundredths-will at high speed. rest on the: water; by the far advanced: steps; While themain part ofthe weight at the. boat is carried by th-e'air? forces, acting on the wing-like-memberzfoi meme bers). Thus, a total gliding ratio of' 1125* can-- be obtained Without difiiculty, which means: that: a boat shapedin this way hasonly about: athird; of the resistance of'an about iO-k'in-ot plane-boat, although it also can obtain this; gliding ratio-at a speed up to a multifoldvalue, if: desired;

Due to the; fact that the Weight resting: on. the wateryh'a-s thusbeen reduced to a minimum; the gliding ratio of the bottom surfaces will, be of secondary importance, and'th'ereiore" one is free to a very great extent to-shape saidbottom'surefaces; in accordance with: the; demands of seaworthiness and stability in contradistinctionto the bottoms of a commonplane-boat, in which everything must submit to the demand, of a With increasing airlift the water forces on thepontoon bottoms decrease, which results in a reduction of stresses.

As amatter of fact, the air forces in av boat according: to the invention afford a possibility of obtaining a laterally-stabilizing SffCtai1Tth8 taleing of turns. However, except atvery high speed, this effect as well as the latera1-- pressure of the air' in general in the taking ofturns is so low that, as aru-le, the boat should-be steered. by means of members in the water. The-stability, in the longitudinal direction is obtainedauto-- matically b the-boat raising the vstern-more and more at-higherspeedso that the angle of incidEIICErOf the-wing member is reducedifromi about 5 to 2? or 3or-1ess.. If a, boatis constructed with: the centre of gravity; intheaerodynamiccentre of pressure, thisboat can begin to fly. com,- pletelyat hig-h'speed. In: spite thereof itisstable in the longitudinal; direction because, due toits' vicinity'to-the water-surface; the pressurecentre wanders a: directionopposite-to that of axW-ing inthe free air. Anangleincrease-will cause-a movement of the pressure centre-backwardsand an angle decrease a forward movement of the saidcentre-so that balanceis obtained. Due-to leakage of pressureair from the lower to=-the upper,v side a-n-increase Of the: size. ofthe opening betweenthe pontoon; andrthe Watersurfacer results in a: reduction of-theiliftingyforce; Thus: the boat I is;- prevented from. rising:- higher? than 3 to the position at which the lifting force and the total weight balance each other.

In order that the water esistance shall be as little as possible, the water line breadth should not be broader than necessary at the speed in question. At higher speed the breadth at the step should be reduced in proportion to the increase of the speed. This is obtained by longitudinal steps on the pontoon bottoms, particularly before the aforementioned, transverse step.

A lateral stabilization in a boat moving normally on the water is obtained by the abovementioned inwardly and downwardly directed bottom pins on the pontoons, which preferably incline more downwardly at the front end than at the rear end and which in taking turns function in such a way that in the turn the inner pontoon is pressed down and offers a considerable resistance along the turning radius, while the outer pontoon is pressed upwardly and together with the inner pontoon compensates the tilting moment of the centrifugal force. This device is combined with a rudder (possibl also fins) in the water and/or in the air. A rudder in the water as well as fins can be adapted to be raised in order to reduce the draught of the boat and to form a protection against large floating bodies. In order to protect the front fins against large floating bodies, the said front fins may be yieldingly mounted outside the hull of the boat. Preferably, the centre of gravit of the boat is situated at a short distance before or in the pressure centre of the air on the intermediate wing member and at a larger distance behind the pressure centre of the water on the said fins. If the centre of gravity lies before th air pressure centre, the firstmentioned distance is made preferably equal to 10%, at the most, of the last-mentioned distance. A suitable value of the ratio between the said distances is thus in many cases about 1:20.

In certain cases it might be desirable to provide stabilizing means in the air. The said means preferably consist of fins on the rear side edges of the intermediate member. The fins should be directed obliquely upwardly and outwardly. Sometimes they are also of importance for protecting persons on-board the boat from being hurt by the air propeller, particularly if two propellers are used. Such fins may be provided simultaneously with or instead of the above-mentioned planes moving in the water.

Boats according to th present invention should preferably be driven by means in the air, i. e. air propellers or jet engines. Water propellers or other drivin device in the water can only be used in exceptional cases. Air propellers are preferably arranged as pushing propellers in casings at the back on the upper side of the wing members. In small boats there is preferabl used a motor in the front portion of the boat, which motor, by a shaft extending to the rear portion of the boat and b a belt extending to the propeller casing, drives the propeller shaft at a suitable speedusually considerably lower than that of the motor. In large boats there is preferably provided an extension shaft between an aero engine which should be placed in or before the pressure centre, and the propeller which is placed above the rear portion of the wing.

Particularly in large ocean boats according to the invention it might be advantageous to completely or partially fill the airplane wing-profiled intermediate member with a gas that is lighter than air, e. g. helium or hydrogen, in order to obtain an increased carrying capacity. The

said gas may be contained in balloons within the intermediate member. For the same purpose Autogiro wings driven by the air stream may be arranged on the boat.

The seaworthiness of a boat according to the invention will be influenced advantageously by the following factors:

(1) The slight pressure of the pontoons on the water.

(2) The shape of the pontoon with a narrow carrying surface which can easily cut through the water, and relatively high longitudinal steps to the broader surfaces carrying the forepart 0f the boat at starting and at low speed.

(3) The automatic adjustment of the boat to a certain trim angle for each speed and its capacity of maintaining this angle relatively unchanged in spite of the waves.

The invention is illustrated in the accompanying drawings by way of an example.

Fig. 1 shows a side view of the boat. Figs. 2 and 3 show the right boat half, viewed from above, and from below respectively. Figs. 4 and 5 show the boat in profile approximately on the line IXIV of Fig. 1, on a straight course, and turning to starboard, respectively.

I is the right pontoon and 2 the left pontoon. 3 and 4 are inwardly and outwardly extending planes diving into the water at high speed, which planes will be described more particularly below and which terminate rearwardly at the step 5. 5 is the air space between the rear portion of the pontoons and the water surface. I is the airplane wing-like portion connecting the pontoons and containing engine room, cabins, and so on. I and 'i show the form of the bottom of the pontoons at the fore and the rear ends thereof, respectively. la is the rudder and lb the fins, if such are used. 8 is the motor and 9 the propeller. The hand wheel Ill and the person operating the same are indicated in the front of the boat. In Fig. 1 the arrows I I and I2 show the air pressure centre, and the water pressure centre respectively, at high speed, while the arrow l3 shows the centre of gravity of the boat. The surface I in Fig. 2 is the side surface ofthe wing and the line I5 shows the wheel cabin. The line I6 is the front edge of the wing and the line I! the rear edge thereof.

In Fig. 4 the reference letter A shows the water line and a shows the floating line breadth at rest or at low speed, B shows the water line and b the floating line breadth at middle speed, and C shows the water line and c the floating line breadth at high speed. The inclined planes 3, 4 shown in Figs. 4 and 5 incline inwardly and downwardly so that their upwardly directed normal inclines inwardly and backwardly. They may either constitute a stationary, rigid portion of the pontoons or preferably consist of flexible strips, e. g. of spring steel or sheet iron, fixed to the said pontoons at about the longitudinal center line of the bottom thereof and extending inwardly and downwardly forming a low angle with the horizontal. In the example illustrated, these inwardly and downwardly inclined planes are disposed approximately at an angle of 20 to the horizontal and while this angle may be varied to some extent, it must be less than 45 in order to achieve the desired upward thrust when the boat is advancing through the water. Due to the fact that their normals incline in the said manner the effect shown in Fig. 4 is obtained, viz. that their upper side is maintained dry at straight course and a high speed, which to a great extent contributes to reducing the friction relatively to the water, while the inward inclination of the normals causes the effect shown in Fig. 5 viz. that when the boat through the centrifugal force (the arrow I8) when turning tends to skid on the water, the inner pontoon l is pressed down into the water and the outer pontoon 2 is pressed upwardly. The arrows I9, show the pressure of the water against the upper side of the plane 3, and against the lower side of the plane 4 respectively, while the arrows 21, 22 show the underpressure on the underside of the plane 3. The arrow 23 represents the impulsive force of the water against the edge 24 of the pontoon, the said force reducing the movement of the boat in the lateral direction. Due to the edge 25 the water does not contact the side of the inner pontoo-n 1 whereby the friction and thus also the reduction of the speed when turning are dimin ished. The fins 1b contribute to the stability when turning.

Having now described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A boat comprising a pair of pontoons in spaced relation and an intermediate connecting wing member having the profile of an airplane wing extending across and rigidly connected to the pontoons, said wing member being adapted substantially to sustain the weight of the boat when the latter is traveling forward at high speed, the connections between the wing member and the pontoons being such that no lateral air passages are provided between the under surface of the wing and the pontoons, a longitudinally extending inwardly and downwardly inclined fin secured to the under surface of each of said pontoons, the planes of said fins forming a low angle with the horizontal whereby said fins sustain a portion of the weight of the boat and give lateral stability when the boat is travelin forward and upon the taking of turns exert a downward force on the pontoon closer to the center of turning and a lifting force on the other pontoon.

2. A boat as claimed in claim 1, in which the centre of gravity of the boat is located at a short distance forwardly of the pressure centre of the air on the intermediate wing member and at a greater distance behind the pressure centre of the water on the said fins.

3. A boat as claimed in claim 1 in which the centre of gravity of the boat is located at a short distance forwardly of the pressure centre of the air on the intermediate member and at a greater distance behind the pressure centre of the water on the said fins the ratio between the said two distances is not greater than 1: 10.

4. A boat as claimed in claim 1, in which the centre of gravity of the boat is located approximately in the vertical line through the pressure centre of the air on the intermediate member but behind the pressure centre of the water on the said fins.

5. A boat as claimed in claim 1, in which each of the fins is inclined so that its normal is directed inwardly and backwardly.

6. A boat as claimed in claim 1, in which the fins are provided under the forward portion only of the pontoons, the said forward portion of the pontoons terminating rearwardly in a transverse step located forward of the centre of gravity of the boat whereby at high speed no portion of the boat rearwardly of the step will contact the water.

IVAN TROENG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,413,383 Besson Apr. 18, 1922 1,799,183 Skarlund Apr. 7, 1931 1,857,347 Beebe May 10, 1932 1,890,113 Hitt Dec. 6, 1932 2,354,453 Gazda July 25, 1944 2,363,421 Huard 1 Nov. 21, 1944 2,373,019 Dix Apr. 3, 1945

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