US2998792A - Waterborne vehicles - Google Patents

Description

United States Patent WATFJRBORN'E VEHICLES Herbert G. Hasler, Bursledon, England, assignor to Dracone Developments Limited, London, England Filed May '4, 195 9, Ser, No. 310,672 g Claims priority, application Great Britain May 13, 19 58 '6 Claims. (Cl. 114-665) The invention relates to power-operated or towed flexible barges.

At certain critical speeds of a flexible barge, the bow or nose tends to dive and cause the barge to execute unstable movements commonly termed porpoising. The critical speeds principally depend on the density of the cargo and the shape of the nose of the barge.

The invention aims to minimise the instability of waterborne vehicles by counteracting their diving tendency and thus making them easier to tow or propel.

According to the invention, the diving force exerted on the nose is counteracted by providing one or more hydro foils which balance the effect on the nose of speed variations. Each hydrofoil is preferably so shaped and mounted that it exerts a lifting force as the barge is being propelled or towed through the water. The hydrofoil should also be designed so that it exerts a minimum drag on the barge and is not liable to damage when striking waves or solid objects and so that it clears itself of weed or other floating matter which may become attached to it.

The hydrofoil may be given a dihedral and can be pivotally or rigidly attached either directly to the nose of the barge or to the tow rope.

Examples of the invention are illustrated diagrammatically in the accompanying drawings, in which:

FIGS. 1 and 2 are side and end views, respectively, of the nose of a barge fitted with a hydrofoil according to the invention, and

FIGS. 3, 4; 5, 6; 7, 8; 13, 14, are corresponding views of bargm fitted with modified hydrofoils.

Referring to the drawings, the hydrofoils in all the figures have dihalral.

In FIGS. 1 and 2 there is shown the nose 1 of a barge fitted directly with an arcuate hydrofoil 2. The outermost ends of the hydrofoil break the water surface on both sides of the nose of the barge whereby the righting moment which is exerted is considerably increased. The outer ends, however, could lie on the surface of the water so that one arm of the hydrofoil will penetrate more deeply whenever the nose 1 begins to roll.

The hydrofoils 3, 4 in FIGS. 3 and 4 are interconnected at 5 below the nose 1 to form a hydrofoil assembly similar to the single hydrofoil of FIGS. 1 and 2 except that the assembly is substantially channel-shaped.

In FIGS. 5 and 6, two hydrofoils 6, 7 are interconnected by an arm 8 above the nose 1, such arm 8 itself being in the form of a hydrofoil connected to the nose.

FIGS. 7 and '8 illustrate three hydrofoils 10, 11, 12. The hydrofoils 10, 11 act similarly to the hydrofoils 3, 4 in FIG. 4, but are not interconnected, whilst the hydrofoil 12 is completely immersed.

'In FIGS. 11 and 12, the hydrofoil =12 in FIGS. 7 and 8 is replaced by two hydrofoils 13, 14 mounted parallel to the hydrofoils 10, 11 respectively.

In the arrangement according to FIGS. 11-14, each hydrofoil is in the form of a ladder assembly on each side of the nose, that is to say, in the form of a number of lifting members 16 interconnected one above the other by members 17 so that at normal speeds of the barge one or more of the upper lifting members is at or above the water level. The two ladder assemblies are connected to the barge by cross-members 18 (FIG. 12) which lie below the water and which may themselves be in the 2 form' of lifting members or a cross member 19 (FIG. 14) lying abovethe water. In a modification of arrangement, the ladder assemblies can incorporate some of the features 'ofthe, dihedral systems described above".

The hydrofoil 'accordingto the invention can be easily fitted or removed to or from the nose even when the barge is fully loaded and afloat. -"ltmaybe made of any suitable material which is either rigid or flexible,'solid or hollow. If the hydrofoil is itself made buoyant, it will assist in keeping the barge afloatin'an upright position when" the barge is at rest.

As aforementioned, the hydrofoil is designed principally to overcome the diving force exerted on the nose when the barge is in motion. The lifting force exerted by the hydrofoil may, however, be such as to lift the nose above its normal trim when the barge is being propelled or towed at high speeds.

The angle between the cord of the hydrofoil and the longitudinal axis of the barge may be varied by means of adjustments which can be made whilst the barge is in motion. The adjustment may be effected by means of a manual control or automatically by a mechanism that is influenced by and responds to variable such as wave movement, direction and tension of the tow rope, and the like. Another way is to vary the angle differentially so that one side of the hydrofoil temporarily generates more lifting power than the other side and this effect may be used to provide anti-rolling moment.

If the aforementioned angle of the cord of the hydrofoil is negative, the hydrofoil may also be used to cause the nose to trim more deeply, or even cause the whole barge to dive and remain fully submerged. Additional hydrofoils may be fitted to parts of the barge other than the nose.

The invention provides several advantages. The barge can now be towed or propelled at any desired speed Without the risk of diving, even if the barge has little or no positive buoyancy. The whole barge may be made to adopt a position in the water which is better suited to propulsion on the surface and to the negotiation of waves. The draft of the barge can be reduced. By helping the nose to run steadily through the water without causing rolling or yawing, the hydrofoil considerably reduces rolling and yawing of the remainder of the barge. The gain in efficiency as effected by the hydrofoil more than offsets the slight extra drag caused by the hydrofoil itself.

Whenever the tension of the tow rope slackens, the hydrofoil acts as an automatic brake on the nose of the barge, because the lifting force exerted by it causes the nose to be raised which in turn increases the drag exerted by the hydrofoil because of the change in the angle of incidence. This eflfect is of value in preventing the barge from overriding a slack or broken tow rope.

When the hydrofoil is mounted to exert a diving moment on the nose of the barge, the drag on the latter is reduced and it may be towed more steadily in heavy seas.

I claim:

1. In combination, a partly submerged flexible barge which is adapted to be towed or propelled, and surface piercing hydrofoil means mounted on the barge adjacent its bow portion and being shaped and inclined so that it exerts a lifting force on the bow portion of the barge as the barge is moved through the water sufiicient to counteract the diving tendency of the barge.

2. The structure of claim 1, and wherein the hydrofoil means extends laterally outwardly and upwardly and is of sufficient length to exert an anti-rolling moment on the barge during towing or propulsion. 3. The structure of claim 1, and wherein said hydrofoil means defines a dihedral angle.

4. The structure of claim 1, and wherein an outer end 3 4 portion of saidhydrofoil means normally lies adjacent 1,776,700 Pegna Sept. 23, 1930 the water surface. 1,976,046 Tietjens Oct. 9, 1934 5. The structure of claimll, and wherein said hydrofoil 2,257,406 Von Burtenbach Sept. 30, 1941 means comprises.at least two laterally outwardly .and up- 2,274,200 Hill Feb. 24, 1942 wardly extending hydrofoil elements interconnected by 5 2,391,926 Scott Jan. 1, 1946 atleast one which itself in the'formiof 1a -hydrofoil 2,649,266 1Darrieus Aug. 18, 1953 element.

.6. The structure of Claim 1; and Wherimsidhytlrufdil FOREIGN PATENTS means 1s buoyant 9 1,154,146 France Oct. 28, 1957 .References Ciledwinethe fileof this patent 10 1 9 France 3, 1953 UNITED STATES PATENTS 130L738 'Potter AprLZZ, 1919

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