GB2343417A - Triangular vessel with low structural stresses in waves - Google Patents

Abstract

The vessel includes a triangular main hull A which is supported on three floats B via respective support arms C. The arms are pivoted to the hull and to the floats on mutually spaced transverse horizontal axes, D and E. The angle of the support arms can be independently adjusted according to prevailing conditions to increase the stability of the vessel. The front arm is steerable at J. The hull further incorporates sealed buoyancy units, (G) and K, on opposite sides.

Description

TRIANGULA VESSEL WITH LOW STRUCTURAL STRESSES IN WAVES TECHNICAL FIELD OF THE INVENTION This invention relates to water craft.

BACKGROUND One of the foremost design problems with all types of vessels is to build into the hull or hulls and structure the strength required to resist the powerful forces of wave action.

In many sea disasters especially in the case of large vessels the powerful wave forces can fracture the vessels hull and at least cause hull plates to buckle and welds to break with the resulting water ingress.

Large multihull sailing vessels such as catamarans and trimarans are especially prone to wave forces which cause the structure between the hulls and floats excessive stress loadings and also can cause fractures to the long slender floats. The leeward hull is also prone to plough in under a wave and cause a sudden braking effect so that a dangerous pitchpole and rollover situation is a very real possibility.

SUMMARY OF THE INVENTION The present invention proposes a water craft comprising a main hull which is supported above the water in use by two spaced trailing floats and a leading float positioned between and ahead of the two trailing floats.

The main hull is preferably of substantially triangular form with an angular bow and a transversely extending stern.

The floats are preferably pivotable about respective transverse horizontal axes.

The floats are preferably pivoted at or adjacent to their respective centres of buoyancy.

Preferably, the floats are pivotally mounted on respective arms which connect the floats to the hull and are themselves pivoted to the hull about respective transverse horizontal axes.

The angle of each of the arms is preferably adjustable.

The angles of the arms are preferably independently adjustable.

Preferably the hull incorporates fixed sealed buoyancy units located at opposite sides of the hull.

BRIEF DESCRIPTION OF THE DRAWINGS The following description and the accompanying drawings referred to therein are included by way of non-limiting example in order to illustrate how the invention may be put into practice. In the drawings: Figure 1 is a port side elevation of a first form of three hull triangular vessel in accordance with the invention; Figure 2 is a plan elevation of the vessel shown in Fig. 1; Figure 3 is a plan elevation of a second form of three hull triangular vessel in accordance with the invention, in the form of a triangular power watercraft; and Figure 4 is a port side elevation of the vessel shown in Fig. 3.

DETAILED DESCRIPTION OF THE DRAWINGS Figures 1 and 2 show a high speed triangular ferry with three sealed floats pivoting on suspension arms providing low structural stresses and smooth ride potential in waves.

Figures 3 and 4 show a high speed planing power craft with triangular layout and three floats pivoting on suspension arms which may be convertible to a sailing yacht.

Each form of the vessel includes a triangular main hull A which is supported on three floats B via respective support arms C. The arms are pivoted to the hull and to the floats on mutually spaced transverse horizontal axes, D and E. The angle of the support arms can be independently adjusted according to prevailing conditions to increase the stability of the vessel. The front arm is steerable at J. The hull further incorporates sealed buoyancy units, G and K, on opposite sides.

The above vessels are only two of the vessel types which could be designed based on the triangular three float layout. For example fishing vessels which are prone to sudden capsize in rough conditions and also trawl nets snagging.

Trawl nets may be hauled in over the wide stem between the floats so providing positive lateral stability.

In a more basic design the floats may be designed to pivot directly onto the main hull, at the centres of buoyancy.

It is possible to design a vessel with other shaped main central hull provided that the three floats are positioned at the three points of a triangle.

A further technically advanced vessel may be developed by employing computers to control or assist the suspension system with the object of achieving an even smoother ride in wave conditions.

The many advantages of designing a vessel or yacht on a triangular plan form with the floats positioned at or close to the three points of the triangle are as follows.

Any sudden vertical movement of the hulls or floats due to wave action will not cause any degree of structural stress.

The floats may be fixed rigidly to the central hull.

The preferred method of mounting the floats is to provide a pivot on or close to the centre of buoyancy of each float so that it will change angle with waves independently and naturally also to change angle for planing as the vessels speed is increased.

A further preferred system for mounting the floats is to provide suspension arms from the central hull and the floats attached by pivot so as to change angle to waves and planing as previously. The suspension system may be preset to any variations of power or tension so that the legs or arms of the suspension units will move to allow the floats to change height vertically relative to the main central hull according to wave conditions.

A further aspect of the three point independent suspension system is that each suspension unit may be adjusted for height and travel so adjustments can be made by the crew as required of the powered vessel or yacht to take account of wind and sea conditions.

By adjusting the height of the suspension on the leeward and windward sides the yacht can be heeled to windward so as to compensate for the wind heel angle of the sails so providing the best sail efficiency and maximum speed potential.

The high speed power vessels suspension can be adjusted so that as speed increases by raising the height of the bow of the vessel, lift can be obtained from the airflow under the vessel.

The ability to raise the bow of the vessels main central hull provides an important reduction in water drag to the floats so that a reduction in power will be required to maintain a given speed or that a higher speed can be attained for any given fuel consumption.

When the vessel is moving at a slow speed or is stationary the main central hull will take up the main percentage weight of the vessel on the water. This is optional and variable.

The underside of the main central hull will preferably incorporate sealed buoyancy units positioned each side to provide lateral stability in the event of collision damage and loss of one of the rear floats and will take the main weight of the central hull when the vessel is at rest.

The buoyancy units will also provide a controlled longitudinal air flow underneath the main central hull and set up a powerful air cushion between the vessel and the waters surface.

The buoyancy units will be lifted clear of the waters surface when the vessel is cruising at speed. In view of the unacceptable number of sea disasters in the past and also the present time a large percentage of these being caused by excessive structural stresses in large waves also capsize situations the triangular three float layout is put forward with some urgency.

It will be appreciated that the features disclosed herein may be present in any feasible combination. Whilst the above description lays emphasis on those areas which, in combination, are believed to be new, protection is claimed for any inventive combination of the features disclosed herein.

List of References FIGURE 1 A Hull B Planing floats C Suspension legs D Pivot (upper) incorporating hydraulics E Lower pivots. (Floats pivoted on centres of buoyancy) G Sealed Buoyancy H Arrows showing leg and float movement in response to wave action J Steering pivot K Buoyancy units. One each side of hull. (Sealed) FIGURE 2 A Hull B Planing floats C Suspension legs D Pivot (upper) incorporating hydraulics E Lower pivots. (Floats pivoted on centres of buoyancy) I Bow float steering. (Pivoted to change angle laterally) J Steering pivot K Sealed buoyancy units FIGURE 3 A Main hull-cockpit cabin unit B Planing floats C Suspension legs D Upper pivots incorporating hydraulics E Lower pivots. (Floats pivoted on centres of buoyancy) J Steering pivot K Buoyancy units (sealed) FIGURE 4 A Main hull-cockpit cabin unit B Planing floats C Suspension legs D Upper pivots incorporating hydraulics E Lower pivots. (Floats pivoted on centres of buoyancy) H Arrow shows leg and float movement in response to wave action.

J Steering pivot K Buoyancy units (sealed)

Claims (9)

1. CLAIMS 1. A water craft comprising a main hull which is supported above the water in use by two spaced trailing floats and a leading float positioned between and ahead of the two trailing floats.
2. 2. A water craft according to Claim 1, in which the main hull is of substantially triangular form with an angular bow and a transversely extending stern.
3. 3. A water craft according to Claim 1 or 2, in which the floats are pivotable about respective transverse horizontal axes.
4. 4. A water craft according to Claim 3, in which the floats are pivoted at or adjacent to their respective centres of buoyancy.
5. 5. A water craft according to any preceding claim, in which the floats are mounted on respective arms which connect the floats to the hull and the arms are pivoted to the hull about respective transverse horizontal axes.
6. 6. A water craft according to Claim 5, in which the angle of each of the arms is adjustable.
7. 7. A water craft according to Claim 6, in which said angles are independently adjustable.
8. 8. A water craft according to any preceding claim, in which the hull incorporates fixed sealed buoyancy units.
9. 9. A water craft according to Claim 8, in which said buoyancy units are located at opposite sides of the hull.

   10, A water craft substantially as described with reference to and as shown in Figures 1 and 2 or Figures 3 and 4 of the drawings.