US3738303A - Method of building boats with twin hulls - Google Patents

Abstract

A method of building boats of the catamaran type. Thus, during the building of a boat which will have twin hulls, a pair of single hull boats are simultaneously launched, with these boats fixed to each other in side-by-side relation. The thus-launched boats are then separated and laterally displaced one with respect to the other up to a predetermined distance therebetween, while one of the boats is guided for movement with respect to the other along a path extending in a precisely perpendicular direction horizontally across the decks of both boats. This guiding of the boats during their lateral displacement with respect to each other is brought about by fixing at least one beam on one of the boats extending perpendicularly across and beyond the other boat, and then mounting on this other boat a guide frame structure which extends around the beam to cooperate therewith during the lateral displacement of the boats from each other. After the boats have been positioned in this way, they are interconnected with a connecting structure which extends between the hulls.

Description

United States atet [1 1 Sakura June 12, 1973 METHOD OF BUILDING BOATS WITH TWIN HULLS [75] Inventor:

[22] Filed: May 25, 1970 [21] Appl. No.: 40,152

Shoichi Sakura, Shimizu, Japan [52] US. Cl. 114/77 R, 114/61 [51] Int. Cl B63b 3/02 [58] Field of Search 114/77 R, 77 A, 61,

114/65, 56, 83, 26-30, 123, 235 R, 43.5, 72, 28; 9/2 R, 2 C, 2 F, 2 S, 6, 6.5

Primary ExaminerMilton Buchler Assistant Examiner-Stuart M. Goldstein AttorneySteinberg & Blake [57] ABSTRACT A method of building boats of the catamaran type. Thus, during the building of a boar which will have twin hulls, a pair of single hull boats are simultaneously launched, with these boats fixed to each other in sideby-side relation. The thus-launched boats are then separated and laterally displaced one with respect to the other up to a predetermined distance therebetween, while one of the boats is guided for movement with respect to the other along a path extending in a precisely perpendicular direction horizontally across the decks of both boats. This guiding of the boats during their lateral displacement with respect to each other is brought about by fixing at least one beam on one of the boats extending perpendicularly across and beyond the other boat, and then mounting on this other boat a guide frame structure which extends around the beam to cooperate therewith during the lateral displacement of the boats from each other. After the boats have been positioned in this way, they are interconnected with a connecting structure which extends between the hulls.

9 Claims, 6 Drawing Figures PAIENIED JUN I 2 I973 SKUINZ FIG.

NNNNNNNWNAVW INVENTOR .S'HO/CH/ SA KURA ,F'M RNEYS FIG.5

INVENTOR 57/0/61 .54 KUP/I BY I A RNEYS METHOD OF BUILDING BOATS WITH TWIN HULLS BACKGROUND OF THE INVENTION The present invention relates to boat building methods.

In particular, the present invention relates to the building of boats of the catamaran type. During conventional building of boats which have twin hulls, the hull building procedure takes place on the slipways. However, experience has demonstrated that it is impossible to build a twin hulled boat of large size on ordinary slipways.

Attempts have been made to build a catamaran type of boat simply by fixing to each other single hull boats with a desired spacing therebetween, after such boats have been built on slipways and launched into the sea. However, considerable difficulties are encountered by following this type of procedure. It is unavoidable that there will be considerable differences between the two boats in draught, trim and heel, respectively, even though the ballast and weight are adjusted. It has thus proved to be extremely difficult with these operating procedures to connect in a precise manner a pair of boats which are separately towed at predetermined relative positions while being under the influence of waves and winds.

SUMMARY OF THE INVENTION It is accordingly a primary object of the present invention to provide a method which will avoid the above drawbacks.

In particular, it is an object of the invention to provide a method which makes it possible to build boats of the catamaran type in a highly precise manner even though the boats are of a relatively large size.

In particular, it is an object of the invention to provide a method which makes it possible to achieve a precise positioning of single hull boats with respect to each other in preparation for interconnecting them in order to form the twin-hull boat.

According to the method of the invention a pair of single hull boats are simultaneously built on slipways and are fixed to each other in a side-by-side relation. In this condition they are launched and then subsequent to launching they are separated and then displaced laterally one with respect to the other to achieve the required distance between the single hull boats. During this lateral displacing of the boats with respect to each other they are precisely guided by a beam fixed to and extending laterally beyond one of the boats across and beyond the other of the boats with this other boat having a guide frame structure surrounding and coacting with the beam so as to achieve a precise guided movement of the boats laterally from each other during displacement to achieve the required distance therebetween. The beams and guide frame structures used to guide the boats during their lateral displacement apart from each other are installed prior to separating of the boats from each other in the condition they had during building on. the slipways. The initial separation of the two ships from each other takes place after they have been launched and while they are on the sea. When the desired distance between the boats is achieved, they are joined to each other while maintained precisely at the desired positions with respect to each other by providing a connecting structure situated between and in terconnecting the boats.

BRIEF DESCRIPTION OF DRAWINGS The invention is illustrated by way of example in the accompanying drawings which form part of this application and in which:

FIG. 1 is a schematic end view of a pair of boats which are still on slipways, FIG. 1 illustrating the beam and guide frame structure used in the method of the invention;

FIG. 2 is a schematic representation of the manner in which the boats are displaced laterally from each other after they are launched and cut apart from each other;

FIG. 3 is a schematic plan view of the procedure illustrated in FIG. 2;

FIG. 4 is a schematic transverse elevation showing the details of the guide frame structure and the cross section of a beam extending therethrough;

FIG. 5 is a schematic representation, in a transverse view similar to that of FIG. 4, of the manner in which final minor precision adjustments are carried out; and

FIG. 6 is a schematic end elevation of the completed vessel.

DESCRIPTION OF PREFERRED EMBODIMENTS Referring to FIG. 1, it will be seen that a pair of single hull boats l and 1' are built on slipways 5 and are fixed to each other in side-by-side relation by the single hull joint portion 4. When the single hull boats l and l of FIG. 1 are in a condition illustrated in FIG. 1, they are launched from the slipways 5.

However, a guide structure is first provided, if convenient. This guide structure includes an elongated beam 2 of box-shaped configuration in cross section fixed to the deck 11' of the boat 1 and extending therefrom perpendicularly across and beyond the deck 11 of the boat 1. A pair of guide frame structures 3 are mounted on the deck 11 surrounding the beam 2 so as to coact therewith for the precise guiding of the boats during their displacement apart from each other, as described below. While these components 2 and 3 are shown mounted on the boats 1 and 1' prior to the launching thereof in FIG. 1, it is to be noted that under certain circumstances it is not convenient to mount these components before launching. Thus, it may happen that the installation of beams 2 and guide frame structures 3 will impede the construction work and the movement of equipment such as cranes and the like around the slipways. Under these latter circumstances it is possible to mount the guide structure 2,3 on the boats subsequent to the launching thereof.

Considered in greater detail, as can be seen from FIG. 3 in particular, a pair of the beams 2 are fixed directly to the deck 11' and extend therefrom perpendicularly across and beyond the boat 1 at the region of the bow and stern of the boats. Each beam 2 is surrounded by a pair of the guide frame structures 3 which are fixed to the boat 1. Each pair of guide frame structures 3 is transversely arranged in spaced relation with respect to each other along a beam 2 and across the deck 11 of the boat 1. After the guide frame structures 3 are mounted in position the beams 2 can be passed therethrough and fixed to the boat 1,. At their free ends the beams 2 carry stop plates 8 which extend beyond the beam 2 and are in the nature of end stop flanges for the beams 2.

As is schematically illustrated in FIG. 5, the beam 2 is of a rectangular hollow cross section and is reinforced in its interior by suitable reinforcing means. In addition it is preferred to provide a rolling contact for the beam 2 as it moves through the frame structure 3. For this purpose the frame structure 3 is provided with rollers 7 (FIG. 4) situated along the corners of the cross section of the beam 2 for having rolling contact with the exterior surface thereof to provide for the rolling contact during relative movement of the beam 2 longitudinally with respect to the frame structure 3.

Thus, either the beam structure 2 and frame structure 3 is mounted prior to or subsequent to launching. In any event, after this guide structure is mounted on the boats as described above, the interconnecting joint 4 between the launched single hull boats is cut so that the boats are separated from each other. Through a suitable chain block or winch installation 6, schematically illustrated in FIGS. 1 and 2, the boats which had been severed from each other along the joint 4 are displaced apart from each other with the boat 1 advancing laterally toward the left, as indicated by the arrow in FIG. 2, so that it becomes displaced apart from the boat 1' until the left frame structure 3 of FIG. 2 engages the stop 8. This operation is also illustrated in FIG. 3 where the solid-line boat 1 is displaced to the dotted line position. The rolling contact achieved for the beams 2 during movement of the frame structures 3 therealong greatly facilitates the separating operation. The stops 8 provide a precisely determined distance between the boats. Furthermore, the beams 2 extend precisely perpendicularly along paths which extend horizontally across the boats, so that an extremely precise displacement of the boats with respect to each other is achieved.

When the boats are thus separated from each other so as to be situated at the precisely determined distance from each other, as determined by the stops 8, or by suitable marks on the beams 2, the frames 3, and the deck 11, it is possible to carry out minor adjustments bringing about an extremely precise interrelationship of the positions of the boats l and 1 with respect to each other. For this purpose the rollers 7 can be removed, if necessary and an adjusting mechanism as illustrated in FIG. is operated. This mechanism includes locating blocks or jigs respectively fixed on the one hand to the outer side surfaces of beam 2 and on the other hand to the inner side surfaces of the frame structure 3. Between these positioning jigs or blocks 10 are arranged jacks 9 which can be hydraulic or mechanical jacks capable of expanding or contracting so as to control the distance between those jig elements 10 fixed to the frame structure 3 and those which are fixed to the beam 2. Through this operation of the jacks 9 it is possible to adjust the relative height, heel and trimming to determine in an extremely precise manner the correlative positions of the single hull boats with respect to each other.

After the boats are thus positioned very precisely with respect to each other according to the above method of the invention, the beams 2 and frame structures 3 are maintained completely fixed without any further possible movement therebetween, and then a connecting structure (FIG. 6) is positioned between and fixed with the boats thus interconnecting the boats so as to permanently connect them to each other while transferring to this connecting structure the strength for opposing external forces, so that this strength for opposing external forces need no longer be carried out by the components 2 and 3. It is now possible with the thus-interconnected hulls, to remove the box beams 2 and frame structures, since they have been replaced by the connecting structure interconnecting the boats and newly loaded and fixed, and thus the building of the twin-hull boat is completed.

As is apparent from the above considerations, according to the method of the invention the pair of single hull boats are simultaneously launched while temporarily connected to each other at a small distance from each other. They are then separated and use is made of the beams 2 of the box-shaped cross section and the guide frame structures 3 until the required distance between the boats is achieved after cutting of the joint 4. At this point, practically all of the required adjustments have been completed. The adjustments carried out by way of the jacks 9' are extremely minor adjustments. In other words, by using the beams of a boxshaped cross section it is possible for the two single hull boats to be correlatively positioned on the sea in a manner which is far more convenient and far more precise than has hitherto been possible with conventional methods. I

It is to be noted that it is unnecessary to control the metacentric height (G.M.) of the single hull boat itself, because a pair of the single hull boats are connected together under conjoint conditions, so that they float with a high degree of stability. Although the metacentric height (G.M.) will naturally be positive, the metacentric height (G.M.) of the twin-hull boats will always be in the positive region at any stage of cutting and widening, or in other words displacing of the boats apart from each other, due to the use of the beam of box-shaped cross section with its consequent high strength and weight, according to the method of the invention. As a result the buoyancy tanks and ballast are rendered unnecessary.

It is thus apparent from the above that with the invention the beam of box-shaped cross section functions as a displacement guide or jig used during increase of the distance between the two boats during shifting of one with respect to the other to the required distance while providing through the roller 7 the rolling contact be tween the guide frames and beams. In addition, these beams and guide frames are used as positioning and adjusting jigs so as to set and determine the correlative positions of the boats by shifting, through the use of pushing and pulling forces, the guide frames both horizontally and vertically while the beams extend therethrough and have the rolling contact therewith. In addition to the above advantages, the beam of box-shaped cross section functions to provide a high degree of stability for the single hull boats, preventing any significant heeling from taking place during the operations when the boats are displaced apart from each other, and also they avoid any unfavorable influence from external forces such as waves and winds which tend to bring about upsetting through heeling moments caused by the joint block structure which is loaded on the boat. Furthermore, the beams of box-shaped cross section provide the important advantage as acting as reinforcement against external forces, thus preserving and maintaining the hull shapes in their proper configurations and facilitating the building of the twin-hull boat.

Thus, with the present invention the pair of single hull boats are launched while temporarily connected together under conjoint conditions in relatively close side-by-side relation. Then they are cut apart from each other and displaced to the desired distance with respect to each other utilizing the beam of a box-shaped cross section with its high strength, so that the pair of single hull boats can be buoyed up with a high degree of stability without requiring the use of a buoyancy tank and ballast.

During the continuous shipbuilding operations of catamaran-type boats having twin hulls, the beams of box-shaped cross section and the guide frames and other components used during building operations can be repeatedly used over and over since the beams and guide frames, and the components associated therewith will simply be moved from the completed structure so that it is available for further use on additional boats which are to built.

It is thus clear from the above that the method of the invention can be used in the building of marine structures where it is required to connect even more than two bodies during the building of special ships similar to twin-hull boats where the construction takes place largely while afloat on the sea.

What is claimed is:

I. In a method of building a boat having twin hulls, the steps of building a pair of single hull boats on slipways and fixing the boats to each other in side-by-side relation, simultaneously launching the pair of single hull boats which are fixed to each other in side-by-side relation, then separating the thus-launched boats from each other, laterally displacing one of the boats while guiding said one boat for movement with respect to the other along a path extending in a precisely perpendicular direction horizontally across the decks of both boats, and then fixedly interconnecting the boats with a connecting structure extending between the hulls, including the steps of fixing to one of the boats at least one elongated beam extending perpendicularly from said one boat across and beyond the other, mounting on the other boat a guide frame structure extending around said beam and cooperating therewith during lateral displacement of the boats one with respect to the other for performing the step of guiding the boats precisely along said horizontal path while providing the predetermined distance between the boats.

2. In a method as recited in claim 1, the step of bringing the guide frame structure into engagement with a stop carried by said beam for determining the distance between the boats.

3. In a method as recited in claim 1, the step of carrying out minor adjustments between the beam and guide frame structure when the boats are at said predetermined distance from each other for precisely determining the relative positions of the single hull boats prior to interconnecting of the boats by the joint block structure.

4. In a method as recited in claim 1, the step of providing a rolling contact between the guide frame structure and the beam during lateral displacement of the boats one with respect to the other.

5. In a method as recited in claim 1, the step of providing for said guide frame structure a pair of guide frames laterally spaced from each other transversely with respect to the other boat along said beam.

6. In a method as recited in claim 1, the step of connecting a pair of said beams to one said boat adjacent the bow and stern thereof, and extending parallel to each other transversely and perpendicularly across the other boat, and also connecting a pair of said guide frame structure to said other boat surrounding said beams, respectively.

7. The combination of claim 1 and wherein said beam and guide frame structure are mounted on the boats prior to launching thereof.

8. In a method as recited in claim 1 and wherein said beam and guide frame structure are mounted on said boats subsequent to launching thereof.

9. In a method as recited in claim 1 and wherein after the hulls are fixed to each other by the connecting structure said beam and guide frame structure are removed for further use in the manufacture of additional twin-hull boats.

Claims (9)

1. In a method of building a boat having twin hulls, the steps of building a pair of single hull boats on slipways and fixing the boats to each other in side-by-side relation, simultaneously launching the pair of single hull boats which are fixed to each other in side-by-side relation, then separating the thus-launched boats from each other, laterally displacing one of the boats while guiding said one boat for movement with respect to the other along a path extending in a precisely perpendicular direction horizontally across the decks of both boats, and then fixedly interconnecting the boats with a connecting structure extending between the hulls, including the steps of fixing to one of the boats at least one elongated beam extending perpendicularly from said one boat across and beyond the other, mounting on the other boat a guide frame structure extending around said beam and cooperating therewith during lateral displacement of the boats one with respect to the other for performing the step of guiding the boats precisely along said horizontal path while providing the predetermined distance between the boats.

2. In a method as recited in claim 1, the step of bringing the guide frame structure into engagement with a stop carried by said beam for determining the distance between the boats.

3. In a method as recited in claim 1, the step of carrying out minor adjustments between the beam and guide frame structure when the boats are at said predetermined distance from each other for precisely determining the relative positions of the single hull boats prior to interconnecting of the boats by the joint block structure.

4. In a method as recited in claim 1, the step of providing a rolling contact between the guide frame structure and the beam during lateral displacement of the boats one with respect to the other.

5. In a method as recited in claim 1, the step of providing for said guide frame structure a pair of guide frames laterally spaced from each other transversely with respect to the other boat along said beam.

6. In a method as recited in claim 1, the step of connecting a pair of said beams to one said boat adjacent the bow and stern thereof, and extending parallel to each other transversely and perpendicularly across the other boat, and also connecting a pair of said guide frame structure to said other boat surrounding said beams, respectively.

7. The combination of claim 1 and wherein said beam and guide frame structure are mounted on the boats prior to launching thereof.

8. In a method as recited in claim 1 and wherein said beam and guide frame structure are mounted on said boats subsequent to launching thereof.

9. In a method as recited in claim 1 and wherein after the hulls are fixed to each other by the connecting structure said beam and guide frame structure are removed for further use in the manufacture of additional twin-hull boats.

Images