DESC:FIELD OF INVENTION:
The present invention generally relates to ballast tanks. More particularly, the present invention relates to a securing device for fabricating and assembling a ballast tank, which enables to conveniently weld and assemble all the elements of aft ballast tank in longitudinal direction.

BACKGROUND AND PRIOR ART:
Floating structures such as boats, ships, vessels, have ballast tanks to provide hydrostatic stability to reduce or control buoyancy. These ballast tanks are provided at various locations for maintaining stability of the floating structure during sea voyage. The location of the ballast tank varies according to the type of floating structure.

Submarines are provided with ballast tanks for diving and surfacing. These ballast tanks provide reserve buoyancy to the submarine. The ballast tanks are welded to a pressure hull on the submarine.

The conventional process of fabricating and assembly of a ballast tank is time-consuming and tedious, due to the peculiar shape of the submarine. Thus, there is a need of a supporting structure which enables convenient welding and assembly of ballast tank elements.

The present invention thus discloses an assembly jig for welding and assembly of the said aft ballast tank to a submarine.

SUMMARY OF THE INVENTION:
It is an object of the present invention to provide an assembly jig for assembling and welding of the said emergency blowing aft ballast tank to submarine pressure hull.

It is another object of the present invention to provide an assembly jig to conveniently weld and assemble elements of aft ballast tank, in a longitudinal direction.

It is another object of the present invention to provide better control over welding and provide dimensional accuracy.

Accordingly, the said assembly jig comprises a circular steel base structure welded with plurality of support structure, vertical angle members, ground plates, inter-connecting angular members, slotted plates and flat bars; wherein the aft ballast tank elements are supported at top, and other elects are welded around the periphery of the jig. Thus, all elements of aft ballast tanks are welded to form the aft ballast tank structure.

The assembly jig helps to assemble all the elements of aft ballast tank by providing the base support for aft ballast tank. This aft ballast tanks are welded to submarine pressure hull which provide reserve buoyancy to the submarine thus enabling the submarine to dive and surface.

BRIEF DESCRIPTION OF DRAWINGS:
The figures below show an exemplary embodiment:
Figure 1 illustrates a schematic side view of the assembly jig for manufacturing of emergency blowing Aft ballast tank
Figure 2 illustrates schematic top view of the assembly jig for manufacturing of emergency blowing Aft ballast tank
List of reference numerals
Part ref Description
1 Base plate
2,3 Inter-connecting angular member
4 Vertical angle members
5 Support structure
6 Inter-connecting angular member
7 Ground plates
9 Vertical slotted plates
10 Vertical flat bars
11 Bottom plates
12,14,15,16,17 Flat bars
13 Plate
18,19,20 Securing members

DETAILED DESCRIPTION OF THE INVENTION
The invention is described herein in detail with the help of figures appended at the end of the specification. The figures illustrate the preferred embodiment as well as other embodiments that define the scope of the present invention. However, it may be understood that the figures presented herein are intended to exemplify the scope of the invention only. The person skilled in art may note that by no means the figures limit the scope of the invention. Any variation in the drawings by any other person will be falling in the scope of the present invention.

The present invention provides an assembly jig for assembling and welding of the emergency blowing aft ballast tank of a submarine to a submarine pressure hull.

As illustrated in Figures 1-2, a schematic view of the assembly jig for manufacturing of emergency blowing aft ballast tank is disclosed. Accordingly, the said assembly jig comprises a base plate (1) welded with plurality of support structures (5) on the bottom portion; plurality of vertical angle members (4) wherein one end is welded on said support structures (5) and other end welded on plurality of ground plate (7); plurality of inter-connecting angular members (2,3,6) welded to said support structures (5) and said vertical angle members (4); plurality of vertical slotted plates (9) placed on the top periphery of said base plate (1) which forms the shape of ballast tank; plurality of vertical flat bars (10) and plurality of bottom plates (11) welded on said vertical slotted plates (9); plurality of flats bars (12, 14, 15, 16, 17) welded on both sides of said vertical slotted plates (9) for strengthening; and a plate (13) welded on said vertical slotted plates (9) for adjusting the diameter of aft ballast tank during welding along the base plate (1).

The said assembly jig for manufacturing of emergency blowing aft ballast tank is fabricated in a circular steel structure with pipe in center, wherein the aft ballast tank elements are supported at top, and other elects are welded around the periphery of the jig as shown in the figures.

In a preferred embodiment according to the present invention, an assembly jig for ballast tank comprises; a base plate (1), wherein said base plate comprises plurality of plates welded together; plurality of support structures (5) welded on bottom portion of said base structure (1); plurality of vertical angle members (4) welded on said support structures (5) to form the stand for base plate; plurality of ground plate (7), wherein other end of said vertical angle members (4) are welded on said ground plate (7); plurality of inter-connecting angular members (2,3) welded to said support structures (5); plurality of inter-connecting angular members (6) welded to said vertical angle members (4); plurality of vertical slotted plates (9) placed on the top periphery of said base plate (1) which forms the shape of ballast tank, wherein each slot rests the circular member of aft ballast tank where the intermediate vertical members are welded to form the aft ballast tank; plurality of vertical flat bars (10) welded at the outer periphery of said vertical slotted plates (9); plurality of bottom plates (11) welded at the base of said vertical slotted plates (9) which rests on the circular base plate; plurality of flats bars (12, 14, 15, 16, 17) welded on both sides of said vertical slotted plates (9) for strengthening; and a plate (13) welded on said vertical slotted plates (9) for adjusting the diameter of aft ballast tank during welding along the base plate (1).

In a same preferred embodiment according to the present invention, said vertical slotted plates (9) is fixed with base plate (1) by means of securing members (18, 19, 20).

In a same preferred embodiment according to the present invention, said securing members (18, 19, 20) are selected from nut, bolts and washers.

In a same preferred embodiment according to the present invention, said base plate (1) is a circular base plate.

In a same preferred embodiment according to the present invention, said plurality of plate in base plate (1) have a thickness of 30mm.

In a same preferred embodiment according to the present invention, said support structures (5) are six in numbers.

In a same preferred embodiment according to the present invention, said support structures (5) are selected from I-beams.

In a same preferred embodiment according to the present invention, said ground plate (7) is a rectangular ground plate.

In a same preferred embodiment according to the present invention, said ground plate (7) are six in numbers.

In a same preferred embodiment according to the present invention, said base structure (1) material is selected from steel.

Further, the assembly jig for emergency blowing aft ballast tank helps to assemble all the elements of aft ballast tanks by providing the base for aft ballast tank.

In an exemplary embodiment according to the present invention, the circular member with smallest diameter is inserted in the bottom slot and the vertical members are welded on it. After full welding next circular member with higher diameter is inserted in the next slot and it is welded with the vertical members from bottom and new vertical members are welded from the top. In this manner all elements of aft ballast tanks are welded to form the aft ballast tank structure. This aft ballast tanks are welded to submarine pressure hull which provide reserve buoyancy to the submarine thus enabling the submarine to dive and surface.

Further, the said assembly jig is not limited to aft ballast tank of scorpene submarine, and can also be used for similar structure by modifying the size accordingly.

Furthermore, the said assembly jig for fabrication of emergency blowing aft ballast tank provides the advantage to fabricate the aft ballast tank frame wise from bottom to top making it convenient to assemble the aft ballast tank structure. The stage wise assembly further gives better control over welding and the dimension of final assembly is easy to achieve within tolerance.

The foregoing descriptions are merely specific embodiments of the present invention, but are not intended to limit the protection scope of the present invention. Any variation or replacement readily figured out by a person skilled in the art within the technical scope disclosed in the present invention shall fall within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
,CLAIMS:1. An assembly jig for ballast tank comprising;
a base plate (1), wherein said base plate comprises plurality of plates welded together;
plurality of support structures (5) welded on bottom portion of said base structure (1);
plurality of vertical angle members (4) welded on said support structures (5) to form the stand for base plate;
plurality of ground plate (7), wherein other end of said vertical angle members (4) are welded on said ground plate (7);
plurality of inter-connecting angular members (2,3) welded to said support structures (5);
plurality of inter-connecting angular members (6) welded to said vertical angle members (4);
plurality of vertical slotted plates (9) placed on the top periphery of said base plate (1) which forms the shape of ballast tank, wherein each slot rests the circular member of aft ballast tank where the intermediate vertical members are welded to form the aft ballast tank;
plurality of vertical flat bars (10) welded at the outer periphery of said vertical slotted plates (9);
plurality of bottom plates (11) welded at the base of said vertical slotted plates (9) which rests on the circular base plate;
plurality of flats bars (12, 14, 15, 16, 17) welded on both sides of said vertical slotted plates (9) for strengthening; and
a plate (13) welded on said vertical slotted plates (9) for adjusting the diameter of aft ballast tank during welding along the base plate (1).

2. The assembly as claimed in claim 1, wherein said vertical slotted plates (9) is fixed with base plate (1) by means of securing members (18, 19, 20).

3. The assembly as claimed in claim 2, wherein said securing members (18, 19, 20) are selected from nut, bolts and washers.

4. The assembly as claimed in claim 1, wherein said base plate (1) is a circular base plate.

5. The assembly as claimed in claim 1, wherein said plurality of plate in base plate (1) have a thickness of 30mm.

6. The assembly as claimed in claim 1, wherein said support structures (5) are selected from I-beams.

7. The assembly as claimed in claim 1, wherein said ground plate (7) is a rectangular ground plate.

8. The assembly as claimed in claim 1, wherein said base structure (1) material is selected from steel.