DESC:FORM 2

THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENT RULES, 2003

COMPLETE SPECIFICATION
(See Section 10 and Rule 13)

Title of invention:
DESIGN OF SUBMARINE LOADING AND LAUNCHING PONTOON

Applicant:
Mazagon Dock Shipbuilders Limited
A company Incorporated in India under the Companies Act, 1956
Under Ministry of Defence,
(A Govt. of India Undertaking)
Having address:
Dockyard Road, Mazagon,
Mumbai - 400010, Maharashtra, India

The following specification particularly describes the invention and the manner in which it is to be performed.
CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY
[001] The present application claims priority from Indian Patent application no. (201821042484) filed on 12th November, 2018.

TECHNICAL FIELD
[002] The present disclosure described herein, in general, relates to a design of Submarine Loading and launch Pontoon (SLP). More specifically, the design of SLP for construction, transportation, launching and docking of Scorpene class submarine.

BACKGROUND
[003] The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also correspond to implementations of the claimed technology.
[004] A conventional method of submarine construction is to fabricate sections of the submarine and assemble them at a dry dock and subsequently launch the submarine post completion of construction. The launching of submarines from dry docks depends on tides. Specifically, the launching of submarines from dry docks is possible only during high tides. The dependency on high tides for launching poses a challenge of time delay to launch the submarine. Another challenge faced is that the submarine occupies the dry dock until submarine construction is entirely completed, thereby increasing the occupancy time. A Submarine loading and Launching Pontoon (SLP) facilitates in overcoming the above challenges. Firstly, after the assembly of the submarines in the dry docks, submarines sections may be shifted to wet basin for outfitting and launching. This reduces the occupancy time of dry dock for a single submarine construction. Secondly, a draft of the SLP with submarine on top may be two meters, thereby reducing the dependency on the high tide for launching. Post completion of the outfitting of the submarine, the submarine along with the SLP is taken to a naval dock and the submarine is separated from the SLP by ballasting the pontoon. There may be modifications in the SLP design to facilitate better construction, transportation, launching and docking of submarines.
OBJECTIVES OF THE INVENTION
[005] It is an objective of the invention to provide a pontoon capable of loading marine vessels.
[006] It is another objective of the invention to provide a pontoon for launching marine vessels, such as ships and submarines, in sea.
SUMMARY
[007] Before the present pontoon for launching submarines in sea is described, it is to be understood that this application is not limited to the particular marine vessels described, as there can be multiple possible embodiments which are not expressly illustrated in the present disclosure. It is also to be understood that the terminology used in the description is for the purpose of describing the particular implementations or versions or embodiments only, and is not intended to limit the scope of the present application. This summary is provided to introduce aspects related to a pontoon for launching marine vessels in sea. This summary is not intended to identify essential features of the claimed subject matter nor is it intended for use in determining or limiting the scope of the claimed subject matter.
[008] In one implementation, a pontoon for launching marine vessels in sea is disclosed. The pontoon comprises a plurality of ballast tanks present across entire area of the pontoon. The pontoon further comprises a water inlet mechanism for filling water into at least one of the plurality of ballast tanks. The plurality of ballast tanks are formed by partitioning entire volume of the pontoon. Entire volume of the pontoon is partitioned using slats positioned across length and width of the pontoon. A top surface of the pontoon, present above the plurality of ballast tanks, is designed to load a marine vessel, such as a ship and a submarine. Stabilizing structures such as keel blocks, bilge blocks, wedges, and cradle are used to stabilize the marine vessel on the top surface. One or more propellers may be attached beneath the pontoon for propelling the pontoon into and out of sea.

BRIEF DESCRIPTION OF THE DRAWINGS
[009] The foregoing detailed description of embodiments is better understood when read in conjunction with the appended drawing. For the purpose of illustrating the disclosure, there is shown in the present document example constructions of the disclosure; however, the disclosure is not limited to the specific methods and apparatus disclosed in the document and the drawing.
[0010] Figure 1 illustrates a rendered view of a Submarine loading and Launch Pontoon (SLP), in accordance with an embodiment of the present disclosure.
[0011] Figure 2 illustrates structures for stabilizing a marine vessel, in accordance with an embodiment of the present disclosure.
[0012] The figure depicts an embodiment of the present disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following discussion that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION
[0013] Some embodiments of this disclosure, illustrating all its features, will now be discussed in detail. The words "comprising," "having," "containing," and "including," and other forms thereof, are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items. It must also be noted that, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. Although any apparatuses and methods similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present disclosure, the exemplary, structures and methods are now described. The disclosed embodiments are merely exemplary of the disclosure, which may be embodied in various forms.
[0014] Various modifications to the embodiment will be readily apparent to those skilled in the art and the generic principles herein may be applied to other embodiments. However, one of ordinary skill in the art will readily recognize that the present disclosure is not intended to be limited to the embodiments illustrated, but is to be accorded the widest scope consistent with the principles and features described herein.
[0015] Figure 1 illustrates a rendered view of a Submarine loading and Launch Pontoon (SLP), alternatively referred as poonton (100). The SLP (100) may be a simple rectangular barge. A ballasting arrangement for the SLP (100) may be designed to suit safe landing of a marine vessel, such as a ship and a submarine, on ballasting SLP (100) tanks. The SLP (100) may have a hull form. The hull form may have a rectangular box with sufficient depth and adequate freeboard to cater for the waves during movement. In one case, entire volume of the SLP (100) may be partitioned to for several ballast tanks (100a, 100b, 100c, 100d). Although the ballast tanks (100a, 100b, 100c, 100d) are shown to be present in Figure 1 on one side only, other ballast tanks may be similarly present within remaining volume. In one case, the ballast tanks (100a, 100b, 100c, 100d) may be formed by partitioning entire volume of the SLP (100). The partitioning may be done using slats (104, 106) positioned across length and width of the pontoon (100). Further, a water inlet mechanism (102) may be present for filling water into the ballast tanks of the SLP (100). Water may be pumped into the ballast tanks (100a, 100b, 100c, 100d) with the help of external ballast pumps. Further, deballasting operation may be performed by pumping out the water using the ballast pumps, and when the SLP is docked in dry dock, drain plugs may be removed to empty the ballast tanks (100a, 100b, 100c, 100d).
[0016] Scantlings of the SLP (100) may be bare minimum that may facilitate reduction of the draft of a vessel. The SLP (100) may comprise of a flat deck (top surface) with no declivity and no railings on the flat deck. In one case, stabilizing structures may be used to stabilize the marine vessel on the flat deck. Referring to Figure 2, structures for stabilizing a marine vessel are illustrated. A marine vessel such as a submarine (200) may be supported from bottom by a keel block (202) and on sides by bilge blocks (204). The keel block (202) and the bilge blocks (204) may rest on flat surface of a cradle (206). The cradle (206) may rest on the SLP (100). Further, wedges may also be used along with the blocks to stabilize the marine vessel. The SLP (100) may be divided into six transverse and three longitudinal bulkheads respectively. The flat deck may be provided with thread strips for safe working of crew during mooring. The accesses to a set of tanks may be through manholes in the flat deck wherein the accesses are immediately adjacent to a watertight bulkheads. In one aspect, the manholes may be provided with rubber packing. In another aspect, central tanks may be accessed through vertical manholes that may have dimension of (600mm*400 mm), wherein mm indicates length in millimeters. The SLP (100) comprises of double bollards for mooring the SLP (100). In one aspect, the double bollards may be of the size of 315 mm.
[0017] In one embodiment, the flat deck of the SLP (100) is especially designed for Scorpene Class Submarines. The principal dimensions for the embodiment may be 78meters (m) of overall length, 15m of beam, depth of 3m and maximum draft of 2.15m. The flat deck may further comprise of cradle. In one aspect, the flat deck of the SLP (100) may have a load carrying capacity of 50 tons per squared meters (t/m2) up to 1200 mm on both sides from a centerline. The centerline is the longitudinal center line of the SLP (100). Further, from 1200 mm to 4200 mm of the centerline, the load bearing capacity may be up to 20 (t/m2) and 5 (t/m2) for the remaining part of the SLP (100) flat deck. The SLP (100) may be towed by a towing boat i.e. tugs. Alternatively, the SLP (100) may comprise propellers for propelling the SLP (100) into sea.
[0018] Exemplary embodiments discussed above may provide certain advantages. Though not required to practice aspects of the disclosure, these advantages may include those provided by the following features.
[0019] The proposed design for Submarine loading and Launching Pontoon (SLP) facilitates in enhancing launch activity of the submarine.
[0020] The proposed design for Submarine loading and Launching Pontoon (SLP) facilitates in overcoming an in-house requirements for construction, transportation, launching, and docking of Scorpene class submarines. However, the same facilitates to carry out advanced outfitting and repair/refit of marine vessels in place of a dry dock..
,CLAIMS:
1. A pontoon (100) for launching marine vessels in sea, the pontoon (100) comprising:
a plurality of ballast tanks (100a, 100b, 100c, 100d) present across entire area of the pontoon (100);
a water inlet mechanism (102) for filling water into at least one of the plurality of ballast tanks (100a, 100b, 100c, 100d);
a top surface, of the plurality of ballast tanks (100a, 100b, 100c, 100d), designed to load a marine vessel.

2. The pontoon (100) as claimed in claim 1, wherein the marine vessel comprises ships and submarines.

3. The pontoon (100) as claimed in claim 1, wherein at least one of keel blocks (202), bilge blocks (204), wedges, and, cradle (206) are used to stabilize the marine vessel on the top surface.

4. The pontoon (100) as claimed in claim 1, wherein the plurality of ballast tanks (100a, 100b, 100c, 100d) are formed by partitioning entire volume of the pontoon (100).

5. The pontoon (100) as claimed in claim 4, wherein entire volume of the pontoon is partitioned using slats (104, 106) positioned across length and width of the pontoon (100).

6. The pontoon (100) as claimed in claim 1, further comprising propellers for propelling the pontoon (100) into and out of sea.

7. The pontoon (100) as claimed in claim 1, further comprising thread strips for safe working of crew during mooring.

8. The pontoon (100) as claimed in claim 7, further comprising double bollards for mooring the pontoon (100).