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:
FORWARD REGION HULL FORM

Applicant:
BUOYANCY CONSULTANTS AND ENGINEERING LLP
Susheela Building, F2/3, A Wing, Panaji, Goa 403 001

The following specification 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 patent application number 201721034864 postdated to 2nd January 2019.

TECHNICAL FIELD

[002] This invention relates to an improved foreship hull for a displacement type vessel.
BACKGROUND OF THE INVENTION

[003] The structure of the hull depends on the type of vessel. The stem is typically sloping or a straight line up to the water line and above that sloping or a combination of a bulb and a raked bow primarily below the water line to combat wave resistance.

[004] The length of entrance for conventional ships/vessels are considerably high when compared to the proposed fore/stem design of the vessel under consideration. This leads to an increase in the length of conventional vessels. Also, certain vessels use bulbous bow to reduce the wave making resistance which actually adds up to difficulty in construction and expenditure.

[005] The optimal speed for these vessels is determined by the water line length, slope angles of the foreship and the proportion of outwardly sloping frame lines in the bow and by strength of the available propellers.

[006] Existing, conventional hull forms have a stem flaring out which leads to increase in length of the entrance as well as considerable amount of air drag. Due to this flaring, for vessels operating in heavy sea, the fore region is reinforced with extra steel. This leads to increase in construction costs

[007] To reduce the existing drawbacks of the existing prior art the present invention discloses a foreship hull as disclosed below.

SUMMARY OF THE INVENTION

[008] The present invention claims an improved foreship hull form wherein the foreship is defined as the fore part of the vessel and stem line is defined as curved edge stretching from the keel below upto the gunwale of the vessel, wherein a stem line rises up from the baseline from Station where parallel middle body ends and Length of Entrance starts and becomes in line with forward perpendicular and at the waterline level the stem line rakes inward towards the hull.

BRIEF DESCRIPTION OF DRAWINGS

[009] The foregoing detailed description of embodiments of a foreship hull is better understood when read in conjunction with the appended drawings. For the purpose of illustrating of the present subject matter, an example of the foreship hull is provided as figures; however, the invention is not limited to the specific system disclosed in the document and the figures.
[010] In the detailed description, an embodiment of a foreship hull is described in detail with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawings to refer various features of the present subject matter.
[011] Figure 1 illustrates the profile view of Hull form From Forward perpendicular to Station where parallel mid body starts.
[012] Figure 2 illustrates the waterlines of the foreship part of the vessel
[013] Figure 3 illustrates the body plan of the foreship part of the vessel
[014] Figure 4 illustrates the effective power at various speeds
[015] Figure 5 illustrates the angle made by the stem line with the deck

[016] It should be noted that the terms “first”, “second”, and the like, herein do not denote any order, quantity or importance, but rather are used to distinguish one element from another. Further, the terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.

DETAILED DESCRIPTION
[017] 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 as used herein and in the appended claims, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise.

[018] 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 of a foreship hull. However, one of ordinary skill in the art will readily recognize that the disclosure for the present invention is not intended to be limited to the embodiments described, but is to be accorded the widest scope consistent with the principles and features described herein.

[019] In most cases the foreship displays transverse symmetry about the center line of the vessel. The hull diverges outward from the base line. The underside of the vessel is flat or has a deadrise that merges into a point of curvature.

[020] The present disclosure relates to a foreship hull. The design of foreship according to the invention is intended for displacement hulls in the speed range of up to 10knots. Increase from 10 knots to 14 knots is possible but reduces the efficiency. Effective power for one of the example hull (LOA= 140 m, Breadth =24.6 m, Depth = 12.6 m, Draft = 9 m) at various speed has been provided in Figure4. Effective power is defined as product of vessel resistance and velocity. The new bow shape is primarily intended to be used in vessels that are engaged in transport of bulk and liquid cargos which may be carried in bulk or unitized.

[021] According to the present invention, a new foreship hull is claimed which reduces or eliminates the drawbacks of existing hull forms. The Length of Entrance is the length from the forward perpendicular to the forward end of the parallel middle body or maximum section. The stem line rises up from the baseline from Station where parallel middle body ends and the Length of Entrance starts and becomes in line with forward perpendicular. At the waterline level the stem line rakes inward towards the deck. The ratio of Length of Entrance to vessel length is in the range of 0.25 to 0.30. The angle made by the stem line with the deck is in the range of 10° to 25°, as shown in Figure 5.

[022] The length of entrance (the distance from the forward perpendicular to the start of the parallel middle body) for the hull form in the present invention is defined with respect to the length of parallel middle body (length up to which the section area continuously remains the same) as ratio of Length of Entrance to parallel middle body length is in the range of 0.30 to 0.40. The length of entrance is also function of speed of vessel with positive correlation coefficient. The length of parallel middle body is in turn dependent on the cargo carrying capacity of the vessel with positive correlation coefficient. The shape of the hull within the length of entrance is shown in Figure 1, 2 and 3.

[023] The rise of hull from the baseline starts from station where length of entrance starts and becomes perpendicular to the baseline at forward perpendicular. The stem at forward perpendicular rakes inward at the waterline level. This fore shape hence aids in achieving an optimal balance between the frictional resistance and wave making resistance at the design speed of the vessel. The length of entrance being short now, the overall length of the vessel gets reduced, thus decreasing the construction cost with more cargo carrying capacity.
[024] The following is a non-limiting example of the preferred ratios between length overall (LOA), breadth (B), draught (T) and depth (D) for one embodiment.
In one embodiment, it may be specified that LOA = 76 m, B = 14 m, T = 5.5 m and D = 7.1 m yields the following ratios

LOA /B = 5.4
B/T = 2.5
LOA /T = 13.8

[025] In another embodiment, it may be specified that LOA = 140 m, B = 24.6 m, T = 9.0 m and D = 12.6 m yields the following ratios
LOA /B = 5.69
B/T = 2.73
LOA /T = 15.55

[026] The foreship hull form in the present invention gives more cargo carrying capacity, decrease in length of vessel, reduces slamming of waves against the vessel sides and fore regions. The hull form claimed in the present invention requires reduced construction material and has significantly lower power requirements and fuel consumption. The hull form claimed in the present invention results in reduced or no green water on the deck.
,CLAIMS:We claim:

1. An improved foreship hull form wherein
the foreship is defined as the fore part of the vessel and stem line is defined as curved edge stretching from the keel below up to the gunwale of the vessel;
and wherein
a. a stem line rises up from the baseline from Station where parallel middle body ends and Length of Entrance starts to become in line with forward perpendicular and
b. at the waterline level the stem line rakes inward towards the hull.
2. The improved foreship hull form of claim 1 wherein ratio of
3. Length of Entrance to parallel middle body length is in between range of 0.30 to 0.40.
4. The improved foreship hull form of claim 1 wherein the ratio of Length of Entrance to vessel length is in between range of 0.25 to 0.30.
5. The improved foreship hull form of claim 1 wherein the angle made by the inward raking stem line with deck is in range of 10? to 25?.