U.S. patent application number 11/877487 was filed with the patent office on 2008-03-06 for steering and propulsion arrangement for ship.
This patent application is currently assigned to AKER FINNYARDS OY. Invention is credited to Janne Andersson, Kai Levander, Olli Salmela, Jari Sirvio.
Application Number | 20080053356 11/877487 |
Document ID | / |
Family ID | 8565466 |
Filed Date | 2008-03-06 |
United States Patent
Application |
20080053356 |
Kind Code |
A1 |
Sirvio; Jari ; et
al. |
March 6, 2008 |
STEERING AND PROPULSION ARRANGEMENT FOR SHIP
Abstract
A large ship having a hull about 100 meters or more in length,
so that the ship is suited for transoceanic traffic, with a narrow
wedge-like bow and the broadest part of the underwater hull being
located amidships, includes at least one steerable rudder propeller
device at the forebody of the ship. The steerable rudder propeller
device(s) at the forebody of the ship substantially provide(s) the
steering and control of the ship and produce(s) a part of the
propulsive force pushing the ship forward at least substantially
within all speed ranges. In harbour manoeuvering, the steerable
rudder propeller device(s) at the forebody of the ship provide(s),
as needed, at least about 20% of the ship's total propulsive power.
When steering ahead in sea traffic, the steerable rudder propeller
device(s) at the forebody of the ship provide(s) at most about 10%
of the ship's total propulsive power.
Inventors: |
Sirvio; Jari; (Turku,
FI) ; Salmela; Olli; (Turku, FI) ; Andersson;
Janne; (Turku, FI) ; Levander; Kai; (Turku,
FI) |
Correspondence
Address: |
SMITH-HILL AND BEDELL, P.C.
16100 NW CORNELL ROAD, SUITE 220
BEAVERTON
OR
97006
US
|
Assignee: |
AKER FINNYARDS OY
PL 132 (Laivakatu 1)
Helsinki
FI
FI-00151
|
Family ID: |
8565466 |
Appl. No.: |
11/877487 |
Filed: |
October 23, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10543582 |
Aug 11, 2005 |
|
|
|
PCT/FI04/00024 |
Jan 19, 2004 |
|
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11877487 |
Oct 23, 2007 |
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Current U.S.
Class: |
114/61.28 ;
114/164; 114/61.27 |
Current CPC
Class: |
B63H 5/08 20130101; B63H
2005/005 20130101; B63H 2005/1254 20130101; B63B 1/06 20130101;
B63H 5/125 20130101 |
Class at
Publication: |
114/061.28 ;
114/164; 114/061.27 |
International
Class: |
B63B 1/00 20060101
B63B001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 30, 2003 |
FI |
20030132 |
Claims
1-5. (canceled)
6. A method of operating a large ship having a hull about 100
meters or more in length, so that the ship is suited for
transoceanic traffic, with a narrow wedge-like bow and the broadest
part of the underwater hull being located amidships, said ship
comprising at least one propulsion device at the rear of the ship
and at least one steerable rudder propeller device at the forebody
of the ship and arranged so that it does not extend significantly
below the base line of the ship, said method comprising: employing
said at least one steerable rudder propeller device at the forebody
of the ship to substantially provide the steering and control of
the ship and to produce a part of the propulsive force pushing the
ship forward at least substantially within all speed ranges, in
harbour manoeuvering, employing said at least one steerable rudder
propeller device at the forebody of the ship to provide, as needed,
at least about 20% of the ship's total propulsive power, and when
steering ahead in sea traffic, employing said at least one
steerable rudder propeller device at the forebody of the ship to
provide at most about 10% of the ship's total propulsive power.
7. A method according to claim 6, wherein at the forebody of the
ship in the underwater section of the hull at a distance from the
base line of the ship, there is an area, which is designed
sufficiently flat so that it enables the mounting and free turning
of said at least one steerable rudder propeller device, and that
the bottom of the ship hull from said area towards the stern is
smoothly shaped so that said at least one steerable rudder
propeller device, while the ship is moving ahead, can be directed
according to the shape of the ship hull, whereby the flow behind
said at least one steerable rudder propeller device towards the
hull surface can be minimized accordingly.
8. A method according to claim 7, wherein the ship is provided with
a bulb and said area is situated behind the bulb.
9. A method according to claim 6, wherein there are at least two
steerable rudder propeller devices at the forebody of the ship.
10. A method according to claim 6, wherein all the propulsion
devices of the ship are permanently situated outside the ship
hull.
11. A method according to claim 6, wherein said at least one
steerable rudder propeller device is mounted to the forebody of the
ship in a region of the hull that is above the base line of the
ship, and the lowest point of the hull in a transverse section
through said region of the hull is in said region of the hull.
Description
[0001] This is divisional of U.S. patent application Ser. No.
10/543,582 filed Aug. 11, 2005, which is a national stage
application filed under 35 USC 371 based on International
Application No. PCT/FI2004/000024 filed Jan. 19, 2004, and claims
priority under 35 USC 119 of Finnish Patent Application No.
20030132 filed Jan. 30, 2003.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a steering and propulsion
arrangement in a large ship suited for transoceanic traffic, which
arrangement comprises a number of propulsion devices situated
partly at the rear and partly at the forebody of the ship.
[0003] From prior art are known steerable rudder propeller devices,
which are driven either by a mechanical force transmission means or
an electric motor arranged inside the device. The device enables
the turning of the propeller device about its vertical axis, and
the propulsive force of the propeller can thus be turned in desired
direction. In addition, the propeller's rotational speed and
direction of rotation may be adjusted and/or the angle of propeller
blades changed.
[0004] Rudder propeller devices have been arranged at the forebody
for instance in ferries that move in two directions. In these
vessels the forebody and rear of the hull have been nearly
identical. This kind of a hull configuration is not suitable for
other types of vessels. Further, rudder propeller devices have been
utilized in various kinds of landing crafts, the rear of which has
generally been designed conveniently so that it enables the
landing. In this case the rudder propellers, if any, at least some
of which extend deeper down than the bottom of the vessel, are made
retractable so that they can be protected when the aim is to steer
the vessel as long as possible ashore.
[0005] During the centuries the hull of large ships suited for
transoceanic traffic has developed so that it is characterised by a
bow being typically narrow like a wedge, the broadest part of the
underwater hull being located amidships and the propellers being
traditionally situated at the rear of the vessel. Large ships refer
here to ships, whose length is about 100 meters or more, whereby
particularly such ship types as large cruisers are included, but
also for instance icebreakers etc. The manoeuvering of such vessels
into harbour requires considerable propulsive efficiency at the
forebody of the vessel. The present equipment used for manoeuvering
the bow produces propulsion, however, only sideways and can be used
only when the vessel does not move or moves at low speed. However,
some special arrangements are known where a rudder propeller or the
like is mounted in a specific recess made to the bottom of the
vessel's front part. These solutions surely improve the
manoeuvrability of the vessel when harbour manoeuvering is
concerned, but in practice they are not applicable to steering
ahead at higher speeds.
[0006] Rudder propeller devices have been arranged also at the rear
of large ships to either partially or completely replace the actual
rudder. When large ships provided with such rudder propellers steer
for instance in a fairly narrow passage, lateral drift might become
a problem tending to impair the manoeuvrability of the ship due to
the considerable lateral surface thereof.
[0007] A purpose of the present invention is to provide a novel
steering and propulsion arrangement for large ships that normally
move in one direction and are suited for transoceanic traffic, in
which arrangement the above described problems are as far as
possible eliminated. An aim is that the solution can with advantage
be utilised in various modes of operation and steering of a
ship.
SUMMARY OF THE INVENTION
[0008] According to the invention the forebody of the ship is
provided with one or more steerable rudder propeller devices, which
are arranged so as to substantially provide the steering and
control of the ship, to produce a substantial part of the
propulsive force pushing the ship forward at least substantially
within all speed ranges, and in addition, arranged so that they do
not extend, at least not significantly, below the base line of the
ship. The base line of the ship refers here to the lowest hull
section determining the draught of the ship.
[0009] The solution according to the invention provides the bow of
the ship with steerable propulsive power. The ship bow can be
manoeuvered when the ship stands still in harbour. When steering
ahead, the propulsion of the fore propeller device is directed
forward, whereby a considerable auxiliary power in forward
direction is provided. If a malfunction occurs in the propeller
device at the rear of the ship, the rudder propeller device at the
front is still able to steer the vessel safely ahead.
[0010] In addition, with the invention savings can be made in the
constructions costs, as the rudder propeller device at the front
replaces the traditional bow-thrusters and reduces the power demand
of the propeller devices at the rear.
[0011] The invention facilitates the manoeuvering of the bow when
the ship does not move or moves ahead. The propulsive force
produced by the rudder propeller device can be fully directed,
whereas a stationary bow-thruster produces only a transverse
force.
[0012] In large vessels the manoeuvering of the bow makes the power
demand so high that as many as 4-6 bow-thrusters of the present
kind would be required at the forebody. These devices are used only
for harbour manoeuvering. A rudder propeller device arranged at the
forebody can have more power and 2-3 devices could replace even six
bow-thrusters.
[0013] In addition, it is advantageous for large vessels, if a part
of the propulsive power pushing the vessel forward is produced at
the front. If one does not want to increase the draught of a large
ship, the diameter of the propellers is limited. This results in a
situation, where the ship needs to be provided with several
propellers. To arrange several propellers at the rear would be
complicated, and rudder propeller devices arranged at the front
would make the situation easier, as they produce a part of the
propulsive force.
[0014] Owing to the invention the vessel's ability to survive
damage in the propulsion devices or powerhouse has improved. For
moving the ship ahead and manoeuvering it in problematic situations
there are now propulsion devices available also at the front, in
addition to the propulsion devices at the rear. Further, in
contrast to rudder propellers arranged at the rear of the ship
only, the steering of the ship by means of rudder propellers
situated at the front can be dynamic so that no lateral drift
occurs when the ship steers in a passage.
[0015] In a practical embodiment at the forebody of the ship, i.e.
in the underwater section of the hull at a distance from the base
line of the ship, there is an area, which is designed sufficiently
flat so that it enables the mounting and free turning of said one
or more rudder propeller devices. In addition, the bottom of the
ship hull from said area towards the stern is smoothly shaped so
that the rudder propeller devices, while the ship is moving ahead,
can be directed according to the shape of the ship hull, whereby
the flow behind the rudder propeller device towards the hull
surface can be minimized accordingly. In case the ship is provided
with a bulb, said area is situated behind the bulb.
[0016] The rudder propeller devices at the forebody of the ship are
dimensioned and arranged to be driven so that they cover, as
needed, at least about 20% of the ship's total propulsive power in
so-called harbour manoeuvering. Further, when steering ahead in sea
traffic the rudder propeller devices at the forebody cover
preferably at most about 10% of the ship's total propulsive power.
Thus it can be secured that in harbour manoeuvering there is as
much power available as in manoeuvering arrangements provided with
fore propeller passages. On the other hand, in normal steering
ahead much lower power levels are sufficient so as to make the flow
no longer hit the hull, which is advantageous from hydrodynamic
point of view. Higher power levels are possibly required in
so-called "take home" situations, in which a part of the other
power supply is for some reason not in use.
[0017] In order to ensure sufficient fore propeller power there are
preferably at least two rudder propeller devices at the forebody of
the ship. The rudder propeller devices as such may be mounted at
the forebody either side by side, one after the other or
overlapping each other.
[0018] In practice all the propulsion devices of the ship are
permanently situated outside the ship hull. By such an arrangement
it can be ensured that the ship's propulsion devices do not
significantly decrease the displacement of the ship.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In the following the invention is described by way of
example with reference to the attached drawings, in which
[0020] FIG. 1 shows a ship, seen from the side, where conventional
propeller devices are situated at the front;
[0021] FIGS. 2-4 show how a rudder propeller device according to
the invention, seen from the side, is arranged at the front of the
ship, whereby the bow is shaped in a different manner; and
[0022] FIGS. 5-8 show how one or several rudder propellers, seen
from below, are arranged at the front of the ship.
DETAILED DESCRIPTION
[0023] In a conventional solution according to the case shown in
FIG. 1 there are three propeller devices arranged at the front of
the ship on both sides, which devices affect only in the lateral
direction of the ship, and contribute to the manoeuvering of the
ship to quay and to its bringing off the quay respectively, and
possibly to performing manoeuvering movements in the harbour area.
When a large ship is concerned, the bow-thrusters require a lot of
power, which is of no use in the ship's normal steering ahead.
[0024] FIGS. 2-4 show how rudder propeller devices are arranged at
the forebody of a vessel. Free turning of the rudder propeller
device requires space and therefore the underwater hull requires
modifications in comparison with traditional solutions. FIG. 2
shows the use of a rudder propeller in a ship lacking a bulb. In
FIG. 3 there is a small low bulb and in FIG. 4 a large deep
bulb.
[0025] FIGS. 5-8 show how one or several rudder propeller devices
can be arranged at the forebody either one after the other, side by
side or overlapping each other. By adjusting the turning angle of
the device the propulsion of the propeller is directed as the
situation requires. Thus the ship can be steered ahead or astern,
to quay, or the drift of the bow can be corrected in side wind or
in curve.
[0026] Thus the invention utilizes a known rudder propeller device
already in general use, which device enables the directing of the
propeller's propulsion around the vertical axis of the propeller
device. The propeller is rotated either by a mechanical force
transmission means or an electric motor arranged inside the device,
which are known as such and are therefore not shown in detail.
[0027] By one or several rudder propeller devices according to the
invention arranged at the forebody of the ship the bow can be
manoeuvered by turning the propeller device. The bow of the ship
can be manoeuvered when the ship does not move at all or moves
ahead. When steering ahead the propulsion of the rudder propeller
device is directed so that significant propulsive efficiency
forward is produced. When steering ahead the flow of the rudder
propeller device is aligned with the hull surface so that the flow
does not occur directly against the hull surface.
[0028] When rudder propeller devices are arranged according to the
invention at the forebody of a large ocean-going vessel,
traditional bow-thrusters are not needed at all. The power relating
to the rudder propeller devices situated at the front reduces the
need of propulsive efficiency at the rear.
[0029] Owing to the invention the vessel's ability to survive
damage in the propulsion devices or powerhouse has improved. For
moving the ship ahead and manoeuvering it in problematic situations
there are propulsion devices available also at the front, in
addition to the propulsion devices at the rear.
[0030] The invention facilitates the manoeuvering of the bow both
when the ship does not move and when it moves ahead. The propulsion
provided by the rudder propeller device can be fully directed,
whereas a traditional bow-thruster provides only a transverse
force.
[0031] The invention is not limited to the above-described
embodiments, but several modifications are conceivable within the
scope of the appended claims.
* * * * *