EP1740447A1

EP1740447A1 - Tugboat

Info

Publication number: EP1740447A1
Application number: EP04737692A
Authority: EP
Inventors: Tsvyatko Danov Yochev; Hristinka Georgieva Ivanova
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-03-08
Filing date: 2004-07-07
Publication date: 2007-01-10
Also published as: BG65236B1; WO2005085056A1; BG108621A

Abstract

The present invention relates to a tugboat, with application in maneuvering of a vessel. A problem for better maneuvering during tugging has been solved. The tuboat comprises a hull, where on the hull deck is positioned a movable command cabin and are installed devices for ropes for tying the tugged vessel. To the hull (1) are installed two Z- drives (2) in close proximity to the tugboat hull (1) periphery, they are positioned at max distance one from the other. On one of the hull (1) boards, in symmetry to the transverse plane are installed joint devices (5) for side contact and device (7) for front contact with tugged vessel bow. On the other hull (1) board, also in symmetry to the transverse plane, are installed joint devices (5) uniform with the mentioned above joint devices (5) for side contact and a device (8) for front contact.

Description

TSVYATKODANOVYOCHEV

HRISTINKA GEORGIEVAIVANOVA

VARNA, BULGARIA

TUGBOAT

FIELD OF INVENTION

The present invention is related to a vessel which is a tugboat, with the application for executing or assisting the maneuvers of another vessel as ship, barge or similar.

BACKGROUND OF THE INVENTION

From the present state of the art is known a vessel such as tugboat, with the application to execute or to assist the maneuvers of another vessel. The tugboat is with a specific hull, slightly elongated and oval at its lower part, with bow and stern. The hull is symmetrical regarding the center plane. A propeller with fixed or variable pitch is installed under the hull, between its transverse plane and the stern, for generating of a traction force. The propeller axis lies in the center plane. The propeller is bare or positioned inside a nozzle that may be fixed or rotating around a vertical axis.

There are known designs with two fixed or variable pitch propellers. These propellers are positioned at equal heights under the hull between thc ransverse plane and the stern. The propeller axes are symmetrical in regard to the center plane. Both propellers are bare or each of them can be positioned inside a nozzle, which can be fixed or rotating around a vertical axis.

Well-known is a design with a Voith-Schneider drive type, positioned under the hull, between the transverse plane and the stern and with its axis lying in the center plane.

Another design known from the state of the art is with one fixed or variable pitch propeller, which is bare or is positioned inside a nozzle. The propeller is positioned under the hull between the transverse plane and the bow. In the center plane the propeller hub is fixed by a vertical shaft. This vertical shaft provides for propeller rotation and operation in all directions in the horizontal plane. This propeller is called Z-propeller or Z-drive.

The steering of the tugboat with one- or two-propeller drive, operating as bare or inside fixed nozzles, is carried out by diverting the propeller water stream from a rudder, within the limits of a pre-determined sector relative to the center plane. The rudder is with one blade for each propeller, the blade is positioned behind the propeller, in a vertical plane, in regard to propeller axis, or the rudder is with two blades for each propeller, vertically positioned behind and sideways to the propeller. For one- and two-propeller drives positioned inside rotating nozzles, the direction of the water stream from the propeller is diverted by the nozzles themselves, within the limits of a pre-determined sector relative to the center plane. For a Voith-Schneider drive the traction force is steered in all directions by controlling the angle of attack of the rotating vertical blades. For Z-propeller the traction force is steered by turning the propeller itself in all directions in a horizontal plane. In the center plane, on the deck of the tugboat_Λ close to and behind the transverse plane of the tugboat there is a towing hook for attachment of a tow rope delivered from the tugged vessel and/or a towing winch with a guiding device for delivery of the tow rope from the tugboat to the tugged vessel. On the tugboat bow there is a fender for pushing and behind it there is a device for attachment of a fixing rope that can be delivered from or to a pushed vessel. On the deck of the tugboat there is a command cabin where from the tugboat itself and the tugging operation are controlled. The command cabin is stationary.

The traction force for tugging is transferred to the tugged vessel by towing or pushing. The towing is carried out by the abovementioned towing rope that might be single or double, attached to the forecastle or to the poop of the tugged vessel. The pushing is carried out as the bow of the tugboat, via pushing fender, contacts in a small area from the prismatic part of the tugged vessel board. The tugboat bow may be secured against sliding by a short fixing rope with one of its ends tackled on the abovementioned device, behind the pushing fender of the tugboat and the other end tackled on a suitable outfit on the deck of the tugged vessel. In the operational horizontal plane, the drives and the rudders are projected either in the center line of the tugboat or symmetrically to it. Relative to the transverse line, they are always on the same side. In the same plane, the point of the tugboat traction force application, which represents the axis of the towing hook or respectively the bow of the tugboat, is projected on the center line. To provide for the control of the tugboat traction force direction, the projection of the point of application of this force should always be positioned at some distance alongside the center line from the projection of the drives and the rudders on the same line. This circumstance determines the capability of the tugboat to apply its traction force in a selected direction when its center plane is orientated in this direction. When towing, there is also a need for the tugboat to be preliminarily positioned at a point that is in the same direction of towing, regarding to the fixing point of the towing rope on the tugged vessel.

The drawbacks of these tugboats are the following:

when towing :

Tugboat propellers water stream has a stopping effect on the tugged vessel that causes unfavorable power-energetic, technological and economical consequences; The alteration in the direction of the traction force requires technological time which reduces the time available for reaction against any interfering hydro- and meteorological influences and prolongs the operatiNe time for the maneuver; There is no possibility for simultaneous reduction of the effects of above mentioned two drawbacks, because at all other equal conditions, they alternatively depend on the tugging rope length; Successive individual influences on the longitudinal and the transverse components of the motion of the tugged vessel can be assigned to the same tugboat only when the longitudinal speed of the vessel is very low, hydrological and meteorological rest are required and there is a necessity of considerable time for the alteration of the tugboat position before any influence; An improvement of. the possibility for alteration of the tugboat traction force direction by attachment on the towing hook of two ropes with their far ends fixed oh the forecastle, respectively on the poop, of the tugged vessel, the ropes should be at points positioned symmetrically and at max possible distance from the center plane of the vessel, such, so called "at moustache" attachment, requires ropes that are equal in strength and elasticity. Also, additional efforts and time are necessary for precise equalization of the ropes in length and their permanent control. Otherwise, at a significant side movement of the tugboat, there is a risk of getting on and hanging up of a slack rope over its rudders, propellers or any structural elements; The tugboat with its size and towrope length deprives a considerable part of maneuvering water area alongside and abeam of the tugged vessel.

When pushing :

- i f the bow of the tugboat is not in fixed position, its traction force direction may be selected only within a very small angular sector around the horizontal projection of the perpendicular to the tugged vessel board contact surface. Otherwise, the tugboat slides over the tugged vessel board and this would require time-consuming corrections and may even discredit the maneuver;

- the possibilities for selection of a location to fix the tugboat bow are limited. Usually, the tugged vessel design provides for opportunities for this action at four points only - one in fore and one in aft side of the prismatic part on each board;

- The tugboat is always within the limits of the most strongly expressed influence from the tugged vessel hydrodynamic field, for this reason it can operate with its full efficiency only when there is no longitudinal speed of this vessel. Otherwise, part of its power resources that are in direct progressive dependence on this longitudinal speed, would be applied to withstand the predetermined traction force direction;

- with its length the tugboat deprives part of the water area for maneuvering alongside the width of the tugged vessel.

SUMMARY OF THE INVENTION

The teclinical problem to be solved by the present invention is to create an equipment such as a tugboat with improved operational and technological abilities and opportunities characterized in the following:

- increased self-dependent maneuverability;

- a possibility the tugboat to be used for towing and pushing in the areas around tugged vessel where its hydrodynamic field influence is smallest;

- a possibility for separable or simultaneous influence on the longitudinal and transverse components of the tugged vessel motion and a rapid alteration of the operational regimes;

~ reduction of the deprived part of water area for maneuvering.

The above listed technical problems according to the present invention have been solved by the development of a tugboat with the following design features:

The tugboat hull configuration can be approximated to a parallelepiped. One of the largest in area sides of the parallelepiped is the bottom of the hull. The medium vertical plane, in parallel with the longest sides of the parallelepiped is the center plane of the tugboat and the medium vertical plane perpendicular to the center plane is the transverse plane. Inside the hull are situated the propulsion complex, auxiliary devices, control devices and all other devices and compartments inherent and/or required by the Marine Register Regulations.

In the center plane, close to both ends of the hull, and under the hull, at equal distances from the transverse plane are installed two Z-drives of arbitrary type - propellers, Voith-Schneiders or another type drives with separable control of the direction and the power of their traction force. Both Z-drives are positioned close to the periphery of the tugboat hull at a max distance one from the other.

In the middle of one of the boards are positioned tugboat contact_devices for contact with the bow of the tugged vessel. In the middle of the other board are positioned tugboat contact devices for contact with the stem of the tugged vessel. These devices are used alternatively.

The bow contact devices comprise a side contact device and a front contact device. The side contact device consists of two joints with horizontally rotating arms with variable length; the joints are positioned in symmetry with the transverse plane. At the end of each arm there is a support with soft coverage for contact with the appropriate part on the board or with the appropriate side of the bulb of the tugged vessel. The front contact device is positioned in symmetry with the transverse plane, between the side contact device joints. It represents a vertical plate with soft coverage that swings in a vertical plane. It is installed at the end of a horizontal beam that can be pushed perpendicularly outside the tugboat board at a required length. The plate with soft coverage contacts frontally with the structure elements of the bow, stem or bulb respectively, by adapting its incline to theirs.

The stern contact devices comprise a side contact device and a front contact device. The side contact device is completely uniform to the above described. With its supports with soft coverage it contacts with the corresponding walls of the rudder blade or with the stem sections on the boards of the tugged vessel. The front contact device is unifomi with the above described, with the only difference, that its contact plate with soft coverage is removable and can be replaced by another one from a set of similar plates that are designed to contact with different elements of the tugged vessel stern, respectively to the rear edge of rudder blade, to the hub of vessel propeller, to the base of propeller blades, to stern tube or to stcrnpost.

The connection between the tugboat and the tugged vessel is executed by two tensioning ropes. They are attached, rolled and delivered one at a time to each board of the tugged vessel by two devices representing winches. The winches are installed in the central plane, one at each end of tugboat deck. With these winches the length and the tightness of each rope can be adjusted in positive or negative direction.

With the bow front contact device, bow side contact device and the tensioning ropes the tugboat hull is firmly and monolithically connected to tugged vessel.

In another case, by means of the stern front contact device, for example, contacting with the rudder blade of the tugged vessel, and the stern side contact device establishing contact the rudder blade walls of the tugged vessel and the tensioning ropes, the tugboat hull is firmly and monolithically connected to tugged vessel.

On the tugboat deck there is a command cabin for controlling the tugboat and the tugging operation. The command cabin is movable and can be set aside from its normal position in a transverse direction to the tugboat hull — fore from the bow or aft from the stern of the tugged vessel to avoid contact with bow and stem and to provide a better view.

The advantages of the present invention include the following:

- by controlling the direction and the traction force magnitude of the Z-drives, during a self-dependent maneuvering, the tugboat is able to turn around each selected point or to move in each direction under an arbitrary selected angle;

- when towing or pushing in the conventional manner, the tugboat is more efficient because it is capable to turn and to alter its position faster than the conventional tugboats. Moreover, the tugboat according to the present invention is capable to tow the tugged vessel in a "reversed moustache" mode — with two ropes fixed at its hull ends and the other ends of these ropes are fixed at one point on the forecastle, respectively on the poop of the tugged vessel;

- when the tugboat is fixed either to the bow or to the stern of the tugged vessel, with its contact devices and tensioning ropes, it covers a very small part of the water area for maneuvering;

- when the tugboat is fixed to the bow or to the stern of the tugged vessel its drives operate at points where the hydrodynamic field of the tugged Nessel is weak or practically missing; - the fixed tugboat is capable to influence, individually or simultaneously, on the longitudinal and the transverse components of the tugged vessel motion and/or to apply to the tugged vessel a rotary motion;

- the speed of traction force direction alteration is higher than that of the conventional tugboats;

- by simultaneous fixing of two tugboats, one to the bow and the other to the stem of the tugged vessel respectively, is created a possibility the safety and the other measurable parameters of the maneuvering operation as time, speed, accuracy and energy consumption to be brought to levels that are unattainable for the conventional tugboats.

BRIEF DESCRIPTION OF THE DRAWINGS^' The applied figures show as follows:

— fig.1 - general view of the tugboat;

— fig.2 - longitudinal view of the tugboat;

— fig.3 - transverse view of the tugboat;

— fig.4 - side view of the tugboat as fixed to the tugged vessel bow;

— fig.5 - bird's eye view of the tugboat as fixed to the tugged vessel bow;

— fig.6 - side view of the tugboat as fixed to the tugged vessel stem;

— fig.7 - bird's eye view of the tugboat as fixed to the tugged vessel stern; - fig.8 - longitudinal layout of the tugboat when towing with one rope;

- fϊg-9 — transverse layout of the tugboat when towing with one rope;

- fig.10 - longitudinal layout of the tugboat when towing with two ropes in "at moustache" mode;

- fig.11 - transverse layout of the tugboat when towing with two ropes "at moustache" mode;

- fig.12 - an option with transverse layout of the tugboat when towing with two ropes "at reversed moustache" mode;

- fig.13 - an other option with transverse layout of the tugboat when towing with two ropes;

DESCRIPTION OF PREFERED EMBODIMENTS

According to the description and the figures, the exemplary accomplishment of the present invention comprises a hull 1 with a layout that can be approximated to a parallelepiped. The hull 1 lies in the water on its side with largest surface. Inside the hull 1 are positioned the propulsion complex, auxiliary mechanisms, control devices and all other devices and compartments not shown on the figures which are specific and/or required by the Marine Register Regulations. In the center plane, close to both ends of the hull 1, and under the hull 1, at equal distances from the transverse plane of the hull 1 are installed two Z-drives 2. The Z-drives 2 are with variable pitch propellers 3 operating inside the nozzles 4. Both Z-drives 2 are positioned close to the ends of the hull 1 of the tugboat and are at max distance one from the other.

In the middle of one of the hull 1 board are positioned side contact devices 5 with adjustable length arms and with supports with soft coverage 6 for side contact with the bulb walls, respectively with fore sections of both boards and a front contact device 7 for contact with the bulb, respectively with the stem of tugged vessel.

In the middle of the other hull 1 board are positioned side contact devices 5 entirely uniform with the above described, they have joint devices 5 with alternative length amis with supports with soft coverage 6 for side contact with rudder blade and front contact device 8 for contact with the rear edge of rudder blade

The connection of the tugboat to the tugged vessel is accomplished by tensioning ropes 9. At both ends of the hull 1 deck of the tugboat are installed two winches 10 for fixing, rolling and delivery of one rope to each board of the tugged vessel. By means of devices 10 it is possible to adjust the length and to tighten each rope in positive or negative direction.

By means of a front contact device 7 for front contact with bow structure elements and a side contact device 5 for side contact with the structure elements of the bow and tensioning ropes 9, the hull 1 of the tugboat can be fixed firmly and monolithically to the tugged vessel.

By means of a front contact device 8 for front contact with the rudder blade of the tugged vessel and the side contact device 5 for side contact also with the rudder blade of the tugged vessel and tensioning ropes 9, the hull 1 of the tugboat can be fixed firmly and monolithically with the tugged vessel.

On the deck of the tugboat there is a command cabin 11 for controlling of the tugboat and the tugging operation. The bridge 11 is mobile and can be moved sideways from its standard position in direction fore from the bow or aft from the stem of the tugged vessel to avoid contact with them and to provide a better view.

APPLICATION OF THE INVENTION

The application of the invention is shown on figures 4 to 13.

Fig.4 and fig.5 show the tugboat fixed to the tugged vessel bow. The tugboat is tied and under the tension of ropes 9 to the tugged vessel. By means of the front contact device 7 which pushing out beam, in this case, is completely taken in, the tugboat directly contacts with its board to the bulb, respectively to the stem of the tugged vessel. The side contact devices 5 are shown in operation mode. They are symmetrically rotated and have their plates with soft coverage 6 uniformly protruded to contact to the hull of the tugged vessel. These devices are fixed. In this way, the hull 1 of the tugboat is firmly connected to the hull of the tugged vessel. By generating a traction force with the required power and direction from Z-drives 2 the desired tugging of the tugged vessel is accomplished.

Fig.6 and fig.7 show the tugboat fixed to the stern of the tugged vessel, where the tugboat, as tightened by the ropes 9, via the front contact device 8, contacts with the edge of the tugged vessel rudder blade. The stern contact devices are shown in their operating mode - the front contact device 8 is shown as pushed out in forward direction by its horizontal beam to access the rudder blade edge, and the side contact devices 5 are symmetrically rotated, with their plates with soft coverage 6, uniformly protruded and fixed. In such a way, the tugboat hull 1 also is firmly connected to the tugged vessel hull. By generating a traction force with the necessary power and direction by the Z-drives 2, is accomplished the desired tugging of the tugged vessel.

Fig.8 shows the attachment of the tugged vessel to the tugboat where the towing is performed with one towing rope. The tugboat rope 9 is positioned inline with the center line of the tugboat. The maneuvering of the tugboat and the resulting maneuvering of the tugged vessel are faster executed and in any desired forward direction.

Fig.9 shows an attachment of the tugged vessel to the tugboat where the towing is executed with one towing rope. The towing rope 9 is positioned transversely to the center line of the tugboat. The maneuvering of the tugboat and the resulting maneuvering of the tugged vessel are executed faster and in any desired forward direction.

Fig.10 shows attachment of the tugged vessel to the tugboat where the Lowing is executed by two ropes. The direction of towing is alongside the central plane of the tugboat. Both ropes 9 are fixed at "moustache" mode - at a single point on the tugboat and on both sides of the tugged vessel boards. When towing to port or to starboard only one of the ropes is loaded. When towing ahead both ropes are loaded.

Fig.11 also shows attachment of the tugged vessel to the tugboat where the towing is executed by two ropes. The direction of towing is transverse to the central line of the tugboat. Both ropes 9 are fixed at "moustache" mode - at a single point on the tugboat and on both sides of the tugged vessel boards. When towing to port or to starboard only one of the ropes is loaded. When towing ahead both ropes are loaded. Fig.12 also shows attachment of the tugged vessel to the tugboat where towing is executed by two ropes. The direction of towing is transverse to the center line of the tugboat. Both ropes 9 are fixed at "reversed moustache" mode - in two points on the tugboat and at a single point on tugged vessel bow. When towing ahead both ropes are loaded. When towing to port or to starboard both ropes are loaded too.

Fig.13 also shows attachment of the tugged vessel to the tugboat where the towing is executed by two ropes. The direction of towing is transverse to the center line of the tugboat. Both ropes 9 are fixed on both sides of the tugboat and on both sides of the tugged vessel. When towing to port or to starboard only one of the ropes is loaded. When towing ahead both ropes are loaded.

Bibliography: The Nautical Institute on Pilotage and Shiphandling, 202 Lambeth Road, London SE1 7LQ, UK, ISBN 1870077075

TERMINOLOGY

1. tugboat hull

2. Z- drive

3. propeller

4. nozzle

5. side contact device

6. contact plates

7. contact device for contacting tugged vessel bow

8. contact device for front contact with tugged vessel stem

9. rope

10. winch

1 1. command cabin

Claims

1. A tugboat comprising a hull, where on the deck is positioned a command cabin and are installed devices for ropes for tying of a vessel for tugging, and to the hull are installed drives and a support for pushing of a vessel for tugging, characterized in the following: the hull (1) is with configuration that can be approximated to a parallelepiped with a base corresponding to the side with the largest surface, where in the center plane, close to both ends of the hull (1), and at equal distances from the hull (1) transverse plane are installed two Z-drives (2), that are in close proximity to the periphery of the tugboat hull (1) and are at max distance one from the other, and on one of the hull (1) boards, in symmetry with the transverse plane, are installed joint devices (5) for side contact with the bow sections of the two boards and a device (7) for front contact with bow stmcture elements, respectively the stem, the tugged vessel bulb, and on the other hull (1) board, also symmetrically to the transverse plane, are installed devices (5) that are entirely uniform with the mentioned above devices (5) for side contact with the walls of the rudder blade or the stem sections on both boards and a device (8) with replaceable plates for front contact with the stem stmcture elements, respectively, the rear edge of rudder blade, the propeller hub, the base of propeller blades, the stem tube or the stempost of the tugged vessel, where the command cabin (11) for controlling the tugboat and the tugging operation is with mobile attachment and there is a possibility the command cabin to be moved.

2. A tugboat in accordance with claim 1, characterized in this, that the joint devices (5) for side contact are with alternative length arms and are equipped with contact plates (6).

3. A tugboat, in accordance with claim 1, characterized in this, that with device (7) for front contact with bow stmcture elements, respectively stem, bulb and device (5) for side contact with the bow sections of both boards or with the tugged vessel bulb walls and tensioning ropes (9), the tugboat hull (1) is tied firmly and monolithically to the tugged vessel.

4. A tugboat, in accordance with claim 1, characterized in this, that with device (8) with replaceable plates for front contact with the stem structure elements, respectively the rear edge of rudder blade, the propeller hub, the base of propeller blades, the stem tube or the stempost and device (5) for side contacts with rudder blade walls or the stem sections on both boards of the tugged vessel and the tensioning ropes (9), the tugboat hull (1) is tied firmly and monolithically to the tugged vessel.

5. A tugboat, in accordance with claim 1, characterized in this, that the mobile attachment of the command cabin (11) provides for the command cabin to be moved and fixed sideways from its standard position in direction fore from the bow and aft from the tugged vessel stem.