RU217176U1 - HULL OF THE SHIP-TUG - Google Patents

Abstract

The utility model relates to the field of shipbuilding and can be used in the construction of autonomous vessels of the auxiliary fleet for the implementation of maritime maneuvers, including in unmanned navigation. The technical task to which the proposed utility model is directed is to ensure the safe and fast performance of maritime maneuvers (escort, canting, mooring-unmooring) with autonomous control that does not require the participation of people directly on board the ships. The technical result lies in the fact that the proposed design of the hull of the tugboat allows you to position the rudder propellers in the diametrical plane of the vessel, which helps to carry out safe movement in all directions, in particular with a lag, compensating for different types of pitching and performing maneuvers without being tied to the presence of a tank and stern in kind of their identity. To achieve all the necessary maneuvering characteristics in autonomous mode, it is necessary to position the rudder propellers in the center plane of the ship. The technical result is achieved due to the interconnection of all technical solutions in the construction of the automatic tug to achieve the most favorable hydrodynamic characteristics when performing marine maneuvers.

Description

The utility model relates to the field of shipbuilding, namely the hull solution of a tugboat, and can be used in autonomous tugboats in unmanned navigation for the safe performance of mooring operations of marine vehicles (cargo ships), including for providing escort, tilting with high levels of maneuverability.

BACKGROUND OF THE INVENTION

Modern shipbuilders and developers, such as Damen, Abu Dhabi Ports, Robert Allan Ltd and others, in the process of substantiating their technological solutions, distinguish three generations of tugs.

The first generation includes traditional tugs, and all its previous technological solutions for many years.

The second is modern tugs with full-revolving rudder propellers (hereinafter - VRK) or azipods (Azimuthing stern-drive tug - ASD - "Azimuth tug"), which, as a rule, were located in the stern area and in pairs. This technical solution influenced the development of the appearance of the hull. A class of rotary tugs (Rotor tug) was formed.

The third generation includes tugs based on actively developing technologies of unmanned navigation (BES).

The following design solutions are known according to patent documents.

Pusher tug (RF Patent RU 2204500 C2, publ. 20.05.2003)

The invention relates to shipbuilding, in particular to the design of pusher tugs. SUBSTANCE: pusher tug contains a body with two stops mounted on the end of the bow and a coupling lock with gripping claws. The pusher is equipped with a fairing. A guide is placed on the outer side surface of each stop. The fairing has an arrow shape in plan. The guides are made in the form of a strip. An elongated slot for the guide is cut out on each side surface of the fairing. The guides are installed perpendicular to the side surface of the fairing. The bottom of the fairing is made with a tongue covering the end face of the nose section of the hull. EFFECT: reduction of resistance to movement of the pusher tug during the course without a barge is achieved.

Marine vessel with a movable keel (patent No. WO 2009109697).

The main idea of the invention is to preserve the basic principle of the keel while reducing the lateral area during side step maneuvers, while the keel plays an active role in the maneuvering of the sea vessel. This can be extended by providing a marine vessel with an omnidirectional propulsion system and a keel arrangement having an active keel assembly with a first active keel and a second active keel, both of which are rotating members of the keel.

Hull and keel (WO 2001038166).

It is an object of this invention to provide a hull and keel design that solves the fixed ballast displacement problem of boats that create bow and stern waves that interact to limit the maximum speed of the hull through the water as described above. It is the goal to do so without excessive width, without size restrictions, and with the ability to return to an upright position after tipping over.

Accordingly, the present invention provides a hull and keel in which the keel has sufficient buoyancy to support any ballast and sufficient additional buoyancy to support the weight of the hull to which it is attached so that the hull rests on or near the surface of the water.

Buoyancy can be such that the hull is located slightly above or slightly below the surface of the water. However, it is preferred that it rest on the surface of the water, or simply on it, and not in it.

An invention is known according to US patent 20150191224, relating to the design of a tug, and specifically, to an improved shell of a tug designed for towing and maneuvering ships or similar ships, as well as for assisting ships that are in danger due to damage or accidents.

The invention according to US 20190283850 relates to a tug having azimuth propulsion units.

In the context of the present invention, the expression "azimuth propulsion plant" means a propulsion plant, the direction of movement of which in the horizontal direction can be changed by 360°. Such azimuth propulsion systems are already known per se, for example in the form of a nozzle containing a propeller.

The tug has special requirements in terms of traction and maneuverability. For example, it is desirable for the tug not only to produce a propulsive force in the forward direction, but also in the aft direction and even in the lateral direction, although the propulsion power produced in the lateral direction will be less than the propulsive power produced in the longitudinal direction.

It is known that the tug has three azimuth propulsion units. Two azimuth propulsion units are provided in the first longitudinal position, on opposite sides of the middle plane of the tug. The third azimuth propulsion unit is located in a longitudinal position different from the longitudinal positions of these two azimuth propulsion units. In this famous tug, which is known in the field as the Rotor® tug, each propeller unit has a propeller shaft and a main shaft. The propeller can rotate at least 360 degrees around the main shaft, and the main shafts extend parallel to each other, in the vertical direction, when the tug is level.

Known tug according to patent CA 2144460. During towing escort, the tug is designed to assist at high speed in the management and stopping of the vessel, which must be helped with a towing cable coming from the towing winch and connected to the vessel, which is being assisted. While working in the harbor, the tug can be applied to normal towing and buffering tasks.

In addition, the development of a new type of tugs was necessary to assist and escort tankers in dangerous and coastal waters, i.e. outside safe harbors.

The general disadvantages of the described designs are that they are unable to implement the traction force with a lag, there is no possibility of quick maneuvering, and there is also a high risk of cavitation.

TECHNICAL PROBLEM

The technical task to which the proposed utility model is directed is to ensure the safe and fast performance of maritime maneuvers (escort, canting, mooring-unmooring) in the implementation of autonomous control that does not require the participation of people directly on board the ships.

The technical problem is achieved by the proposed hull of the tugboat, including a ship set in the form of two sides rigidly connected to the bottom, identical in design, identical tank and stern, rigidly connected to the rest of the ship set, the hull contours are made taking into account the dissected flow of water when moving forward and the flow created by the rudder propeller, through holes are diametrically symmetrically made in the bottom of the hull for accommodating rudder propellers, and one is made closer to the tank, and the other - to the stern, a keel structure with vertical and horizontal parts is attached to the bottom, having in cross-section view of an inverted letter T, the vertical part of which is attached to the bottom of the hull with one surface, and the other to the horizontal part, while the vertical part of the keel structure is made with concave side ends, and the horizontal part is a rhombus with truncated tops, the geometric arrangement of holes for placement in and rudder columns is determined taking into account the keel structure attached to the bottom, and the keel structure is made along the entire length of the hull bottom between the holes for accommodating the rudder propellers, next to which there are holes for the jet system, the location and shape of which are made taking into account the physical and geometric parameters of all the others elements of the hull and units of the tug vessel.

TECHNICAL RESULT

The technical result lies in the fact that the proposed design of the hull of the tugboat allows for safe movement in all directions, in particular with a lag, compensating for different types of pitching and performing maneuvers without being tied to the presence of a tank and stern due to their identity. The result is achieved by the possibility of positioning the rudder propellers in the center plane of the vessel, which ensures that all the necessary maneuvering characteristics are performed offline

The technical result is achieved due to the interconnection of all technological solutions in the construction of a tugboat to achieve the most favorable hydrodynamic characteristics when performing marine maneuvers.

ESSENCE OF THE UTILITY MODEL

The proposed design of the hull of the tugboat implements the concept of developing an azimuth tugboat with the ability to operate in autonomous and remote navigation without a crew on board, with the ability to perform all types of marine maneuvers quickly, safely, and also to carry out significant traction forces with various positions of the rudder propellers. (VRK) that meets only one condition - to be in the diametrical plane of the bottom of the tug.

It is impossible to obtain a wide choice of the position of the ARC relative to the diametrical plane and each other when they are located in the aft part. The location of the VRK in the diametrical plane expands the choice of maneuvers and traction.

Due to the possibility of the location of the WRC in the diametrical plane, we obtain:

the ability to use the position of the ROV without restrictions, which allows you to carry out all possible sea maneuvers with different positions of the ROV relative to each other and in the diametrical plane;

the absence of a rotation radius equal to the length of the hull of the tug vessel when turning on the spot;

the possibility of keeping the tugboat on the course without frequent taxiing due to uniform effort due to the location of the RVK in the diametrical plane, both in direct motion and in lag (sideways) motion.

fast approach and retreat with a lag, as well as high traction force when pressed by a larger area of \u200b\u200bthe hull than by the tank;

lack of binding to the stern and tank during maneuvers;

low risk of cavitation;

when using an automatic mooring device, both rotary on the forecastle and stern, and stationary onboard, there is no uneven load on the structure and components of the entire tugboat, which is typical for the location of the ARC in the stern;

this solution reduces the negative impact on the propeller, which is typical for the paired arrangement of rudder propellers in the stern due to the hydrodynamic influence on each other.

Identical in design, identical tank and feed provide a reduction in maneuvering time due to constructive binding, for example, when working on an injection, and also to ensure high maneuvering characteristics, in particular when moving with a lag and turning on the spot with a reduction in time for performing the maneuvers themselves .

The positive effect of the location of the rudder propellers in the center plane of the vessel and identical forecastle and stern enhances the equipment of the tug vessel with a special keel design, which has a vertical ridge resembling a classic keel and a vertical symmetrical plane in the lower part of the horizontal on both sides, which ensures smooth movement lag, compensates for all types of pitching and yaw and neutralizes the effect on the wave, as well as the horizontal part of the keel is an auxiliary emphasis on the approach

The essence of the utility model is illustrated by graphic materials, which show:

In FIG. 1 - the main view of the tugboat is presented.

In FIG. 2 is a bottom view of the tugboat.

In FIG. 3 is a front view.

In FIG. 4 shows an isometric view.

In FIG. 5 - a view of the keel structure is presented.

In FIG. 6 - shows the image of the section of the keel structure.

The device contains

1 - ship hull,

2 - keel design,

3 - holes for the rudder propeller in the center plane of the vessel,

4 - holes of the jet system,

5 - identical tank and feed,

6 - horizontal part of the keel,

7 - vertical part of the keel.

The device works as follows.

When the vessel moves, the hull cuts the flow of water and, due to the bypass, creates optimal hydrodynamic conditions. When moving forward, the flow created by the front ASP cuts the vertical part of the keel structure and creates a force formed between the bottom of the hull and the horizontal part, and the rear ASP creates a standard force. The horizontal and vertical parts of the keel structure compensate for pitching during any movements and yaw. During the lag movement of the ARC, it is necessary to turn 90 degrees, and for a complete turn on the spot, one ARC is shifted in one direction, and the second in the opposite direction. For non-linear movement, the RTO must be shifted in the appropriate direction to create the required flow. Together, all constructive solutions provide the described maneuvers (movement). In the event of a failure of the RSC, holes are provided in the hull for equipping the tugboat with a water jet installation. This combination of hull solutions ensures safe and optimal performance of the vessel's maritime maneuvers even in autonomous mode without a crew on board.

DEVICE RELIABILITY

The reliability of the device has been confirmed by experiments.

In order to justify the rigidity of the structure, an experiment was carried out describing the state and behavior of the nodes under different loads on statics and stability, depending on the design of the ship itself, on the navigation area, location of elements, etc., as well as on the selected material for the keel structure.

APPLICATION.

DESCRIPTIONS OF FOREIGN PATENTS-ANALOGUES.

WO 2009109697 - MARINE VESSEL WITH MOVABLE KEEL

Marine vessels, in this case especially tugs, are equipped with a keel to provide directional stability, generate steering forces and dampen roll. Currently, the so-called ASD (Azimuthing Stern Drive) and conventional tugs are equipped with a keel that extends more or less along the length of the hull. These keels have a low aspect ratio, making them ineffective as climbing surfaces, and because they are fixed and still have a large lateral area, they greatly reduce the possibility of sidestep. The so-called tractor Escort Tug Boats are equipped with either a cycloidal propeller (VSP - Voith Schiffstechnik Cycloidal Propeller) or a Z-drive in the bow and a large fixed keel at the stern to provide steering power. While there is some improvement in offshore roll damping, the bypass is significantly reduced given the extreme position of the fin in relation to the center of gravity and traction.

The aim of the present invention is to avoid the aforementioned problems and to achieve a marine vessel with improved maneuverability and excellent seaworthiness.

The main idea of the invention is to preserve the basic principle of the keel while reducing the lateral area during side step maneuvers, while the keel plays an active role in the maneuvering of the sea vessel. This can be extended by providing a marine vessel with an omnidirectional propulsion system and a keel arrangement having an active keel assembly with a first active keel and a second active keel, both of which are rotating members of the keel.

The keel, or active keel, is not a rudder. The rudder only affects the yaw of the vessel on which it is used. In addition, the rudder only generates a turning force around the vessel's center of gravity.

A particular advantage in towing operation is that the keel plays an active role in applying steering force to the vessel being handled. The active keel acts intentionally in relation to the towing point of the marine vessel.

The definition of active means that the active keel unit as a whole, i.e. the first and second active elements of the keel are not fixed, but that they can be moved, i.e. rotate about a vertical axis of rotation about the center line, or keel line, of a seagoing vessel. Thus, the active keel unit is a rotational keel unit. The active keel block is located below the usually more or less flat bottom of the sea vessel. The active keel block affects both the yaw and the sway of the sea vessel.

By arranging the first active keel element and the second active keel element independently of each other, the hydrodynamic environment for the first keel element can be improved to improve maneuvering efficiency. Direction adjustment, i.e. angle of attack individually for each active member of the keel, the optimum amount of lift can be achieved.

In connection with a marine vessel traditionally having a long keel with a low aspect ratio, such as an ASD tug, the active keel unit preferably includes a first active keel element and a second active keel element. Because the keel elements are close together and aligned along the ship's centerline, they exert a hydrodynamic influence on each other. The stern active keel element will encounter the flow at a different angle of attack than the forward active keel element, since the forward active keel element can influence the direction of the flow. Thus, the active keel member can move, i.e. rotate about a vertical axis of rotation relative to the centreline, or keel line, of a seagoing vessel. Thus, the active members of the keel are rotational members of the keel.

When the active elements of the keel rotate, the angle of attack of the keel in relation to the water flow may differ from the angle of attack of the ship's hull. This will allow the tug to generate more lateral lift or broken power with a lower angle of attack for the tug itself. Therefore, this will allow the tug in escort mode to operate with the bow closer to the direction of the head. The advantage will be seen in better handling and stability of the tug in given working situations.

The active keel unit, consisting, for example, of a first active keel member and a second active keel member, is preferably provided with a support frame slipping forward from the support member, a longitudinal support member and an aft support member. The support frame provides a means of protection and stability in connection with docking and possible collision situations.

By providing the first active keel element and the second active keel element with a common base plate, the hydrodynamic environment for both keel elements can be improved to increase lift. The common base plate may act as an end plate or end wing for the wing sections of the keel element.

The active keel members can be pivoted to a transverse position to minimize resistance to lateral movement of the tug to provide better lateral pitching capability than can be achieved with a fixed keel provided with the same area.

Thus, an omnidirectional propulsion system, such as a controllable propulsion system such as a steerable thruster or a cycloidal propeller, provides the main steering force for the marine vessel.

This position is beneficial due to the increase in indirect towing effort when the tug is in tracking mode. In this way, the angle of the active keel elements can be easily coordinated to provide maximum lift and therefore tug steering effort for a given tug. It also provides safe tracking at high speeds by providing corrective steering or braking forces, such as when towing tanker trucks at speeds of about 10 knots or more. This is an advantage since tugs, which are normally designed to be escorted at such high speeds, are less manoeuvrable due to their fixed keels. In the event that the active keel takes the form of two keels replacing a single, fixed, poor quality keel, the keel system according to the invention provides the distinct advantage of higher lifting efficiency than a single fixed keel. This allows tugs that are normally designed to operate at low speed, i.e. inherently ASD tugs, escort at higher speeds due to the ability to develop higher steering forces.

Since the active elements of the keel are aligned along the center line of the vessel, they exert a hydrodynamic influence on each other. By adjusting the direction, i.e. angle of attack individually for each active member of the keel, it is possible to achieve the optimum amount of lift.

When the active elements of the keel rotate, the angle of attack of the active keel block in relation to the water flow may differ from the angle of attack of the ship's hull. This will allow the tug to generate more lateral lift or broken power with a lower angle of attack for the tug itself. Therefore, this will allow the tug in escort mode to operate the bow closer to the direction of travel. The advantage will be seen in better handling and stability of the tug in given working situations.

In this embodiment, the omnidirectional propulsion system will typically be a controllable propulsion system (not shown) either at the forward or aft end of the marine vessel. The marine vessel may even be provided with a plurality of such propulsion units both at the forward and aft ends of the marine vessel. Thus, a steerable propulsion unit, such as a steerable thruster, provides the main steering force for the marine vessel.

Since the keel elements are aligned along the center line of the marine vessel, they exert a hydrodynamic influence on each other. By adjusting the direction, i.e. angle of attack individually for each active member of the keel, it is possible to achieve the optimum amount of lift.

When the active elements of the keel rotate, the angle of attack of the active keel block in relation to the water flow may differ from the angle of attack of the ship's hull. This will allow the tug to generate more lateral lift or broken power with a lower angle of attack for the tug itself. Therefore, this will allow the tug in escort mode to operate the bow closer to the direction of travel. The advantage will be seen in better handling and stability of the tug in given working situations.

WO 2001038166 - HULL AND KEEL

Traditionally, boats have relied on ballast within the boat or a heavy outer keel, combined with the width of the hull, to resist capsizing forces and provide self-healing capability. The added weight means that in order to move, the boat's hull must displace the water it floats on around the hull. This displacement of water creates a bow wave at the front of the boat, a stern wave at the back of the boat, and a trough between the two waves. The interaction of these two waves limits the maximum speed of the boat through the water, because as the speed of the hull increases, the size of the bow and stern waves also increases, and the boat settles deeper into the created chute and cannot escape. Typically, the maximum speed in knots of this type of displacement hull is the ratio of the square root of its water length in feet. There are currently two methods to overcome this hull speed limit. The first method is to design long, narrow hulls, since the general rule does not apply to hulls that are five times the width long, since these narrow hulls cut through the water without creating stern waves that can interact. However, these hulls alone do not provide much resistance to capsizing forces, so two or three hulls are used together and generally do not use ballast (catamarans and trimarans). The disadvantages of this arrangement are excessive width and the inability to return to a vertical position after capsizing. The second method is to design hulls with flat surfaces and no fixed ballast, boats can stop being displacement types by being able to climb out of the trough on the bow wave and slide or flat on the surface of the water. The disadvantages of this arrangement are that the size is limited due to the lack of a fixed ballast with a lightweight design and again the inability to return to an upright position after capsizing.

It is an object of this invention to provide a hull and keel design that solves the fixed ballast displacement problem of boats that create bow and stern waves that interact to limit the maximum speed of the hull through the water as described above. It is the goal to do so without excessive width, without size restrictions, and with the ability to return to an upright position after tipping over.

Accordingly, the present invention provides a hull and keel in which the keel has sufficient buoyancy to support any ballast and sufficient additional buoyancy to support the weight of the hull to which it is attached so that the hull rests on or near the surface of the water. Buoyancy can be such that the hull is located slightly above or slightly below the surface of the water. However, it is preferred that it rest on the surface of the water, or simply on it, and not in it.

The length of the keel is five times the width of the keel to prevent the formation of waves at the bow and stern, which can interact to limit the maximum speed. That is, the total length of the keel is five times the width of the keel at its widest part. (The rate of change in the width of the keel along its length may follow common practice). Preferably, where the hull and keel meet, the hull on either side of the keel should be as close as possible to a horizontal flat plane on or near the surface of the water. The effect of this is to smooth out any waves the keel may create and allow the hull to provide immediate resistance to capsizing forces. The width of these surfaces will vary depending on the specific design. Alternatively, in some designs, these surfaces may exhibit some curvature or slope that deviates from a flat horizontal plane.

Preferably, the hull and keel should be constructed from the lightest boat building materials available, such as carbon or glass fiber reinforced plastics, or wood or steel, or a combination of these or other materials.

US 20150191224 - TUG

The present invention relates to an improved shell for a tug intended for towing and maneuvering ships or similar ships, as well as for assisting ships that are in danger due to damage or accidents.

Said tugboat includes a shallow hull, symmetrical both transversely and longitudinally, which has a flat bottom and vertical sides connected to said lower part by a double pallet, parts at the bow and stern symmetrically inclined upwards from said flat bottom, and generally rectangular profile, seen in plan, with flat, straight ends and flat, straight sides connected by rounded edges.

In addition, said tug contains omnidirectional thrusters that are supported by inclined parts of said hull and extend below the level of said lower part and protection means (keels or skeg) that are supported by said hull and extend from said thrusters below and are centered relative to the center line of the bow and stern of said corps.

However, said known tug has some disadvantages.

The first disadvantage is that said tug has a bottom (i.e. a submerged part of the hull) which is flat and has a low draft, so that the flow of water can be moved without obstruction by the propellers of the propellers, which must comply with the following two requirements.

The first requirement for said tug relates to the depth of the hull, which must be less than the length of the tug, typically 1.8 m, and propulsion units that fully protrude from the specified plane under the hull for another 3 m.

With regard specifically to the first requirement, the bottom of the specified tug is a flat keel, so that the flow of water is not disturbed by the propellers.

The second drawback, connected with the fact that the bottom is flat and with a shallow draft, results from the fact that the specified tug does not offer the required resistance to lateral drag when it is engaged in towing or escorting.

Another disadvantage of this tug is the difficulty of transferring power to a vessel that is being towed/pushed when next to it. In such a situation, the tug has its longitudinal axis parallel to the axis of the pushed/towed vessel, and if it uses the full rated power of the engines, without being supported in the underwater part, but only at the level of the rubber wing placed on the shear strike, it experiences difficulties for pushing this vessel, because the force applied by the propulsors at the point of delivery risks capsizing the tug, creating a high capsizing moment. As an example, it should be considered that the thrust exerted by a tug with 60 tons of pull on a fixed point of stress, if applied from the side while the tug is escorting the vessel during maneuvering, will cause a capsizing moment at least equal to the result of multiplying 60 tons by 3.5 meters (distance between the center of the propellers and the stress point), which is unacceptable for such a tug.

US 20190283850- TUG

The invention relates to a tug having azimuth propulsion systems.

In the context of the present invention, the expression "azimuth propulsion plant" means a propulsion plant, the direction of movement of which in the horizontal direction can be changed by 360°. Such azimuth propulsion systems are already known per se, for example in the form of a nozzle containing a propeller.

The tug has special requirements in terms of traction and maneuverability. For example, it is desirable for the tug not only to produce a propulsive force in the forward direction, but also in the aft direction and even in the lateral direction, although the propulsion power produced in the lateral direction will be less than the propulsive power produced in the longitudinal direction.

It is known that the tug has three azimuth propulsion units. Two azimuth propulsion units are provided in the first longitudinal position, on opposite sides of the middle plane of the tug. The third azimuth propulsion unit is located in a longitudinal position different from the longitudinal positions of these two azimuth propulsion units. In this famous tug, which is known in the field as the Rotor® tug, each propeller unit has a propeller shaft and a main shaft. The propeller can rotate at least 360 degrees around the main shaft, and the main shafts extend parallel to each other, in the vertical direction, when the tug is level.

As a general rule, the object of the invention is to provide a tug which performs better in respect of the above aspects than hitherto known tugs.

The aim of the invention is to provide a tug that can produce more power than the rotary tugs known so far without increasing draft. The aim of the invention is to provide a tug that can produce the same power as the rotary tugs known so far, while reducing the draft. In known tugs, an increase in power can be realized by using two stronger propeller units, but the consequence of this is that the dimensions of the propeller units also increase, which negatively affects the draft of the ship.

In order to realize the above objects, the tug of the present invention may have three azimuth propulsion units, viewed from above, lying in a triangular pattern, with at least the main axis of two such propulsion units on opposite sides of the middle sectional plane of the tug extending at an angle relative to the vertical line when the tug is level. Such an angle is preferably formed by or includes an angle with the median sectional plane of the tug. Such an angle may be formed by or include an angle in a plane parallel to said midsection plane.

SA 2144460 - TUG

During escort towing, the tug is designed to assist at high speed in steering and stopping the vessel that needs to be assisted by means of a towline coming from the towing winch and connected to the vessel being assisted. While working in the harbor, the tug can be applied to normal towing and buffering tasks.

In addition, the development of a new type of tugs was necessary to assist and escort tankers in dangerous and coastal waters, i.e. outside safe harbors.

For these so-called escort tugs, completely different tugs are installed compared to conventional harbor tugs. First, the escort tug's escort speed must be at least as high as the tanker's lowest operating speed. The most economical escort speed is the highest permitted operating speed for tankers in a particular area or, if no such restrictions exist, the highest permitted speed at which illegal traffic is safe. In practice, this means that the tracking speed can be even 13 to 14 knots. Accordingly, the tug should be able to perform its escort tasks at this speed, as well as simply follow the tanker at this speed. In addition, the escort tug must be able to function in all weather conditions. Such prerequisites require that the escort tug be able to function in all conceivable directions and, if necessary, be able to change direction at maximum speed. In addition, an escort tug like this must have maximum traction. In view of such requirements, the only useful propulsion apparatus in the current escort tugs is, in fact, a propeller capable of turning around 360 and having a large traction thrust.

Primarily, two types of tugs are known in the art suitable for escort towing, one of which is the so-called tractor tug, in which the towing winch is located on the aft deck and in which the propeller means were located on the front side of the towing winch, closer to the bow of the ship. Another type is the so-called stern drive tug, in which the towing winch is placed on the forward deck and in which the propeller means were located in the stern of the ship. Thus, tractor tugs and sterndrive escort tugs represent state-of-the-art technology. A disadvantage, especially associated with a sterndrive tug, is that although the hull side surface area of its hull is quite large, it is not advantageous in terms of its shape, and the force application point is located too far back, so that lateral forces are difficult to achieve.

On the other hand, the box keel or lamellar keel was often used to improve directional stability in conventional ships, but not in tugboats.

Accordingly, it is an object of the present invention to provide a new tug for towing escort and/or harbor use while achieving an improvement over prior art designs.

To achieve this goal, in the invention, in order to improve the stability of the tug and the towing, steering and equivalent properties that the tug should provide assistance, a towing passage or equivalent is arranged through which the traction force of the towing cable connected to the forecast towing winch is towed to the vessel, which help is needed. The towing eyelet is located in accordance with the towing angle and in close proximity to the deck plane or in the deck plane. The hull of the tug is shaped so that the hydrodynamic point of application of the hull can be provided upwards and up to the abutment of the towing eyelet or its equivalent in order to reduce the torque of the tug and bring the cable force and the hydrodynamic force in the longitudinal direction to each other.

Claims (1)

The hull of the tugboat, including two sides, rigidly connected to the bottom, identical in design, identical tank and stern, rigidly connected to the rest of the hull, the hull contours are made taking into account the dissected water flow when moving forward and the flow created by the rudder propeller, in the bottom of the hull is diametrically symmetrically made through holes for placing rudder propellers, and one is made closer to the tank, and the other - to the stern, a keel structure with vertical and horizontal parts is attached to the bottom, having a cross-sectional shape of an inverted letter T, the vertical part of which is attached to one surface to the bottom of the hull, and the other - to the horizontal part, while the vertical part of the keel structure is made with concave side ends, and the horizontal part is a rhombus with truncated tops, the geometric arrangement of holes for accommodating rudder propellers is determined taking into account the keel structure attached to the days hull, and the keel structure is made along the entire length of the hull bottom between the holes for accommodating rudder propellers, next to which there are holes for the jet system, the location and shape of which are made taking into account the physical and geometric parameters of all other elements of the hull and units of the tug vessel.

Images