AU2003228152A1 - Vessel - Google Patents

Description

WO 03/091093 PCT/NO03/00136 Vessel The invention relates to a towboat, as indicated in the introductory part of claim 1. By "towboat" is meant every kind of towboat which is constructed and equipped for towing, hauling and 5 rescuing boats and ships and other seagoing structures. Background Vessels are in general designed and built for specific purposes. Thus, most vessels are made as special purpose vessels, such as ferries, fishing boats, fish carriers, tigs, supply boats, fireboats, 10 boats for oil pollution service, etc., each having special structures and specifications. Simple combination-vessels are also known, for instance boats having holds that can be used for different purposes or in different ways. However, the development of combination-vessels has been limited. An example of an existing combination-vessel is a ring net vessel, which can be 15 used as a trawler. Towboats have been built over the decades, having a low freeboard, high engine power and special demands concerning stability. A conventional towboat must have a towing hook or a towing point positioned an adequate distance in front of traditional rudders or propellers. This is 20 necessary in order to achieve good turning ability when using the rudder. Towboats can be equipped with different propulsion systems, both conventional, ASD, and so-called "tractor" and escort-boats. Such vessels have not been used for purposes other than towing, and in some cases fireboats and icebreakers. The special demands on stability etc. have made it difficult to modify towboats to enable them to be used for other purposes, in periods when they are not used for 25 towing. Thus, nowadays towboats are purely special purpose vessels, having relatively high operating costs. In GB patent application 2.071.580 - (Van Balen), a vessel is described, which must be characterized as an early version of what now is called a "service vessel for offshore work". The 30 main feature of this vessel is that the shaping of the sections at the waterline is such that they can be extended to increase the draught, if it is to be used as an open sea towboat. The known vessel can be used for open sea towing, but can not be used as a towboat or as a fish carrier, because it is too big, it does not have a towing hook, which a conventional towboat WO 03/091093 PCT/NO03/00136 2 needs, and furthermore, the distance between the rudder and a possible towing point is too short in relation to the distance between the towing point and the bow, among other things. In Norwegian patent publication 132.896 - (Pran) there is also described a vessel for offshore 5 work, towing in open sea and anchor handling. A relatively small tank and a larger hold is suggested. In combination with container load on the deck, this results in poor stability. Object The main object of the invention is to provide a towboat that can be used for other tasks, 10 possibly simultaneously. The purpose of this is to arrange a vessel that has satisfactory properties for several tasks. The switch-over from one task to another should be possible with a minimum of readjustment and a minimum of time delay. In particular, it is an object to develop a towboat, which is suited for transport of living fish, 15 possibly with simultaneously towing, and which possibly is provided with equipment for counting fish, delousing fish and similar. It should also be possible to adapt the vessel for other purposes, such as ice breaking and in connection with deployment of oil booms and/or sucking up pollution. 20 The invention The invention is stated in claim 1. Further preferred embodiments of the invention are indicated in claims 2-7. A vessel according to the present invention can funciton as a fish carrier function and as a 25 towboat. This can be acheived by utilizing the tank volume to obtain better stability. By filling the tank with water or with water and fish, or possibly other fluids a stable ballast can be acheived in novel manner. Such a vessel can, alternatingly or simultaneously, be used for towboat operation and as a fish 30 carrier. When used as a towboat, one will provide as most mass as possible by filling the tanks to the maxumum with water or water and fish, or other fluids.

WO 03/091093 PCT/NO03/00136 3 Fish carriers and towboats of today have high downtime. With the vessel according to the invention, it is possible to use the same vessel for both purposes, and possibly others, without lengthy preparation. 5 By filling the tanks with water, or possibly with water and fish, the weight is increased and the freeboard is lowered. This again results in higher effective pull and higher otter-effect when towing. Besides, the stability is increased, which allows for a bigger engine, which results in a higher pull ("ie bollard pull"). 10 Another, and a substantial advantage, is that in rescue operations, for instance when pulling off ships that have run aground with a tugboat, one gets substantially increased mass and hence increased pulling force. Alternatively, the vessel can be arranged with fixed ballast, so that the demand on stability is 15 fulfilled also with empty or partially empty tanks. Example In the following, the invention is described in further detail, with reference to the drawings, in which: 20 Fig. 1 is a side elevation view of a vessel according to the invention, which is arranged with an engine room at the stern and a hold midships, Fig. 2 is an equivalent view of an alternative embodiment, which in addition can be used as an icebreaker and a firefighting vessel, and 25 Fig. 3 is an equivalent side elevation view of a further embodiment, where the engine room is positioned midships in connection to the hold and with a double rudder propeller unit ("tractor") In Fig. 1 a vessel according to the invention is shown, in which a hold 11 is arranged midships. 30 At the rear end of the hold 11, an engine room 12 is arranged with a single or a double propulsion engine 13. At the forward end of the hold 11 there is space 14 for day room, ballast tanks or similar. A hydraulically controlled hatch 15, 16 is arranged at the bottom of fore and aft of the hold 11, for filling and evacuation of the same. The hold 11 can possibly be divided into multiple separate parts.

WO 03/091093 PCT/NO03/00136 4 The vessel has a bow thruster 17 and also an additional side thruster 18 arranged in the hull, in front of a propeller 19 and a rudder 20. Between the stern and a deck house 27 there is arranged a deck 21, possibly with coaming and hatches 39. 5 At the rear end of the deck house 27 there is arranged a towing hook 22 and a towing block 23. In the example, these parts are arranged approximately midships. In a conventional boat type, they can be arranged between the rudder stock and midships. Approximately at the centre of the deck 21, in longitudinal direction, astern of a hatch, there is arranged a towing bridle 24 over a winch 25 with a bobbin winder 26. With such equipment, the vessel can be used as a towboat in 10 an ordinary manner, if the vessel has the required stability in regard to the pulling force (bollard pull). The deck house 27 has a companionway 28 leading to the engine room 12, through a passage 29 that is on the side of the hatch of the hold 11. The passage 29 can, for instance, rise up to the 15 level of the rail, while the lower part is recessed below the deck, in the hold 11. On the opposite side of the hatch of the hold 11, there are arranged two channels 30 for air inlet and exhaust discharge, respectively, the latter leading to a funnel 31 protruding up and out from the deck house 27. Inside the deck house 27 there are arranged pumps and other equipment for 20 handling cargo, for instance living fish. Above the deck house 27, there is arranged a crane 32, an automatic sorter 33 and a light boat 34. In front of the deck house 27 is the superstructure 35 of the vessel, with its wheelhouse and crew facilities in a known manner. The vessel has rubber fenders at the bow and at the stern 36, 37, 25 and a bulbous bow 38. This example of an embodiment or the invention can be modified in different ways, as will be apparent from the following. In these Figs 2 and 3, the same reference numbers are used for equal or corresponding elements and parts as in Fig. 1. 30 Fig. 2 shows an alternative embodiment with an icebreaking bow 40, a water cannon 41 on the top of the superstructure 35 for firefighting, and a cloak 42 under the towing bridle 24. The cloak 42 has an entrance door 43 for access down to the engine room 12.

WO 03/091093 PCT/NO03/00136 5 Hence, this example has the advantage of a still greater range of uses, as it can be used alternately, and with short switch-over time, as a towboat, a fish carrier, ice breaker and a fire float. 5 Fig. 3 shows an embodiment with a propulsion machine 50 arranged midships in an engine room 51, and with a double rudder propeller unit 52 extending downwards. The engine room 51 can have the shape of a shaft. Below the forepart of the vessel, there is arranged a combined foil and docking support 53, and under the stern a skegg 54. 10 With this propulsion system, the towing line 55 can be inserted in the stern, below a towing bridle 56, and further onto the towing winch 25. The towing hook 22 can in this case be moved astern because the turning characteristics, which are required on a conventional towboat, are not necessary due to the location and type of the propeller. 15 The vessel can also be formed with other types of propulsion units than the illustrated double propeller unit 52, for instance a propulsion unit of the Voith Schneider-type. Alternatively, a diesel-electric aggregate that gives electricity supply to an electric motor below the stern, can be arranged in the engine room 51. Other propulsion systems may also be of interest, such as waterjets and integrated electric engine propellers. 20 With a so-called ASD-solution with two propellers astern, it is possible to have a towing winch in front of the superstructure, with a towing point at the bow. This vessel can be constructed to have a small freeboard when the hold 11 is filled with water, or 25 possibly also contains fish. This contributes to good stability, which is of particular importance if the vessel is used as a towboat in this situation. In this way a vessel is obtained, which can be better utilized, without downtime and with minimal preparations when alternating between different jobs. If the vessel has been used as a fish carrier for transportation of fish, for instance from a net cage to a fishmanger, and the hold 11 has no water, water can quickly be filled into 30 the hold 11, so that the boat enters a towboat configuration. This may also take place when the vessel is on the way between two job locations.

WO 03/091093 PCT/NO03/00136 6 A particular advantage of the vessel according to the invention is that it can be used for at least two substantially different purposes simultaneously. Previously, two different vessels where built for such purposes. 5 Compared to a fish carrier, the extra costs will mainly be the costs for fenders, towing hook, towing winch and some additional engine power. Since both towboats and fish carriers nowadays have lengthly downtime and seldom can be used effectively, the exploitation ratio can be substantially enhanced due to the invention. In practice, this vessel can tow and transport cargo simultaneously. This is a development that can have a large utility value beyond the 10 economic aspect. It will for instance be possible to have more vessels available, strategically located at selected places along the coast, which can tow fish farms when algal problems or ice problems makes it necessary to move net cages at short notice. Regarding emergency preparedness, it will be a great advantage for costal areas to have more 15 vessels available nearby, which can be brought into action at shipwrecks and similar. The vessel according to the invention can then be used both for towing and drainage, as pumping facilities can easily connected to a suction hose and the hold can provided room for sucked fluid. In this manner, a new type of rescue vessel is obtained. By furnishing the vessel with fire extinguishing equipment and a ice breaking bow as shown in Fig. 2, the range of use will be widened further. 20 Both amendments will imply relatively low additional costs. In conjunction with the deck house 27, different types of equipment for processing fish can be arranged inside or outside, such as counting equipment, sorting equipment, delousing equipment, cleaning equipment, RSV installation, aeration plant and similar. Moreover, there can be 25 provided additional drainage pumps for emergency pumping or drainage of oil spillage, or drainage of wrecked boats. The deck area and the hold can also be used for transport of oil booms, for deployment in polluted sea areas, and for equipment for suction of oil from oil booms. 30 Furthermore, the vessel according to the invention can be equipped with facilities for rendering ballast water harmless, for instance by radiation treatment, including ballast water from ships and other marine constructions.

Claims (7)

1. Towboat of the kind that has a towing point (22, 23; 56), such as a towing hook, towing winch, towing hawse or towing block, positioned with a free area behind it, so that a towline can move freely to both sides, as the deck house (27) of the towboat and additional superstructure are 5 placed in front of the towing point (22, 23), characterized by at least one hold (11) for transportation and/or treatment of fish, which hold extends in both longitudinal directions from the midship of the vessel, and that this hold (11) has arrangements for rapid intake and outlet of water from the sea, for intake of sea water for circulation and/or for increasing the draught of the vessel, for enhancement of the towing force 10 of the vessel.

2. Towboat according to claim 1, characterized in that there is arranged an access passage (29), on at least one side of the vessel, to an engine room (12), through or beside the hold (11), preferably in such way that it rises 15 upwards toward the edge of the side of the vessel.

3. Vessel according to claim 1, characterized in that the engine room (51) forms a shaft in the hold (11), with hold on both sides. 20

4. Vessel according to anyone of claims 1-3, which has a propulsion system (50) in the middle or the forward part of the vessel, characterized in that an arrangement (25) for fastening a towline is arranged astern in the deck area (21). 25

5. Vessel according to anyone of claims 1-4, characterized in that it has a towing point placed at the bow.

6. Vessel according to anyone of claims 1-5, 30 characterized in that it has equipment for handling oil booms and similar equipment for oil recovery and/or equipment for intake of oil pollution from sea areas.

7. Vessel according to anyone of claims 1-6, characterized in that it has equipment for rendering ballast water harmless.