AU3030900A

AU3030900A - Semi-immersible heavy-lift cargoboat

Info

Publication number: AU3030900A
Application number: AU30309/00A
Authority: AU
Inventors: Peter Andersen; Hans Van Mameren
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 1998-12-23
Filing date: 1999-12-10
Publication date: 2000-07-31
Anticipated expiration: 2019-12-10
Also published as: EP1140616A1; WO2000038976A1; AU762581B2; KR20010089684A; CN1257810A; KR20070116292A; DE59908830D1; TW452558B; CA2356675A1; KR20080049111A; PL348882A1; DE29823737U1; ATE261367T1; CA2356675C; DK1140616T3; NO20013077D0; CN1147410C; EP1140616B1; ES2217866T3; NO20013077L

Abstract

The invention relates to a semi-immersible heavy-lift cargoboat with floodable and freeable bottom and side tanks for loading and unloading cargo according to the float-on/float-off and/or roll-on/roll-off method. Said cargoboat also comprises a diesel-electric driving arrangement. Said heavy-lift cargoboat is provided with diesel engines being the main engines. Said diesel engines drive at least one azimuth rudder propeller. A lateral thrust installation is provided in the forebody in order to improve manoeuvrability. The trimmed attitude can be trimmed in relation to the cargo by placing water ballasting in the upper and lower tanks.

Description

GR 98 P 8652 P Description Semi-submersible deadweight cargo vessel 5 The invention relates to a semi-submersible deadweight cargo vessel. Such cargo vessels are used principally for transporting large and heavy bulk materials and are distinguished by a tonnage of far 10 more than 10,000 t. In contrast to conventional cargo vessels in which the cargo is loaded and unloaded with cranes, and which are therefore subject to limits in terms of the dimensions of the freight to be transported, semi-submersible deadweight cargo vessels 15 are particularly suitable for transporting bulky items, for example complete oil drilling platforms, port crane systems or medium-sized to large water vessels or parts thereof. For this purpose, semi-submersible deadweight cargo vessels are usually composed of a front part in 20 which the drive system and the command and crew rooms are located, and a rear part which is essentially embodied as a hollow-walled float which has ballast tanks and a planar transport platform. By flooding the ballast tanks it is possible to 25 submerge the semi-submersible deadweight cargo vessel to such an extent that the transport platform sinks below the water line so that floatable cargo, or cargo which is loaded on a pontoon for example, can be placed on it or removed from it. Conversely, by freeing the 30 ballast tanks it 'is possible to raise the transport platform under the cargo to be transported in order to load on said cargo. In addition to this float-on/float-off method, cargo can also be loaded and unloaded with what is referred to as the 35 roll-on/roll-off method by raising or lowering the transport platform of the semi-submersible deadweight cargo vessel to the level of the quay.

GR 98 P 8652 P -2 It is known to provide cargo vessels with an electric vessel's drive. In diesel-electric systems, the electric propeller motor is usually supplied by generators which are driven by diesel engines and/or 5 gas turbines. A diesel-electric drive requires higher investment costs in comparison with diesel engines which are coupled directly to the vessel's propeller, but it provides the advantage or more efficient use and makes possible a high torque on the propeller shaft, 10 even under very large load conditions. In addition, with diesel-electric drives there is no risk of inadequate machine control if the propeller leaves the water, for example in rough seas. In conventional diesel-electric drives, all the 15 electric parts of the system are accommodated inside the vessel, and engines, gear mechanisms and drive shafts are aligned flush with one another. Other unsatisfactory aspects of this are the occurrence of high mechanical and hydrodynamic losses and restricted 20 maneuverability in comparison with propellers which are driven from outside the vessel. A comparatively uneconomical consumption of fuel is also disadvantageous. The invention is based on the object of 25 providing a semi-submersible deadweight cargo vessel which has a high level of fuel efficiency and is distinguished by good maneuverability. The means of achieving this object comprises a semi-submersible deadweight cargo vessel with floodable 30 and freeable bottom and side tanks for loading and unloading cargo in accordance with the float-on/float off and/or roll-on/roll-off method and a diesel electric drive system which has, as main machines, diesel engines which drive at least one azimuth rudder 35 propeller, in which a transverse thrust device is provided in the forebody in order to improve the maneuverability and in which the attitude can be GR 98 P 8652 P - 2a trimmed with respect to the cargo by introducing water ballast GR 98 P 8652 P -3 into upper and lower tanks. A semi-submersible deadweight cargo vessel which is designed in such a way has, in comparison with known vessels of this type, a lower level of fuel 5 consumption and is particularly maneuverable. The cause of this is, firstly, the use of an azimuth rudder propeller which permits both particularly good maneuverability and better vessel resistance. This permits more precise handling characteristics, in. 10 particular during loading and unloading, and therefore makes it possible to largely dispense with the aid of tugs. Other factors which contribute to good maneuverability are the good stability of the vessel owing to the trimmable attitude, and the transverse 15 thrust device in the forebody. A high level of fuel efficiency is ensured by virtue of the fact that the azimuth rudder propellers are driven by a diesel-electric drive system. It is particularly advantageous to arrange the 20 diesel-electric drive system in the forebody so that optimum utilization is made of the space available on the vessel with respect to the transportation suitability of the deadweight cargo vessel. The arrangement of the essential pieces of equipment in the 25 forebody ensures maximum possible variability for loading and unloading cargo onto and off the transport platform in the afterbody, which is not subject to any structural restrictions in this way. It is also particularly advantageous to drive 30 the azimuth rudder propeller by means of an electric motor which is arranged outside the vessel and which is fed by a generator driven by the main machines. The use of electric motors which are arranged outside the vessel for driving one or more azimuth rudder 35 propellers provides the advantage of particularly high fuel efficiency. This drive technology which is known in practice under the designation SSP is also distinguished by a low level of vessel resistance with GR 98 P 8652 P - 3a a very wide variety of vessel bodies and does not require any additional cooling because the water flowing around the electric motor GR 98 P 8652 P -4 has a cooling effect. Furthermore, the SSP drive is associated with low use and maintenance costs. According to a further feature of the invention, the azimuth rudder propeller is embodied as 5 an azimuthing rudder double propeller. Double propellers are associated with higher procurement and maintenance costs in comparison with single screws, but providing two propellers makes it possible to have a smaller propeller diameter, enabling the semi 10 submersible deadweight cargo vessel to be constructed with a smaller draft, which reduces costs. According to one advantageous development of the invention, the transverse thrust device is also driven electrically, contributing to making the design of the deadweight 15 cargo vessel fuel-efficient and cost-effective. In one preferred embodiment, the transverse thrust device in the forebody can be controlled from a central navigation console in the wheelhouse and from two bridge side wings of the semi-submersible 20 deadweight cargo vessel, in order to ensure maximum visibility when maneuvering. This is also promoted if, according to a further advantageous feature of the invention, the flooding and freeing of the bottom and side tanks can be controlled from a control console on 25 the rear side of the wheelhouse. The switching and signaling boards of the semi-submersible deadweight cargo vessel are expediently accommodated in a sound-insulated machine control room in order to damp the level of sound 30 emitted by the vessel's machinery. For this purpose, it is also advantageous to provide, according to a further feature of the invention, the main machines with sound dampers. In order to make operating costs particularly 35 low, according to one advantageous development of the invention, the diesel engines can be operated with heavy oil which has a viscosity of approximately 3,500 s GR 98 P 8652 P - 4a Redwood. Low operating costs are also promoted if, according to one further advantageous GR 98 P 8652 P -5 development of the invention, diesel engines which can be operated with marine diesel oil are provided as auxiliary machines. The auxiliary machines are advantageously installed here on a vibration-damped 5 base so that a minimum possible noise level is generated. According to one further feature of the invention, the exhaust gas line of the drive system is movably arranged in order to ensure maximum possible 10 variability with respect to operating lines in a favorable way in terms of sound. The invention also proposes that loading gear, preferably hydraulically operated vessel's cranes, be arranged on the foredeck, so that the conventional lift-on/lift-off method can 15 also be applied for loading and unloading. Finally, it is proposed that two anchor winches with an anchor chain be arranged on the forebody and an anchor winch with an anchor cable be arranged on the af ter body, in order to ensure reliable three-point lashing. 20 Further details and advantages of the subject matter of the invention emerge from the following description of a preferred exemplary embodiment. In the associated drawing, in particular: FIG. 1 shows a side view of a semi-submersible 25 deadweight cargo vessel; FIG. 2 shows a plan view of the semi-submersible deadweight cargo vessel according to FIG. 1, and FIG. 3 shows a side view of an azimuth rudder double 30 propeller. The semi-submersible deadweight cargo vessel illustrated in figures 1 and 2 has an overall length of 156 m. The length between the casting leads is 145 m. The cargo deck has a length of 126 m, a width of 35 32.26 m and a free cargo area of approximately 4,065 m2 . The height of the sides in the vicinity of the cargo deck is 10 m, while the draft GR 98 P 8652 P -6 of the semi-submersible deadweight cargo vessel is 7.50 m with freeboard and 19.0 m with the cargo deck lowered. The semi-submersible deadweight cargo vessel 5 has a dead weight of 18,000 t with freeboard. This is composed of 2,000 t heavy oil (HFO 380) which serves as fuel for the main machines, 172 t marine diesel oil which is used as fuel for the auxiliary machines and for which a loading capacity of approximately 200 m 3 is 10 present, 300 t fresh water, for which there is a corresponding loading capacity of 300 m 3 , 25 t lubricating oil, 20 t supplies for the crew, 20 t spare parts and 15,463 t payload. The average molded draft is approximately 7.5 m with this dead weight in sea water 15 with a specific density of 1,025 t/m 3 . This corresponds to the draft with freeboard. The semi-submersible deadweight cargo vessel also has a loading capacity of approximately 40 m 3 for dirty oil and of approximately 5 m 3 for waste water. 20 Accommodation for 22 crew members and 16 passengers is provided on the forebody, above the foredeck. 3 diesel engines with a rotational speed of approximately 720 min-, which serve as the main machines, are also arranged on the forebody. With the diesel engines which 25 are embodied as 9-cylinder series-mounted machines it is possible to generate electrical power of approximately 3,645 kW each. With electrical losses of approximately 8.7% of the generator when driving, and without supplying the vessel's electrical system, a 30 power of 8,675 kW can thus be made available. The semi-submersible deadweight cargo vessel is also equipped with two auxiliary machines, embodied as diesel engines, for generating power for the vessel's electrical system, said machines supplying a generator 35 power of 720 kW each with a rotational speed of 720/900 min-. A third diesel generator, which has a rotational speed of 1800 min- 1 and a generator power in accordance with the SOLAS regulations is provided for GR 98 P 8652 P - 6a when the vessel is docked and for emergencies.

GR 98 P 8652 P -7 Two azimuth rudder double propellers, which are each driven by means of electric motors arranged outside the vessel and can generate an operating speed of 14 kn are used as the vessel's drive. This drive, 5 which is referred to as an SSP drive (illustrated in FIG. 3) is supplemented by two electrically driven transverse thrust devices which improve the maneuverability and stability of the deadweight cargo vessel. Trials have shown that the lowered deadweight 10 cargo vessel can be readily controlled precisely against a wind force of 6 to 7 Beaufort using the two transverse thrust devices. A multiplicity of winches are provided for fastening the cargo on the cargo deck. Sound protection 15 measures, for example the spatial separation of machine rooms and accommodation, noise-proofing encapsulation of the accommodation on the foredeck or sound damping for the main machines, ensure ergonomic working conditions. The semi-submersible deadweight cargo 20 vessel can be lifted from the lowered draft of 18 m to a draft of 7.50 m within 4 hours by pumping empty the ballast tanks using compressed air. As a result of the low consumption by the main machines of 46.98 mT/24 hr it is possible for the semi-submersible deadweight 25 cargo vessel, which can also be a dock vessel depending on the application, to be at sea for a period of 34.6 days longer, basing the calculation on 360 days, than comparable conventional vessels. This means that additional cargo can be transported for the same 30 operating costs. The high fuel efficiency is also due to the fact that, depending on requirements, just one or two diesel engines of the main machines are operated. Last but not least this also allows for ecological factors.

Claims

1. A semi-submersible deadweight cargo vessel with floodable and freeable bottom and side tanks for 5 loading and unloading cargo in accordance with the float-on/float-off and/or roll-on/roll-off method and a diesel-electric drive system which has, as main machines, diesel engines which drive at least one azimuth rudder propeller, in which a transverse thrust 10 device is provided in the forebody in order to improve the maneuverability and in which the attitude can be trimmed with respect to the cargo by introducing water ballast into upper and lower tanks.

2. The semi-submersible deadweight cargo vessel as 15 claimed in claim 1, characterized in that the diesel electric drive system is arranged in the forebody.

3. The semi-submersible deadweight cargo vessel as claimed in claim 1 or 2, characterized in that the azimuth rudder propeller can be driven by means of an 20 electric motor which is arranged outside the vessel and which is fed by a generator driven by the main machines.

4. The semi-submersible deadweight cargo vessel as claimed in one of claims 1 to 3, characterized in that 25 the azimuth rudder propeller is embodied as an azimuthing rudder double propeller.

5. The semi-submersible deadweight cargo vessel as claimed in one of claims 1 to 4, characterized in that the transverse thrust device is driven electrically. GR 98 P 8652 P -9

6. The semi-submersible deadweight cargo vessel as claimed in one of claims 1 to 5, characterized in that the transverse thrust device can be controlled from a central navigation console in the wheelhouse and from 5 two bridge side wings.

7. The semi-submersible deadweight cargo vessel as claimed in one of claims 1 to 6, characterized in that the flooding and freeing of the bottom and side tanks can be controlled from a control console on the rear 10 side of the wheelhouse.

8. The semi-submersible deadweight cargo vessel as claimed in one of claims 1 to 7, characterized in that switching and signaling boards are accommodated in a sound-insulated machine control room. 15

9. The semi-submersible deadweight cargo vessel as claimed in one of claims 1 to 8, characterized in that the main machines are provided with sound dampers.

10. The semi-submersible deadweight cargo vessel as claimed in one of claims 1 to 9, characterized in that 20 the diesel engines can be operated with heavy oil which has a viscosity of approximately 3,500 s Redwood.

11. The semi-submersible deadweight cargo vessel as claimed in one of claims 1 to 10, characterized in that diesel engines which can be operated with marine diesel 25 oil are provided as auxiliary machines. GR 98 P 8652 P - 10

12. The semi-submersible deadweight cargo vessel as claimed in claim 11, characterized in that the auxiliary machines are installed on a vibration-damped base. 5

13. The semi-submersible deadweight cargo vessel as claimed in one of claims 1 to 12, characterized in that the exhaust gas line of the drive system is movably arranged.

14. The semi-submersible deadweight cargo vessel as 10 claimed in one of claims 1 to 13, characterized in that loading gear, preferably hydraulically operated vessel's cranes, are arranged on the foredeck.

15. The semi-submersible deadweight cargo vessel as claimed in one of the preceding claims, characterized 15 in that two anchor winches with an anchor chain are arranged on the forebody and an anchor winch with an anchor cable on the afterbody.