KR20080049111A - Semi-immersible heavy-lift cargoboat - Google Patents

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

Semi-submersible heavy cargo ship {SEMI-IMMERSIBLE HEAVY-LIFT CARGOBOAT}

The present invention relates to a semi-submersible heavy cargo ship. Such cargo ships are especially used for large and heavy individual consignments and have a loading capacity of more than 10,000 tons. Unlike conventional cargo ships in which cargoes are loaded and unloaded by cranes, which limits the dimensions of the cargo to be transported, semi-submersible heavy cargo ships, for example, provide full offshore platforms, port crane installations or medium to large ship transport. It is particularly suitable for transporting bulky cargo such as means or parts of such ships. To this end, the semi-submersible heavy cargo ship consists of a stern formed by a float with a drive unit, a captain's room and a crew compartment and a hollow wall with a flat transport platform and ballast tanks in accordance with the invention.

By filling the ballast tanks, semi-submersible heavy cargo ships can be submerged such that the transport platform is lowered below the waterline to accommodate or deliver a cargo on a floating cargo ship or for example a pontoon. Conversely, by emptying the ballast tank, the transport platform can be lowered below the cargo to be transported in order to put the cargo to be transported in the dock. In addition to this float-on / float-off method, the so-called roll-on / roll-off method, in which the transport platform of semi-submersible heavy cargo ships is raised or lowered to the height of the pier. The roll-off method may also be used to load and unload cargo.

Cargo ships with electric ship driving devices are already known. In a diesel electric drive, the electric propeller engine is powered by a generator driven by a diesel engine and / or a gas turbine. Diesel electric drives require higher investment costs compared to diesel engines directly connected to the propellers, but have the advantage of being more efficient, and the rotation moment of the propeller shaft can be very high even under very high load conditions. In addition, in such diesel electric drive devices, there is no danger of insufficient engine control, for example if the propeller is out of the water in rough seas.

In a conventional diesel electric drive device, all electric drive devices are arranged in the boat and the engine, gear device and drive shaft are aligned with each other at the same height. This results in high mechanical / hydrodynamic losses and is undesirable in that the steering performance is limited compared to propellers driven from the outside of the ship. It also has the disadvantage that fuel consumption is relatively uneconomical.

The article “Condock I” in Schiff & Hafen, Vol. 11 (1979), discloses a semi-submersible vessel for accommodating aquatic containers or floating containers. The semi-submersible vessel has a bottom tank and a side tank that can be emptied or filled for loading and unloading cargo according to the float on / float off and / or roll on / roll off, and at the stern as a main engine. Has a diesel engine. A transverse thrust device is provided at the fore to improve steering performance.

It is an object of the present invention to provide a semi-submersible vessel having a large flat loading platform for holding bulky cargo and capable of maintaining its own position without the aid of a tug or anchor.

The object is that the diesel engine is part of a diesel electric drive device, the diesel electric drive device is arranged in the fore part to supply energy to at least one electric azimuth rudder propeller disposed below the stern, The loading surface is formed with a flat transport platform, and the azimuth rudder propeller is achieved by enabling accurate position control with the transverse thruster during the descent even when the wind is very strong.

By placing the diesel electric drive at the bow, it is desirable to provide optimum ship space utilization with respect to the transport capacity of heavy cargo ships. This arrangement is not subject to any structural limitations if most of the device components are placed in the bow, ensuring optimum variability for loading and unloading cargo on the stern transport platform.

Moreover, it is preferable to drive an azimuth rudder propeller by the electric motor installed offboard. Here, the electric motor is powered by a generator driven by the main engine. The use of off-board electric motors to drive one or more azimuth rudder propellers provides the advantage of particularly high fuel efficiency. In addition, the drive technology, actually known as SSP, is characterized by low ship resistance in a wide variety of hulls, and does not require additional cooling because cooling is accomplished by water circulating the motor. SSP drives also have low operating and maintenance costs.

Azimuthing rudder propellers are already known from the brochure of, for example, ABB "Azimuthing Electric Propulsion Drive", but the selection of a drive system for the type of vessel introduced in this brochure is a form of loading surface and a vessel on which the loading surface is installed. This was not done in terms of automatic positioning.

According to another feature of the invention, the azimuth rudder propeller is formed as a double azimuth rudder propeller. Dual propellers have higher manufacturing and maintenance costs than screw drives, but the propeller diameter can be chosen smaller because two propellers are provided. As a result, semi-submersible heavy cargo ships with smaller draft can be formed, resulting in less cost. According to one preferred refinement of the invention, the transverse thrust device is also electrically driven to design a fuel efficient and economical heavy cargo ship.

In one preferred embodiment, the transverse thrust device disposed in the bow portion can be controlled from the two bridge side wings of the semi-submersible heavy cargo ship in the steering compartment to ensure optimal viewability during steering. According to another preferred feature of the invention, the filling or emptying of the bottom tank and the side tank can also be controlled by a control desk on the stern side of the helm, which also helps ensure visibility.

The dashboard and signal indicator of a semi-submersible heavy cargo ship is preferably installed in a soundproof engine control room to dampen the sound level emitted from the ship's engine. It is also preferred that the main engine has a sound absorber according to another feature of the invention.

In order to significantly lower the sailing cost, according to a preferred refinement of the invention the diesel engine can be operated with heavy oil having a Redwood viscosity of approximately 3,500 s. In addition, according to still another preferred improvement of the present invention, the provision of a diesel engine capable of being operated by marine diesel oil as an auxiliary engine helps to reduce the navigational cost. At this time, the auxiliary engine is preferably installed on a base where vibration is attenuated, so that a noise level as low as possible is generated.

According to another feature of the invention, in order to ensure optimum variability with respect to the acoustically advantageous operation of the exhaust gas line of the drive, the exhaust gas line of the drive device can be movably installed.

Other details and advantages of the invention are set forth in the description of the preferred embodiments below.

1 and 2, the LOA of a semi-submersible heavy cargo ship according to one preferred embodiment of the present invention is 156 m. Repair Soy (LBP) is 145 m. The cargo deck, which is 126 m long and 32.26 m wide, has a free surface of approximately 4,065 m ² . The mold depth in the area of the cargo deck is 10 m, the draft of semi-submersible heavy cargo ships is 7.50 m in plan, design and construction freeboard and 19.0 m in descent of the cargo deck.

The deadweight of semi-submersible heavy cargo ships is 18,000 tonnes in freeboard plans and designs. The tonnage weight of the cargo is 2,000 tonnes of heavy oil (HFO 380) used as the main engine fuel, 172 tonnes of marine diesel oil for a loading capacity of approximately 200 m ³ used as the auxiliary engine fuel, correspondingly 300 m ³ It consists of 300 tonnes of fresh water, 25 tons of lubricating oil, 20 tons of stockpile for crew, 20 tons of replacement parts and 15,463 tons of actual load. The average draft at these tonnes of cargo is approximately 7.5 m in seawater with a specific density of 1,025 t / m ³ . This is consistent with drafts in planning, design, and construction freeboard.

Semi-submersible heavy cargo ships also have a loading capacity of approximately 40 m ³ for dirty oil and a loading capacity of approximately 5 m ³ for waste water. At the top of the deck in the fore part is 22 seafarers and 16 passengers. In addition, three diesel engines with a rotational speed of approximately 720 min ⁻¹ , which are used as main engines, are arranged in the bow. Approximately 3,645 kW of power each can be generated by a diesel engine formed as a nine-cylinder in-line deployment engine. Thus, the power loss of the generator during driving is approximately 8.7%, and 8,675 kW of power can be supplied when no power is supplied to the ship electrical system.

The semi-submersible heavy cargo ship is also equipped with two auxiliary engines, which are configured as diesel engines for the generation of electric current in the ship's electrical system, which supply the generator power of 720 kW each at a speed of 720/900 mim ⁻¹ . . In the event of a ship staying in the port or in an emergency, a third diesel generator is provided with a speed of 1800 min ⁻¹ and a generator power in accordance with SOLAS.

The drive system uses two azimuth rudder double propellers driven by an electric motor placed on the outside of the ship and capable of operating speeds of 14 kn. The so-called SSP drive device, shown in FIG. 3, is supplemented by two electrically driven lateral thrust devices, which improve the steering performance and safety of the heavy cargo ship. Using two lateral thrust devices, it has been found that the settled heavy cargo ship can be precisely controlled for wind powers of 6 to 7 Beaufort.

Multiple winches are used to secure the cargo on the cargo deck. Ergonomic working conditions are ensured, for example, by sound insulation such as spatial separation of engine rooms and quarters, encapsulation of noise on decks, or sound absorption facilities for the main engine. By emptying the ballast tanks with compressed air, semi-submersible heavy cargo ships can be lowered from a draft of 18 m to a draft of 7.50 m within four hours. Due to the low fuel consumption of 46.98 mT / 24hr of the main engine, semi-submersible heavy cargo ships, which may be dock vessels depending on the application, are 34.6 days a year compared to conventional ships compared to the year 360 days. I can sail further. This means that additional cargo can be transported at the same sailing cost. High fuel efficiency is also demonstrated by the fact that only one or two diesel engines in the main engine can be operated when necessary. Thus, in particular, human convenience and environmental aspects are taken into account.

As mentioned above, the semi-submersible heavy cargo ship according to the present invention can maintain its own position without the aid of a tugboat or anchor and can accommodate bulky cargo and is fuel efficient.

1 is a side view of a semi-submersible heavy cargo ship,

2 is a plan view of the semi-submersible heavy cargo ship according to FIG.

3 is a side view of a double agitation rudder propeller.

Claims (1)

Float-on / float-off and roll-on / roll-off or any of the above, filled or empty for loading and unloading cargo It includes bottom and side tanks that can be stowed, diesel engines as the main engine, and lateral thrust devices provided in the bow to improve steering performance, and balances the cargo by providing water ballast to the upper and lower tanks. Semi-submersible heavy cargo ships formed to be.

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