FI126556B - Lashing dock for a freighter - Google Patents

Description

BACKGROUND OF THE INVENTION The present invention relates to a cargo ship bridging bridge which is attached directly or indirectly to the hull structures of a cargo ship.

The tipping bridge is a support frame mounted on the deck of a cargo ship intended for the transport of containers to which support bars are used to support the containers.

In a cargo ship, containers are usually carried under deck and over deck in several rows and queues and over several layers. The ship's deck has removable cargo hatches to close the hold below. Containers are carried over the hatch covers. Deck support structures for containers, so-called. mooring bridges are spaced so that the cargo hatch can be removed and lowered by crane when unloading and reloading the ship.

After the containers have been loaded onto the ship, at least some of the containers on top of the deck are secured at their ends by strut bars and strut screws.

Surfing bridges are typically located in the transverse direction of the ship's hull, extending from ship to ship. Due to the narrow and high structure of the bridging bridges, hull vibration due to the ship's engine running and propeller rotation may cause strength and vibration problems to the bridging bridge structures. The vibration dampener allows the damaging vibration of the surge bridge to be suppressed and the structures of the surge bridge to be lighter.

Known vibration dampers are separately mounted support or damper structures, which are connected to the bridging bridge and, for example, to the cargo hatch. At the same time, they prevent or hinder the transport of containers. Vibration dampers are also known in which large masses can be moved by separate actuators to different positions of the surge bridge, e.g. in the height direction, and at the same time change the vibration characteristics of the surge bridge. Known vibration-damping arrangements of anchorage bridges are shown, for example, in the following patents: KR20130134587A, KR20130115633A, KR20120113365A.

The solutions in which the vibration damper is connected to the bridging bridge and, for example, to the cargo hatch prevent the containers from being loaded. place. At the same time, these require separate installation and disassembly work before and after commissioning - and between storage use situations. Heavy-duty damping solutions do not require manual handling but require cranes or other accessories. This slows down the use of the systems and causes additional costs. Systems with separate actuators, such as cylinders or motors, are complex, expensive, and prone to malfunction. The object of the present invention is to provide a bridging bridge which does not have the above problems. The bridging bridge according to the invention is characterized in that at least one non-linearly acting vibration damper, i.e., the damping capacity of the vibration dampener, extends over a wide oscillation area, and the vibration damping element includes a damping element and a damping element.

A preferred embodiment of the vibration damper according to the invention is characterized in that the resilient element is non-linear in function, i.e. the magnitude of the spring force is affected by the rate of deformation of the resilient element.

Another advantageous embodiment of the vibration dampener according to the invention is characterized in that a single vibration dampener comprises a plurality of mass elements and flexible elements and / or damping elements.

Another preferred embodiment of the vibration dampers according to the invention is characterized in that the properties and location of the vibration dampers are optimized on the basis of vibration analyzes for each surge bridge structure and cargo ship.

The vibration dampener according to the invention can reduce the vibration tendency of the surge bridge and at the same time make the surge bridge more lightweight. The vibration dampener is simple in design, maintenance free and inexpensive to manufacture.

The invention will now be explained in more detail by means of preferred embodiments, with reference to the accompanying drawings, in which:

Figure 1 shows a mortise bridge and a stack of containers with two support bars connected.

Figure 2 is a side elevation view of the surge bridge and container stack with the vibration damper connected to its surge bridge.

Figure 3 shows a surge bridge with three vibration dampers installed.

Figure 4 shows a principle view of the functional components of a vibration dampener.

Surfing bridges 1 are typically located on the cargo ship weather deck in the transverse direction of the ship, and containers / stacks 7 are disposed between the bridging bridges so that the container support bars 8 can be secured between the containers and the surging bridge.

As the cargo ship travels at sea, the ship's engine and propeller cause vibration to the ship's hull. This vibration acts as an excitation and generates vibration on its surge bridge 1. Figures 2 and 3 show vibration dampers 2 attached to their surge bridge. The vibration dampener 2 is typically attached to the upper part of the surge bridge, but other locations are possible. As the surge bridge 1 oscillates with its hair due to excitation oscillation from the ship's structures, the mass of the oscillation damper 2 begins to oscillate in different phases, whereby the oscillation of the surge bridge 1 does not increase at a harmful high speed and amplitude.

Figure 4 illustrates in more detail one embodiment of the vibration damper according to the invention. The vibration damper 2 consists of a mass element 3 attached via a resilient element 5 and / or a damping element 4 to the body part 6 of the vibration dampener 2. The body part 6 is fixedly (e.g. by welding) or detachably (e.g. by bolt connection) to the bridging bridge. Alternatively, the resilient element 5 or the damping element 4, or both, may be directly attached to its surge bridge 1. One or more pieces of vibration dampers 2 may be attached to one of its surge bridges. Further, it is possible that one vibration dampener 2 has a plurality of mass elements 3 and flexible elements 5 and / or damping elements 4. The vibration of the mass element 3 of the vibration dampener 2 is in turn controlled by the elastic element 5 and the damping element 4. Due to the vibration dampener 2, the structures of the surge bridge 1 are less stressed and can be made lighter.

The typical critical oscillation frequency of the bridging bridge 1 is in the range Ι-ΙΟ Hz. The operation of the vibration dampener 2 can be tuned to a certain critical frequency or to a wider frequency band by adjusting the properties of the various components (e.g., the size of the mass element 3, the stiffness of the flexible element 5 and the damping element 4). The mass element 3 in the vibration dampener 2 may be, for example, 100-1000 kg depending on e.g. the vibration characteristics of the burial bridge 1.

The resilient element 5 may be linear in function, whereby the spring force is determined as a function of the spring compression (deformation) (e.g., helical spring) - or the resilient element may be non-linear, in which case the magnitude of the spring force is affected e.g.

The damping element 4 may be, for example, a liquid or gas filled shock absorber. Friction between vibrating (moving) and fixed structures can also act as a damping factor. The vibration dampener 2 can also be implemented without the damping element 4, and it is also possible to integrate the flexible element 5 and the damping element 4 into one functional component. The resilient element 5 of the vibration dampener 2 may be an elastic rubber component, a resilient rod or other element allowing vibration and deformation instead of a helical spring. It is also possible to use a resilient element 5 in the structure, which also has damping properties, e.g. due to internal friction.

It will be apparent to one skilled in the art that the invention is not limited to the above embodiments, but may vary within the scope of the appended claims. For example, the properties and location of the vibration dampers 2 can be optimized based on vibration analyzes for each of the surge bridge structures and cargo ships. Further, the properties of the vibration dampers 2 can be varied by adjusting the stiffness, damping capacity of the elements 4, 5 and / or the weight of the mass element 3. The operation of the vibration dampener 2 is linear or non-linear depending on the properties of the mass element 3, the resilient element 4 and the damping element 5, i.e. the damping capacity extends over a narrow or wide range of vibration frequencies.

If necessary, the symbols which may be presented in the specification together with other characteristics may also be used separately.

Claims (7)

1. A lashing bridge (1) for a cargo ship which is directly or indirectly connected to the cargo ship's hull structures, characterized in that at least one non-linear vibration damper (2) is connected to the lashing bridge (1), i. The damping capacity of the vibration damper extends over a wide range of vibrations, to which vibration dampers belong a mass element (3) which is connected to the lashing bridge (1) by means of an elastic element (5) and / or a damping element (4). 2. Lashing bridge according to claim 1, characterized in that the elastic element (5) is non-linear in function, i.e. the magnitude of the spring force is affected by the deformation rate of the elastic member. Lashing bridge according to claim 1 or 2, characterized in that a vibration damper (2) has several mass elements (3) and elastic elements (5) and / or damping elements (4). Lashing bridge according to one of claims 1 to 3, characterized in that the characteristics and position of the vibration dampers (2) on the basis of vibration analysis are optimized for the respective lashing bridge construction and cargo ship. 5. A lashing bridge according to any one of claims 1-4, characterized in that the properties of the vibration dampers (2) can be changed by adjusting the stiffness, damping ability of the elements and / or the weight of the mass element (3). 6. A lashing bridge according to any one of claims 1-5, characterized in that the mass of the pulp element (3) is between 100 and 1000 kg. Lashing bridge according to any one of claims 1-6, characterized in that the damping element (4) is a liquid or gas-filled shock absorber.