NO20092940A1 - Maximum control of roller damping tanks - Google Patents

Abstract

The invention relates to a system for finding the correct water level in roll cushioning tanks in ships. The system includes illuminated roll damping tanks with camera surveillance. By getting camera surveillance of the roller damping tanks, you will see how the wave goes in the tank and you can adjust the water level until the wave goes counter-phase to the ship's movement.

Description

Roll damping tanks.

Roll damping tanks are referred to as a passive roll damping system. My claim is that it is a dynamic system that must be adjusted according to the stability/trim of the vessel, in addition to wave frequency. This is currently impossible, especially on large vessels with several roll damping tanks. Standing on board such a large vessel and having to feel the boat when these tanks are properly adjusted and "synchronised" is not only difficult but almost impossible. In the stability papers for ships with roll damping tanks, there are 1 or 2 conditions with a stated quantity for filling these tanks. This can only be considered as examples and it may happen that the example will work in practice in the condition mentioned, but in all other conditions it will at best work worse and at worst against its purpose. As far as I know, we currently have no system for continuous monitoring of such tanks in order to make maximum use of the roll damping tanks' capabilities. This means that the wrong fluid level is largely used on these. In my opinion, this poses a safety risk for crews, as ships will wobble more. It poses a risk of damage to the ship and a risk of damage to cargo. In the extreme, this can have catastrophic/fatal consequences for the ship and crew.

By getting a monitoring system, it will, in my opinion, reduce damage to cargo, stress on vessels and it will also be much more comfortable to be on board.

As far as I know, there is currently no good monitoring equipment for anti-roll tanks and it should be mandatory and required by law.

My idea for a monitoring system is the following: Illuminated roll damping tanks with camera monitoring. By getting camera surveillance of the roll damping tanks, you will see how the "wave" goes in the tank and you can easily adjust the level to counter phase. So if the wave comes late, it indicates that there is too little liquid in the tank and you are topping up. If the wave comes early, it indicates that there is too much liquid in the tank and you are escaping. Also in relation to having several roll damping tanks, it becomes very easy to "synchronize" the tanks so that you make maximum use of the force in the free liquid surface moment.

Anti-roll bars are a wonderful aid, but their value is dramatically reduced by the lack of monitoring capabilities.

Such a system will also increase understanding of the roll damping tanks' function. And also help the ship designers in the further development of such tanks.

Technical.

Adaptation of camera and light will have to be done specifically for each ship and adapted. Paint on the tanks should probably be light as it gives a better light transmission. There is no measuring system to measure the amount of liquid in the tank.

The novelty is the visual monitoring of the movement of the liquid in the tank in order to be able to adjust to the correct level with visual control.

Claims (1)

Claim 1: Device for a tank in a ship, which tank is designed to accommodate a quantity of water which, by swinging movement in the tank and in counter-phase with the ship's movement, can prevent the ship from rolling in the sea, characterized in that the device includes: means that can monitor and record the phase relationship between the swinging movement of the water and the movement of the ship, and a system that can regulate the water level in the tank so that the water level is adjusted to counter phase. Claim 2: Device in accordance with claim 1, characterized in that the means include camera monitoring by a camera inside the tank. Claim 3: Device in accordance with claims 1-2, characterized in that the system is designed to fill up water in the tank when the wave arrives late Claim 4: Device in accordance with claims 1-32, characterized in that the system is designed to release liquid when the wave comes early. Claim 5: Device in accordance with claims 1-4, characterized in that when the ship includes several roll damping tanks, their operation is synchronized.