GB2314044A

GB2314044A - A floating structure with ballast tanks

Info

Publication number: GB2314044A
Application number: GB9612257A
Authority: GB
Inventors: Christopher David Slennett
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-06-12
Filing date: 1996-06-12
Publication date: 1997-12-17
Also published as: GB9612257D0

Abstract

A floating structure 1, eg pontoon and mooring facilities for boats, is supported by buoyancy chambers or floats 4 extending beneath the structure and incorporates ballast chambers or tanks 6 into which water can be admitted via holes 3. The ballast tanks 6 serve to increase resistance to rolling by virtue of the weight of the water in the tanks. The tanks 6 may be manually filled or be adapted to be self filling/self draining. The tanks 6 may be fitted to existing floats or direct to the structure (Fig 3), or be integrally formed with the floats (see Fig 4). An air vent (8, Fig 4) may be provided. The ballast tanks can be made of reinforced polyethylene.

Description

Title:- Floats and Ballast tanks.

This invention improves the stability of floating structures that tend to sway and or oscillate when a load is applied either by wave motion, the wash from a passing vessel, some vertical down force or weight being transferred from one side to another.

For example, but not limited to, pontoons and mooring facilities for boats and other craft are particulaxly prone to this problem. It is especially true of individual pontoons and landing stages that are made up of one, two or a very limited number of elements.

In order to make the structure as stable as possible it is desirable to make it as hea) as possible, making it necessary to have large floats with at least 30% of the float volume below the water line.

A way of achieving the maximum weight and stability is to encase the floatation material, usually expanded polystyrene, in a concrete / fibre reinforced outer shell varying in thickness. Another solution is to make the decking of concrete.

In all cases the manufacturer tries to increase stability by increasing the size and weight of the structure commensurate with the cost of materials and labour required to produce the product.

The invention provides for the stability of the structure to be improved by fitting ballast tanks to exiting floats, fitting new floats with integral ballast tanks or fitting ballast tanks direct to the structure by any means, the ballast tanks being manually filled or adapted to be selffifling and self draining.

Drawings: Specific examples are shown in: Figure 1. Shows in cross section a pontoon deck 1 supported by two floats 4. The floats and the ballast tank casing 6 being attached to the decking 1. The outer casing 5 being designed to take the weight of the float and the whole structure.

Figure 2. Illustrates the ballast tanks 6 attached to existing floats 4. The ballast tank being below the water line 2.

Figure 3. Shows ballast tanks 7 attached directly to the floating structure 1.

Figure 4. Shows a cross section of a float with an integral ballast tank being part of the construction of the float, extending the casing of the float, or the material from which the float is made 9, below the bottom of the floatation block fording a chamber thai fills with water thus becoming a ballast tank under the float, attached to the float, and or to the pontoon or directly to the pontoon In all cases the holes 3 should be approximately 1/4" (a quarter of an inch) in diameter.

When a downward load 10 is applied to one side of a pontoon 1 then the weight of the water in the ballast tank 6 resists the upward motion 11.

When the pontoon is first put in the water the ballast tank 6 is empty and the whole structure relatively light The pontoon slowly settles in the water and the ballast tanks fill through the small holes 3.

An air vent 8 is provided to allow air to escape.

The holes in the bottom of the ballast tanks 3 are not large enough to allow any significant amounts of water to leave the chamber while the tank 6 is immersed and mow

Claims

Claims:1. This invention improves the stability of a floating structure supported by bouyancy chambers extending beneath the structure to below the water line by, incorporating or adding ballast chambers, those ballast chambers being adapted to admit water slowht into their interiors, being self filling, and or self draining ballast tanks or otherwise filled ballast tanks, reducing movement on or relative to the water.
2. Floats as in claim 1 using an integral ballast chamber.

3. Floats as in claim 1 using the extended casing of the ballast chamber to encase the floatation material.
3. Floats as in claim 1 with a ballast chamber attached.
4. Existing structures as in claim 1 with separate ballast chambers attached.
5. Floats or ballast chambers as in any of the above claims being self filling or self draining.
6. A float with an integral ballast tank being part of the construction of the float, extending the casing of the float, or the material from which the float is made, below the bottom of the floatation block forming a chamber that fills with water thus becoming a ballast tank under the float, attached to the float, and or to the pontoon or directly to the pontoon.
7. Floats, ballast tanks or any combination of both as described herein and illustrated in the accompanying drawings.