GB2532513A

GB2532513A - Modification to rising flood protection barrier GB2479125

Info

Publication number: GB2532513A
Application number: GB1420841.7A
Authority: GB
Inventors: Stuart Brindley Charles
Original assignee: Individual
Current assignee: Individual
Priority date: 2014-11-22
Filing date: 2014-11-22
Publication date: 2016-05-25
Also published as: GB201420841D0

Abstract

A balance mechanism of a hinged barrier submerged in water comprises moving the centre of mass or gravity of the barrier arm relative to its centre of buoyancy or volume such that the barrier rises or sinks in the water. This mechanism may be used a flood protection barrier, and can be useful when the barrier is less or more dense than the water in which it is immersed.

Description

Modification to Rising Flood Protection Barrier GB2479125 Description The manner in which the flood protection bather of Patent GB2479125 operates is described and illustrated in the Description and Drawings of the Patent cited. That barrier has 'neutral' buoyancy when fully immersed in water, that is to say, the mass of the bather is equal to that of the volume of water it displaces when fully immersed. This modification enables bathers that may be of mass greater, or less than that of the volume of water they displace when fully immersed, to operate and function in the same manner as the bather of Patent GB2479125.

Were the barrier of GB2479125 fully immersed in a more or less horizontal attitude in water of sufficient depth, it would rotate to a position with its crest uppermost, or lowest depending upon whether its centre of gravity was further from, or closer to the crest, respectively, than the centre of buoyancy when in the original more or less horizontal attitude. The bather would assume an attitude in which centres of buoyancy and gravity were points on a common vertical, but would neither float towards the surface above, nor sink towards the 'bed', or floor' below.

The barrier of GB2479125 is prevented from assuming either of these two limiting attitudes, firstly by the inclination of the foundation surface upon which it comes to rest when raised, and secondly by coming to rest upon the 'bed', or 'floor' when lowered. Theoretically, there is no load upon the retaining hinge.

The modification here described enables bathers of mass greater, or less than the volume of water they displace when fully immersed to operate and function in the same manner as the barrier of GB2479125 within practicable limitations.

Practical limitations on consistency of densities of construction materials, production of structural sections, calculated values and magnitudes, errors of calculation and mistakes in manufacture, seasonal variation in the density of the water in which the bather is to be immersed (temperature, silt load, salinity), possibly other factors, may cause departure from the ideal of 'neutral' buoyancy.

In such instances, a permanent vertical load would be imposed upon the restraining hinge, which, within limits, should not adversely affect operation.

Consider, first, the situation of 'neutral' buoyancy in which the centres of gravity and buoyancy coincide. With the barrier in the fully raised position, as the higher water level subsides the exposed crest provides a moment causing the barrier to rotate towards the lowered, 'not in use' position, but, once the surface levels either side of the barrier equalise, and the barrier is fully immersed, rotation ceases. In order to lower the bather to the 'prone' position upon the 'bed', or 'floor', it would be necessary to move the centre of gravity of the bather some distance towards its 'crest'.

Likewise, if the barrier is at rest upon the 'bed', or 'floor', should the bather need to be raised against an impending flood, it would be necessary to move the centre of gravity some distance towards its 'base'. The barrier rotates towards the surface, the rotation ceasing when the crest protrudes to a sufficient height above the surface to equalise the moments of the barrier and the reduced volume of water displaced by its immersed portion. At this point, the surfaces of the water on either side are separated. The rising water level on the side of impending flood thereafter provides the necessary moment to complete the rotation for the base of the barrier to make contact with the surface of the foundation upon which it is supported in the fully raised position.

In the first of the foregoing situations, should the mass of the bather be somewhat less than that of the volume of water displaced when fully immersed, rotation would cease with the crest still protruding above the surface. It would be necessary to increase the distance of separation of centres of gravity and buoyancy in order for the bather to rotate to the desired at rest' position. Conversely, if greater, the barrier would rotate to the 'at rest' position even in the absence of any separation of centres of gravity and buoyancy.

With the bather in the 'prone', 'at rest' position upon the 'bed, or 'floor', were it of lesser mass than the fully immersed volume of water displaced, it would be necessary to maintain the centre of gravity at some distance towards the crest in relation to the centre of buoyancy for the barrier to remain at rest upon the 'bed', or 'floor'. Were it of greater mass, the centre of gravity would need to be moved somewhat further towards the base in order to raise the bather than would be needed for a barrier of neutral' buoyancy.

The physical conditions that apply to each of the situations afore described are illustrated schematically in the drawing, Figure 1, of the present patent application.

The modification to the bather of GB2479125 that enables a barrier of mass less, or greater than the mass of water it displaces when wholly immersed, consists of the additional distance by which its centre of gravity would need to be moved, towards, or away from the 'crest', respectively, in order to operate and function in the manner of that bather, in excess of the distances that would have been necessary were it to have had 'neutral' buoyancy.

The additional distances by which the movement of the centres of gravity may be extended are limited by the physical conditions pertaining to individual situations, primarily the overall heights of the bathers. These limitations determine the limits within which the mass of the bather may vary above, or below that pertaining to neutral buoyancy.