Apparatus for the combatting of underwater growth on submerged structures

An apparatus for the removal or inhibition of underwater growth on an elongate submerged body. It includes at least one collar adapted to extend loosely around the elongate submerged body (28). The collar includes a breaker device to apply impact force on the underwater growth to break it up. The breaker device includes a voluminous body (16) into which ambient water flows in and out. The device can advantageously include rollers (12). The apparatus on a smaller scale can act to inhibit the settlement of new underwater growth.

FIELD OF INVENTION 
The present invention relates to apparatus for the combatting of underwater 
growth on submerged structures, in particular underwater growth in 
offshore marine structures. More particularly the invention relates to an 
assembly of apparatus incorporating the use of a device to eliminate 
marine growth and/or to prevent subsequent establishment of marine growth 
on submerged offshore marine structures. 
BACKGROUND OF INVENTION 
The use of apparatus to combat marine growth in offshore marine submerged 
structures is well known in the prior art. Various attempts have been made 
to produce practical and cost-effective apparatus to resolve and/or to 
contain the problem. Examples of such prior art apparatus have been 
disclosed in U.S. Pat. No. 1,266,050 and U.S. Pat. No. 1,036,907 patents 
granted to A. L. Reynolds, U.S. Pat No. 1,279,732 patent granted to C. L. 
Lockwood, U.S. Pat. No. 4,676,692 patent granted to T. H. Clifden and U.S. 
Pat. No. 5,026,212 patent granted to Christopher N. Do. The prior art 
apparatus generally adopt elaborate structures to maintain the buoyancy of 
the apparatus underwater and at the water surface level. For example U.S. 
Pat. Nos. 1,266,050 and 1,036,907 teach the use of float to provide the 
buoyancy. Similarly U.S. Pat. No. 1,279,732 also teaches the use of float 
members ringed together in a collar to provide the buoyancy required to 
keep the apparatus buoyant. 
The use of floats in combination with the true "operative elements" of the 
prior art apparatus adds to the number of component parts in the assembly, 
resulting in increase in manufacturing, storage, handling and operational 
costs. 
SUMMARY OF INVENTION 
Thus it is an object of the present invention to provide an apparatus for 
the combatting of underwater growth on submerged structures where the use 
of structures to solely or substantially solely provide buoyancy for the 
assembly of apparatus is eliminated or minimized. 
The invention consists of an apparatus for the removal or inhibition of 
underwater growth on an elongate submerged body comprising a collar 
adapted to extend loosely around the said elongate submerged body. The 
collar includes a means to apply impact force on the underwater growth. 
The means comprises a voluminous body into which ambient water flows into 
when the body is submerged into the water and from which water flows out 
when the body is removed from the body of the water. 
The voluminous body comprises a breaker device with a chamber body for the 
accommodation of water. Rotatable rollers are secured spaced apart to the 
voluminous body. Alternatively cylindrical discs can be secured to the 
voluminous body. 
In another aspect, the rotatable rollers can include chambers for the 
accommodation of water. 
In another aspect, the apparatus can include an array of collars stacked 
vertically and spaced apart. Each collar includes at least one breaker 
device. The breaker device delivers impact force onto the underwater 
growth passively in response to ambient water movement.

DETAILED DESCRIPTION 
Throughout the drawings, the integers are referenced by the same numeral. 
A first embodiment of the invention is shown in FIG. 1. The first 
embodiment includes a pair of breaker rollers (12) connected together by a 
shaft (14). The breaker rollers (12) are mounted onto the shaft in any 
conventional manner such that the breaker rollers are rotatable about the 
shaft (14). Alternatively the rollers can be non-rotatably fixed to the 
shaft the breaker device (10) includes a cylindrical chamber body (16), 
positioned between the breaker rollers (12). In the present embodiment the 
chamber body (16) encloses the shaft (14). The ends of the chamber body 
(16) are closed with caps (18). The chamber body includes buoyant material 
(20) such as polystyrene or polyurethane, secured to the upper end of the 
chamber (16). Alternatively the chamber body can contain a small quantity 
of free floating buoyant material. Apertures (26) are provided at the top 
and bottom ends of the chamber. 
When the apparatus is made from light material such as plastics, the 
overall specific gravity of the entire device is less than that ambient 
water than buoyant material need not be introduced into the chamber body. 
In a variation of the above embodiment, a pair of discs (13) or a pair of 
rollers (12) can be secured to the ends of the cylindrical chambers 
instead of to a shaft (see FIG. 3). As before, the terminal ends of the 
cylindrical chamber body are closed by cap means (18). 
The cylindrical chamber body (16) if necessary can contain buoyant material 
such as polystyrene or polyurethane material or any other suitable 
non-biodegradable material. 
Referring back to FIG. 1, the chamber body (16) includes at least one 
aperture (26) each at the lower and upper end of the chamber respectively 
through which water flows into the chamber. A plurality of pairs of 
breaker rollers are stringed together to form a collar (22) (see FIG. 5) 
each pair of breaker roller being spaced apart from the adjacent pair. Any 
suitable connecting means can be adopted to string together the pairs of 
breaker rollers. The mode of attachment of the pair of breaker rollers to 
the connecting means would depend on the nature of connecting means 
employed. Preferred connecting means are extruded plastics straps, and 
other long lasting non-biodegradable, non-rusting and flexible material is 
suitable. Steel cables, ropes or natural fibrous material can be used as 
connecting means. It is generally advisable to use more lasting, 
non-deteriorating material to form the connecting means. Appropriate 
aperture can be provided at the upper and lower end of the chamber body 
through the connecting means can be stringed to form a ring. Alternatively 
each pair of breaker rollers can be independently connected to an adjacent 
pair of breaker rollers. 
Two sets of collars consisting of a plurality of pairs of breaker rollers 
can be attached together at, at least two vertically spaced apart 
positions. If necessary additional sets of collars consisting of pairs of 
breaker rollers can be attached to form a stacked series of collars. (see 
FIG. 9) 
The working of the apparatus and other additional features of the apparatus 
will be described now in relation to an offshore tubular support structure 
as seen often in wharves and in offshore oil exploration rigs. A collar 
whose length exceeds the circumference of the submerged support structure 
is prepared. The pairs of breaker roller units are stringed spaced apart 
in the collar (see FIGS. 5 and 9). The free ends of the collar are secured 
together by any conventional means known to the art. If the submerged 
structure is deep, then additional collars with breaker rollers stringed 
thereon can be linked together in spaced apart vertical stacks to give the 
required depth (see FIG. 9). When a collar of stringed breaker rollers is 
introduced into the water, water flows into the cylindrical chamber via 
the apertures (26) at the lower end of the chamber, displaced atmospheric 
air from within the chamber escaping out via the apertures at the upper 
end of the chamber. 
Each breaker device (10) filled with water knocks against the side wall of 
the submerged structure (28), by the force of ambient force originating 
from wave action, undersea current etc. The swaying action of the collar 
with the stringed breaker device results in the breaker rollers exerting 
intermittent hammering force against the aquatic fouling matter on the 
submerged structure, such as barnacles colonies. As the other collar of 
stringed breaker devices (12) is not secured to the submerged structure, 
but is free moving, the collar is free to rotate around the submerged 
structure. 
To produce a more effective hammering action against the fouling matter, 
the breaker roller (12) can be grooved or geared (see FIG. 3). In 
environments where there is more calcerous fouling matter to be removed, 
the external contact surface of the breaker roller with the calcerous 
fouling matter can be further hardened by the provision of hardened 
surface material, such as steel or other suitable durable material. 
The collars can further include vanes, fins, etc to facilitate the 
rotational movement of the collars around the submerged structure. 
Other embodiments within the scope of the invention concept can be 
envisaged. FIG. 4 shows another variant of embodiment. The breaker rollers 
(30) are substantially larger than the breaker rollers shown in FIG. 1. 
These rollers are hollow and are designed to receive and hold water. 
Apertures (32) are provided to facilitate the inflow of water. The shaft 
(34) can be hollow and be designed to receive water as in the shaft (14) 
of the first embodiment, or alternatively be solid or sealed. The mounting 
of the breaker rollers (30) onto the shaft (34) can be according to any 
known means. The breaker rollers (30) are stringed to a collar means by 
conventional means. Alternatively the rollers (30) can be non-rotatably 
secured to the shaft (34). 
FIGS. 10 and 11 illustrate yet another embodiment of the invention. The 
embodiment is similar to the embodiment illustrated in FIG. 1, except that 
the cylindrical chamber (16) is replaced with a plurality of individual 
chambers (17). Each chamber (17) is tubular with a central hole (19) 
running therethrough, and at least two aperture holes (26) through water 
enters the chamber and the air is displaced. The chambers are stacked onto 
the shaft (14). The size of the breaker device can be varied by the 
addition or subtraction of the number of individual chambers (17) along 
the shaft (14). The length of the shaft (14) is selected according to the 
number of chambers that are to be used on a specific configuration of the 
breaker of the device. It will be appreciated that this configuration 
permits convenient transportation of the breaker device to the site. 
Although each breaker device described so far illustrates the provision a 
roller at each end of a shaft, it can be envisaged that additional rollers 
can be provided along the shaft (14, 34) or the rollers can be provided at 
any place along the shaft and need not be restricted to the terminal ends 
of the shaft member. Further in a collar of stringed breaker devices, each 
device can be of different configuration according to the embodiments 
describes herein. 
FIGS. 7 and 8 shows yet another embodiment of the invention consisting of a 
hollow chamber (36) encapsulatingly secured around a shaft member (38). 
The chamber body (38) includes apertures (26) at the upper and lower ends 
of the chamber body to facilitate the inflow and outflow of water and the 
displacement of atmosphere air inside the chamber. 
The chamber body can be partially filled with floating material such as 
polystyrene or polyurethane. As in earlier embodiments of the apparatus, 
the chamber bodies can be stringed together to form a collar. 
When the breaker device is of large dimension, it can be used as a device 
to eliminate the aquatic foul up. A large sized breaker device exerts 
greater hammering force on the aquatic foul up material as compared to a 
smaller size breaker device. Thus once the aquatic foul-up is broken up or 
eliminated, smaller size breaker device can introduced onto the 
sub-structures. The smaller size breaker device can function as a device 
to prevent subsequent growth or establishment of aquatic foul-up material. 
Other types of preventive device can be used, such as brushes on the 
collar ring. 
The size of a breaker device to be used at a given site would depend on 
such parameters as nature and size of aquatic foul-up on the submerged 
structure; the size of natural forces for example, the wave and tide 
action, underwater currents, etc. 
The collars can advantageously include, fins, vanes or other devices to 
facilitate the rotation of the collar around the submerged elongate body. 
Further features can be secured to the collar to inhibit the settlement of 
new underwater growth. The latter features include scrapers and brushes.