WO2003027420A1

WO2003027420A1 - Tower and tower construction

Info

Publication number: WO2003027420A1
Application number: PCT/ZA2002/000147
Authority: WO
Inventors: Petrus Albertus Coetzer
Original assignee: Petrus Albertus Coetzer
Priority date: 2001-09-27
Filing date: 2002-09-20
Publication date: 2003-04-03
Also published as: ZA200401899B

Abstract

A tower which includes a plurality of containers positioned over a defined area, each container containing ballast, and an upwardly extending structure which is located within the defined area and which is anchored to the containers.

Description

TOWER AND TOWER CONSTRUCTION

BACKGROUND OF THE INVENTION

This invention relates to generally to the construction of a tower. The invention is described hereinafter with reference to the construction of a tower which is suitable for use in a telecommunications network, eg. a tower in a GSM or cellular network, but this is by no means limiting for the principles of the invention can be used for the construction of any elongate upwardly extending structure referred to broadly herein as "a tower".

When a GSM tower is erected it is essential to ensure that the tower is adequately supported on a strong foundation structure. The height of a GSM tower can be considerable and it may therefore be exposed to substantial wind loading.

In many instances GSM towers are at remote sites. The provision of adequate equipment and material at remote sites can be problematic. For example the mixing and placing of good quality concrete, at a site which is difficult to access, using semi-skilled or unskilled labour, can be a challenging exercise which, if not properly carried out, can have serious consequences.

SUMMARY OF INVENTION

The invention provides in the first instance a tower which includes at least one ballast container and an upwardly extending structure which is anchored to the container. Preferably use is made of a plurality of the ballast containers. The containers may be arranged in any suitable configuration and may be of any suitable shape and size.

In one form of the invention each container has an upwardly facing open mouth. The mouth may be closable by means of one or more covers.

Each container may be made from any appropriate material and for example may be made from steel, from reinforced concrete slabs or the like.

The containers may be arranged to form an enclosure. In plan the enclosure may be of any appropriate shape and may be polygonal. A single array of the containers may form the enclosure. Additional containers may be added, at any time, to the array eg. at the time of construction or subsequently thereto, as required, to increase or enhance the ballast effect thereof, if necessary. For example a second array may form a second enclosure around the first array with the various containers being attached to each other, where appropriate.

The word "ballast" as used herein denotes any massive material which is placed inside a container. The ballast may for example be sand, rock, or a cementitious or other settable material.

The ballast is used to provide a massive anchor for the upwardly extending structure and to provide a load distribution mechanism.

The arrangement of ballast containers, in any appropriate configuration, preferably extends over a substantial defined area to ensure that a stable support for the upwardly extending structure is provided. The upwardly extending structure may be of any appropriate type and for example may comprise a lattice tower, a tubular mast or the like. The structure may be camouflaged, if required, and may have the external appearance of a tree such as a palm tree, a pine tree or any other selected tree which lends itself to being implemented in a camouflaged form.

A plurality of supports, struts, braces, or other anchoring or supporting members may extend from the upwardly extending structure to the ballast containers. This may be done in any appropriate way. For example in a preferred form of the invention members of a support frame, which extends from the upwardly extending structure, are anchored to one or more of the ballast containers.

The upwardly extending structure may extend from a centrally located tubular shaft.

Equipment housings or rooms may be positioned inside the enclosure formed by the ballast containers. These housings may be added to, or removed from, the construction as required.

The ballast containers may also form part of a perimeter boundary eg. a fence or wall.

The invention provides, in the second instance, a method of erecting a tower which includes the steps of positioning a plurality of containers on a suitable site in a predetermined configuration, filling the containers with ballast, and erecting an upwardly extending structure, which is anchored to the containers, on the site. The method may include the steps of anchoring a plurality of support members to at least some of the containers and fixing the structure to the support members.

The upwardly extending structure may be in the form of a lattice tower, a tubular mast or of any other suitable form or shape.

The ballast which is placed in the containers may be selected from sand, rock, and a cementitious or other settable material.

Preferably the ballast containers are positioned to form an enclosure and the upwardly extending structure is erected inside the enclosure.

A perimeter fence or wall may be erected using the containers as a foundation.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is further described by way of example with reference to the accompanying drawings in which:

Figure 1 is a plan view of a tower according to one form of the invention, and Figure 2 is a side view, partly sectioned, of the arrangement shown in Figure 1.

DESCRIPTION OF PREFERRED EMBODIMENT

The accompanying drawings illustrate a tower arrangement 10 which is erected in accordance with the principles of the invention. The tower arrangement includes a lattice tower or mast 12 and a base structure 14. The tower 12 extends from a central location of the base structure. The base structure is formed from a plurality of containers 16 which, as is shown in Figure 1, are generally trapezoidal in shape, when viewed in plan. Each container 16 is made from an appropriate material such as sheet metal, reinforced concrete slabs or the like. The containers 16 are shaped in size so that they can be placed adjacent each other, on a prepared defined site 20 which has been levelled, to form an enclosure 22 which has a polygonal configuration. Adjacent containers are secured to one another by means of bolts 24 which are passed through registering holes in adjacent and abutting side walls of the containers.

Figure 1 illustrates twelve containers. This is only by way of example though for the number of containers can be varied taking into account ease of handling, site conditions, the load imposed by the tower, stability requirements, wind loading on the tower, and the like.

Before adjacent containers are bolted to one another a plurality of support members such as struts or braces 26 of a base support frame 28 are positioned between selected adjacent pairs of containers. Consequently when the containers in question are bolted together the struts 26 are firmly fixed in position.

The struts extend to support legs 30 of the base support frame 28. Centrally located inside the support legs is an upstanding hexagonal tubular shaft 32. The tower 12, which in this example is a lattice structure, is erected over the legs 30 in a conventional manner. Depending on the design though the tower 12 could be secured directly to the containers, without making use of the struts.

Before the tower is erected the containers 16 which are constructed or arranged in such a way that they form holders or tank-like structures, are filled with ballast 34 of any suitable type. The ballast may for example comprise sand or rock which is taken from on-site resources or local supply sources. It is also possible to make use of a settable material eg. a low grade cementitious mix. An important consideration in this regard is that the ballast should be massive ie. have substantial weight. Clearly this parameter is influenced by the quantity of material inside each container and this in turn is related to the volume of each container. The ballast effect is also related to the density of the ballast material and to the number of containers which are employed in making up the polygonal enclosure 22. Each container may be covered by means of a lid eg. a concrete slab 36.

The enclosure 22 should extend over a fairly substantial area so that a relatively large base structure is provided. This also helps to distribute the load. It is evident that the base structure makes effective use of the ballast as the ballast material is at a perimeter of the base structure, a location at which the ballast exhibits a maximum stabilising effect.

It is evident that additional containers may be added to an existing arrangement at any time to increase the ballast or anchoring effect of an assembly of containers. For example the base structure 14 could be formed from a single ring or array of containers, or two or more rings. In the latter case the containers would possibly be made smaller than normal with the ballast effect then being enhanced through the use of a greater number of containers.

The area inside the enclosure 22 is, in plan, divided into six wedge-shaped segments 40. In this example four of the segments designated 40A, 40B, 40C and 40D respectively have erected inside them respective housings 42 which are complementary in shape to the shape of the respective segments and which are adjacent the tubular shaft 32, in a fan arrangement around the shaft. The housing inside the segment 40A constitutes a first equipment room, the housing inside the segment 40B constitutes a second equipment room, the housing inside the segment 40C constitutes a third equipment room, and the housing inside the segment 40C constitutes a fourth equipment room which, in this case, houses an electrical generator 46 and electrical control gear 48. The equipment rooms house telecommunication equipment of a kind which is known in the art. This equipment is used to transmit and receive signals from one or more antennas, not shown, which are mounted to an upper end of the lattice tower 12. Housings can be added to, or removed from, the assembly as required to meet equipment needs.

The enclosure 22, formed by the ballast containers 16, acts as a foundation structure for a perimeter fence or wall for the tower. In the illustrated example a palisade fence 50 is fixed to support posts 52 which are erected at, and which are clamped between, respective junctions of adjacent pairs of containers 16. The palisade fence is topped with coils 54 of barbed tape, razor wire or the like.

A gate 56 is formed in the security fence. This gate opens onto doors 58 and 60 which provides access to the respective equipment rooms. Cables 64 between the various housings on the one hand between the housing and the antennas on the mast 12 on the other hand, pass through the tubular shaft 32 which provides a convenient means of connecting the electrical apparatus in one housing with electrical equipment in an adjacent housing. The tubular shaft also protects the cables, at least to some extent, from unauthorised access and against the elements. The tower of the invention holds a number of benefits. All that is required at the chosen site is that, if necessary, the site should be levelled. The ballast containers are erected without requiring special equipment. As has been indicated the ballast material can be obtained on site from local resources. The need for a high volume of quality concrete, on site, is substantially reduced. The arrangement of the segment shaped housings inside the enclosure 22 reduces the cabling required to enable electrical connections to be effected. No gravel or paving is required on site. Once the ballast containers have been filled the erection of the tower 12 can take place. There is no need to wait for concrete to cure.

The site "footprint" is compact, typically with an 8m diameter for a 36m high tower.

The fencing requirement is also reduced for, in the first place, the area of the site is normally smaller than the area of a corresponding conventionally constructed site and, secondly, the ballast containers help to achieve substantial height for the security fence.

Claims

1. A tower which includes at least one ballast container and an upwardly extending structure which is anchored to the container.

2. A tower according to claim 1 wherein the at least one ballast container has an upwardly facing mouth.

3. A tower according to claim 1 or 2 wherein the at least one ballast container is made from steel or concrete.

4. A tower according to any one of claims 1 to 3 which includes a plurality of the containers arranged to form at least an enclosure.

5. A tower according to claim 4 wherein the enclosure, in plan, is polygonal.

6. A tower according to claim 4 or 5 wherein adjacent containers are secured to one another.

7. A tower according to claim 4, 5 or 6 wherein the enclosure is defined by two arrays of the containers.

8. A tower according to any one of claims 4 to 7 which includes at least one equipment housing inside the enclosure.

9. A tower according to claim 8 wherein the housing is adjacent a centrally located tubular shaft from which the structure extends.

10. A tower according to any one claims 1 to 9 wherein the ballast is selected from sand, rock, and a cementitious or other settable material.

11. A tower according to any one of claims 1 to 10 wherein the upwardly extending structure is a lattice tower or a mast.

12. A tower according to claim 11 wherein the structure is camouflaged to resemble a tree.

13. A tower according to any one of claims 1 to 12 which includes a plurality of anchoring or supporting members which extend from the upwardly extending structure to the at least one ballast container.

14. A tower which includes a plurality of containers positioned over a defined area, each container containing ballast and an upwardly extending structure which is located within the defined area and which is anchored to the containers.

15. A tower according to claim 14 wherein the structure is anchored to the containers by means of a plurality of support members which are engaged with the structure and at least some of the containers.

16. A method of erecting a tower which includes the steps of positioning a plurality of containers on a suitable site in a predetermined configuration, filling the containers with ballast, and erecting an upwardly extending structure, which is anchored to the containers, on the site.

17. A method according to claim 16 which includes the steps of anchoring a plurality of support members to at least some of the containers and fixing the structure to the support members.

18. A method according to claim 16 or 17 wherein the upwardly extending structure is in the form of a lattice tower or a mast.

19. A method according to claim 16, 17 or 18 wherein the ballast is selected from sand, rock, and a cementitious or other settable material.

20. A method according to any one of claims 16 to 19 wherein the ballast containers are positioned to form an enclosure and the upwardly extending structure is erected inside the enclosure.

21. A method according to any one of claims 16 to 20 which includes the step of erecting a perimeter fence or wall using the containers as a foundation.