AU2016101554A4 - System, method, and device for use with overhead cables - Google Patents

Abstract

James & Wells ref: 302176AU A cable block and use of same in providing a catenary support system for replacing an overhead cable is disclosed herein. The cable block includes a body having an interior and an exterior, and including an opening between the interior and exterior. A main gate is moveable between a closed position blocking the opening, and an open position permitting passage through the opening. A pulley is positioned within the interior of the body. ArAx A etA300

Description

SYSTEM, METHOD, AND DEVICE FOR USE WITH OVERHEAD CABLES

TECHNICAL FIELD

Embodiments of the disclosure relate to systems, methods, and devices for use with overhead cables. More particularly, embodiments of the disclosure relate to a cable block and use of same in providing a catenary support system for replacing an overhead cable.

STATEMENT OF CORRESPONDING APPLICATIONS

This application is based on the provisional specification filed in relation to New Zealand Patent Application No. 711784, the entire contents of which are incorporated herein by reference.

BACKGROUND

The replacement of overhead transmission lines is a significant undertaking in a number of regards, but especially so in the context of high power transmission conductors given the potential for damage to infrastructure located beneath such conductors, and associated health and safety risks.

Catenary support systems are known for this task, in which a series of cable blocks are hung on the existing cable between two pylons, and deployed along the cable by a robot towing a support rope to which the cable blocks are connected. The support rope is subsequently tensioned such that the cable blocks flip over and take the load of the existing cable. The cable is then pulled through the cable blocks, with the replacement cable pulled through after it.

Existing cable blocks intended for this purpose require the manipulation of fasteners such as nuts in order to perform distinct operations to (a) secure the block to the support rope, and (b) secure the block to the existing cable.

Overhead power line workers are typically required to work from suspension ladders hung from the pylon itself. Combined with the relatively bulky safety clothing and harnesses required in such working positions, the worker's mobility, reach, and dexterity is restricted. The design of existing cable blocks does not account for these working conditions - both in terms of ease of use (and therefore efficiency), but also risk management.

While safety protocols are typically put in place to restrict access to a hazard area below the working position, there is still a risk of injury to personnel if the cable block (or parts thereof) are dropped - as well as the potential for damage to the cable block or other equipment should it fall from height, and time lost in recovering such dropped equipment.

Further, existing cable block design is such that there are instances during installation in which a cable block is only retained by the grip of the worker - again introducing potential for the blocks to be dropped from height.

Even if no errors are made, improving ease of use in such hazardous working environments can assist in reducing stress and fatigue levels of workers - in turn improving the wellbeing of the worker and increasing the likelihood of better decision making or more efficient use of the labour unit.

It is an object of the present invention to address the foregoing problems, or at least to provide the public with a useful choice.

All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country.

Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like, are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense, that is to say, in the sense of "including, but not limited to".

Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.

SUMMARY

According to one aspect of the present disclosure there is provided a cable block, including: a body having an interior and an exterior, and including an opening between the interior and exterior; a main gate, moveable between a closed position blocking the opening, and an open position permitting passage through the opening; a pulley positioned within the interior of the body.

According to one aspect of the present disclosure there is provided a catenary support system, including: a plurality of a cable blocks substantially as herein described; and a support line for suspension between two support structures, to which the cable blocks are secured.

According to one aspect of the present disclosure there is provided a method of deploying a catenary support system, including: securing a plurality of a cable blocks substantially as herein described to a support rope; positioning the cable blocks on an existing cable suspended between two support structures; and towing the support line along the existing cable from one of the support structures to the other; suspending the support line between the support structures; and tensioning the support line such that the existing cable bears against the cable blocks. A cable block is a device hung from a support line suspended between two support structures, used to support an overhead cable. It is envisaged that exemplary embodiments of the cable block herein described may have particular application to the replacement of high voltage power transmission conductors suspended between pylons.

Such conductors are typically formed of a plurality of strands - such as the Aluminium Conductor Steel Reinforced (ACSR), All Aluminium Conductors (AAC), or All Aluminium Alloy Conductor (AAAC). While characteristics of the conductor will vary depending on its specification, by way of example the conductor may be an ACSR "Chukar" conductor, being substantially 3.092kg/m with a diameter of 40.7mm.

In an exemplary embodiment the support line, and therefore cable blocks, may be deployed along the existing cable by a pulling robot. Pulling robots, or tugs, such as the Model No. LKE 85 'Pulling Robot' supplied by ZECK GmbH at the time of filing, are well known in the art for traversing a span while towing a support line and attached cradle blocks.

The support line may be any suitable line known in the art, but by way of example may be Ultra-High Molecular Weight Polyethylene (UHMwPE) fibre rope - such as that marketed under the Dyneema® brand by Koninklijke DSM N.V. at the time of filing the application.

Once the support line (and cable blocks) have been towed along the existing cable, a tensioning device (for example, a ground based tensioner) may be used to secure and tension the support line. Tensioning of the support line, such that it rises above the existing cable and pivots the cable blocks from a resting position on the cable to taking the weight of the cable.

The existing cable may then be pulled through the cable blocks. A towing line may be secured to the end of the existing cable, to subsequently pull a replacement cable through the cable blocks.

In an exemplary embodiment, the body may include a spine having a first end and a second end, a first lateral arm extending from the first end of the spine, and a second lateral arm extending from the second end of the spine, wherein the opening is located between unconnected ends of the first and second lateral arms. Such a configuration may be generally "C" shaped, although it should be appreciated that reference to such a shape is not intended to be limiting with regard to curvedness or symmetry.

It should be appreciated that reference to the interior of the body is not intended to imply that features located therein are completely enclosed. Rather, the interior defines a space through which a line or cable may pass.

Description of exemplary embodiments of the body and features associated therewith may now be made with reference to sides, ends, and faces of the body. It should be appreciated that these terms are used to describe locations or points relative to others on the body, and are not intended to place limitations on shape or proportions unless expressly stated.

In an exemplary embodiment the body may be made from an electrically non-conductive material. It is envisaged that the cable blocks and catenary support system may be used in the vicinity of live conductors - in which case a current may be induced in a non-connected conductor on which the cable block is used. In such an environment it may be beneficial for devices (such as the cable block) contacting the conductor to be non-conductive to reduce the likelihood of shorting, or arcing, occurring through the device. Further the risk of corona discharge in high voltage systems can be exacerbated by the presence of irregular shapes or sharp edges of a conductor - making it preferable for devices in contact with conductors to be non-conductive.

In an exemplary embodiment the body may be made from a plastics material. For example, the plastics material may be polymide nylon with glass fibre reinforcing. It should be appreciated that this is not intended to be limiting, and that any other suitable plastics material known to a person skilled in the art may be used. In an exemplary embodiment the body may be moulded as a unitary part.

It is envisaged that in addition to the electrical insulation properties of suitable plastics, such materials may also provide suitable mechanical properties in terms of strength while not having the hardness of metals such as steel. Existing cable blocks made of steel may present a higher risk of cutting into and damaging the aluminium strands of the cable if dropped onto or dragged along the cable.

In an exemplary embodiment, the cable block may include at least one pulley guard between the body and a flange of the pulley. It is envisaged that this may reduce likelihood of stray conductor strands becoming jammed between pulley and body. In an exemplary embodiment the cable guard may extend over a portion of the pulley.

In an exemplary embodiment the pulley guard may include a surface forming a substantially continuous profile with the pulley in at least one direction.

In an exemplary embodiment the pulley guard may be located on a face of body facing away from the end from which the existing cable is pulled through.

In an exemplary embodiment, the opening into the interior of the body, and the main gate, are located on a side of the body, between the location of the pulley and an end of the body distal from the pulley.

The main gate may be any suitable structure for selective blocking of a line passing sideways through the opening. For example, the main gate may be an arm, moving about a point of connection to body on one side of the opening. For example, the point of connection may be a hinge allowing pivotal movement of the gate relative to the body.

In an exemplary embodiment, the main gate may open into the interior of the body. It is envisaged that this may assist with ease of installation - allowing the cable block to effectively be clipped onto the cable in one motion pushing or pulling motion, potentially one handed.

In an exemplary embodiment, the main gate may bear against body in the closed position to prevent opening towards the exterior due to internal forces presented by the cable or support line. This may reduce the likelihood of the cable or support line escaping from the interior in use - instead requiring a worker to push the gate inwardly to allow removal.

In an exemplary embodiment the cable block may include a gate catch between an unconnected end of the main gate and the body in the closed position to assist with balancing the loading forces through the side of the body in use. For example, the gate catch may include a catch protrusion on the body to be received by a catch recess on the main gate, or vice versa.

In an exemplary embodiment the gate catch may include a locking device requiring release by a user before the main gate is permitted to open.

In an exemplary embodiment the main gate may be biased towards the closed position. It is envisaged that this may assist in enabling installation of the cable block with a reduced number of operations required by the worker, potentially one handed.

In an exemplary embodiment the cable block may include a main gate biasing device - for example a spring such as a torsion spring in the hinge. It should be appreciated that this is not intended to be limiting, and that other mans for biasing the main gate may be used, whether passive or active.

In an exemplary embodiment, the cable block may include support line locating means for locating the support line relative to the body.

In an exemplary embodiment, the support line locating means may be located within the interior of the body. In doing so, the main gate may be used to not only retain the cable as previously described, but the support line as well.

In an exemplary embodiment the support line locating means may include a recess in the interior of body at an end distal to the pulley.

In an exemplary embodiment, the support line locating means may include a second gate moveable between a position blocking the recess from the interior, and a position opening the recess to the interior. For example, in an exemplary embodiment the second gate may pivot about a point of connection to the body. The recess may include a cavity on one side for receiving the second gate as it moves into the open position.

In an exemplary embodiment the second gate may be biased towards the position blocking the recess. As in the case of the main gate, it is envisaged that this may assist with ease of installation - the worker being able to push or pull the support line through the main gate, and then through the second gate, without needing to remove and reattach fasteners.

In an exemplary embodiment, the support line locating means may be located at an apex of the interior of the body. In doing so, the interior of the body may guide the support line towards its retention means to assist with installation.

In an exemplary embodiment, a support line clamping device may be provided to restrict relative movement of the cable block along the support line. This may assist in ensuring that the cable blocks are spaced at requisite intervals along the cable when deployed.

In an exemplary embodiment support line clamping device may be one or more components separate to the cable block - for example clamps positioned on the support line on either side of the cable block.

In an exemplary embodiment the cable block includes a support line clamping device. For example, the support line clamping device may include a bearing surface selectively applied to the support line. Force may be applied between the bearing surface and the support line by any suitable means known in the art - for example a locking lever, or a biasing device such as a spring.

In an exemplary embodiment, the cable block may include a main fulcrum protrusion extending from the body into the interior. In use, when the support line is tensioned, the main fulcrum protrusion serves to provide a surface against which the cable may bear and pivot. By defining the position at which this occurs, it is envisaged that this may assist in consistently achieving complete pivoting of the cable block through a desired range of motion and in a desired direction.

In an exemplary embodiment the main fulcrum protrusion extends from a position between the pulley and the end of the body distal from the pulley. In embodiments in which the support line locating means is located within the interior of the body at the end distal from the pulley, this position may assist in limiting the travel of the cable within the interior to assist with pivoting, while still allowing a desired spacing between the support line and cable.

In an exemplary embodiment, the surface of the main fulcrum facing the pulley may be angled towards the distal end of the body from the pulley. More particularly, the surface of main fulcrum facing the pulley may be concavely curved. It is envisaged that this may reduce the likelihood of impact between the cable and the cable block occurring during pivoting of the cable block, by proving a smooth transition through this range of motion.

In an exemplary embodiment, the surface of the main fulcrum may be shaped such that its apex is laterally offset from the centre of mass of the cable block, away from the main gate. It is envisaged that this may assist in encouraging pivoting of the cable block in a repeatable manner, such that when multiple cable blocks are used they pivot in the same direction.

In an exemplary embodiment the cable block may include a second fulcrum protrusion extending from the main gate toward the main fulcrum protrusion in the closed position. The second fulcrum protrusion may work together with the main fulcrum protrusion to provide the previously describe bearing surface during pivoting. It should be appreciated that while the second fulcrum protrusion is described with reference to the main fulcrum protrusion, in an exemplary embodiment the cable block may only include a fulcrum protrusion extending from the main gate.

In an exemplary embodiment the surface of the secondary fulcrum protrusion facing the pulley may also be angled towards the distal end of the body from the pulley.

In an exemplary embodiment, the cable block includes a gap between main fulcrum protrusion and the secondary fulcrum protrusion when the main gate is closed, sufficient for the support line to pass through. This allows the main gate to be used for entrance and exit of the support line from the interior.

In an exemplary embodiment, the point of connection of the main gate to the body may be on the side of the opening distal from the pulley. It is envisaged that this may assist with ease of operation in embodiments including the fulcrum protrusions, and the support line locating means located within the interior of the body.

In an exemplary embodiment, the cable block may include a counterweight. The counterweight may be positioned to assist in pivoting the cable block in a desired direction and motion - particularly during tensioning of the support line to take the weight of the cable. The counterweight may be provided by any suitable means known in the art - for example a solid mass attached to the body, whether releasably or fixed.

In an exemplary embodiment the counterweight may be located proximate the end of the body at which the support line locating means is located.

In an exemplary embodiment, the counterweight may be located on the side of the main body having the opening into the interior. It is envisaged that this may encourage pivoting of the cable block in a direction which reduces the likelihood of the cable striking, or bearing heavily against, the main gate during pivoting - thereby reducing the likelihood of the main gate failing and allowing release of the cable.

The cable block may include a shroud for the counterweight on the exterior of the body to provide relatively continuous profile and reduce likelihood of snagging.

The system may include a delivery line, used to lift the cable blocks to a working position at which they may be secured to the support line and the cable.

In an exemplary embodiment, the delivery line may include a main line, and a plurality of secondary lines. Each secondary line may be secured by one end to the main line, spaced apart from the other secondary lines. A cable block may be secured to a free end of one or more of the secondary lines.

In an exemplary embodiment, the cable block may include an eye on the exterior of the body at the end proximate to the pulley. In use, the eye may be used to secure the cable block to the delivery line. For example, a fastener such as a carabineer may connect the delivery line to the eye.

The secondary lines may be approximately 1.0 to 1.5m in length, providing sufficient slack for a user to secure a cable block to the support rope or cable before requiring release from the delivery line. This helps to reduce the risk of the cable block being dropped from height during installation - a potential safety hazard, in addition to probable damage to the equipment and lost time in completing the task.

It should be appreciated that while the delivery line is described in the context of delivering the cable from the ground to height and securing it to the cable, such an arrangement may also be used in the subsequent removal and transportation to ground once installation is complete.

The various steps or acts in a method or process may be performed in the order shown, or may be performed in another order. Additionally, one or more process or method steps may be omitted or one or more process or method steps may be added to the methods and processes. An additional step, block, or action may be added in the beginning, end, or intervening existing elements of the methods and processes.

BRIEF DESCRIPTION OF DRAWINGS

Further aspects of the present invention will become apparent from the following description which is given by way of example only and with reference to the accompanying drawings in which: FIG. 1A is a perspective view of an exemplary cable block; FIG. IB is a face on view of an exemplary cable block; FIG. 1C is a face on view of another exemplary configuration of the exemplary cable block; FIG. ID is a side view of an exemplary cable block; FIG. IE is a base view of an exemplary cable block; FIG. 2 is a face on view of the exemplary cable block with the main gate and second gate open; FIG. 3A-D illustrate the range of motion of the exemplary cable block about an exemplary cable during tensioning of an exemplary support line; FIG. 4 illustrates an exemplary delivery line system for transportation of the exemplary cable block to and from an elevated working position; and FIG. 5A-L illustrate the installation and use of a catenary support system on a high power transmission line.

DETAILED DESCRIPTION FIG. 1A is a perspective view of a cable block 100, including a generally 'C' shaped body 102. The body 102 includes an opening 104 between the exterior and interior of the body 102, the opening 104 having a first opening side 106a and a second opening side 106b.

By way of reference, the body 102 has a first end 108, and a second end 110, a left side 112 and a right side 114, and a front face 116 and a rear face (not seen in FIG. 1A). A pulley 118 is rotatable mounted to an axle 120 extending through the interior of the body 102 between the left side 112 and right side 114. The pulley 118 is positioned at an end of the interior distal from the first end 108. A pulley guard 112 extends from the front face 116 of the body 102, and partially over the pulley - as will be described further below with reference to FIG. ID.

The cable block 100 includes a main gate 124 extending across the opening 104. The main gate 124 is connected to the first opening side 106a by way of a hinge, allowing pivotal movement which will be described further below with reference to FIG. 2.

The cable block 100 also includes a main fulcrum protrusion 126 extending laterally from the left side 112 of the interior of the body 102 towards the right side 114. The main fulcrum protrusion 126 is located between the pulley 118 and the end of the interior proximate the first end 108. A second fulcrum 128 extends in the opposite direction from the main gate 124, with a support line gap 130 therebetween.

The support line gap 130 allows the passage of a support line (not shown in FIG. 1A) through to a support line locating recess 132 at the end of the interior proximate the first end 108. The support line locating recess 132 includes a gate cavity 134. A second gate 136 is pivotally connected to the body 102 via a hinge, and is moveable between a position blocking the recess 132 from the interior, and a position within the gate cavity 134 opening the recess 132 to the interior. A cylindrical counterweight 138 is secured to the right side 114 of the exterior of the body 102, in a location between the opening 104 and the apex of the exterior of the first end 108.

An eye 140 is located on the exterior of the body 102 at the second end 110. The eye 140 allows for connection of the cable block 100 to a delivery line via a releasable fastener such as a carabineer (not illustrated in FIG. 1A) - as will be described further below with reference to FIG. 4. FIG. IB shows the cable block 100 face on. The free end of the main gate 124 extends beyond the opening 104, such that when closed it bears against the body 102 on the second opening side 106b. A catch protrusion 142 extends through an aperture (not seen in FIG. IB) in the main gate 124 to allow the main gate 124 to act as load bearing member across the opening 104.

The main fulcrum projection 126 and second fulcrum projection 128 have surfaces (144 and 146 respectively) facing the pulley 118, angling towards the first end 108 of the body 102. More particularly, the surface 144 of main fulcrum projection 126 is concavely curved. As well as creating a smoother transition profile for the cable as the cable block 100 pivots, the surfaces 144 and 146 also serve to funnel the support line into the gap 130. FIG. 1C illustrates an exemplary embodiment in which the main fulcrum projection (labelled 126a in FIG. 1C) and second fulcrum projection (labelled 128a in FIG. 1C) have surfaces (144a and 146a respectively) facing the pulley 118 which are shaped to shift their apex to a point away from the counterweight (not illustrated in FIG. 1C, put located on the same side of the block 100 as the opening 104). It is envisaged that this may assist in encouraging pivoting of the cable block 100 in a repeatable manner, such that when multiple cable blocks are used they pivot in the same direction.

Returning to FIG. IB, it may be seen that the support line locating recess 132 is located at the apex of the interior of the body 102, with the sides of the interior guiding a support line to the recess 132 after passing through the gap 130.

In an exemplary embodiment, shown in FIG. IB only, a shroud 148 for the counterweight is provided on the exterior of the body 102 to provide relatively continuous profile and reduce likelihood of snagging. FIG. ID shows the cable block from the right side, on which the counterweight 138 is located. The pulley guard 122 extends from the front face 116 of the body 102 beyond the pulley.

As seen in FIG. IE, the pulley 118 includes a groove 150 between flanking flanges 152. The pulley guard 122 extends over the flanges 152 to prevent exposure of the gap between the pulley 118 and the body 102. Inner surfaces 154 of the pulley guard 122 are shaped to produce a substantially continuous profile 156 with the groove 150 of the pulley 118. FIG. 2 shows the main gate 124, and the second gate 136, in their respective open positions - i.e. permitting access to opening 104 and recess 132 respectively.

Both gates 124 and 136 are biased towards their closed positions - i.e. in the directions A and B respectively - by torsion springs in their respective hinges (not clearly seen). This allows for passing of the cable and/or support line laterally through the opening 104 without the need for manipulation of a fastener by a worker, automatic closure of the main gate 124, and subsequently prevention of escape through the opening 104 without positive action by the worker - i.e. acting against the bias of the main gate 124. A similar principle applies to the passage of the support line through the second gate 136. FIG. 3A through FIG. 3D shows the motion of the cable block 100 relative to an existing cable 300 and support line 302. In FIG. 3A, the cable block 100 hangs by its pulley 118 from cable 300. The support line 302 is slack at this stage. On tensioning the support line 302, the cable block 100 pivots about the cable 300 from the pulley 118 onto the main fulcrum protrusion 126 as seen in FIG. 3B and FIG. 3C. Once the support line 302 is fully tensioned, it bears at least part of the load of the cable 300 resting on the pulley 118. FIG. 4 illustrates a delivery line system 400, used to lift cable blocks lOOa-n to a working position at which they may be secured to the support line and the cable (not shown in FIG. 4).

The delivery line system 400 includes a main line 402, and a plurality of secondary lines 404a-n. Each secondary line 404a-n is secured by one end to the main line 402, spaced apart from the other secondary lines 404a-n. The cable blocks lOOa-n are secured to free ends of the secondary lines 404a-n using carabineers 406a-n through eyes 140 (not seen clearly in FIG. 4 - but see FIG. 1A).

The main line 402 may be passed over one or more pulleys 408 to facilitate lifting of the cable blocks 100a-n. FIG. 5A-5L illustrates a high voltage power transmission line 500, in various stages of installation and use of a catenary support system utilising a plurality of cable blocks - for example cable block 100. As seen in FIG. 5A, the high voltage power transmission line 500 includes a series of pylons - including first pylon 502a and second pylon 502b - each having an insulator assembly 504 supporting a stringing sheave 506 from which an existing cable 508 is suspended.

In the first step of installation of the catenary support system, support line blocks 510 are secured to the pylons 502, and support line container 512 positioned on the ground on the far side of the first pylon 502a - as seen in FIG. 5B.

As seen in FIG. 5C, a support line 514 is passed over the first support line block 510a and secured to a pulling robot 516 positioned on the existing cable 508. Cable blocks 100 are lifted to the level of the existing cable 508 - for example using delivery line system 400 of FIG. 4 - and secured to the existing cable 508 and support line 514. An anchor line 518 is secured to a ground anchor 520 and passed over the second support line block 510b. A shackle 522 is located at the distal end of the anchor line 518, for securing the anchor line 518 to the support line 514.

Once the support line 514 has been run out and secured to the anchor line 518 by shackle 522, the support line 514 is connected to a hoist 524 - for example a TIRFOR® hoist supplied by the TRACTEL Group at the time of filing the application - as shown in FIG. 5D.

The support line 514 is then tensioned using the hoist 524, as seen in FIG. 5E, until the existing cable 508 is supported by the cable blocks lOOa-n as seen in FIG. 5F. FIG. 3A-D illustrate the range of motion of the cable blocks lOOa-n through this tensioning process.

The existing cable 508 can then be pulled through the stringing sheaves 506a and 506b, in turn pulling a replacement cable 526 secured to its trailing end by a conductor joiner 528 through the cable blocks 100a-n - as seen in FIG. 5G. Once the replacement cable 528 is pulled through - as seen in FIG. 5H - it may be secured in place as known in the art.

The catenary support system is then recovered by releasing the tension in the support line 514 using the hoist 524, such that the cable blocks 100a-100n hang on the replacement cable 526 as seen in FIG. 51. The support line 514 is then disconnected from the anchor line 518, and the hoist 524 disconnected from the support line 514 - to be recovered by support line container 512 - as seen in FIG. 5J.

As the support line 514 is recovered, the cable blocks 100a-100n are removed from the replacement cable 526 and support line 514 at the first pylon, as seen in FIG. 5K. Once the support line blocks 510a and 510b, support line 514, and anchor line 518 are removed, the replacement conductor 526 is fully installed in the high voltage power transmission line 500, as seen in FIG. 5L.

The entire disclosures of all applications, patents and publications cited above and below, if any, are herein incorporated by reference.

Reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that that prior art forms part of the common general knowledge in the field of endeavour in any country in the world.

The invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the disclosure, individually or collectively, in any or all combinations of two or more of said parts, elements or features.

Where in the foregoing description reference has been made to integers or components having known equivalents thereof, those integers are herein incorporated as if individually set forth.

It should be noted that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the spirit and scope of the invention and without diminishing its attendant advantages. It is therefore intended that such changes and modifications be included within the present invention.

Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof as defined in the appended claims.

Claims (5)

1. A cable block, including: a body having an interior and an exterior, and including an opening between the interior and exterior; a main gate, moveable between a closed position blocking the opening, and an open position permitting passage through the opening; a pulley positioned within the interior of the body.

2. A cable block as claimed in claim 1, including support line locating means for locating a support line relative to the body, located within the interior of the body at an end distal to the pulley.

3. A cable block as claimed in claim 1 or claim 2, including a main fulcrum protrusion extending from the body into the interior, and a second fulcrum protrusion extending from the main gate toward the main fulcrum protrusion in the closed position, wherein the cable block includes a gap between the main fulcrum protrusion and the secondary fulcrum protrusion when the main gate is closed, sufficient for a support line to pass through.

4. A cable block as claimed in any one of claims 1 to 3, wherein the body is made of an electrically non-conductive material.

5. A method of deploying a catenary support system, including: securing a plurality of a cable blocks, as claimed in any one of claims 1 to 4, to a support line; positioning the cable blocks on an existing cable suspended between two support structures; and towing the support line along the existing cable from one of the support structures to the other; suspending the support line between the support structures; and tensioning the support line such that the existing cable bears against the cable blocks.