GB2522487A

GB2522487A - Apparatus and method for measuring the depth of utility poles

Info

Publication number: GB2522487A
Application number: GB1406241.8A
Authority: GB
Inventors: Kenneth Moss Hughes
Original assignee: Individual
Current assignee: Individual
Priority date: 2014-04-07
Filing date: 2014-04-07
Publication date: 2015-07-29
Anticipated expiration: 2034-04-07
Also published as: GB2522487B; GB201406241D0

Abstract

Apparatus and a method for measuring the depth to which a pole (42) has been sunk are disclosed. The apparatus comprises an outer sleeve (10) having a hollow interior, configured with a pointed end portion (20) to be driven into ground (40) adjacent to the 10 place at which a pole (42) has been sunk. The outer sleeve (10) has a closable aperturethat, when opened, connects its interior to its exterior. A measuring pole (14) of known length that can be manipulated through the aperture to engage a lower end of the pole whereby the length of the measuring pole that projects above the ground can be measured to determine the depth. The measuring pole (14) may have an end portion 15 (36) that extends at right angles to its length to engage with a lower end surface of thepole (42).

Description

Apparatus and method for measuring the depth of utility poles The present invention relates to apparatus and method for measuring the depth of utility poles.

Utility poles of wood, metal or concrete are in widespread use to support overhead power transmission and telecommunication cables. When such poles are installed, a lower end portion of the pole is sunk underground. In order that the installed pole is sufficiently secure and stable, the lower end must be buried to a predetermined minimum depth. A typical (but not universal specification) is that at least the lower 2m of a pole must be sunk into the ground.

Poles made in recent times carry a depth marker. The depth marker is a known distance from the bottom of the pole (which distance may be indicated by the marker].

Therefore, by measuring the height of the marker above the ground, the depth of pole buried in the ground can be determined. However, there are still very many poles in use that pre-date the use of depth markers. Modern inspection regulations require that the pole cannot be assessed as safe unless the depth to which it has been sunk can be determined as sufficient. This can result in poles that are actually safe being replaced because the depth to which they have been sunk cannot be established with certainty. It is clear that this could cause utility companies to incur significant unnecessary expense.

An aim of this invention is to provide apparatus and a method by which the depth of an existing utility pole can be measured in a convenient and cost-effective manner.

To this end, from a first aspect, the present invention provides apparatus for measuring the depth to which a pole has been sunk comprising: an outer sleeve having a hollow interior, configured to be driven into ground adjacent to the place at which a pole has been sunk, the outer sleeve having a closable aperture that, when opened, connects its interior to its exterior; a measuring pole of known length that can be manipulated through the aperture to engage a lower end of the pole whereby the length of the measuring pole that projects above the ground can be measured to determine the depth.

Thus, the depth to which a pole has been sunk can be determined with no more groundwork being required than is necessary to drive the sleeve into the ground -typically drilling a small vertical hole.

Preferably, the outer sleeve is provided with a pointed closure at one of its ends to assist on its being driven into the ground. The aperture of the outer sleeve is typically an elongate slot.

The apparatus may further include an inner sleeve that is a close sliding fit within the outer sleeve. The extent to which the inner sleeve is introduced into the outer sleeve can determine the extent to which the aperture is open or closed.

An inlet valve is typically provided on the outer sleeve to which a source of pressurised fluid can be connected. A flushing tube may be provided within the outer sleeve to which pressurised fluid is delivered through the inlet valve.

In a typical embodiment, the measuring rod comprises an long portion that is of sufficient length to reach an expected sunk depth of a pole and a short turned portion that can engage with and be retained by a bottom surface of a pole.

From a second aspect, this invention provides an assessment method for measuring the sunk depth of a utility pole comprising: a. introducing an outer sleeve into ground adjacent a pole to be assessed; b. opening an aperture in the outer sleeve adjacent to the pole; c. causing a measuring pole to project through the aperture to engage with a lower end surface of the pole; and d. measuring the extent to which the measuring pole projects above ground level and thereby calculate the depth of the measuring pole below ground, being the sunk depth of the pole.

in typical embodiments of the invention, prior to step a., a hole may be formed, typically by drilling, adjacent to the pole to facilitate introduction of the outer sleeve into the ground.

Advantageously, between steps b. and c., pressurised fluid is ejected through the aperture to facilitate projection of the measuring pole. The pressurised fluid is typically air or water.

Step b. is typically performed by partially or completely removing an inner sleeve from the outer sleeve, the inner sleeve serving to close the aperture during step a., thereby preventing soil from entering the outer sleeve through the aperture.

Methods embodying the invention are typically applied to the assessment of the safety of utility poles.

An embodiment of the invention will now be described in detail, by way of example, and with reference to the accompanying drawings, in which: Figure 1 shows the individual components of a preferred embodiment of the invention; Figure 2 shows the assembled preferred embodiment of the invention in a closed condition; Figure 3 shows the assembled preferred embodiment of the invention in an open condition; and Figure 4 is a diagram that illustrates operation of the embodiment of the preceding figures.

This embodiment of the invention comprises three principal components: an outer sleeve 10, an inner sleeve 12, and a measuring pole 14.

The outer sleeve 10 is formed from a length of tube. in this embodiment, the tube is steel, although other materials, such as polymer composites, might alternatively be used. An upper end of the tube is open, and the sower end is closed by a conical pointed point 20. A slot 22 is formed through the tube, extending from close to the point 20 approximately three-quarters of the length of the tube towards the upper end. A Hushing 24 tube is located against the inner wall of the outer sleeve 10, and extends from close to the point 20 to close to the upper end. The lower end of the flushing tube 24 is open and the upper end is closed. The flushing tube 24 is spaced circumferentially around the inner wall of the outer sleeve by approximat&y 900. An ifflet valve 26 is connected to the flushing tube through the wall of the outer sleeve 10.

in this embodiment, the outer sleeve has a diameter of 52 mm and a length of 2.1 m, and the flushing tube has a diameter of 15 mm.

The inner sleeve 12 is a length of tube formed from stainless steel or other materials, such as polymer composites. The outer diameter of the inner sleeve 12 is chosen to be a sliding fit within the outer sleeve [50 mm in this embodiment) and is approximately the same length as the outer sleeve 10. A slot 30 is formed along the length of the inner sleeve 12, the slot being of width sufficient to accommodate the flushing tube 24.

The measuring rod 14 is formed from a length of steel rod. A short lower end portion 36 of the rod 14 is turned through 90° and has a tip 38 formed with a sharpened point.

The length of the measuring rod 14, not including the lower end potion, is known accurately. In this embodiment, this length is 2.43 m.

An optional shield 34 is carried on the measuring rod above the upper end of the outer sleeve 10. In this embodiment, the shield is formed from a skirt of flexible material that can slide, in use, up and down on the measuring rod 14.

For use, the inner sleeve 12 is inserted into the outer sleeve 10. The flushing tube 24 is received into the slot 30 in the inner sleeve 12. The inner sleeve 12 is inserted until its lower end passes the lower end of the slot 22 in the outer sleeve 10, such that the slot 22 is completely closed by the inner sleeve 12. This configuration is shown in Figure 2.

A hole is drilled vertically down into the ground 40 adjacent to a pole 42, such as a utility pole carrying power or telecommunications cables, that is to be assessed. The hole is drilled to a depth in excess of the expected sunk depth of the pole 42. The apparatus, assembled as described in the last-preceding paragraph, is then driven into the hole, as close as possible to the pole 42, and with the slot 22 in the outer sleeve 10 facing the pole 42.

Next, the inner sleeve 12 is withdrawn upwards from the outer sleeve 10. Withdrawal of the inner sleeve 12 uncovers the slot 22 in the outer sleeve 10.

An external source of pressurised fluid (not shown] is connected to the inlet valve 26 through a hose 28. The pressurised fluid may be air or water, the best fluid for any given soil type being found easily by experimentation. The fluid passes through the flushing tube 24 to the bottom of the outer sleeve 10 and flows upwardly within the outer sleeve 10 to emerge through the open upper end of the outer sleeve 10. This flushes out any debris that might have fallen into the outer sleeve 10. The shield 34 protects an operator of the apparatus against being struck by water and debris that is flushed from the outer sleeve 10 during this operation.

The measuring rod 14 is then introduced into the inner sleeve 12, with its tip 38 facing towards the pole 42. The measuring rod 14 is then drawn upward. It turned end portion 36 eventually will engage with the bottom of the pole 42, which will prevent further upward movement. The height of the top of the measuring rod 14 above ground level can then be measured directly Since the length of the measuring rod 14 to the turned end portion 36 is known, it is a straightforward matter to calculate the length of the rod which is below ground, which is equal to the sunk depth to which the pole 42 is sunk.

Once the outer sleeve 10 has been flushed clean, as described in the last-but-one preceding paragraph, there is a possibility that ground water will enter the hole. if this happens, a pump can be connected to the inlet valve 26, and operated to draw water from the inner sleeve (thus reversing the flow as compared with the flushing operation discussed above). This step can also be used to clear the outer sleeve in cases where a liquid such as water is used to flush the outer sleeve.

if it is unclear to an operator whether or not the tip 38 of the measuring rod 14 has properly engaged with the bottom end of the pole 42, a camera can be lowered into the outer sleeve 10 to provide a clear image of the position of the tip. This is possible because the flushing and optional pumping operations have left the bottom of the pole free from obstruction.