The following steps are performed (please note: this description omits preliminary steps such as consulting the risk assessment and method statement documents, implementing traffic management, inspecting the column for damage, corrosion or poorly fitted components, etc.)…
- If the initial visual inspection indicates that the column is safe to test, the test machine is manoeuvred into place so that a padded ram at the base of the front of the machine is in contact with the base of the column. If the column is hexagonal then the ram is placed against a flat face of the hexagon.
- The test equipment is secured to the base of the column by means of a sling at ground level which is tightened to prevent overloading of the column foundations.
- Lasers are attached to the column at heights of 200mm and 2000mm above ground level and their beams targeted towards a camera mounted on a tripod which is placed adjacent to the column.
- The test software is calibrated to take into account the background light conditions so that the camera will accurately register the movement of the lasers during testing.
- The ID and location of the column to be tested are entered into the test software. In addition any observations on the state of the column as a result of the visual inspection can also be entered.
The following load factors are entered into the test software which calculates a test load in accordance with BS EN 40 standards:
- Column dimensions (including the bracket arm).
- Column characteristics (material, shape, style, number of doors, etc.)
- Location factors (elevation, exposure, ground type, topography, etc.)
- Wind load factors for the test locality.
- Additional load factors created by attachments such as signs, banners, seasonal decorations, CCTV cameras, replacement LED luminaires, etc.
- Using a manually operated hydraulic ram the test machine gradually and gently applies increasing force on the column until the required loading is achieved. The test operator can monitor the response of the column in real-time as a graphical representation on the computer screen. At the same time the test assistant maintains a visual check of the condition of the column. If any negative reaction is observed by either operative the test is aborted immediately.
- The test load is released and the column is allowed to gradually return to its starting position.
- A second test may be used where 30% of the calculated test load is applied as before and then the column is released in one go and is allowed to oscillate and come to rest naturally.
- By viewing the graphical test results the operator is able to make an informed decision on the condition of the column. The column’s test result status is recorded. In the case of a failure the cause and any remedial actions can be recorded along with any other useful observations.