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sufficiently high priority, and is not considered cost-effective. |
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Inspection following complaints or in advance of planned access for maintenance works may be appropriate in some circumstances. The general inspection of manholes or inspection chambers for the sole purpose of determining their condition is not cost-effective and is not therefore recommended. Whenever a manhole or inspection chamber is entered for any purpose (for example, to clear a blockage or for inspection of the sewer), an inspection should be carried out and a report completed. |
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It is possible that the need for replacement of covers and frames will be identified from reports from the public highway authorities or from observations from employees involved with day-to-day maintenance of the sewerage system. When a report is received, a list of any work required should be made and given a priority. The work should then be scheduled to be carried out within the response time appropriate to the priority assigned. All reports should be stored and monitored. Where a significant number of defects are reported in a small area it may be costeffective to carry out a survey of all the manholes and inspection chambers in that area with a view to carrying out a planned maintenance programme. |
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Repairs of inspection chambers and manholes should be done to the same specification as new chambers. The methods involve work in confined spaces, and appropriate safety precautions should be strictly enforced and observed. |
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5.4.12
Suggested Schedule for Inspection of Manholes |
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During an inspection of a manhole the following items should typically be included: |
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check that the cover or frame is not broken or cracked, that it does not rock more than 10 mm, and that the eyes and keyways are not excessively worn; |
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check that the cover is flush with the ground level within specified tolerances; |
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check that the opening in the cover and access shaft is sufficient for safe access (it is usually considered adequate where there is a clear opening of 600 mm or more); |
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