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Winching or dragging is the technique of pulling a shaped bucket through the sewer pipe. The bucket collects sediment which is then emptied out at the point of access, normally into a skip. |
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The winch operation can be done by hand, but in most cases the winches are power driven. Winching is most effective in heavily silted sewers up to 900 mm diameter. Winching is used infrequently because it is very slow, and it can often cause damage to the fabric of the sewer. |
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Traditionally, the larger diameter outfall sewers were cleaned by manual methods, i.e. by labourers shovelling sediment into skips which were transported through the sewer to the manhole and thence removed. However, as the sewer environment is hazardous, the number of occasions that operatives are required to work in sewers should be minimized. |
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Solids Removal and Disposal. |
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It is important that the displaced solids or sediment are removed from the sewer system, and disposed of at a licensed tip. |
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Depending on local labour costs, local excavation and pipe replacement may be cheaper than some of the above methods, and should be considered. Care should be taken to present additional debris entering the sewer system during this work. |
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5.4.9
Rodent Control in Sewers |
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Rodent control in sewers is not only needed to minimize health risks, but to prevent structural damage to the sewers, inspection chambers and manholes, resulting from the burrowing of |
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