More Information on Road Gullies:
Road gullies collect surface water from the street, and join to the drainage system where it is then taken to a watercourse, storm drain or soakaway. Road gullies have combination sockets to twinwall connections as well as underground drainage pipe sockets, making them a flexible solution for a wide range of applications, including airports, motorways to car parks and car parks and more. The road gully also has a trap to prevent unpleasant odours, as well as preventing sediment from entering the drainage system.
A road gully is simply a small chamber covered by a metal grating located in the gutter of a roadway. It's used to collect surface water in the street and are the responsibility of the local councils Highways Authority.
Up until 1990 or so, road gullies tended to be big items of clayware, but their inherent fragility was always a difficulty. They were slowly replaced with pre-cast concrete components, which are considerably more robust but also much heavier. The larger 450mm diameter units weigh a lot more than a single operative can be reasonably expected to handle, and so they will need to be craned into position by an excavator. Until the positioning and levelling of the gully was right first time, subsequent alterations were difficult, involving the craning-out of this unit and making necessary adjustments to the bedding cement before craning the unit back into place. Nowadays, road gullies are usually manufactured from HDPE - making them much lighter, much more cost effective, and far easier to install as it is simply a matter of surrounding the plastic road gully in concrete.
Road gullies are much bigger than the smaller yard gullies illustrated above, but operate in precisely the same way. They tend to have 150mm diameter outlets, rather than 100mm, and come in a variety of diameters and depths. Road gullies used within carriageways are usually utilised to drain an area not exceeding 250m².
Over the last few decades, these heavy and awkward units have themselves been replaced by lightweight plastic units, that no longer provide the strength and resistance to deformation under load normally delivered by a clayware or pcc unit, but rather act as a liner mould for in-situ concrete casting. Once set up and the connecting pipework is finished, the surround concrete is placed and vibrated/compacted to give the required strength to resist deformation. A single operative can handle and install these units with comparative ease, and therefore they offer a substantial saving in both labour and costs.