M40 UK Highways are required to undertake detailed drainage inspections of their drainage asset once every 10 years. This requirement has generally been undertaken by flushing water downstream to the next manhole in order to see that the drainage system is operational. The issue with this approach is that since the introduction of the Highways Agency Drainage Data Management System (HADDMS) very little data is recorded that can be input into HADDMS. There is also a further issue of flushing the cross carriageway drain whilst flushing the central reserve drainage as it is not possible for operatives to lift manholes in the adjacent carriageway or verge at the same time due to health & safety issues.
The traditional method of inspection (flushing) would also not provide any visual identification of defects so further costly CCTV surveys would need to be undertaken to identify defects. This would mean further traffic management costs would be incurred due to second visits to site.
In December 2017 Crown Recycling presented a proposal that would satisfy the detailed inspection requirements (whilst visually showing any defects in the cross carriageway drainage preventing the system from flowing) and at the same time capture meaningful information that could be uploaded into HADDMS.
This solution required the use of a haloptic camera that is capable of viewing upto 200m of pipework. All footage is viewed and recorded wirelessly onto a tough pad and provided as evidence of the survey being undertaken. The invert levels of the pipes within the manhole are also collected on site along with the GPS co-ordinates of the manhole itself. This information along with other HADDMS compliant data is recorded onto electronic data capture devices so that it can be easily input into HADDMS at the end of the survey.
Any defects that were recorded were sent to the client the following day ensuring that they were kept up to date immediately following the shift.
All of this work was undertaken at the same time as the stripping of the overburden from the top of the filter drain in the central reservation ensuring that roadspace was maximised.