Pipeline Inspection

Inside the early eighties and speaking generally, the only internal pipeline inspection was either carried out by the sewer inspection companies, who will be inspecting mostly dry sewer pipe（Underground Sewer Pipe） sections over brief distances; usually not exceeding 150m and who would stop when the pipe became surcharged towards the point exactly where the camera would turn into submerged along with the oil business support companies who would run 'intelligent pigs' although the oil pipes to assess weld integrity, pipe wall thickness and situation to be able to assess pipeline longevity and secure operating pressure.

At this time the water businesses who were largely oblivious for the internal condition of their pipelines, adits, aqueducts and tunnels have been starting to possess concerns concerning the integrity of their assets, numerous of which had been constructed for the duration of the Victorian era or much more recently inside the early fifties and had never been inspected and had been unsuccessfully trying to discover firms and/or gear that could carry out such surveys.

In some situations they had been capable to de-water the pipelines（Water Supply Pipes） and if big sufficient diameter, they would send a confined space team in to carry out a visual survey; such surveys were clearly fraught with prospective dangers, not least of which included the danger of collapse, flooding along with the accumulation of toxic gasses.

De-watering came with its personal set of potential dangers for the structural integrity on the concrete, tunnelled and brick constructed pipelines; in many situations, tiny leaks produced by displaced joints, erosion and localised harm etc. enabled the leaking water to seek out a path through the ground and more than quite a few years, earth would be washed out from around the pipe, frequently resulting in large water filled voids forming around the outside in the pipeline.

The newly de-watered pipeline which would usually be partially reliant on the head of water within the pipeline (wanting to push the walls out), to preserve its structural integrity, could suddenly be subjected to numerous tons of water outside in the pipeline (looking to push the walls in), producing localised locations of external high stress, which would frequently lead to pipe failure and localised collapse, causing subsidence in the ground above the pipeline manifesting as holes inside the ground that would appear 'over-night'.

At around this time there was an growing demand from the Water Firms to send divers up water filled pipes（Tap Water Pipe） armed with CCTV cameras, to survey for as far as their nerve or umbilical length would permit.

Within a really short time period the HSE Diving Executive, showed a keen interest inside the security aspect of sticking divers up pipes and ahead of extended an excursion range of about 30m as a maximum was considered protected, delivering that all the needed safety precautions were in place.