Pipeline Inspection

Inside the early eighties and speaking usually, the only internal pipeline inspection was either carried out by the sewer inspection companies, who could be inspecting mainly dry sewer pipe（Underground Sewer Pipe） sections more than short distances; usually not exceeding 150m and who would stop in the event the pipe became surcharged to the point exactly where the camera would become submerged and also the oil market assistance companies who would run 'intelligent pigs' even though 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 had been largely oblivious for the internal situation of their pipelines, adits, aqueducts and tunnels had been beginning to have issues regarding the integrity of their assets, numerous of which had been constructed during the Victorian era or far more lately within the early fifties and had never been inspected and were unsuccessfully attempting to find organizations and/or gear that could carry out such surveys.

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

De-watering came with its personal set of prospective dangers for the structural integrity from the concrete, tunnelled and brick constructed pipelines; in many instances, modest leaks developed by displaced joints, erosion and localised damage and so forth. enabled the leaking water to discover a path through the ground and more than quite a few years, earth would be washed out from around the pipe, often resulting in large water filled voids forming about the outdoors in the pipeline.

The newly de-watered pipeline which would typically be partially reliant around the head of water within the pipeline (looking to push the walls out), to preserve its structural integrity, could abruptly be subjected to several tons of water outdoors on the pipeline (wanting to push the walls in), creating localised locations of external higher stress, which would typically lead to pipe failure and localised collapse, causing subsidence of the ground above the pipeline manifesting as holes in the ground that would seem 'over-night'.

At around this time there was an escalating demand in 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 quick period of time the HSE Diving Executive, showed a keen interest in the security aspect of sticking divers up pipes and prior to long an excursion range of about 30m as a maximum was deemed protected, providing that all of the required security precautions were in place.