Pipeline Inspection

Within the early eighties and speaking typically, the only internal pipeline inspection was either carried out by the sewer inspection businesses, who would be inspecting mainly dry sewer pipe（Underground Sewer Pipe） sections over brief distances; usually not exceeding 150m and who would stop if the pipe became surcharged towards the point where the camera would turn out to be submerged and also the oil business assistance businesses who would run 'intelligent pigs' even though the oil pipes to assess weld integrity, pipe wall thickness and condition in an effort to assess pipeline longevity and secure operating pressure.

At this time the water companies who were largely oblivious for the internal condition of their pipelines, adits, aqueducts and tunnels were starting to have concerns in regards to the integrity of their assets, several of which had been constructed for the duration of the Victorian era or far more recently inside the early fifties and had in no way been inspected and had been unsuccessfully wanting to find companies and/or gear that could carry out such surveys.

In some cases they had been capable to de-water the pipelines（Water Supply Pipes） and if huge adequate diameter, they would send a confined space team in to carry out a visual survey; such surveys have been naturally fraught with possible dangers, not least of which incorporated the danger of collapse, flooding as well as the accumulation of toxic gasses.

De-watering came with its personal set of possible dangers towards the structural integrity of the concrete, tunnelled and brick constructed pipelines; in many situations, modest leaks created by displaced joints, erosion and localised damage and so forth. enabled the leaking water to locate a path by way of the ground and over quite a few years, earth would be washed out from around the pipe, often resulting in huge water filled voids forming about the outdoors on the pipeline.

The newly de-watered pipeline which would often be partially reliant on the head of water within the pipeline (trying to push the walls out), to preserve its structural integrity, could suddenly be subjected to a number of tons of water outside of the pipeline (wanting to push the walls in), creating localised places of external higher pressure, which would often cause pipe failure and localised collapse, causing subsidence in the ground above the pipeline manifesting as holes inside the ground that would seem 'over-night'.

At about this time there was an growing demand in the Water Businesses 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.

Inside a very short period of time the HSE Diving Executive, showed a keen interest within the security aspect of sticking divers up pipes and ahead of extended an excursion selection of about 30m as a maximum was regarded as safe, offering that all the needed security precautions have been in location.