In early eighties and speaking generally, the only internal pipeline inspection was either completed by the sewer inspection companies, who would be inspecting mainly dry sewer pipe sections over short distances; typically not exceeding 150m and who would stop if the pipe became surcharged enough where the camera would become submerged and the oil industry support companies who would run ‘intelligent pigs’ although the oil pipes to assess weld integrity, pipe wall thickness and symptom in to assess pipeline longevity and safe operating pressure.

At the moment the river companies who had been largely oblivious for the internal condition of the pipelines, adits, aqueducts and tunnels were starting out have concerns in regards to the integrity of their assets, most of which have been constructed during the Victorian era or more recently noisy . fifties and had never been inspected and were unsuccessfully trying to find companies and/or equipment which could perform such surveys.

Occasionally we were holding capable of de-water the pipelines if big enough diameter, they would send a confined space team directly into do a visual survey; such surveys were obviously fraught with potential dangers, most famously which included the possibility of collapse, flooding and the accumulation of toxic gasses.

De-watering came with a unique set of potential risks for the structural integrity with the concrete, tunnelled and brick constructed pipelines; in most cases, small leaks produced by displaced joints, erosion and localised damage etc. enabled the leaking water to discover a path from the ground well as over many years, earth would be pale from across the pipe, often leading to large water filled voids forming throughout the outside of the pipeline.

The newly de-watered pipeline which could be partially reliant on the head water from the pipeline (trying to push the walls out), to maintain its structural integrity, could suddenly encounter several tons of water outside the pipeline (looking to push the walls in), creating localised regions of external ruthless, which would often lead to pipe failure and localised collapse, causing subsidence of the ground across the pipeline manifesting as holes in the earth that will appear ‘over-night’.

About this time there was clearly a growing demand in the Water Companies to transmit divers up water filled pipes with CCTV cameras, to survey for as far his or her nerve or umbilical length would permit.

In a very short period of time the HSE Diving Executive, showed a passionate desire for the safety aspect of sticking divers up pipes and eventually an excursion array of around 30m like a maximum was considered safe, providing that most the necessary safety precautions were available.

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