Laser Scanning of Confined Spaces - Innovative Approach Reduces Costs

CSTS demonstrate the right thinking, as AMP6 places greater need for water companies and contractors to innovate, during a recent project for major utility provider.

All too often, improved safety management comes at a cost both financially and to resource.  CSTS and their technology partners are proud to be able to offer their clients improved safety management with the added benefit of time, financial and resource savings.

The Challenge

As built drawings of assets (particularly those underground) are often hard to come by.

With many water company assets being underground and classified as confined spaces, the retrospective production of drawings can be hazardous, time consuming and expensive.

Recently CSTS were approached by a major utility company to survey a large sewer overflow structure, detention tank and interconnecting chambers, with a view to compiling a detailed set of general arrangement drawings to include handrails, accesses, assets and any silt build-ups:

  • up to 25m in depth
  • complex 4 stage multi landing accesses
  • high through flows (highly weather dependent)
  • history of hazardous atmospheres (low oxygen)

CSTS (in conjunction with their technology partners) have developed systems to safely enter even the most awkward of confined spaces and collect data to produce highly accurate as built drawings:

The Strategy

Surveying of confined spaces is not normally described as a new innovation. Conventionally undertaken by a team of surveyors with theodolites and tapes, the method has changed little over the years.  Whilst this can be effective, it requires several surveyors who need to gain access to points on the structure to survey them. 

Whilst the use of laser scanning is now commonplace, the use of this technology in confined spaces is still relatively rare.

3D laser scanning provides the ultimate non-contact solution many confined spaces demand.

In this application a single surveyor was able to set up the instrument in each chamber (3 set ups for the largest chamber) from a position of relative safety and capture detail (remotely) to sub millimetre accuracy.  At 5 minutes per set up the largest chamber (25m deep, 40m diameter) was completed in 20 minutes.

The Outcome

Using this technique enabled the team to keep within the ethos of the confined space regulations by 'preventing the need to enter'.  The entry wasn't completely prevented, however the number of operatives required to enter the space and the length of time they were in the space was greatly reduced.

  • Less time
  • Fewer resources required
  • Less risk
  • Less operational impact
  • Better results
  • Reduced cost

The 'point cloud' of data obtained from the survey was manipulated to estimate silt build-ups, the presence of handrails, the precise shape and dimensions of channels in the invert and, going forward, the information can be used to predict flow behaviour and identify defects.

Whilst safety is always at the forefront of decision making, undoubtedly one of the most significant savings offer to the client on this project was cost.  It is estimated that the client was able to save 50% of the total cost by opting to use laser scanning over more traditional methods. 

Contact CSTS

To see how CSTS can help you, contact our Support Team directly on 01925 244144 or supportteams@csts.co.uk.