Sandon Sewer Rising Main Rehabilitation

Project Details

The Die Draw technique was applied to 1,067 metres of 18” ductile iron pipeline using a 450mm PE100 SDR 26 liner. The challenging conditions required innovative solutions, and both 500m and 567m pulls were completed in around three hours respectively.

Project details:

Client:Public Sewer Services (PSS)/Anglian Water
Project:Sandon Sewer Rising Main Rehabilitation
Location:Sandon, Chelmsford
Completion date:October 2024
Pipeline Length: 1067m (2 pulls of 567m and 500m)
Liner material type:PE 100
Liner dimension: 450mm OD, SDR 26
Host pipe:18” Ductile Iron Pipeline (1980s)
Operating fluid: Sewage
Operating pressure: 2 bar plus surge accounted for in WIS IGN 4-37-02
PE 100 liner lifetime:100 years

The host pipe crossed under a farmer’s field that could not be dug up. An overground by-pass pipe had been installed prior to Die Draw joining the project. The presence of the bypass pipe, access constraints, and restrictions associated with the farmers field, meant that the Die Draw process was ideally suited to this specific application. Furthermore, this project was characterised by severe time constraints and the ability line the pipe quickly was of paramount importance.

In the end, once the engineering was complete, each of the 2 pulls of 500m and 567m respectively, were completed in around three hours.

Overland Bypass Pipe

Innovation

This project presented some unique challenges, and we’re proud of the innovative solutions that made it possible:

  1. Modular, Reusable Restraint System: We developed a system that can be rapidly redeployed, offering greater flexibility and eliminating the need for permanent concrete foundations. This will significantly reduce setup time on future projects.
  2. Dual Winch Setup: By introducing a dual winch configuration, we’ve enhanced the flexibility of our die draw process, allowing for a wide range of configurations tailored to different project needs. This innovation will expand the versatility of our approach for future applications.

The pictures below show the environment where the frames were to be installed. Environmental considerations, access constraints, and tight time scales meant the construction of concrete foundations was neither practical nor possible. The new modular restraint frames were easy to manoeuvre into place and their flexibility will be a significant asset to projects moving forward

Welding

One of the main advantages of the rural environment is the space to weld up the full length of liner so it can be pulled through in a single insertion. This is a key aspect of the fast insertion times. Initially, we had 2 butt fusion welding machines on site with welding inspector overseeing the welds to ensure everything was completed in line with the required welding standards.

All welds were carried out to WIS 4-32-08 standard

Other challenges faced with this project

  • Limited footprint for winches due to location of over-pumping bypass and pumping station
  • Innovative temporary works solutions were required to accommodate 2 small winches and utilise simple pit designs
  • Saturated ground conditions
  • Farmer harvesting crops
  • Long 500m+ PE 100 pipe strings could not be positioned in a straight line with requirement for numerous rollers
  • Diameter of pipe meant we were restricted to CCTV surveys as opposed to more detailed LiDAR surveys. This meant we weren’t able to get the level of detail on constrictions and bends.

Key Achievements

Efficient Installation: The Die Draw process enabled the installation of 567 metres of liner in just under three hours, followed by a second pull of 500 metres completed in a similar timeframe. This rapid installation minimised downtime and ensured the pipeline was returned to service as quickly as possible.

Pressure Testing and Recommissioning: The rehabilitated pipeline was successfully pressure tested and recommissioned, confirming the integrity.

Minimised Disruption: The speed and efficiency of the Die Draw process significantly reduced disruption to the surrounding area, a critical consideration for the client and the community.

Client Benefits

  • The rehabilitated pipeline now has an extended lifespan, ensuring reliable service for decades to come.
  • The tight-fit liner maximises the pipeline’s bore diameter, preserving flow capacity and avoiding the need for costly future interventions.
  • The environmental benefits of the Die Draw process, including reduced CO₂ emissions, align with the client’s sustainability goals.

Collaboration and Expertise

The success of this project was made possible through the collaboration of Die Draw Ltd’s team and strategic partners. The careful planning, deliberate execution, and innovative thinking demonstrated throughout the project highlight the value of combining technical expertise with practical, adaptable solutions.

Conclusion

The Sandon Sewer Rising Main project is a testament to the effectiveness of the Die Draw process in addressing complex pipeline rehabilitation challenges. By delivering a solution that is both efficient and reliable, Die Draw Ltd has reinforced its position as a trusted partner for utility companies seeking sustainable, cost-effective, and minimally disruptive rehabilitation solutions.

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