Overview

At West Burton B Power Station, Amrose Associates was appointed by Altrad Babcock on behalf of West Burton Energy Ltd to design temporary restraint systems for high-pressure, high-temperature steam pipework repairs.

The objective was to enable safe repair works while maintaining the integrity of the existing pipework stress system.

The Challenge

The pipework formed part of a high-integrity steam system, where failure carries significant safety and operational risk.

A key complexity was that the system had been installed using cold pull, meaning the pipework was pre-stressed during construction to reduce operational stress from thermal expansion.

This introduces significant constraints during repair works. Once the system is disturbed, the original stress state is no longer fully known or controlled. Any unintended movement can:

  • Release or redistribute the pre-load
  • Introduce secondary stresses into the system
  • Accelerate creep damage, ultimately reducing the remaining service life

As a result, a high level of restraint was essential throughout the works. The pipework could not be allowed to move freely at any stage. Instead, it had to be carefully supported and restrained to maintain its existing geometry and alignment and preserve, as far as possible, the original stress balance.

In practical terms, this meant treating the system as a pre-loaded structure, requiring controlled, engineered restraint at all critical points to ensure stability and protect the long-term integrity of the asset.

How We Helped

Acting as Temporary Works Designer, Amrose Associates developed a fully engineered restraint strategy specifically to manage the risks associated with cold pull and prevent any loss or redistribution of pre-stress during the works.

Given the sensitivity of the system it was important to actively control movement and load paths at all times. Our scope therefore included:

  • A detailed site survey to understand the existing pipework geometry, support conditions and potential movement points
  • Careful design of restraint locations and configurations to control forces, moments and load transfer throughout the system
  • Production of engineering drawings for robust, load-bearing restraint structures capable of maintaining position under all stages of the works
  • A defined and sequenced methodology to ensure continuous restraint was maintained during installation, repair and removal, eliminating any window for uncontrolled movement

The solution used steel restraint brackets with integrated jacking bolts which gave a positive, adjustable and controlled interface with the pipework. This meant we could execute precise application of restraint forces and fine-tuning on site to maintain alignment and stability.

In addition, existing supports were gagged where necessary to prevent any unintended movement or release of pre-load so that the pipework remained fully constrained throughout.

Outcome

Our restraint system temporary works design ensured that:

  • The pipework remained stable and aligned throughout the repair process
  • The original cold pull condition was effectively maintained
  • The risk of introducing secondary stresses and creep damage was minimised

By combining practical design with clear installation sequencing, Amrose Associates enabled safe execution of the works while protecting the long-term integrity and performance of the steam system.

If you need a temporary works design specialist on your project, Ask Amrose.