Client: Verallia Knottingley

Service: Structural Assessment & Temporary Works Design

The Challenge

Corrosion was identified in the upper three sections of a steel chimney at a glass bottle manufacturing facility in Yorkshire, leading to reduced wall thickness and a loss of structural capacity. The deterioration was most critical at the bolted flange connections, which are key load transfer points.

With full replacement scheduled for Spring 2026, we were brought in ahead of the winter of 2025. There was a clear need for an interim solution to ensure the chimney could safely withstand environmental loading, particularly during winter storm conditions. The solution needed to mitigate risk without adding unnecessary complexity ahead of more detailed works in the coming year.

How we helped

Amrose Associates carried out a detailed review of inspection and survey data to understand the extent of material degradation and its impact on structural performance.

We developed an initial strengthening concept introducing external steel sections to create a secondary load path, providing redundancy in the event of localised connection failure. Following further design development and client collaboration, the solution was refined to focus directly on strengthening the bolted flange connections.

Key elements of our approach:

  • Assessed the structure based on its current condition and reduced capacity
  • Modelled the chimney to understand its performance under wind loading
  • Designed strengthening at key flange connections to improve stability
  • Specified bolt replacement to ensure reliable connection strength
  • Developed a practical solution for safe and efficient installation at height

The outcome

The final design provided a robust interim strengthening solution, significantly reducing the risk of structural failure during the operational period leading up to full replacement and improved structural resilience under storm loading conditions. 

This project demonstrates the value of targeted, condition-informed engineering interventions in extending asset life and managing risk. By combining detailed analysis with practical design thinking, Amrose Associates delivered a buildable solution that was technically sound and cost-effective.

If you’re facing similar challenges with ageing infrastructure or require interim strengthening solutions, our team can support you with tailored, practical engineering expertise. Ask Amrose.