Oval Village, London

Our engagement began several years before construction when we were approached to develop a retention strategy for the gasholder frame.

We provided:

• Structural assessment of the wrought iron frame under wind loading in temporary conditions
  
• Detailed temporary works sequencing and design for reusable support towers
  
• Jacking system design to transfer frame loads during wall reduction and new beam construction
  
• Construction methodology coordinated with new structural element geometry
  
• Stakeholder engagement materials for heritage and planning approvals
  

The Grade II listed gasholder frame required support while we lowered the top of the existing tank wall and constructed the new capping beam below it. The wrought iron structure was in poor condition, and traditional approaches of dismantling and re-erecting risked heritage approval challenges and structural damage to the delicate ironwork.

We designed a system of temporary support towers needled back through the new capping beam position to the existing tank wall below. This in-situ retention approach maintained the frame's structural integrity throughout the works and avoided intervention into the listed superstructure, significantly improving the likelihood of heritage approvals.

The needled support system enabled Keltbray to proceed with confidence that the fragile heritage structure would remain stable throughout all construction phases.

Transferring the frame's weight onto the new structure required a controlled jacking sequence, but the support towers also needed lateral stability during these operations. Any differential movement or instability could damage the historic ironwork or create unsafe working conditions.

We developed a phased jacking methodology integrated with lateral bracing for the support towers. The towers were designed for reuse through multiple construction stages, maintaining a robust stability path at each phase. Our wind loading analysis verified tower performance throughout the temporary condition.

This reusable tower strategy streamlined construction by eliminating the need for complete tower removal and replacement, saving programme time while protecting the heritage frame.

The gasholder's retention was central to planning approval, requiring clear demonstration that our approach would protect this defining landmark. Multiple stakeholders including heritage bodies, planners, Berkeley Group, and Keltbray, needed confidence in the technical approach before committing to the scheme.

We created detailed construction sequence documentation with visual information showing each phase of the support, wall reduction, and beam construction. The materials clearly demonstrated how the phased approach maintained structural integrity without interfering with the listed structure.

Our comprehensive stakeholder engagement package helped secure the necessary approvals and gave all parties confidence to proceed with this heritage-led development.