Client: International House, Tower Bridge, London
Challenge
Set against the stunning backdrop of the Tower of London, Tower Bridge, The Shard, and St Katharine Docks, International House faced a significant issue with its glass façade. The building was constructed with a batch of glass suffering from Nickel Sulphide (NiS) inclusions—imperfections that can cause spontaneous breakage. When affected, the glass shatters in a distinctive “butterfly” pattern, posing safety risks and aesthetic concerns.
Nickel Sulphide inclusions are rare but unpredictable. According to figures from the Glass and Glazing Federation (GGF), there is an estimated NiS inclusion in 1 square metre for every 10,000 square metres of glass. This statistic underscores the importance of addressing the issue promptly to ensure safety and integrity.
Replacing the flawed glass was imperative, but the building’s prime location presented logistical challenges. Space was at a premium, making conventional cranes unfeasible. The main contractor considered erecting full scaffolding, but this solution was both costly and time-consuming.
Solution
To mitigate the risk of NiS inclusions, we proposed replacing all existing glass with new panes that had undergone the heat soaking process. Heat soaking involves heating the glass to 290 degrees Celsius to force any glass containing NiS inclusions to shatter, significantly reducing future risks. This process can reduce the likelihood of NiS inclusions to as low as 1 square metre in every 1 million square metres of glass.
Understanding the spatial constraints, we innovated by utilising an internal counterbalanced trolley crane. This method eliminated the need for external cranes or extensive scaffolding. We coordinated with ground marshals and implemented pavement closures below to ensure public safety. By working through the night, we minimised disruption and expedited the replacement process.
Results
Our approach proved to be both safer and more efficient. The glass replacement was completed without the high costs associated with full scaffolding. The use of the internal trolley crane allowed for quicker installation while maintaining strict safety protocols. The project was executed seamlessly, preserving the breathtaking views of London’s iconic landmarks throughout the process.
Client Benefit
By choosing our innovative glass replacement solution, the client benefited from significant cost savings and minimised operational downtime. The risk of spontaneous glass breakage was substantially reduced, enhancing the safety and longevity of the building’s façade. Our efficient methodology ensured that the aesthetic integrity of International House remained uncompromised, all while showcasing the magnificent skyline of London.
