08/10/2025
9 amazing engineering facts about how a 700-year-old church was lifted onto stilts in London 🧐
At 50 Fenchurch, a skyscraper is being built next to a listed church tower. The Tower of All Hallows Staining has been suspended on 14 metre steel supports, while a 60,000 sq ft basement was excavated below.
Some incredible facts about this world-first engineering feat:-
1.Laser Scanning and Structural Modelling: Engineers began by laser-scanning every stone to create a precise 3D model of the tower, capturing centuries of settlement and imperfections before any physical work began.
2. Finite-Element Analysis of the Masonry: The model was run through computer simulations to predict how loads would move through the medieval stone once its foundations were replaced with temporary supports.
3. Load-Transfer Frame Design: A bespoke steel frame was built around the tower to carry its entire weight and redistribute forces evenly onto new support points outside the dig zone.
4. Precision Jacking Operation: Hydraulic jacks gradually took the load off the old foundations and transferred it to the steel frame, millimetre by millimetre, to prevent cracking or stress in the fragile masonry.
5. 14-metre-high Temporary Stilts: The tower now rests on a series of steel columns about 45 ft tall, engineered to resist both vertical load and lateral movement during excavation.
6.Excavation of 125,000 Tonnes of Earth: With the tower secure, more than 125,000 tonnes of ground were removed to form a 60,000 sq ft basement beneath, making it one of the most delicate digs ever attempted in London.
7. Continuous Real-time Monitoring: Sensors track every micro-movement of the tower and support frame. Engineers receive live data so any shift can be corrected immediately.
8. Low-Vibration Excavation Methods: Specialised rigs and low-impact techniques were used to keep ground vibration within heritage-safe limits, protecting the tower’s ancient lime mortar.
9. Bottoming-Out and Permanent Base: Once excavation reached full depth, a reinforced concrete plinth was poured beneath the suspended tower, its new long-term foundation.
9 amazing engineering facts about how a 700-year-old church was lifted onto stilts in London 🧐 At 50 Fenchurch, a skyscraper is being built next to a listed church tower. The Tower of All Hallows Staining has been suspended on 14 metre steel supports, while a 60,000 sq ft basement was excavated b...
