One Leadenhall stands as a testament to modern engineering and construction prowess in the heart of London. As a member of the delivery team, I’ve had the rare privilege of contributing to this landmark project, which represents a significant addition to London’s iconic skyline.


Project Overview
One Leadenhall is a 37-floor high-rise commercial tower that pushes the boundaries of urban construction:
● Location: Central London
● Height: 37 floors above ground
● Substructure: 2 basement levels with a 3.5m deep raft slab
● Core: Central RC core rising 39 levels
● Floors: 37 floors of composite construction surrounding the core
This ambitious project demanded innovative solutions and precise engineering to overcome the challenges of building in a dense urban environment.
Substructure Complexities
The project began with major substructure works, including:
● Excavation of two basement levels
● Construction of a massive 3.5m deep raft slab
These elements provided a solid foundation for the towering structure above.
Core Construction
The central reinforced concrete (RC) core, rising 39 levels, presented unique challenges:
● Maintaining vertical alignment over the entire height
● Ensuring structural integrity while optimizing construction speed



Composite Floor System
Surrounding the core, 37 floors of composite construction required:
● Precise coordination between concrete and steel elements
● Efficient floor-by-floor construction methodology
Finan Formworks’ Role
Our company, Finan Formworks, was appointed by PJ Careys to deliver critical aspects of the project:
- Full temporary works design
- Certification of temporary structures
- Shared supervision of the innovative electrically climbed Jumpform system.
This project was quite different in terms of the team as Finan Formworks became part of team Multiplex and P J Careys, responsible for delivery of a major part of the infrastructure.The teamwork between the Principal Contractor, Main Subcontractor, and System Supplier set a new standard, sharing responsibility to achieve seamless delivery aligned precisely with the original plan. This partnership exemplifies the potential of coordinated efforts within the industry to achieve outstanding results.


Project Highlights
The One Leadenhall construction project showcased several innovative approaches:
a. Initial Design and 3D Modeling: Utilizing advanced BIM techniques for precise planning
b. Off-site Manufacturing & Assembly: Enhancing efficiency and quality control
c. Large-scale Night Time Deliveries: Minimizing disruption to London’s busy streets
d. Site Assembly and Commissioning: Coordinating complex on-site operations
e. First Casting and Self-Climbing: Implementing the electrically climbed Jumpform system
f. Rig Adaptations at Level 21: Demonstrating flexibility in construction methods
g. Final Jump to Roof and Dismantling: Completing the core structure safely and efficiently
This collaborative approach between the Principal Contractor, Main Subcontractor, and System Supplier set a new standard for project delivery in the construction industry.
Conclusion
The One Leadenhall construction project exemplifies what can be achieved through innovative engineering, meticulous planning, and seamless teamwork. As this impressive structure takes its place in London’s skyline, it stands as a testament to the skills and dedication of all involved, setting a new benchmark for high-rise construction in urban environments.