Bermondsey Dive Under – Precast Arches

Case Study: Bermondsey Dive Under – London

Client

Network Rail, with Skanska as main contractor and Ramboll as designer.

Project Overview

The Bermondsey Dive Under is a landmark rail infrastructure project in southeast London, just 3.5km from the Tower of London. As part of the Thameslink Programme, this new grade-separated junction was designed to resolve a long-standing bottleneck where Kent and Sussex rail lines crossed near London Bridge station. The scheme features 11 new interconnected structures, dramatically improving capacity and reducing delays for commuters heading into and out of central London.

Units Supplied

ABM Precast Solutions supplied nearly 1,000 precast reinforced concrete units, weighing over 10,000 tonnes in total, to support the Dive Under’s complex viaduct and bridge structures:

✅ Precast Arches for the four main viaduct extensions
✅ Impost units for seamless viaduct integration
✅ Robust Kerb units to enhance durability and safety
✅ Abutment and deck components for multiple bridge spans

The Client Challenge

Network Rail needed to eliminate congestion and delays at one of London’s busiest rail pinch points, all while building adjacent to live tracks and integrating new structures with existing viaducts. The project required absolute precision, safe working practices, and on-time delivery in a dense urban environment with minimal disruption to daily rail operations.

Our Solution

ABM worked closely with Skanska and Ramboll to deliver high-quality, factory-manufactured precast units that could be installed rapidly and reliably. Every component was engineered for long-term performance and designed to fit seamlessly with both new and existing structures. This collaborative approach ensured that technical and logistical requirements were met at every stage, from initial design through to final installation.

The Results

With the Dive Under now operational, Thameslink Sussex lines cross beneath the Kent lines smoothly, removing a critical bottleneck and supporting improved rail capacity for millions of journeys each year. The use of nearly 1,000 precast units enabled safer, faster, and more efficient construction, helping Network Rail deliver a transformative upgrade to London’s rail network on schedule.

Key Takeaways

The Bermondsey Dive Under demonstrates the power of precast solutions for complex urban infrastructure. Early collaboration, precision engineering, and expert project management are essential to delivering results in challenging environments. ABM’s expertise and commitment to quality played a key role in the success of this high-profile project.