Temporary Works

Charing Cross Station, London, UK

Project Brief

LSY Engineering Consultants Ltd was appointed to provide temporary works design and structural engineering support as part of a £20 million programme of upgrades to the 175-year-old Hungerford Bridge at Charing Cross Station.

The project involved the replacement of approximately 2km of country-end platforms with new Glass Reinforced Polymer (GRP) platforms supported on a new framing system incorporating elements of the existing structure. To facilitate the platform replacement works, two self-erecting tower cranes were required to undertake the dismantling and installation operations during a major engineering blockade.

LSY’s involvement focused on the construction phase, where we developed temporary works solutions to support the contractor’s methodology and sequence of works. Our scope included the design of crane base foundations, assessment of structural risks, BIM coordination, and the development of temporary works solutions to protect surrounding infrastructure throughout the construction process.

Challenges

The principal challenge was developing a crane foundation solution capable of safely accommodating substantial outrigger loads while working directly above and adjacent to a complex network of existing underground infrastructure.

The scheme involved two self-erecting tower cranes with maximum outrigger reactions of up to 45.6 tonnes. The proposed crane locations were constrained by numerous buried assets, including:

Cadent Gas assets.
Existing drainage systems and manholes.
Railway infrastructure and associated services.
Thames Water infrastructure.
Transport for London (TfL) tunnels.

Close coordination was required with multiple asset owners and engineering teams to determine the location and sensitivity of the existing infrastructure, demonstrate that the proposed crane foundations would not adversely affect their assets, and secure the necessary approvals to proceed.

The project therefore required detailed assessment of structural, geotechnical, and infrastructure considerations while ensuring the temporary works remained practical, buildable, and fully coordinated with the wider construction programme.

Process

LSY commenced the project with a detailed appraisal of the proposed crane locations, construction methodology, site constraints, and available underground utility information.

This included reviewing:

Asset owner constraints.
Existing ground conditions.
Existing manholes and drainage infrastructure.
Proposed crane loading arrangements.
Tunnel locations.
Underground services and utilities

Detailed structural calculations were undertaken to develop a crane foundation arrangement capable of safely distributing the crane reactions into the existing ground while protecting adjacent assets.

The proposed crane support arrangement incorporated:

2no. 1000mm × 500mm × 70mm outrigger pads
Supported on 3no. 2000mm × 500mm × 70mm steel outrigger spreader pads

Ground bearing assessments and ground movement assessments were undertaken to verify the suitability of the existing ground and assess the effects of the crane reactions on adjacent buried infrastructure. These assessments included:

Existing utility protection checks.
GM1 assessment checks
Ground bearing pressure checks.
Ground movement Analysis
Manhole loading evaluations.
Pipe crushing assessments.
Settlement assessments.

Where crane locations were positioned adjacent to existing manholes, LSY developed temporary strutting and support arrangements to reduce load transfer into the structures and minimise the risk of damage during crane operations.

In addition, LSY worked closely with the geotechnical team to review the effects of crane loading on nearby Thames Water assets and groundwater-sensitive infrastructure, ensuring the foundation design remained compatible with asset owner requirements.

To support installation and construction activities, detailed temporary works drawings were produced including:

Crane foundation section details.
Crane pad layout plans.
Existing service overlays.
Manhole support arrangements.
Temporary strutting details.
Utility coordination drawings.

Building Information Modelling (BIM) was utilised throughout the project to improve coordination between the temporary works, underground assets, permanent works, and contractor operations.

Outcome

The temporary works solution was implemented successfully and enabled the platform replacement works to proceed safely and efficiently as part of the Southern Renewals Enterprise programme.

Following the successful completion of the 22-day engineering blockade, both Charing Cross Station and Waterloo East Station reopened as planned and rail services resumed on programme.

The project demonstrated the importance of early identification of underground infrastructure, proactive engagement with asset owners, and close coordination between structural and geotechnical disciplines when undertaking major infrastructure projects within highly constrained operational rail environments.

By developing a practical and adaptable crane foundation solution, LSY enabled the contractor to undertake the platform replacement works with confidence while protecting the surrounding infrastructure and maintaining programme certainty.

The successful delivery of the project strengthened our relationship with the client and contributed to further appointments across a range of rail infrastructure, temporary works, and major engineering projects throughout London and the wider UK.

Back to all projects

View other Temporary Works projects

Brighton Dome, Brighton, UK

LSY Engineering Consultants was appointed by the groundworks contractor to provide temporary works design services for the structural upgrade of the Grade I Listed Brighton Dome, one of the UK's most significant cultural and performing arts venues. Located within the prestigious Royal Pavilion Estate in the centre of Brighton, the Regency-era building required the construction of a new basement area beneath the auditorium to create a level floor arrangement that would enhance the venue's functionality and accessibility. Our scope included the design of underpinning works, temporary excavation support systems, sheet piling arrangements, and associated temporary works required to facilitate the basement formation safely within the existing historic structure.

Weedon Street Bridge, Sheffield, UK

LSY Engineering Consultants Ltd was appointed by Cadent Gas Ltd, to provide structural engineering services for works associated with Weedon Street Bridge in Sheffield. The project involved the removal of two 24-inch gas mains attached to the east and west elevations of the existing bridge structure. Each pipeline extended approximately 70 metres across the River Don and required careful planning and execution due to the age of the bridge, the scale of the pipework, and the operational constraints of the site. Our appointment included: An initial structural condition survey and reporting. Structural assessment of the proposed temporary works and scaffold arrangements. A post-completion structural inspection to verify that the removal works had not adversely affected the bridge.

Brighton Theatre, Brighton, UK

LSY Engineering Consultants Ltd was appointed as lead Temporary Works Engineer for the restoration of Brighton Theatre, a historic venue located in the centre of Brighton. The project involved the replacement of an existing balcony structure and the formation of new structural openings within the building. Our scope included temporary works design, site supervision, structural engineering support, and BIM modelling to facilitate the safe delivery of the refurbishment works whilst preserving the theatre's historic fabric. The project required a carefully coordinated temporary works solution capable of supporting both the existing balcony and a 450mm thick masonry wall during construction, whilst maintaining access to the theatre and minimising disruption to the surrounding public realm.

Dover Town Hall, UK

LSY Engineering Consultants Ltd were appointed to provide temporary works design and structural engineering support for the refurbishment of Maison Dieu House, a Grade I listed building forming part of Dover Town Hall. The project required careful planning and close technical coordination to maintain the safety and stability of the historic masonry arch structures during construction activities.

Balfour Place, London, UK

LSY Engineering Consultants was appointed to provide temporary works design services for the structural refurbishment of a six-storey listed property with basement accommodation in Mayfair, London. The project involved the removal of several loadbearing structural walls at basement level and the formation of new openings through existing vault structures as part of the wider redevelopment works. LSY's commission was to develop temporary works solutions that would safely support the existing structure during the demolition and alteration phases. Our scope included the design of needling and propping systems to facilitate the removal of basement walls, together with roof support and back-propping arrangements to maintain structural stability throughout the top-down demolition sequence. Challenges The project presented several significant engineering challenges. The property was a listed building located within a sensitive Central London environment, where historic bomb damage from the Second World War had the potential to affect existing ground conditions and foundation arrangements. As a result, excavation works required careful planning and execution to minimise risk. In addition, the existing foundation details at basement level were unknown. This uncertainty necessitated a programme of trial hole investigations to establish the form and condition of the foundations before both temporary and permanent works designs could be finalised. The constrained nature of the site, combined with the requirement to maintain structural stability throughout the demolition process, demanded a highly coordinated temporary works strategy.