Hornsey Depot Bogie Drop Facility

Project outline:
Design and delivery of a bespoke bogie drop facility housed in an extension of an existing Wheel Lathe Building.

Location:
Hornsey, North London

Client:
(GTR) Govia Thameslink Railway

We provided:
Civil & Structural Engineering Services
Project Management

Key collaborators:
(GTR) Govia Thameslink Railway
Network Rail
Walker Construction (UK) Ltd

Hornsey Depot is an Electric Multiple Unit Depot for Class 387, 700 and 717 trains used on Thameslink and Great Northern Routes. These train units are brought to Hornsey for maintenance tasks, as the depot also offers facilities including a wheel lathe, large maintenance shed, train-washing plant, and extensive stabling sidings for commuter stock.

The existing Wheel Lathe Building provides specialist complex train repair and maintenance operations containing a large wheel lathe for the purposes of adjusting train wheels. The existing building is constructed of a steel portal frame with columns fixed onto piled foundations, composite wall and roof panels clad the building, with large Bi-Fold Train Doors located at both south and north entrances.

The scope of the project was to deliver a bespoke bogie drop facility housed in an extension to the north of the existing Wheel Lathe Building.

Bogie drop systems allow the removal/replacement of complete bogies, wheelsets and underframe modules for trains.

The extension area was previously acting as a track access and storage yard for HVAC units with a single-track line running through the yard and existing building. The use and operations of the wheel lathe building had to be carefully considered when designing the bogie drop facility with HVAC unit access through the extension and auxiliary conveyor for the swarf from the Wheel Lathe Building.

Following planning approval in March 2021, Walker Construction (UK) Ltd were appointed as Principal Contractor with INVVU appointed as Multi Discipline Designer, Engineering Lead and Principal Designer for the Bogie Drop Extension. Mechan Ltd were appointed by the client to design and deliver the bogie drop maintenance equipment including the dirty road hatch and winches.

Site surveys and detailed design undertaken by INVVU commenced in December 2021 with final design approvals obtained in April 2022, a very fast paced 5-month survey and design programme. Following liaisons with the depot a closure of the existing Wheel Lathe Building was in place from June 2022 when construction commenced. The project completed and was handed back to the depot in April 2023 following the installation of the Mechan Ltd equipment and completion of testing, commissioning and training.

The works involved very complex Civil engineering practice, with virtually zero tolerance in the setting out. The site had extensive site and time constraints. The Design required extensive R&D Work, collaboration with specialists and unique temporary works solutions. The outcome of the project means process and carbon savings in the train maintenance/infrastructure sector.