Millcroft has developed an adaptable scaffold system to support HS2 tunnel works. The bespoke system is designed to travel through varying tunnel profiles while providing close access for lining operations.
At the heart of the system is a central core that remains constant across the different arrangements. The structure begins in its largest configuration and, as it progresses along the tunnel and the internal profile narrows, the external bays and hop-up brackets are reconfigured to suit the changing geometry. This flexibility lets the scaffold adapt without compromising stability, access or the works programme.
The entire traveller scaffold was fully 3D modelled before installation. This ensured there were no clashes with the tunnel and that close, safe access could be guaranteed for the tunnel lining works. The use of detailed modelling also provided considerable logistical advantages. Accurate load lists were generated directly from the model, making sure the correct materials were delivered to the site at the right time.
Our design team used the 3D model to calculate the exact self-weight of the structure. This allowed rapid comparisons between aluminium and steel decking options. The team also determined the pulling force required to move the structure, which, in its largest configuration, weighs 10.5 tonnes. This was calculated using coefficients for rolling resistance based on the wheel and track system used. As a result, movement methodology could be engineered and verified before works began on site.
To ensure safe movement through the tunnel, a low-level beam and precisely positioned pulling points were incorporated into the design. This prevented any individual component from being overloaded during movement and ensured the structure moved in a controlled, balanced manner.
Millcroft continues to play a key role across multiple sections of the HS2 programme, providing complex access solutions in highly constrained environments. We have a dedicated HS2 team combining project management, in-house design and logistics expertise, enabling us to deliver engineered scaffold systems that meet the technical and safety demands of one of the UK’s most significant infrastructure projects.
