HS2’s Euston tunnellers earn top honour in engineering awards

The complex task of driving an HS2 tunnel under a fragile 120-year-old bridge just outside Euston station, without interrupting West Coast and suburban services, has won its design and construction team one of the top honours in the 2022 Learning Legacy Awards (announced on November 11).

This year’s competition supported by the Institution of Civil Engineers, Permanent Way Institution, and Railway Industry Association - recognised good practice and innovation. It centred on key issues such as reducing emissions, reuse of materials, the landscape, installing and moving utilities, and working in sensitive locations.

Partners Arup, Skanska and HS2 are publishing their report online on how they dealt with work underneath Euston’s notorious Bridge 7, which is directly over two new tunnels.

The six-week project had to cope with the low headroom, buried obstructions, and severely limited access and working space. It was nevertheless completed on schedule.

There was a risk of the bridge (dating to 1902-04) being severely weakened and collapsing. But prestressed ground anchors were successfully inserted to shore up the existing retaining walls, and steelwork and jacks installed to prevent future subsidence.

The other winners in the 2022 technical paper competition were:

Mott MacDonald, VINCI Construction and Balfour Beatty - Driving efficiency and sustainability in material reuse.

HS2 Ltd - Designing with landscape maintenance in mind.

Arup - Streamlining Utilities Ground Movement Assessments.

HS2 Ltd, Balfour Beatty VINCI, Imperial College London and Eminox Reducing emissions in construction through retrofitting and extending the life of non-road mobile machinery.

A total of 28 new technical papers and case studies mean that there are now more than 150, covering a range of topics that also encompass design engineering and architecture, the environment, digital engineering, and health and safety.