CECA profiles HOCHTIEF UK tunnel surveyor Emily Mulley in 30 Under 30 series

CECA has profiled Emily Mulley, a site engineer (surveying) at HOCHTIEF (UK) working on a 3.4km National Grid tunnel in Snowdonia, North Wales, as the latest entry in its 30 Under 30 series.

The series forms part of the association's 30th anniversary celebrations and showcases young professionals in civil engineering, CECA said in the profile.

According to CECA, Mulley takes weekly measurements on the tunnel to keep the tunnel boring machine on its designed alignment. She also monitors nearby infrastructure and site assets, including railway tracks and pylons, for any movement linked to the tunnelling.

CECA said she gained experience through the QUEST scheme during her degree and has continued to take on responsibility since graduating. Her achievements include winning the South West Princess Royal Award for Emerging Engineers in 2025, the association said.

The project

The tunnel is the power supply scheme that National Grid awarded to HOCHTIEF UK in a contract worth £207m (EUR 240m), announced by HOCHTIEF on 27 January 2022.

Lawrence Jackson, managing director of HOCHTIEF (UK), said at the time: "As a leading infrastructure group, we are delighted to contribute with our long-standing expertise in tunnelling works".

Welsh Slate, which supplied the scheme and published a case study in May 2025, said the tunnel runs from Minffordd to Llandecwyn and that the tunnel boring machine, nicknamed Buddug, would bore through what it called Eryri National Park. HOCHTIEF UK is principal contractor, Welsh Slate said, and the scheme forms part of a National Grid initiative to reduce the visual impact of electricity infrastructure.

Welsh Slate described it as the largest scheme of its kind in Wales. Removal of pylons and 400kV overhead lines is scheduled by 2029, according to the case study.

CECA said Mulley's work on National Grid's cable tunnels supports the energy transition, giving her a direct role in preparing infrastructure for changing demands.

Timing

Welsh Slate said in May 2025 that boring was due to start shortly and that the machine was expected to reach Llandecwyn by mid-2026. CECA's profile describes Mulley as taking weekly measurements to keep the machine on alignment.

The series

CECA has invited its members to contribute to both the 30 Under 30 campaign and a parallel 30 Projects for 30 Years campaign as part of the anniversary programme.

The association has more than 300 members across six English regions and the devolved nations of Scotland and Wales. CECA says its members together carry out an estimated 70% to 80% of all civil engineering activity in the UK.

Ben Goodwin, CECA director of policy and public affairs, set out the sector's position when the association marked its 30 years at a Westminster reception. He said: "The challenges facing the sector are significant, from planning delays and pipeline uncertainty to skills pressures," and that members need a stable pipeline, fair and effective procurement, a skilled workforce and a supportive policy environment.

CECA said Mulley aims to keep developing her technical expertise and leadership skills, and that she believes multiple small improvements can together make a meaningful difference to people's lives.