Sub Agent – Civils / Tunnelling

Sub Agent – Civils/Tunnels | Snowdonia National Park
£55,000 – £65,000 (Negotiable, DOE) + Package | Permanent

Location: Snowdonia National Park (Eryri), North Wales


About the Role

An exciting opportunity has arisen for an experienced Sub Agent to join a major civils and tunnelling infrastructure scheme delivered on behalf of National Grid, based within the stunning Eryri National Park.

The project involves constructing a new cable tunnel beneath the estuary near Portmeirion, enabling the removal of 10 pylons and 3.4km of overhead line, and replacing them with 400kV cables routed through a tunnel deep underground – significantly enhancing the visual and environmental quality of this iconic landscape.

You will play a key role in the day-to-day delivery of the civils and tunnelling works, supporting the Project Manager and wider site team to ensure the scheme is delivered safely, on programme, and to the highest quality standards.

The Project Scope Includes:

  • A 3.4km tunnel, 3.5m in diameter, connecting two new shafts
  • Construction of two new headhouses, one at each shaft
  • A new sealing end compound, plus reconfiguration and extension of an existing sealing end compound
  • Installation of two high voltage (HV) electrical circuits
  • Circuit connections between the reconfigured and new sealing end compounds

Key Responsibilities

  • Supervise and manage day-to-day civils and tunnelling operations on site
  • Support shaft sinking, tunnel excavation, lining, and headhouse construction activities
  • Manage subcontractors, plant, and labour resources to ensure efficient delivery
  • Ensure works are carried out in accordance with drawings, specifications, and method statements
  • Monitor progress against programme and escalate risks or delays to the Project Manager
  • Maintain strict compliance with health & safety, quality, and environmental standards, particularly given the National Park setting
  • Assist with technical queries, setting out, and quality control/inspection processes
  • Liaise with engineers, designers, and site management to resolve construction issues

About You

  • Proven experience as a Sub Agent or Senior Engineer within civils and/or tunnelling projects
  • Experience with shaft construction, tunnelling, or underground infrastructure highly desirable
  • Strong understanding of temporary works, groundworks, and heavy civils construction methods
  • Excellent people management skills, with experience supervising subcontractors and site teams
  • Relevant qualifications (e.g., Civil Engineering degree/HNC/HND, SMSTS, CSCS) essential
  • Strong health & safety focus and commitment to environmental best practice
  • Full UK driving licence, with flexibility to be based on-site in Snowdonia

What’s on Offer

  • £55,000 – £65,000 basic salary, negotiable dependent on experience
  • Lodging provided
  • Attractive benefits package
  • Opportunity to work on a landmark national infrastructure project
  • Based in one of the UK’s most beautiful National Parks
  • Long-term career development within a high-profile scheme

Interested?

If you’re a driven Sub Agent with a background in civils and tunnelling, looking to make a visible, lasting impact on the UK’s landscape and infrastructure, apply now to be part of this prestigious scheme.

Apply now

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At a glance

  • Job reference: BBBH9418_1783695001
  • Location: Porthmadog, Gwynedd
  • Job type: Full Time, Permanent
  • Job sector: Other
  • Salary: £55000.00 – £65000.00 per annum + – negotiable
  • Published: July 10, 2026