Know how to install, use and remove tunnelling back-up services
This element covers the critical knowledge required to select appropriate resources, install, operate, and safely remove temporary back-up services in tunnelling environments, such as ventilation, dewatering, compressed air, lighting, and communication systems. Learners must understand how these services support safe and efficient tunnelling operations and comply with statutory regulations and site-specific requirements.
Assessment criteria
Topic Overview
The Cskills Awards Level 2 Diploma in Tunnelling Operations (QCF) is a vocational qualification designed for individuals working in or aspiring to enter the tunnelling industry. It covers essential skills and knowledge required for safe and efficient tunnelling operations, including excavation methods, ground support, ventilation, and emergency procedures. This diploma is part of the Construction & Building Services sector and is recognised by employers across the UK, providing a solid foundation for a career in underground construction.
The qualification focuses on practical competencies such as operating tunnel boring machines (TBMs), installing segmental linings, and managing spoil removal. It also emphasises health and safety regulations specific to tunnelling, such as confined space working, gas monitoring, and fire prevention. By completing this diploma, students demonstrate their ability to work effectively as part of a tunnelling team, contributing to major infrastructure projects like Crossrail or HS2.
Understanding tunnelling operations is critical for the wider construction industry, as tunnels are vital for transportation, utilities, and mining. This diploma ensures that workers are competent in both traditional drill-and-blast methods and modern mechanised techniques. It also prepares students for further progression to Level 3 qualifications or specialised roles in tunnel engineering or site supervision.
Key Concepts
Core ideas you must understand for this topic
- →Ground investigation and classification: Understanding soil and rock types (e.g., clay, chalk, sandstone) and their behaviour during excavation, including water ingress and stability issues.
- →Tunnel excavation methods: Distinguishing between drill-and-blast, tunnel boring machines (TBMs), and sequential excavation methods (SEM/NATM), and knowing when each is appropriate.
- →Ground support systems: Installing primary support (e.g., shotcrete, rock bolts, steel arches) and secondary lining (e.g., cast-in-place concrete or segmental rings) to ensure tunnel stability.
- →Ventilation and environmental control: Managing air quality, dust suppression, and temperature regulation in confined underground spaces, including the use of auxiliary fans and ducting.
- →Health and safety legislation: Applying the Health and Safety at Work Act 1974, Confined Spaces Regulations 1997, and Construction (Design and Management) Regulations 2015 to tunnelling activities.
Learning Objectives
What you need to know and understand
- Know how to select resources for tunnelling back-up services, Know how to install tunnelling back-up services, Know how to use and remove tunnelling back-up services
Assessment Criteria
Key criteria assessors look for in your portfolio
- Award credit for demonstrating accurate selection of back-up service resources based on tunnel type, ground conditions, and project specifications.
- Expect clear evidence of planning installation sequences that minimise disruption to primary tunnelling activities and adhere to safety protocols.
- Look for detailed understanding of operational checks, emergency procedures, and correct removal techniques that prevent damage to permanent works and ensure environmental compliance.
Assessment Guidance
Guidance for achieving higher grades
- 💡Use real-world tunnelling scenarios to illustrate resource selection, referencing relevant codes of practice (e.g., BS 6164, HSE guidance).
- 💡Structure answers to show logical progression: selection → installation → use/maintenance → removal, highlighting risk assessments at each stage.
- 💡Emphasise the importance of communication with other trades and the site management team when installing or removing back-up services to ensure integrated safe systems of work.
- 💡Always reference specific regulations (e.g., Confined Spaces Regulations 1997) when discussing safety procedures – this shows depth of knowledge and earns higher marks.
- 💡Use diagrams to illustrate excavation sequences or support installation – visual aids help demonstrate understanding of spatial and temporal relationships in tunnelling.
- 💡Link your answers to real-world projects (e.g., Crossrail, HS2) to show how theory applies in practice – examiners value contextualised responses.
Common Mistakes
Common errors to avoid in your coursework
- Confusing the roles of temporary back-up services with permanent tunnel infrastructure, leading to incorrect resource specification.
- Overlooking the interaction between different back-up systems (e.g., ventilation and gas monitoring) causing unsafe combinations.
- Assuming standard removal procedures apply in all ground conditions without considering stability or water ingress risks.
- Misconception: Tunnelling is always faster with a TBM. Correction: TBMs are efficient in soft ground but may be slower in hard rock or mixed-face conditions, where drill-and-blast can be more effective.
- Misconception: Ground support is only needed in weak ground. Correction: Even in competent rock, stress redistribution can cause spalling or rockbursts, so support is often required for safety.
- Misconception: Ventilation is only for removing dust. Correction: Ventilation also controls gases like methane or carbon monoxide, regulates temperature, and provides fresh air for workers.
Frequently Asked Questions
Common questions students ask about this topic
Pass / Merit / Distinction Evidence Checklist
How your portfolio evidence is graded for CSKILLS AWARDS, PART OF THE NOCN GROUP Know how to install, use and remove tunnelling back-up services
Every vocational unit is marked against named criteria rather than an exam percentage. Your tutor's brief lists the exact codes for this unit — here is what each band is asking you to do.
Demonstrate baseline knowledge, accurate terminology, and core practical application.
Provide detailed analysis, structured explanations, and clear workplace reasoning.
Deliver thorough evaluation, original problem solving, and fully justified recommendations.
Before You Start
Prior knowledge that will help with this topic
- •Understanding of basic construction health and safety principles, including risk assessment and method statements (RAMS).
- •Familiarity with common construction materials such as concrete, steel, and grout.
- •Basic knowledge of geology and soil mechanics, including soil classification and groundwater effects.
Coursework AI Review
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Key Terminology
Essential terms to know
- Know how to select resources for tunnelling back-up services, Know how to install tunnelling back-up services, Know how to use and remove tunnelling back-up services
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