Information, Quantities and Communicating With Others in Tunnelling — Cskills Awards, part of the NOCN Group National Vocational Qualification Construction & Building Services Revision
This subtopic focuses on the essential skills of reading and interpreting technical documentation such as tunnel alignment drawings, ground investigation r
Topic Synopsis
This subtopic focuses on the essential skills of reading and interpreting technical documentation such as tunnel alignment drawings, ground investigation reports, and method statements to plan work activities. It also covers the accurate calculation of material quantities, including segments, shotcrete, and piping, to avoid delays and waste. Effective communication methods, both verbal and non-verbal, are crucial to ensure safety, coordination, and the accurate relay of information among the tunnelling team and other stakeholders.
Key Concepts & Core Principles
- Tunnel excavation methods: Understand the differences between drill and blast, tunnel boring machines (TBMs), and sequential excavation methods (SEM/NATM), including their applications and limitations.
- Ground support systems: Know the principles of rock bolting, shotcrete (sprayed concrete), steel arches, and mesh, and how they stabilise the tunnel during and after excavation.
- Ventilation and environmental control: Grasp the importance of airflow, dust suppression, and gas monitoring (e.g., methane, carbon monoxide) to maintain safe working conditions.
- Health and safety legislation: Be familiar with the Health and Safety at Work Act 1974, CDM Regulations 2015, and specific tunnelling safety practices like emergency escape routes and rescue plans.
- Plant and equipment operation: Learn to safely operate and maintain tunnelling machinery such as excavators, dumpers, and conveyor systems, including pre-use checks and risk assessments.
Exam Tips & Revision Strategies
- Always check the scale and revision date on drawings before extracting dimensions.
- Show all workings clearly when calculating material quantities to gain method marks even if the final answer is incorrect.
- Practice using standard hand signals and radio protocols to demonstrate clear communication during practical assessments.
- In written tasks, use structured formats (e.g., headings, bullet points) to relay information concisely.
- Double-check numerical answers for realistic values; if you order 10,000 segments for a 10-metre tunnel, you’ve made an error.
Common Misconceptions & Mistakes to Avoid
- Misinterpreting drawing scales or units, leading to incorrect material quantities.
- Confusing metric and imperial units when calculating materials.
- Failing to account for wastage, over-break, or ground conditions in quantity calculations.
- Using ambiguous language or jargon when communicating, causing misunderstandings.
- Neglecting to confirm and repeat back verbal instructions in noisy tunnel environments.
Examiner Marking Points
- Award credit for correctly identifying key information from tunnel design drawings, including alignment, cross-sections, and support specifications.
- Award credit for accurately extracting data from work instructions, such as ring numbers, chainage, and required materials.
- Award credit for demonstrating accurate take-off of materials from drawings, including measuring areas and volumes for excavation, lining, and backfill.
- Award credit for correctly calculating the number of tunnel segments, concrete volume, or reinforcement needed based on given dimensions and wastage allowances.
- Award credit for effectively communicating task details using appropriate terminology, hand signals, or radio protocols in a simulated or real workplace scenario.
- Award credit for producing clear and accurate written records, such as shift reports, material order forms, or inspection requests, that convey critical information.