Client / Site: HydroGen Renewables – Penstock Vault, Argyll Hydroelectric Facility

The Challenge

HydroGen Renewables faced a critical bottleneck in their decommissioning project. A massive penstock vault and turbine chamber had been sealed for over 15 years, and nobody knew what dangers lurked inside. Before any dismantling work could begin, they needed a comprehensive confined space inspection to assess the structural integrity, corrosion levels, and environmental risks.

This wasn’t just any  inspection – it was a high-risk operation with multiple hazards:

• Single entry point – only one way in and out, making emergency evacuation extremely challenging
• Historical water ingress – unknown water damage and potential structural weakening
• Heavy metal residues – toxic contamination from decades of industrial use
• Zero natural ventilation – creating a potentially lethal atmosphere
• Complete darkness – no natural light penetration

The client needed absolute certainty about what was inside before committing to expensive decommissioning work. Any surprises could halt the entire project and cost thousands.

Our Response

Dagger Diving Services deployed a specialist team equipped for the most challenging industrial environments. Our approach combined military-grade safety protocols with cutting-edge detection technology.

Safety First, Always We established a comprehensive safety perimeter with an Emergency Rescue Technician and dedicated Topman maintaining constant line-of-sight communication. Every aspect of the operation was governed by a fully approved Safe System of Work and site-specific POWRA (Point of Work Risk Assessment).

Atmospheric Testing & Control Before anyone entered the chamber, we inerted the space and conducted extensive atmospheric testing using multi-gas detection systems. This protocol allows us to identify any toxic gases, oxygen deficiency, or explosive atmospheres that could endanger our team.

Intrinsically Safe Equipment All equipment used was intrinsically safe, including:

• EX-rated lighting – explosion-proof illumination systems
• ATEX-rated communications – certified safe for potentially explosive atmospheres
• Intrinsically safe recording equipment – ensuring no electrical sparks could ignite gases

Emergency Preparedness We validated our rescue plan with a full dry-run drill using tripod and winch retrieval systems. 

Systematic Inspection Process Our teams worked in pairs under strict permit controls, with continuous atmospheric monitoring and gas clearance tagging. We conducted comprehensive photographic and dimensional surveys, documenting every detail for the client’s decommissioning planning.

The Outcome

Mission Accomplished – Zero Incidents, Full Transparency

Our confined space inspection delivered exactly what HydroGen Renewables needed: complete clarity and confidence to proceed with their decommissioning project.

Key Findings:

• Minor corrosion 
• Evidence of stagnant pooling 
• One structural bracket requiring reinforcement 
• Full photographic survey providing detailed visual documentation
• Comprehensive dimensional data enabling precise decommissioning planning

Project Impact: The client received a detailed inspection report that transformed their decommissioning approach from uncertainty to precision planning. With full risk transparency, they could allocate resources efficiently and proceed with confidence.

Perfect Safety Record:

• 12 confined space entries completed successfully
• 0 accidents, incidents, or near misses
• 100% gas monitoring compliance rate
• 1 improvement to permit system proposed and adopted

Regulatory Compliance: All confined space inspection work was delivered under full compliance with ISO 45001, Confined Spaces Regulations 1997, and CDM 2015. Our emergency rescue capability was validated on-site prior to entry, and our permit controls exceeded industry best practice.

Need a confined space inspection for your industrial project? Dagger Diving Services combines specialist expertise with uncompromising safety standards to deliver the clarity you need. Contact us today to discuss your confined space inspection requirements.