Marine Underwater & Chamber Works
Project Overview
This combined scope covers three specialist underwater and marine chamber operations executed within marine infrastructure across Abu Dhabi. Works included the installation of inflatable stoppers for stormwater system isolation, underwater flap valve installation at Saadiyat coastal infrastructure, and corrective rehabilitation of Sea Side Chamber 1. All operations were carried out by certified commercial divers under strict safety protocols, delivering precision, durability, and full compliance with marine standards.
- Scope 1: Underwater Inflatable Stopper Installation – Stormwater Outfall Chamber
- Scope 2: Underwater Flap Valve Installation – Saadiyat Coastal Infrastructure
- Scope 3: Sea Side Chamber Rehabilitation & Leakage Repair
Project Objectives
- Install inflatable stoppers for temporary isolation of stormwater flow
- Install flap valves (900mm & 800mm) for backflow prevention
- Rehabilitate and seal Sea Side Chamber 1 pipe joints
- Execute all works safely with certified commercial diving teams
- Deliver reliable, long-term performance across all scopes
Scope of Work
Scope 1 – Inflatable Stopper: Mobilization & Diving Setup
- Deployment of full commercial diving system
- Engagement of 4 certified divers and 1 supervisor
- Setup of underwater communication, lighting, and monitoring systems
Scope 1 – Inflatable Stopper: Chamber Cleaning & Preparation
- Removal of debris using air compressor / vacuum pump systems
- Cleaning of chamber walls using high-pressure water jets
- Scrapers used for shell and marine buildup removal
- Clearing of 1-meter storm drain section to eliminate sharp objects
Scope 1 – Inflatable Stopper: Installation, Pressure Testing & Removal
- Positioning and insertion of 2000mm inflatable stoppers into designated locations
- Ensuring correct alignment and seating within the chamber
- Inflation to required pressure levels with continuous 24-hour monitoring
- Controlled deflation and safe dead-weight removal after completion
Scope 2 – Flap Valve: Mobilization & Surface Preparation
- Deployment of equipment, tools, and specialized personnel to Saadiyat site
- Pre-dive safety inspections and detailed dive plan briefings
- Identification and marking of installation locations
- Drilling into existing concrete structures using hydraulic equipment
Scope 2 – Flap Valve: Installation & Pipe Finishing
- Positioning and alignment of 900mm and 800mm flap valves
- Secure fixing through bolting and jointing to concrete structures
- Functional testing to ensure smooth valve movement and proper sealing
- Removal of excess pipe sections using hydraulic disc cutting tools
- Edge smoothing and finishing for safe and proper fitment
Scope 3 – Chamber Rehab: Cleaning & Debris Removal
- Extraction of accumulated mud and debris using airlift systems
- Vacuum pumping and manual removal where required
- High-pressure water jetting to remove marine buildup
- Mechanical scraping to eliminate shell deposits
Scope 3 – Chamber Rehab: Joint Sealing & Leakage Repair
- Securing open joints using existing pipe sections and high-grade rubber seals
- Stainless steel screws used for corrosion-resistant mechanical fixing
- Application of silicone-based sealing system to reinforce joints
- Targeted repair of sanddrop leakage at joint coupling
- Pressure testing to verify sealing effectiveness post-repair
Health, Safety & Environmental – All Scopes
- Strict adherence to commercial diving safety standards across all scopes
- Pre-dive risk assessments and emergency response planning
- Use of certified equipment and trained personnel throughout
- Controlled operations to minimize environmental impact
- Proper handling and disposal of extracted debris and materials
Coating System
Manpower & Equipment deployed across all three scopes:
- Up to 4 Professional Commercial Divers per scope
- Supervisors for topside and underwater coordination
- Hydraulic drilling and cutting systems with full accessories
- Air compressor / vacuum pump and water jetting equipment
- Advanced underwater communication and lighting systems
Technical Highlights
- 2000mm large-diameter inflatable stoppers with 24-hour pressure monitoring
- Dual flap valve sizing: 900mm and 800mm installed at Saadiyat
- Multi-layer sealing system: rubber seals, stainless fixings, and silicone
- Multi-extraction debris removal: airlift, vacuum pump, and manual methods
- Hydraulic disc cutting for precision pipe modification underwater
Challenges & Solutions
Working within confined underwater chambers with debris and marine buildup
Combined jetting, scraping, and suction extraction systems ensured safe and suitable working conditions
Ensuring effective sealing and stability of large-diameter inflatable stoppers
Careful positioning, controlled inflation, and extended 24-hour pressure testing ensured reliable isolation
Precision drilling and valve alignment in submerged, low-visibility conditions
Experienced divers using hydraulic tools and real-time communication systems ensured accuracy
Active leakage from open pipe joints and compromised couplings
Multi-layer sealing approach using rubber, mechanical fixing, and silicone reinforcement provided long-term performance
Final Outcome
All three scopes were successfully completed, delivering: safe stormwater system isolation through inflatable stopper operations; fully functional flap valve installations ensuring reliable backflow prevention at Saadiyat; and a fully rehabilitated, leak-free Sea Side Chamber 1. Each scope demonstrated high precision, safety, and efficiency in complex marine and underwater conditions.
Project Impact
Restored and improved stormwater system isolation and flow control
Enhanced marine infrastructure with backflow prevention and chamber rehabilitation
Demonstrated technical excellence across multiple concurrent underwater scopes
Delivered durable, long-term solutions in demanding submerged conditions