Deconstruction of Failing Pontoon at Portsmouth Port Executive Summary Apex Diving & Marine, a leading provider of specialized underwater engineering and marine salvage services, was contracted by Portsmouth Port Authority to safely deconstruct a structurally compromised pontoon. The project highlighted our expertise in underwater demolition, particularly through the skilled use of Broco thermic lances for precision cutting. By employing advanced underwater staging techniques, our team efficiently segmented the pontoon for crane removal and subsequent transport to a certified scrappage facility. Completed on schedule and with zero incidents, this operation demonstrated our commitment to safety, efficiency, and environmental compliance in challenging marine environments. Company Overview Apex Diving & Marine is a full-service marine contractor specializing in commercial diving, underwater construction, salvage, and demolition. With over 15 years of experience, our certified divers and engineers are trained in cutting-edge technologies, including Broco exothermic cutting systems. These thermic lances, which generate extreme heat through an oxygen-fueled reaction, allow for precise, rapid cutting of metal structures underwater without the need for electrical power—ideal for hazardous or remote marine sites. Our team's proficiency in these tools, combined with expertise in underwater staging, rigging, and project management, positions us as a trusted partner for ports, harbors, and offshore industries. Project Background and Challenge Portsmouth Port identified a failing pontoon—a floating platform critical for vessel mooring and cargo operations—that posed significant safety risks due to corrosion, structural fatigue, and environmental wear. The pontoon, measuring approximately 50 meters in length and constructed from steel and concrete, had begun to list and crack, threatening port operations and nearby waterways. The port authority required a complete deconstruction to minimize disruption to daily activities. Key challenges included: Underwater Accessibility: Much of the structure was submerged, necessitating safe diver access and operations in low-visibility conditions. Precision Cutting: The pontoon needed to be sectioned into manageable pieces for crane lifting, without causing further instability or debris pollution. Logistics and Safety: Coordinating underwater work with surface cranes, ensuring diver safety in tidal currents, and complying with environmental regulations for waste transport and disposal. Timeline Constraints: The project had to be completed within a two-week window to avoid peak shipping seasons. Traditional cutting methods, such as mechanical saws or plasma torches, were impractical due to the underwater environment and the need for non-sparking, high-heat tools. Apex Diving & Marine was selected for our proven track record in similar projects and our specialized skills with Broco thermic lances. Solution and Approach Apex Diving & Marine deployed a multidisciplinary team, including commercial divers certified in underwater welding and cutting, project engineers, and safety coordinators. Our approach emphasized meticulous planning, innovative tool use, and adaptive strategies to address site-specific conditions. Key Skills and Technologies Employed Broco Thermic Lances: Central to the operation, these lances were used for all primary cutting tasks. Operating at temperatures exceeding 5,500°F (3,000°C), they efficiently sliced through thick steel beams and reinforcements. Our divers, trained in Broco's exothermic process, handled the lances with precision to create clean cuts, minimizing material distortion and reducing the risk of underwater sparks or explosions. This skill set allowed us to cut sections up to 2 meters in length per dive, far surpassing conventional methods in speed and safety. Underwater Staging: To facilitate safe access and stability, we installed temporary underwater platforms and scaffolding using modular staging systems, enabling divers to work at multiple depths. Our expertise in hydraulic jacking and buoyancy control ensured the structure remained stable during segmentation. Sectioning and Rigging: The pontoon was divided into 8-10 ton sections through a phased cutting plan. Divers marked cut lines using ultrasonic thickness gauges, then applied Broco lances to sever connections. Each section was rigged with lifting slings and floated or craned to the surface using a 100-ton mobile crane stationed on the dock. Transport and Scrappage: Post-extraction, sections were loaded onto barges and transported to a licensed recycling facility. We coordinated with environmental monitors to ensure no contaminants entered the water, adhering to UK Marine Management Organisation guidelines. Post-project feedback from Portsmouth Port praised our team's professionalism and technical prowess, leading to discussions for future maintenance contracts. Conclusion This case study exemplifies Apex Diving & Marine's core strengths in underwater engineering, particularly our mastery of Broco thermic lances for complex demolition tasks. By combining innovative tools with expert planning and execution, we delivered a safe, efficient solution to a critical infrastructure challenge. For ports and marine operators facing similar issues, Apex Diving & Marine stands ready to provide tailored services that prioritize safety, sustainability, and success.