Untitled Quiz

Near Miss: Lift Bag Released Unintentionally from Crane Hook

• During a saturation dive, a lift bag was connected to a crane to send it to a diver.
• When the crane hook passed through the splash-zone, the lift bag came free from the crane hook and floated on the surface.
• The vessel was in DP mode, potentially causing damage to the thrusters and loss of vessel position while divers were subsea.
• The deck crew noticed the danger and informed the bridge and dive control immediately.
• The current pushed the lift bag away from the vessel, preventing further damage.
• The lift bag was not correctly attached to the crane: it was not folded correctly and was connected through one of its webbing slings instead of being secured to prevent buoyancy.
• The positive buoyancy of the lift bag allowed it to slide out through the safety hook.
• Causes identified include lack of awareness, procedures not being implemented, and a low-risk perception of the task.

Cylinder Explosion on a Vessel

• A cylinder of compressed gas exploded while it was being transported within a rack on a vessel.
• The blast zone for a single cylinder of this size pressurized to 2,400psi was around 1.5 meters.
• The explosion destroyed the rack and propelled other cylinders across the deck.
• The text recommends a risk assessment to ensure cylinders are certified, in good condition, and stored according to industry regulations.

Offshore Platform Decommissioning Near Miss

• During the decommissioning of a monopod offshore platform, the topside unexpectedly moved and detached from the supporting monopod, swinging over workers.
• The crane operator quickly maneuvered the topside away from the workers and lowered it into the water to control its motion.
• The workers disembarked safely without injuries.
• Contributing factors include: inadequate understanding of dynamic forces applied to rigged loads during auto-tensioning, lack of technical assessment for pre-load tension requirements, and over-reliance on previously successful methodologies without assessing their suitability for the specific tasks.
• Recommendations to minimize the risk of similar incidents include: technical assessments of lift plans, use of castellated cut designs, holistic design considerations, and ensuring no workers are under suspended loads.

NTSB: Fire on Vessel - Stray Electrical Current During Welding

• A fire started in a cabin below the main deck of a vessel being stored for the winter.
• Welder were working near the origin of the fire but no evidence of the hot work was found to be the source of the fire.
• The fire watch and welder observed small flames in a cabin, likely caused by the ignition of combustible materials.
• Stray electrical current during welding may have caused wires to overheat and ignite combustible materials.
• Recommendations include placing the welding machine's work clamp as close as possible to the point of welding to prevent stray welding currents.

MAIB: Vessel Collision Caused by Mismatch Between Bridge and Engine Room Control

• A fishing vessel lost control of its propulsion system while berthing and collided with a harbor tug.
• The vessel's propulsion system could be operated from multiple stations, but control was transferred from the bridge to the engine control room with the clutch engaged.
• At the time of handover, the bridge propeller pitch lever was set at zero, while the ECR's propeller pitch lever was set at 100% ahead.
• The propeller pitch automatically advanced when control was accepted in the ECR, causing the vessel to move forward and collide with the tug.
• The pitch levers for the vessel's propulsion control system were not synchronized between the bridge and engine control room during control transfer.