A project to improve safety on crane vessels through pendulation prediction and active control.
Crane vessels are among other operations used for installing valuable and fragile subsea equipment weighing up to 200 t for the production of oil and gas - a highly specialised operation with a lot of safety hazards. Therefore, Maersk Maritime Technology and Maersk Supply Service have developed an early warning tool to avoid unsafe crane operations and make life at sea safer.
Certain “sea conditions” can cause sudden and unpredictable crane movements putting our crews and equipment at risk
Today, a crane operation is carefully planned, however, dynamic influences due to various sea conditions are not taken into account. These affect ship motions, which can make the crane load oscillate, resulting in loss of control and increased risk of damage to equipment and vessel. With very heavy loads, these oscillations will impact the ship stability significantly, in the worst case the ship could even capsize.
Perfect timing of crane operations enhances safety onboard
The crane watch dog project introduces an extension of the safety procedures performed onboard crane vessels before a crane operation. The objective is to predict and avoid large crane load pendulations that could affect ship stability, injure personnel and damage equipment onboard.
Prediction software is currently being tested on Maersk Attender
In cooperation with Safety at Sea Ltd. a planning software tool has been developed that will simulate the crane operation and the ship’s stability during the operation. The planning tool will predict and warn of critical scenarios even before the crane operation has started. This will facilitate the decision making of the Captain before carrying out the crane operation.
This program is currently being tested on Mærsk Attender to verify the functioning of the MRU (Motion sensor) and the accuracy of the predictions. Based on the feedback from the vessel, the system will be refined and rolled out for operational experience on other crane vessels.
One of the work-streams of the project investigates the possibility of installing a device that could actively control pendulation on a crane. The study has been completed and has identified steps and measures that need to be considered in order to develop and implement an APCS (Active Pendulation Control System) device on board the vessels.