The Digital Twin, Heerema Simulation Center (HSC), is able to capture the offshore behavior in a realistic real-time digital environment with high fidelity hydrodynamics and physics and real operator stations. This digital tool completely changed engineering in all phases of the project life cycle since its first use in 2015. Its unique capacity is to ‘Engineer with the Human Factor in the loop’ independent if this Human Factor is the client, designer, fabricator, marine warranty surveyor or the offshore operator. In the conventional engineering tools the Human Factor cannot be included and in the conventional engineering process the preparation is done by engineers without much involvement of the operators. It is as if engineering and execution are separate worlds. Being able to bring these worlds together efficiently in an early stage has already led to an efficiency improvement for all parties (i.e. client, fabricator and offshore operator) involved and has improved the Operational Excellence offshore. In this paper the results of three simulated cases will be described to explain the way the Digital Twin is used for different purposes and objectives and what sort of results can be achieved from ‘Engineering with the Human Factor in the loop’. The Digital Twin is an exceptional tool in our Digital Journey that speeds up the process of implementing changes for a more efficient and safer offshore world.

Diffraction calculations overpredict motion RAO’s and force RAO’s in cases where a small layer of water is present on top of a submerged body. This was observed after conducting model tests on a free floating SSCV Thialf and a captive submerged cylinder. A parameter study is done to get a better understanding of why diffraction calculations overpredict the forces in heave direction. From this study it was observed that unrealistically high water elevations existed on top of the cylinder causing the heave forces to be overestimated. A damping lid is therefore implemented to decrease this water elevation. On top of that, a new method is developed to be able to capture the dependency of the force RAO on the wave height. This method uses the instantaneous submergence height (the height of water on top of the submerged body) to determine the time averaged force RAO for a given wave height and wave frequency.

Over the past years Heerema Marine Contractors (HMC) has developed the QUAD lift method enabling the lift of single piece objects up to 30,000mT. This development is driven by the demand from our clients to install or remove larger topsides, both in size and weight. Lifting with two (or more) vessels simultaneously has been done before. Unique is that the QUAD lift operation is performed on DP. Two vessels lifting the topsides from opposite sides, instead of lifting the topsides from one side, creates the possibility for increasing dimensions and layouts of the topsides. The connection of the two crane vessels to the lifted object means that all actions taken on one ship influences not only the lifted object but also the second crane vessel. This requires a clear communication plan and full understanding of the complete system such as the DP behaviour, stability, ballast operations and crane operations. During a QUAD lift operation the Dynamic Positioning (DP) system plays an important role. Therefore in the development process the DP-system was modified to ensure stability of the DP system throughout the entire operation. A systematic series of tests was performed to gain insight in the DP behaviour of both vessels with the goal to ensure a synchronous move with two vessels connected in a QUAD lift configuration. In 2018 a demonstration QUAD lift is performed using Balder and Thialf to show HMCs commitment to perform this kind of operations in the future. The QUAD lift demonstration lift was prepared and executed in the Heerema Simulation Center (HSC) with the offshore crew in preparation of the actual offshore execution. This paper will address the steps followed to prepare for the offshore execution, describing DP behaviour, vessel coupled dynamics and human factor aspects. Based on the offshore experience validation was performed on the numerical tools used in the preparation.

To reach the sustainable targets and to reduce the investment risk, there is a need for more certainty and predictability regarding the requirements of the future offshore wind installation vessels. To capture the fast changing offshore wind market and its impact on vessel requirements, this paper generates scenarios using Epoch-era analysis. A parametric model is created to determine the performance of a set of vessels defined by their length, beam, depth, crane capacity, speed, and transport strategy in the different scenarios. The strength of combining Epoch-era analysis and parametric modelling is that the performance criteria and input variables can be tailor-made to a stakeholders strategy resulting in robust input variables for the concept vessel design.