Reducing payload motion during offshore operations
T. de Vlieger (TU Delft - Mechanical Engineering)
R. R. Negenborn – Mentor (TU Delft - Transport Engineering and Logistics)
X. Jiang – Graduation committee member (TU Delft - Transport Engineering and Logistics)
Oriol Colomés – Graduation committee member (TU Delft - Offshore Engineering)
F.J. van der Werf – Graduation committee member (Jumbo Maritime)
M. Teunis – Mentor (Jumbo Maritime)
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
Abstract
Offshore lifting operations must have reduced payload motion to increase safety and reduce operating time. When payload is retrieved from the splash zone to the deck, besides the crane block, no additional control can be applied on the underactuated system. Existing studies either assume more control over the payload or develop a control system based on a new crane. To reduce payload motion on current crane vessels, a conceptual model needs to be developed.
In this thesis, various state-of-the-art solutions are considered based on four criteria: Time reduction, motion reduction, initial investment required and power required. Eventually, the quantified criteria and an analytic hierarchy process established that the most promising concept is based on an automated side loader of a garbage truck.
The selected concept is developed based on a design process that focuses on optimized material usage. The geometry is determined according to requirements and forms the starting point of the circular design process. A dynamic analysis is conducted to obtain the dynamic response of the payload and eventually the reduced payload motion. The design cycle is complete after a finite element analysis has been conducted to verify the structural integrity of the model. After more than 20 cycles of the design process, the conceptual model is optimized and over 85% of motion is reduced in the X direction. The payload motion in Y- and Z-direction is 20% and 29% respectively.
The simulation results in this study show that the conceptual model is able to reduce the payload motion during offshore lifting operations whilst staying within the limits set by offshore standards. The motion reduction of the payload creates a safer and more efficient environment to execute offshore lifting operations.