International Journal of Maritime Engineering

DIGITAL TWINS IN MARITIME SAFETY: A BREAKTHROUGH IN HULL STRUCTURAL INTEGRITY MONITORING VIA CUTTING-EDGE CONVERSION METHODS AND BASE MODE SELECTION ALGORITHMS

Do Kyun Kim — 2025-01-03

Maritime vessels constantly experience various environmental loads, leading to cumulative fatigue damage on their hull structures, which can ultimately result in structural failure. Despite existing efforts to measure these structural responses, limitations in both sensor availability and measurable hull data present significant challenges. This study presents a ground-breaking approach within the sphere of Digital Twins in Maritime Safety. Our novel conversion method uses limited sensor data to estimate comprehensive hull responses, introducing an innovative base mode selection algorithm for improved accuracy. Leveraging extensive data from the Magellan container ship, including strain gauge measurements and wave spectra, we validate our model's robustness. As a unique feature, we offer a stress contour for the complete non-watertight bulkhead, underscoring our model's spatial precision. This pioneering approach optimises the use of limited measurements, marking a transformative breakthrough in hull structural integrity monitoring.

Experimental Testing of Riveted Carvel Planks on Frames for Traditional Timber Structures

Jean-Baptiste Souppez — 2025-01-03

Traditional wooden boats are characterised by closely spaced frames, riveted to thick planks, leading to high thickness-to-span ratios. However, the effect of such closely spaced frames and thickness-to-span ratio remains uncharacterised. Consequently, four-point bending tests are undertaken to quantify the ultimate flexural strength and flexural modulus of wooden planks with up to 3 frames and thickness-to-span ratios from 0.0267 to 0.200. The results show that (i) a greater number of frames for a given span yields a reduction in specific stiffness but a constant specific strength; (ii) a maximum thickness-to-span ratio of 0.080 and 0.050 is recommended to ensure the strength and stiffness exceed regulatory default properties, respectively, and (iii) additional factors of safety would be needed for traditional construction to be included in existing structural regulations. These findings provide novel insights into the structural design of traditional wooden boats and may contribute to their future inclusion in regulatory frameworks.

PROPOSED AMENDMENTS IN SOLAS AND MARPOL CONVENTIONS TO LIMIT VOC EMISSION FROM OIL TANKER LOADING AND SHIP BUNKERING OPERATIONS

Satinder Virdi — 2025-01-03

Exhaust gas emissions are regulated at international and national levels, but venting vapours from oil tanks is a cause of concern due to a lack of regulatory control. Oil tanker loading operations and ship bunkering operation results in a considerable amount of 'Volatile Organic Compound' (VOC) in the surrounding environment. The presence of toxic components in this VOC emission has the potential to affect the health of seafarers as well as local air quality. Numerous tankers engaged in loading operations within the same port has a solid potential to increase the toxic emission to a dangerous level locally. Loading ports near highly populated areas expose the local population to toxic VOC concentration. A few ports in Europe, the USA and South Korea have strict local environmental rules prohibiting VOC emission from oil tanker loading operations. There is a need for international and national regulations to limit or stop the release of VOCs from oil tankers and monitor VOC exposure risks at the local level. The research objective is to analyse the current status of international and national rules and regulations related to VOC emission and monitoring VOC exposure risks during loading operations in an oil tanker and ship bunkering operations. Existing international (SOLAS and MARPOL Conventions) and national regulations (EU, USA, Norway) are described and analysed regarding the contemporary tanker design and standard tanker operating practice. A critical analysis determines the effectiveness and adequacy of the current regulations and tanker industry working practices. Finally, amendments to existing international conventions are proposed to minimise or stop the VOC emission and monitor VOC exposure risks to seafarers and the surrounding population near tanker terminals and ports. Solutions are also proposed to amend the existing tanker design and operating practices to stop the VOC emission, including toxic hazard assessment in vapour vent design and prevent exposure to VOC emission.