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In order to provide the basis for a fair comparison, an indicator was developed to measure the amount of work that goes into the construction of a vessel. The foundation for this Compensated Gross Tonnage was laid in the 1970s by the OECD to compensate for the differences in work involved in producing a gross ton (GT) of ship in different sizes and types. Since 2007, the CGT of a vessel of a certain type as a function of its size (measured in GT) has been expressed as CGT=A×GTB. However, no internationally accepted A and B values exist to convert superyachts from GT to CGT. The superyacht building industry believes that this omission results in an under appreciation of the importance of the sector. This paper describes the research carried out into this subject and confirms that the current assignments for superyachts greatly under appreciate the value of the sector. Based on the current data, the most appropriate values for superyachts are 278 for A and 0.58 for B. The spread is quite large and more data would help confirm this finding. [ABSTRACT FROM AUTHOR]

There are hardly any methods available for the estimation of the steel weight of inland ships in the earliest design stages. The few weight estimation methods that are available are out of date, limited to a narrow band of main dimensions and not sensitive enough to be used for innovative designs. In this article, which summarizes key results from the PhD thesis of Hekkenberg (2013), new methods are derived for the estimation of the steel weight of inland dry bulk ships. The estimation methods that are presented are derived from large systematic series of computergenerated ship designs that comply with Lloyds Register's rules regarding their structure and with the European rules for freeboard. The structure and weight of these designs are validated by a comparison of modeled scantlings with the scantlings of midship sections of existing ships. Further validation is done by a comparison of the modeled overall steel weight with the steel weight of actual ships and the weight estimates of existing methods. The designs are used to derive two types of estimation methods: the first is a set of simple formulas that are valid for inland ships with common sizes and L/B ratios and the second is a more complex set of formulas that allows estimation of the steel weight of inland ships with draughts ranging from 1.5 to 4.5 m, lengths of 40-185 m, beams of 5-25 m, and L/B ratios of 4-20. [ABSTRACT FROM AUTHOR]