China
Africa
Explore chapters and articles related to this topic
Transforming Nonlinear Regression
Published in Alan R. Jones, Best Fit Lines and Curves, and Some Mathe-Magical Transformations, 2018
Gross tonnage is often used as a primary cost driver to give an indication of the likely cost of building a ship. Suppose we want to derive a parametric relationship for the Gross Tonnage of ships of these or similar types based on other factors as a precursor to determining the potential cost. Gross Tonnage is in fact a volume measure (even though it might sound like weight) so it seems reasonable to suggest the gross tonnage is related to the Product of the length, beam (breadth) and depth of the ships. Unfortunately we can see that we only have a full set of data for six ships (not really what you would call a statistically significant sample size.) However, for the ones that we do have, we can plot the relationship in Figure 6.28 and perhaps take some encouragement that it is not completely random!
The ship
Published in Alan E. Branch, Michael Robarts, Branch's Elements of Shipping, 2014
Alan E. Branch, Michael Robarts
This phase-in period was intended to ensure that ships were given reasonable economic safeguards, since port and other dues are charged according to ship tonnage. At the same time, and as far as possible, the Convention was drafted to ensure that gross and nett tonnages calculated under the new system did not differ too greatly from those calculated under previous methods. The Convention meant a transition from the traditionally used terms gross register tons (grt) and nett register tons (nrt) to gross tons (GT) and nett tons (NT). Gross tonnage forms the basis for manning regulations, safety rules and registration fees. Both gross and nett tonnages are used to calculate port dues. The gross tonnage is a function of the moulded volume of all enclosed spaces of the ship. The nett tonnage is produced by a formula which is a function of the moulded volume of all cargo spaces of the ship. The nett tonnage shall not be taken as less than 30% of the gross tonnage.
The Southampton system: a new universal standard approach for port-city classification
Published in Maritime Policy & Management, 2021
Toby Roberts, Ian Williams, John Preston
Firstly, an appropriate measure of cargo traffic was identified. Cargo tonnage was chosen as a better measure of cargo traffic than TEU (twenty-foot equivalent unit—an approximate unit of cargo capacity used to describe the capacity of container ships/terminals) as it includes all forms of cargo and not just containers. A method was devised to compare cargo tonnage with passengers. This was done using the gross tonnage and deadweight tonnage of cargo and passenger ships. Gross tonnage represents the overall internal volume of the vessel, whereas the deadweight tonnage represents the maximum additional weight the ship is able to carry. Data were collected on a range of ships that have visited the port of Southampton on the 28 November 2019, or ships due to visit in the future using VTS data (ABP 2019b). The UK’s major-port tonnage by cargo type (Department for Transport 2018b) was used to calculate the percentage of each ship type within UK annual major-port tonnage. This was used alongside the collected VTS data to create a representative sample fleet of UK cargo ships.
The impact of ship size on ports’ nautical costs
Published in Maritime Policy & Management, 2020
We have, as can be seen in Table 1, two types of data available, data about the ship and data about the cargo carried. The data about the characteristics of a ship’s size are: length and volume, measured by deadweight tonnage and also by gross tonnage. Deadweight tonnage (dwt) is a measure which tells how much weight a ship can safely carry. This measure takes also the weight of stores, ballast, fuel, crew and passengers. Gross tonnage (gt) of a ship is a function of the volume of all of a ship’s enclosed spaces. The calculation of gt is based on the volume of the ship in cubic metres (and not on weight). There is of course a strong correlation between the various characteristics of a ship’s size (a correlation coefficient of > 0.95 for the logarithmic form of the characteristics mentioned). Length is not a common unit of measurement for ships (McNicholas 2011, 30).
A study on analysis of green house gaseous emitted from ships through operation information
Published in Journal of International Maritime Safety, Environmental Affairs, and Shipping, 2023
Table 4 shows the annual ship fuel consumption results calculated by the information in Table 2. This is shown in Figure 3 as fuel consumption per ship after conversion. Regardless of the type of ship, the fuel consumption per ship increased as its gross tonnage larger. Passenger ships, oil tankers, chemical tankers, and tugs did not have a substantial difference in consumption based on the difference in tonnage. but, cargo ships and gas carriers did have a large difference in consumption based on the difference in tonnage.