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Trans RINA, Vol 153, Part A4, Intl J Maritime Eng, Oct-Dec 2011


10 20 30 40 50 60 70 80


0 0 50000


100000 Dwt


150000 200000


Figure 6: Total fuel consumption of modern dry bulk carriers6


This data suggests that the fuel consumption for a 110,000 dwt


ship is around 43.4 tonnes per day,


equivalent to 0.39 kg/dwt/day compared to around 0.47 kg/dwt/day for an 80,000 dwt ship, a reduction of 16% in the larger ship.


The importance of these cost elements will change over time and will obviously be more significant when capital costs and fuel costs are high. Assuming the analysis of daily running costs given as an example by Stopford [15] an approximation can be given of the effect of the improvement in capital and fuel costs as shown in Table 9.


Operating costs Maintenance Fuel costs


Other voyage costs


Capital costs Total


80,000 dwt 0.14 0.04 0.30 0.10


0.42 1.00


110,000 dwt 0.14 0.04 0.26 0.10


0.37 0.91


Table 9: Example of potential reduction in unit cost due to an increase in Panamax size


On this basis the unit cost reduction is 9% and this suggests, as with the parcel size evidence, that economy of scale will also tend to a larger size of bulk carrier following the relaxation of the Panama Canal constraint.


6. INFRASTRUCTURE 6.1 THE IMPORTANCE OF INFRASTRUCTURE


The development of new ship types is a function not only of the market demand for


larger ships but also the


capability of shore-side facilities to accept larger ships, the latter factor acting to some degree as a brake on the speed of development. Shore-side facilities include both port facilities for loading and discharge and drydocking facilities for maintenance. These two key facilities are examined below.


6.2 PORT INFRASTRUCTURE


The loading and discharge ports used in the Panamax trades are widely spread. Based on analysis of ports named in Clarkson fixture reports in 2008 and 20099 around 112 separate loading ports and 117 separate discharge ports are noted for bulk cargoes. A relatively small number of ports dominate, with 13 discharging ports and 15 loading ports accounting for 50% of the total weight of bulk cargoes included in the database. Some of these ports can handle capesize tonnage but many are restricted to Panamax dimensions or smaller. This includes some of the larger (in terms of quantity handled) ports such as Mobile, Kamsar, Samarinda, Ghent and Ijmuiden.


For ports that can handle larger


ships, such as Kaoshiung, Rotterdam, Dunkirk, Hampton Roads and Richards Bay, Capesize berths make up only part of the capacity to handle bulk cargoes and smaller ship visits will inevitably continue to be important maintain throughput, at


to least until infrastructure


developments take place. It may be concluded that


the need for development


means that port infrastructure will act to some degree as a brake on the development of the mini Cape fleet, with port constraints acting to reduce owners’ potential to take advantage of increased economies of scale.


It does not


necessarily follow, however, that development in bulk terminal infrastructure will be an inevitable consequence of the potential for larger ships afforded by the canal expansion.


Further review of terminal data [16] reveals that above Panamax size there is no coherence between terminals that will lead to a single optimum Mini-Cape-sized ship, unlike the rigid constraints that led to the emergence of Panamax vessels. A spectrum of ship sizes, as seen in the distribution presented in Figure 3, is likely to emerge, to suit the specific requirements of trades. In the bulk carrier sector, therefore, there is unlikely to be a single class of ship, the “New Panamax” bulk carrier, which will emerge in response to the relaxation of the canal constraint.


Within this spectrum it is likely that sub-


classes may develop to serve specific trades. A good existing example is the existing “Kamsarmax” sub-class of bulk carrier designed to transport bauxite from the port of Kamsar in Guinea. Limitations in the port permit a slightly longer and deeper


version of what would


normally be regarded as Panamax, with dimensions 229m x 32.26m x 14.4m (LxBxT) [17].


In the bulk sector it is most often draft that restricts port entry and, on this basis, naval architects may see some scope in maximising volume by increasing beam whilst maintaining draft at lower levels. This should be done with caution, however, in particular due to restrictions in


9 Sourced from Clarkson’s Shipping Intelligence Network, http://www.clarksons.net/sin2010/


A-220 ©2011: The Royal Institution of Naval Architects


Tonnes per day


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