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


OPPORTUNITIES FOR IMPROVED EFFICIENCY AND REDUCED CO2 EMISSIONS IN DRY BULK SHIPPING STEMMING FROM THE RELAXATION OF THE PANAMAX


BEAM CONSTRAINT (DOI No: 10.3940/rina.ijme.2011.a4.213) P W Stott and P N H Wright, Newcastle University, UK, SUMMARY


In 2014 the Panama Canal Authority is scheduled to bring into commission new locks that will eliminate the long standing Panamax beam constraint of 32.2m. The expansion of the canal is aimed at increased capacity for container transits but will clearly have consequences for all types of vessel. There is an emerging demand for dry bulk carriers that are larger than the current Panamax limit of around 85,000 dwt but smaller than the Capesize class of around 160,000 dwt and the expansion of the canal will facilitate this development.


Larger vessels will permit economies of


scale and greater efficiency in the dry bulk shipping sector compared to what is currently possible with conventional Panamax ships. The relaxation of the constraint will additionally permit the development of more efficient hull forms than is possible within the existing beam constraint and the expansion of the Panama Canal’s locks will therefore (eventually) contribute directly to the reduction of CO2 produced by dry bulk shipping.


The use of the Panamax


constraint is far wider than the dry bulk sector, however, and the potential for reduction in carbon emissions for other sectors currently constrained to 32.2m beam is recommended for further study to evaluate the total carbon reduction ‘windfall’ that could result from the expansion of the Canal.


NOMENCLATURE dwt


TEU


LCB Δ


Deadweight (tonnes) foot


Handysize Smaller dry


Handymax / Supramax


Twenty-foot Equivalent Unit, being a single twenty container.


standard shipping bulk carriers, typically between about 10,000 and 40,000 dwt.


Dry bulk carriers between about 40,000 and 60,000 dwt with Panamax beam.


Panamax Limiting beam dimension of about 32.2m or a class of dry bulk carriers between about 60,000 and 85,000 Panamax beam.


dwt with U-Panamax


“Unconstrained-Panamax” being ships with deadweight


similar to the GT


“traditional” panamax class described above but without being restricted by the Panamax beam limitation. Gross Tonnage


Capesize Dry bulk carriers too large to transit the Panama Canal, typically around 160,000 dwt.


Mini-Cape Dry bulk carriers too large to transit the Panama Canal


PSD L


B T


CB D


Kd GZ KMt but smaller than the


traditional Capesize class of vessels (typically between about 85,000 and 120,000 dwt).


Parcel Size Distribution function (tonnes).


Length between perpendiculars (m) Breadth Extreme (m) Draught (m)


Block Coefficient Depth (m)


Deadweight / Displacement ratio Righting Lever (m)


Transverse metacentre (m) ©2011: The Royal Institution of Naval Architects A-215 1. INTRODUCTION


To the designers of the Panama Canal in the first decade of the last century the limiting dimensions of the locks must have seemed very large indeed. Given that the size of a large dry cargo ship at the time was around 7,000 dwt [1]


ships abreast and almost three in line.


the chambers could have accommodated two Ships have


become larger, however, and by the end of the twentieth century the limiting dimensions of locks had become an issue because of the limitations they impose on the capacity of the Canal, in particular the capacity for transit of containers.


The justification for the expansion [2]


indicated that the capacity for transit of containerised cargo will be exceeded by demand from 2011 and that unless the Canal expands, its relevance to shipping will erode to the detriment of the Panamanian economy.


After many years of study the funding for a $5.8 billion expansion was announced


in 2006, aiming to be


completed in 2014 exactly one hundred years after the Canal first opened to shipping. The maximum size of container vessel that can transit the Canal will increase from around 4,800 TEU to around 12,000 TEU when the project is completed.


will benefit, however, the relaxed constraint


It is not only container vessels that also


applying to bulk carriers and other vessel types that may benefit from the shortened route between the Atlantic and Pacific oceans.


Fn V w t


Longitudinal Centre of Buoyancy (m) Displacement (tonnes) Froude number


Volume of displacement (m3) Taylor Wake Fraction Thrust deduction


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