Design indexing – benchmarking

Design indexing – benchmarkingThe PEDI is based  on the required propulsion power at 70% scantling draft and a given speed. Each vessel is therefore associated with a number of PEDI-values corresponding to different speeds.

The prime objective of fault-tolerant control systems is to handle faults and discrepancies using appropriate accommodation policies. The issue of obtaining information about various parameters and signals, which have to be monitored for fault detection purposes, becomes a rigorous task with the growing number of subsystems. The structural approach, presented in the paper, constitutes a general framework for providing information when the system becomes complex. The methodology of this approach is illustrated on the ship propulsion benchmark.

The benchmarking method is based on the hydrodynamics of the hull. Knowledge about the dimensions and cargo carrying capacity is therefore essential for the calculation of PEDI.

In order to benchmark a vessel, the following is required: 

  • Lenght between perpendiculars

  • Lenght overall

  • Breadth 

  • Depth

  • Lightweight

  • scantling draught and deadweight

  • MCR

  • NCR

  • Service allowance (sea marging)

​For container ships: 

  • Norminel TEU capacity

​Calibration point:

  • Design draught and deadweight 

  • Design speed​

The power requirement for the different speeds is found using the statistically validated power prediction tool, Ship-DESMO (1). The power prediction method finds the resistance of the hull in calm water and accounts for hull and propeller interaction as well as shafting efficiency. 

The predicted powers are calibrated against the vessels design point. The design points are specific to each vessel in the database and consists of interrelated values for a particular loading condition, speed and power requirement, often contract specified values is used. This calibration ensures that innovative hull design is reflected in the PEDI-value. ​

Once the PEDI-values have been found, the ship is benchmarked against a group of ships of the same type and comparable size. Ships will always be compared at the same speed in order to achieve a fair ranking. 

Energy Efficiency Design Index (EEDI) was introduced since 2013 for recent built vessels to measure energy efficiency of sea going vessels. This factor already has created a great influence on global maritime industry. However, any requirement linked to the energy efficiency of inland vessels does not exist. This paper attempts to evaluate EEDI for inland cargo vessels of Bangladesh. According to the results of this analysis, which has been based on 351 existing inland cargo vessels, EEDI that was developed for seagoing vessels cannot be implemented for evaluation of inland cargo vessels due to limitation of carrying capacity and installed main engine power. So, the main objective of this paper is to provide EEDI reference line for inland cargo vessels of Bangladesh.

According to IMO, ships engaged in international trade in 1996 contributed about 1.8% of the total world’s CO2 emissions which is approximated as 2.7% in 2007 and this percentage could go two or three times higher by 2050 if Present trend continues [1]. In order to reduce CO2 emission, Marine Environment Protection Committee (MEPC) at its 62nd session adopted Resolution MEPC.203 (MEPC, 2011a) [2] which includes amendments to MARPOL Annex VI. It introduces new chapter 4 which intends to improve energy efficiency for ships through a set of technical performance standards. The amendments, which entered into force on 1 January 2013, require that every ship has the International Energy Efficiency (IEE) Certificate on board. In order to obtain the IEE Certificate a ship has to comply with the Energy Efficiency Design Index (EEDI) and the Ship Energy Efficiency Management Plan (SEEMP). The EEDI is mandatory for all new ships and SEEMP for all ships of 400 GT and above engaged in the international shipping. The EEDI is a simple formula that estimates CO2 output per ton-mile at one design condition.

Within the framework of discussion and deliberation leading to the EEDI adoption and beyond, considerable work has been contacted in order to prepare a suitable EEDI formulation and pave the way towards its adoption by the shipping industry. Anink and Krikke [3] analyzed the EEDI formula and correlation between the index values for all individual ship types for several types of vessels. Delta marines [4] evaluated the calculation of EEDI for conventional vessels, Ro-Ro and Ro-Pax ships. Larkin, Ozaki, Tikka and Michel [5] investigated the influence of design parameters on the energy efficiency design index. Kanu priya jain [6] investigated the impacts of energy design index in his master of science thesis. Borkowski and Kasyk [7] evaluated the operational approach of energy efficiency design index of container vessel. A Simic [8] has proposed a dependable formula for benchmarking energy efficiency and carbon emissions of inland cargo vessels for UK, which should be similar to already accepted approach for ocean going vessels. Yan Lin, Yan Yun and Guan [9] researched on energy efficiency deign index for sea going LNG carriers. Tien Anh Tran [10] calculated and assessed the EEDI index in the field of ship energy efficiency for bulk carrier. Sin and Oses [11] investigated the improvement of the energy efficiency of vessels as a measure for the reduction of greenhouses gases emission from sea shipping. Vladimir [12] analyzed the effect of ship on EEDI requirements for large container ships. Papunikolaou [13] investigated on energy efficient ship operation. Koos Frouws [14] calculated the emissions of sea going RoRO carriers. Rehmatulla, Calleya and Smith [15] investigated the implementation of technical energy efficiency and CO2 emission reduction measures in shipping.

Due to geographical advantages, waterways are the cheapest mode of transport for transporting passengers and cargoes in Bangladesh. Although, there are more than 1500 Cargo vessels plying all the year round in Bangladesh, but performance of these ships in terms CO2 emission is not known and any regulations related to the energy efficiency for inland cargo vessels still does not exist. Several attempts have made to develop a proper tool for seagoing vessels in terms of energy efficiency that can be found in various papers & reports but there are no suggested benchmarks that could be used for assessment of the energy efficiency of inland cargo vessels for Bangladesh. Having in mind the significance of energy efficiency benchmarking, which already has a huge influence on the global marine shipbuilding industry, this study has been performed based on available data of 351 existing inland cargo vessels of Bangladesh. From this perspective, this research will seek to review the present scenario of inland cargo vessels in terms of EEDI, analyze the results and propose some reliable tool for benchmarking energy efficiency and carbon emission of inland cargo vessels considering existing socio-economic and technical factors in Bangladesh.